Home The impact of using prestressed CFRP bars on the development of flexural strength
Article Open Access

The impact of using prestressed CFRP bars on the development of flexural strength

  • Ahmed Salim Edan EMAIL logo and Wael Shawky Abdulsahib
Published/Copyright: September 30, 2024
Download Article (PDF)
Become an author with De Gruyter Brill
Submit Manuscript Author Information
Open Engineering
From the journal Open Engineering Volume 14 Issue 1

Abstract

The load-carrying capacity and ductility of conventional steel reinforcement may be greatly increased by using ordinary and prestressed carbon fiber-reinforced polymer (CFRP) bars, resulting in reinforced concrete structures with greater sturdiness. This research investigates the flexural behavior of CFRP-prestressed beams with bonded tendons as opposed to conventional steel-prestressed beams. This article examines a less explored topic that often fails because post-tensioned beams with unbonded CFRP tendons are crushed by concrete. The linear-elastic behavior of CFRP accounts for much of the experimentally observed considerable variations in flexural characteristics between CFRP and steel-prestressed beams. Compared to unbonded CFRP specimens, bonded CFRP specimens are much stronger. Our knowledge of CFRP reinforcement in concrete infrastructure is advanced by this work, which highlights the need for better design techniques to increase strength and ductility. It is recommended that CFRP bars be bonded with epoxy resin to restrict fast energy dissipation and avoid concrete failure. As a result, CFRP-reinforced concrete beams will react less linearly and more ductilely. CFRP may improve prestressed concrete beam performance and lifespan in a number of scenarios, as shown by comparative research with traditional steel reinforcement. Six 1,800–mm-long RC beams with a 200 × 300 mm cross-section were examined and divided into three groups, analyzing important loading phases (i.e., cracked, ultimate, and mid-span deflection) using CFRP bars as prestressed tendons to replace the bottom steel rebars. The load-carrying capabilities and ductility of CFRP-reinforced beams were much greater than those of the reference beam. A single beam using normal CFRP bars for reinforcement showed a 21.2 mm mid-span deflection and an ultimate load of 157.2 kN, with a 57.7-kN fractured load. Another beam with normal CFRP bars also showed enhanced performance, with a mid-span deflection of 21.2 mm, an ultimate load of 160.6 kN, and a cracking load of 57.5 kN.

Keywords: carbon fiber-reinforced polymer; flexural resistance; serviceability demands; prestressed concrete beams; steel strand; CFRP bond

1 Introduction

Steel corrosion is more severe in countries that utilize road-deicing chemicals. Because fiber-reinforced polymers (FRPs) can replace steel in concrete reinforcement, they should be researched by the building industry [1]. Research and experiments increasingly use FRP instead of steel rebar or strands in concrete [2]. Due to its increased tensile strength, corrosion resistance, the absence of magnetic characteristics, and lightweight composition, FRP reinforcement behaves differently from steel reinforcement. FRP reinforcement is extensively employed despite its limited flexibility, transverse strength, stress rupture sensitivity, and high cost [3,4]. Carbon fiber-reinforced polymer (CFRP) is the most used FRP because of its better tensile strength and stiffness. However, CFRP bars are generally non-ductile, with a linear stress–strain correlation and the tendency for brittle fracture under uniaxial tension [4].

As reported in engineering construction media, standard flexural design methods for steel-prestressed concrete components assume that steel would yield before the beam fails. When steel yields, it deflects and absorbs inelastic energy, making it ductile [5]. Therefore, to correct this problem, this article presents a substantial study of the flexural behavior of CFRP-prestressed beams and bonded tendons. Test results have shown that despite their similarities, CFRP- and steel-prestressed concrete beams exhibit several differences, with the linear-elastic properties of CFRP reinforcement dominating the observed changes. Post-tensioned beams containing unbonded CFRP tendons have received less investigation into their flexural properties than bonded prestressed beams using CFRP tendons. Concrete crushing typically results from unbonded post-tensioned beam failure. Without cable bonding, tensions dissipate at critical locations and disperse down the tendon. Therefore, the tendon is under less strain than when attached. Thus, bonded specimens are stronger than unbonded ones regardless of the tendon type [6].

In going on to check the durability and fatigue, Belarbi et al. [6] examined post- and pre-tensioned prestressed beams with various CFRP systems under monotonic and fatigue loadings. The CFRP-prestressed beams exhibited ample warning before failure in early experimental testing. Unbonded CFRP cable post-tensioned beams have greater deformability than other CFRP pre-tensioned beams, with their maximal strength being lower than all other bonded beams [6].

All facets of the structural behavior of prestressed concrete beams may be revealed via scientific inquiry. The first smart highway bridge in Calgary had four beams that matched rafters, which Abdelrahman et al. [7] looked into two prestressed CFRP types that were subjected to fatigue and monotonic loads. Before the collapse, pretensioned beams underwent severe deformation. Similar to monotonic loading capacity, the fatigue loading (i.e., 70–100% of the cracking load) sustained over 2 million cycles with only a small change in stiffness [7]. Seven rectangular and T-beam post-tensioned beams with internally unbonded CFRP tendons under simple support were investigated by Heo et al. [8]. The section geometry, loading type, beginning prestressing, and prestressing reinforcement ratio were all tested. Flexural collapse was brought on by concrete crushing, although unbonded prestressed tendons did not fracture. The rectangular beams held up well after the maximum load. The T-beam failure modes were impacted by the loading type. The rectangular sections with bonded CFRP tendons were less flexible than the beams with the additional bonded steel bars. Thus, enhanced ductility was recommended by the resilience assessment [8]. Additionally, Kakizawa et al. [9] studied the structural response of prestressed CFRP beams and their bonding, finding that the mechanism of deflection leading to final failure and the absorbed energy through different loading stages were affected by the system of reinforcement. Partially prestressed beams absorbed more energy than entire beams. Following the breakage of the FRP cable, the fully prestressed beams did not absorb energy. On the other hand, the same power was absorbed by beams that collapsed because the concrete crushed after the peak load [9].

FRP technologies have become more popular for the internal reinforcement of concrete infrastructure due to the growing need for sustainable construction practices. Mertol et al. [10] have demonstrated that prestressed CFRP beams are more durable than steel wire-reinforced concrete beams. To cover the range of mechanical and meteorological scenarios, 15 beams underwent testing for sustained load periods of 9 and 18 months, with continuous seawater spray at 15% by mass, air exposure (54°C), sustained stress (55 and 70% of the bar or wire’s ultimate strength), and testing methods (cyclical loading followed by static testing until failure). While the steel-reinforced beams collapsed after 12 months, the CFRP-reinforced beams withstood 18 months under harsh weather conditions, showing that the steel beams were not as sturdy as the CFRP prestressed beams [10].

To study the bending properties of concrete beams, Abdelrahman and Rizkalla [11] looked at cracks and deflections in eight CFRP-prestressed beams and two standard steel-stranded beams. Experimental observation toward the tension zone’s degree, percentage of prestressing force, and CFRP bar spread. Findings: This study looked at cracking and bending in CFRP-prestressed concrete beams before and after they cracked in different limit conditions. In the compression zone, CFRP beams bend similarly to steel beams as long as the failure is mostly caused by crushing the concrete. The failure of CFRP bars leads to less displacement than the failure of steel-strand prestressed beams. More than steel strand beams, CFRP bars partly prestressed beams have a stable fracture pattern at lower strain levels. Keeping the same issue but detecting a new behavioral feature, which is represented by ductility, three sets of beam experiments were conducted by Zou [12] and Jeong [13], and Abdelrahman [14] provided significant information in developing the structural performance of the reinforced concrete beam, notably ductility, and deformability. Zou’s research indicated that prestressing reinforcement rupture caused beams with low reinforcement ratios and no shear reinforcement to fail. Interpreting the deformed beams with growing cracks were warning indications before the collapse. Beams prestressed by steel strands have higher ductility than CFRP beams with consistent inelastic energy ratios. Jeong found that reinforcing configurations affect ductility. Abdelrahman found that CFRP- and steel-prestressed beams deform similarly under comparable circumstances, but larger prestressing pressures and failure modes decrease ductility. Forth and Beeby [15] have demonstrated that prestressing or CFRP reinforcement may raise the chance of a bonded tendon breaking before the concrete is crushed, which will be addressed later in this article. In unbonded tendons, the absence of these systems prevents significant local strains, leading to little change in stress. To fill in the gaps in the literature, this study investigated the flexural performance of prestressed concrete beams and post-tensioned CFRP bars providing a novel experimental approach to analyze the flexural behavior of rectangular beams by applying static to the two-point stresses using the same number and diameter of CFRP bars to replace the steel rebar in the stress zone. The behavior of these prestressed CFRP bar beams was examined, looking into three distinct areas: the impact of using epoxy resin, cement grout, and CFRP bonding in converting the linear elastic behavior of the reinforced concrete beam to a ductile beam by reducing the rapid energy dissipation (stress released) from the CFRP bar and saving the concrete from crash.

Additionally, this article compares the experimental results of the beams with ordinary or prestressed CFRP bars with the referenced reinforced concrete beam (with traditional steel reinforcement) for strength capacity, ductility, mid-span deflection, and load strength and from the other side, clarifying the major role of the epoxy resin in converting the linear elastic behavior to ductile beam and saving the CFRP prestressed bar. And contributes significantly to the current body of knowledge with a number of useful contributions for future researchers in the fields of civil engineering and materials science:

1.1 Gain a better understanding of CFRP reinforcement

This study has not only deepened our understanding of the flexural behavior of CFRP-prestressed beams, but it also shows how will CFRP react to different environmental situations when compared to drive against traditional steel act as reinforcement Comparably, this contributes to increasing knowledge about the mechanical behavior of CFRP with special emphasis on its linear-elastic properties and brittleness in uniaxial tensile load.

1.2 Novel experimental approach

Thus, the present experimental study introduces a new technique to translate such linear elastic behavior of CFRP-reinforced beams into a ductile response using epoxy resin, cement grout, and bonding of CFRP. This strategy quiets the fast energy use and forestalls concrete disappointment, making it a potential answer for one of the supervisor restrictions of CFRP support.

1.3 A comparative analysis of its performance

This research will act as a comparative analysis performing the CFRP-reinforced beams with that of traditional steel-reinforced ones and indicating empirical data showing strength capacity, ductility or mid-span deflection and load strength, etc. The comparative analysis of CFRP and steel helps to understand that whether in which aspects has CFRP that is better than existing materials such as steel, it will also drive the use of different materials and design aspects in construction affecting future practices.

1.4 Addressing unexplored areas

By concentrating on the flexural characteristics of post-tensioned beams with unbonded CFRP tendons, our study closes a significant gap in the literature. Since this field has received little attention from earlier research, our results provide important new insight into how these beams behave and function under different stress scenarios.

1.5 Practical implications for sustainable construction

In light of the growing imperative for environmentally conscious construction methodologies, our study provides justification for the implementation of FRP technologies, specifically CFRP, as a feasible substitute for steel. The prospective long-term applications of CFRP in infrastructure, which reduce maintenance expenses and prolong service life, are underscored by its demonstrated durability and performance in severe environmental conditions.

2 Experimental work and methodology

The primary objectives of this study were to investigate and examine the effect of replacing the bottom longitudinal steel reinforcement with ordinary or prestressed CFRP bars in concrete beam specimens. This replacement appeared through an experimental gradual trial by casting and testing six reinforced concrete beams divided into three groups (i.e., one, two, and three) depending on whether or not the CFRP bars were used as an alternative to the bottom steel rebars and the scheme procedure is shown in Figure 1:

Figure 1 Research scheme.
Figure 1

Research scheme.

This substitution was accomplished through systematic experimental trials involving the casting and testing of six reinforced concrete beams cast from high-strength concrete (average cylindrical compressive strength = 66.34 MPa), categorized into four groups, using CFRP bars as an alternative to the bottom steel rebars and employing them as prestressed tendons to achieve a robust substitution for the steel strands. The CFRP bars were used as the prestressed tendons to create an improved substitution with a steel strand. Many other experiments were conducted to determine the influence of the concrete compressive strength and longitudinal reinforcement ratio and the losses of prestressed tendons on the behavior of various parameters, including the (1) bonding type, (2) the impact of prestressed CFRP bars, and (3) flexural behavior, including deflection, cracking loads, and the ultimate load capacity of the beam specimens.

2.1 Test specimens

This work employed 200 × 300-mm cross-sectional dimensions and a 1.8-m length for the beams. The characteristics of the materials used in this study are illustrated in Table 1, while Figures 2–4 show the longitudinal profile and cross-sectional details for the shape and type of reinforcement and the mechanical bond for the CFRP reinforcement for each group. To manufacture each beam according to the group characteristics displayed in Table 1 and especially for beams that have CFRP bars bonded with epoxy resin or cement grout, one plastic pipe of 25 mm diameter for each CFRP bar was placed into molds in the bottom layer and fixed by stirrups. After the concrete was poured (almost 20 min), the plastic sleeves were pulled out from the molds to create the perfect longitudinal hollows. Then, after completing the curing time, it is ready to insert the CFRP bars in that longitudinal hollow of the beam (G1B3) and then inject the bonding material (epoxy resin) through side hollows drilled and cleaned previously uniformly distributed from both sides to bond the CFRP bar with the concrete beam. And all the materials tests are clarified in Tables 2–4.

Table 1

Details of specimens and material properties

Group (No.) Beam (No.) Top Reinf. Bottom Reinf. Prestressed Reinf.
Type Bond Type Shape
Group (1) G1B1 Steel (2Ø16) Steel (2Ø12) Concrete — —
G1B2 Steel (2Ø16) CFRP (2Ø12) Concrete — —
G1B3 Steel (2Ø16) CFRP (2Ø12) Epoxy — —
Group (2) G2B3 Steel (2Ø16) Steel (2Ø12) Concrete CFRP (1Ø12) Straight
Group (3) G5B1 Steel (2Ø16) — Concrete CFRP (2Ø12) Straight
G5B2 Steel (2Ø16) — Epoxy CFRP (2Ø12) Straight
Figure 2 Details of the general specimens.
Figure 2

Details of the general specimens.

Figure 3 Details of the specimens from Group 2.
Figure 3

Details of the specimens from Group 2.

Figure 4 Specimen’s details of the Group 3.
Figure 4

Specimen’s details of the Group 3.

Table 2

Average concrete compressive strength of test specimens

Age of Specimens At 28 days of age At test time age
Cylinders Cubes* Cylinders Cubes* Ave. Cyl. Ave. Cube*
Group (1) 61.63 64.92 67.67 68.44 66.57 66.34 (control)
Group (2) & (3) 59.87 62.62 66.23 64.12
Group (4) 60.24 64.66 65.81 66.47

*The values of cube-compressive strength are multiplied by (0.8) to get f’c.

Table 3

Physical-mechanical properties of steel reinforcement

Diameter (mm) Area (mm2) Ultimate strength (MPa) Yield strength (MPa) Modulus of elasticity E (GPa) Elongation % Lo
10 78.50 659.87 517.10 200 12.10
12 113 672.33 533 200 12.30
16 200.96 710.74 577.3 200 13.40
Table 4

Mechanical properties of CFRP bars (manufacturer datasheet)

Steel grip length on both ends (mm) Sectional area (mm2) Tensile force (kN) Tensile strength (MPa) Tensile modulus (Gpa) Ultimate elongation (%)
100 113 105.26 931.2 155 1.8
150 113 138.55 1220.8 155 1.8
200 113 210.21 1859.6 155 1.8

2.2 Sequence of the post-tensioning process

A controlled procedure was employed for prestressing the CFRP tendons through post-tensioning, utilizing PVC pipes of 50-mm diameter, which extended beyond the steel duct, followed by the plastic sleeve being pulled out after pouring the concrete by less than 30 min to prepare the desired straight hollow beam. Upon completion of the casting and curing of all girders, two grips were manufactured to prestress both of the CFRP tendon ends; the ducts were made of an externally threaded hollow steel shaft with a smooth inner diameter (25 mm) and outer diameter (33 mm) and with adapted bolts to lock the prestressing forces on each end bearing plate after completing the desired elongation using the prestress machine. The adhesive material was Sikadur®-30 LP, a thixotropic, structural two-component adhesive with beneficial properties, such as a compressive strength reaching 110 MPa, and tensile strength, axial tension, and flexure reaching 28 and 40 MPa, respectively. It is suitable for use in high-temperature environments. A procedure similar to that of Saed and Rad [16] was employed to install the CFRP bars inside the steel duct by filling it with the adhesive material and then mixing the two adhesive components. Samples of four duct lengths (i.e., 10, 15, 20, and 25 cm) resulted in tensile strengths of 931.2, 1220.8, 1859.6, and 2,086 MPa, respectively. Additionally, all of the samples failed because the CFRP bars slipped through the fracture in the adhesive materials from one or both ends, except the last one, which produced a failure in the CFRP bars at the end of the duct’s length due to an insufficient inside length to reach the tensile strength of the CFRP bar. The adhesive epoxy was then injected into the hollow steel duct from both sides according to the design shown in Figure 5a.

Figure 5 (a) Inserting CFRP bars into a hollow steel shaft, (b) fixing a strain gauge sensor in the middle and quarter length of the strands, (c) assigning a reference point for pulling, and (d) detecting the magnitude of prestressing in the CFRP bars.
Figure 5

(a) Inserting CFRP bars into a hollow steel shaft, (b) fixing a strain gauge sensor in the middle and quarter length of the strands, (c) assigning a reference point for pulling, and (d) detecting the magnitude of prestressing in the CFRP bars.

As shown in Figure 5b, to collect detailed information on the prestressed condition of each CFRP bar, two strain gauges were attached to each bar. One was placed at the midpoint of the tendon and the other at the quarter length. A suggestion was made to tension the strands to around 70% of their maximum strength. The FRP tendons undergo a significant amount of creep and relaxation shortly after tensioning. Therefore, it was anticipated that the tendons would be strained to around 60–65% of their full capacity by the time the beams were tested [17]. Given the duration of the trials, this degree of prestressing seemed to be realistic and would not provide a problem in terms of long-term stress rupture.

The pre-strain value (ΔL) represents a predefined change in the length of 10.5 mm (0.6 σ u) to reach 1,200 MPa, which is stipulated by the member design requirements and illustrated in Figure 5c. To determine individual pre-strain values, a pressure gauge was connected to an electrical hydraulic jack for post-tensioning, with a dial gauge for camber measurement. The surfaces of the CFRP bars were marked.

2.3 Carbon fiber grout and epoxy

2.3.1 Bonding the CFRP tendons using cement grout

The study design called for the CFRP bars to be placed within PVC pipes (25 mm in diameter) that were temporarily fastened with steel stirrups, before casting and being removed for about 30 min to finish the conventional reinforcing. Knowing that the drill bits would reach the longitudinal hollow’s center, three hollows were drilled from the sidewalls of both girders. Once the hollows were clean and open, the CFRP bars were placed with their strain gauges inside, using mineral filler and polymer-reinforced cement grout FOX GROUT FC 155. After 28 days of curing, this cement reached 60 MPa in compression and 2 MPa in bond strength.

2.3.2 Bonding the CFRP tendons using epoxy resin

This investigation used a mixture of epoxy resin type CERMGROUT EP 3 C epoxy, in three parts: (1) 1 kg liquid (hardening material), (2) 2 kg liquid (adhesive material), and (3) 12 kg powder (expansive material). The epoxy resin injection was executed in the same manner to coat the CFRP bars within the longitudinal hollow. After 14 days of curing, the materials reached compressive and tensile strengths of 30–50 and 80–100 MPa, respectively.

3 Experimental results and discussion

3.1 Analyzing the load–deflection behavior of beams with CFRP reinforcement

The load–displacement diagram shows three distinct phases: (1) the uncracked, elastic behavior, which ended at the onset of the first crack; (2) the cracked, elastic behavior, which was bounded by the first crack and ended at the yielding of the ordinary tensile steel rebars of G1B1, G2B3 and represented by the cracking stage of concrete through strain sensors for tension, compression and shear zones and knowing that also, from the strain value of CFRP strain gauges and converted to stress through multiplying the strain value by the modulus of elasticity for beams G1B2, G1B3, G5B1, and G5B2; and (2) the plastic behavior (Pu) which is represented for beams reinforced by CFRP bars at the bottom layer. Due to the progressive variation in the stiffness of the bonded reinforcements after cracking and yielding, the lengthening rate was larger in the second and final stages than in the first. Table 5 demonstrates the cracked experimental beams and ultimate load strength.

Table 5

Cracked and ultimate loads for experimental beams

Beam specimen Cracked load (Pcr.) exp. kN Difference ratio Value Reff . Ultimate load (Pult.) exp. (kN) Difference ratio Value Reff . Deflection at mid-span (mm) Difference ratio Value Reff .
G1B1(Reff.) 21.7 — 114.2 — 44.7 —
G1B2 57.7 2.65 157.2 1.37 21.2 0.47
G1B3 58.5 2.69 160.6 1.40 16.2 0.36
G2B3 137.6 6.34 254.2 2.22 7.3 0.16
G5B1 218.7 10.07 300.2 2.62 32.2 0.72
G5B2 221.1 10.18 309.3 2.70 27.3 0.61

The load–deflection behavior of the reference beam G1B1 was compared to other beams to analyze the key loading stages. G1B2 exhibited a cracked load (Pcr.) of 57.7 kN, presenting a difference ratio of 2.65 compared to the reference beam. As loading progressed, the ultimate load (Pult.) increased to 157.2 kN, with the decreased difference ratio reaching 1.37. The mid-span deflection was measured at 21.2 mm, with a difference ratio of 0.47. This improvement was attributed to replacing the steel rebars in the bottom reinforcement with alternative CFRP bars, specifically leveraging the concrete bond and significantly enhancing the beam strength.

Similarly, in G1B3, the cracked load was measured at 57.5 kN, with a difference ratio of 2.69 compared to the reference beam. As loading continued, the ultimate load increased to 160.6 kN, with a decreased difference ratio reaching 1.4. The mid-span deflection was measured at 21.2 mm, with a difference ratio of 0.36. The substitution in the bottom reinforcement of the steel rebar with alternative CFRP bars, particularly due to the epoxy resin bond, played a crucial role in enhancing the beam strength. In G2B3, the cracked load was notably higher at 137.6 kN, indicating a significant improvement over the reference beam, with a difference ratio of 6.34. The ultimate load increased to 254.2 kN, with a decreased difference ratio reaching 2.22. The mid-span deflection was measured at 7.3 mm, with a difference ratio of 0.16. These enhancements stemmed from adding one prestressed CFRP bar with hollow longitudinal confinement, effectively increasing the beam strength.

Furthermore, G5B1 exhibited a cracked load of 218.7 kN, presenting a considerable improvement compared to the reference beam, with a difference ratio of 10.07. The ultimate load rose to 300.2 kN, with a decreased difference ratio reaching 2.62. The mid-span deflection was measured at 32.3 mm, with a difference ratio of 0.72. These enhancements were achieved by replacing the steel rebar in the bottom reinforcement with alternative prestressed CFRP bars, emphasizing the significant contribution of the concrete grout bond to enhancing the beam’s strength.

In G5B2, the cracked load was even higher at 221.1 kN, indicating substantial improvement over the reference beam, with a difference ratio of 10.18. As the loading progressed, the ultimate load increased to 309.3 kN, with a decreased difference ratio reaching 2.7. The mid-span deflection was measured at 27.3 mm, with a difference ratio of 0.61. This improvement was achieved by replacing the steel rebar in the bottom reinforcement with alternative prestressed CFRP bars; particularly due to the epoxy resin bond, the beam strength was significantly enhanced.

The load-midspan deflection curves depicted in Figure 6 illustrate the impact of the prestressed CFRP bars on reducing the midspan deflection. Specifically, the behavior of beam G2B3 demonstrates linear characteristics with minimal deflection, reaching 7.3 mm, indicative of tension failure, resulting in the cutting of the prestressed CFRP bar. Conversely, beams G5B1 and G5B2 exhibited higher deflection values, albeit within acceptable limits, accompanied by compression failure observed in the upper part of the concrete structure. Importantly, the prestressed CFRP bars in these beams remained intact without experiencing cutting.

Figure 6 Mid-span deflection curves for all groups.
Figure 6

Mid-span deflection curves for all groups.

3.2 Load capacity and ductility in beam reinforcement analysis

The primary findings of the flexural tests, as delineated in Table 6, center on two key parameters. First, attention was directed towards the load-increment metric, which quantifies the relationship between the ultimate load leading to failure and the load at which cracking initiates. Also, the title of the column in Table 6 named by “Yield-Cracked deflection”: it represents the stage that started from the initial crack of the reinforced concrete beam reinforced by CFRP bars to be simulated and in accordance with beams reinforced with steel rebar through recording the strain values of concrete and cfrp bars and then converted to the stress limit which starts from 0.6 σ u and continues to rise, and from the other hand, it was obligated to use this name during calculating the ductility of the beam, because we need yield and ultimate deflection and for this reason we used the phrase of yield values recorded for beams reinforced only. This analysis evaluated the efficacy of substituting high-performance alternatives like CFRP bars for the conventional steel rebars in the lower layer within both ordinary and prestressed configurations. Second, the investigation assessed the ductility by computing the mid-span deflection at two critical loading stages: yield and ultimate loading.

Table 6

Capacity ratio of cracked and ultimate loads and ductility for other beams in comparison to the reference beam

Beam specimen Cracked load (Pcr.) Exp. (kN) Ultimate load (Pult) Exp. (kN) Load-increment ratio Pult Pcr . Yield-cracked deflection (mm) Ultimate deflection (mm) ∆ u / L Ductility µ ∆ ult ∆ y . ( ∆ u M u ) / ( ∆ cr M cr )
∆ ult ∆ y . × Pult Pcr .
G1B1(Reff.) 21.7 114.2 5.26 22.36 44.7 1/36 1.99 10.46
G1B2 57.7 157.2 2.72 10.15 21.2 1/75 2.08 5.65
G1B3 58.5 160.6 2.745 6.5 16.2 1/99 2.49 6.83
G2B3 137.6 254.2 1.847 4.16 7.3 1/219 1.75 3.23
G5B1 218.7 300.24 1.372 17.1 32.2 1/50 1.88 2.58
G5B2 221.1 309.3 1.398 13.5 27.3 1/59 2.02 2.82

The results revealed significant differences in the performance of the beams under consideration. Specifically, the cracked load of each beam was compared to its ultimate load, providing insights into the load capacity and the extent of the additional loading that reduced the beam’s residual strength until eventual failure.

In G1B1, the beam with conventional reinforcement, a load increment (load capacity) of 5.26 was observed, accompanied by a ductility value of 1.99. In contrast, G1B2 exhibited a reduced load increment of 2.72 but displayed higher ductility, at 2.08. Similarly, G1B3 demonstrated a diminished load increment of 2.745 alongside the enhanced ductility of 2.49. G2B3, featuring prestressed CFRP rebar, exhibited the lowest load increment of 1.847 and the lowest ductility of 1.75. Conversely, G5B1, which also utilized prestressed CFRP rebar, showed a reduced load increment of 1.372, yet it boasted higher ductility, at 1.88. Finally, G5B2 displayed a diminished load increment of 1.398 and higher ductility, at 2.02.

When these data are interpreted, it becomes clear that conventionally reinforced beams needed more time to attain their maximal load. On the other hand, using prestressed CFRP rebar bonded with the epoxy resin and cement grout enhanced the beam performance and decreased load increments. This suggests that prestressed CFRP rebar may improve structural resilience and efficiency in beam building. The results of this study showed reasonable deflections through the use of bonding material and through the method of injecting these materials inside the longitudinal hollow from three hollows on both sides, which also reached a partial bond due to the high viscosity of that epoxy resin. This is agreed with the study by Lees and Burgoyne [5], which tends to use partial bonds rather than fully bonded tendons to get a suitable deflection.

Focusing in the final analysis criteria named “ductility,” which represents the ratio of values of ultimate deformations to the values of the yielded deformations, were all in excellent agreement with some previous experimental studies related to computing the ductility of the beams researched by Zou, Jeong, and Abdelrahman’s earlier research [12,13,14]. These validations provided further evidence in favor of the results, emphasizing the critical role that prestressing force, type, and configuration play in dictating the ductility and deformability of reinforced concrete beams. The need to take these aspects into account when designing a structure to achieve maximum performance and safety was highlighted by these validations.

Therefore, it is evident that beams with conventional reinforcement required a longer duration to reach their ultimate load. Conversely, using prestressed CFRP rebar resulted in a notable convergence between the concrete grout and epoxy resin materials, leading to improved performance and reduced load increments. This indicates a potential for enhanced structural efficiency and resilience when employing prestressed CFRP rebar in beam construction.

3.3 Analyzing fracture patterns and failure modes in concrete beams

The examination of the experimental results focused on scrutinizing the characteristics of primary tensile or shear fractures, including their shape, extent, and initiation points, and how they relate to the ultimate rupture mechanism of reinforced concrete beams. The objective of the experiment was to consider and then validate the selection of model parameters. This investigation involved testing six reinforced concrete beams to explore the influence of various mechanical and physicochemical reinforcement factors on the crack patterns in such structures.

In G1B1 (reference beam), failure primarily occurred due to flexural loading, marked by the yielding of the tensile steel reinforcement and tensile rupture of the concrete through significant cracks. Conversely, in G1B2, shear failure was predominant, attributed to the reinforcement of the beam with two CFRP bars embedded in concrete. These bars exhibited high bond confinement and tensile strength, leading to shear failure before significant flexural failure occurred. In G1B3, mid-span debonding was initiated at a flexural crack near the region of the maximum bending moment, further exacerbated by the transfer of shear stresses from the FRP plate to the concrete. In G2B3, flexural cracking ensued, with the yielding of the tensile steel reinforcement preceding the tensile rupture of the prestressed CFRP, ultimately resulting in the concrete being crushed. Similarly, in G5B1 and G5B2, a combination of flexural and shear cracks occurred in the region of the maximum bending moment between supports, with the transfer of shear stresses from the CFRP bars to the concrete contributing to this failure mode. The crack patterns observed in all beams are depicted in Figures 7–9.

Figure 7 Modes of the failure beams in Group 1.
Figure 7

Modes of the failure beams in Group 1.

Figure 8 Modes of the failure beams in Group 2.
Figure 8

Modes of the failure beams in Group 2.

Figure 9 Modes of the failure beams in Group 3.
Figure 9

Modes of the failure beams in Group 3.

In conclusion, this experimental investigation provided valuable insights into the behavior of reinforced concrete beams under various loading conditions and reinforcement configurations. The observed fracture patterns underscore the significance of factors such as material properties, bond confinement, and stress transfer mechanisms in determining the ultimate failure mode of such structures. These findings advance our understanding of reinforced concrete behavior and can inform the development of more robust and efficient structural designs.

3.4 Strains of tensiometric elements

Strain of each girder was measured by using an electrical strain indicator that recorded the tension and compression strains at mid span top and bottom concrete fiber which is located at 50 mm from both edges and the concrete shear strain by locating the mid-distance of the diagonal line between the center of loading to the center of support and for both sides and measuring the strains for each CFRP bar and steel rebar. This is done to examine the behavior of post-tensioned concrete beams under three loading phases selected which are different from one beam to another due to different reinforcement characteristics such as including prestress or not and what type of post-tensioned strand used, to simulate the elastic uncracked stage, yielded-cracked stage, and plastic ultimate stage.

3.4.1 Load strain of steel rebar

The experimental results from the tensile testing for rebar reinforcements on 12 mm rebars indicated that the yielding strain is 2,680 microstrain (µɛ) of G1B1. The prestressed members of G2B3 yielded at maximum load as a result of the microstrain, and all prestressed beams also achieved or almost reached this limit as shown in Figure 10.

Figure 10 Behavior of steel strand strain.
Figure 10

Behavior of steel strand strain.

3.4.2 Load strain in CFRP bars

The strain in CFRP bars in G1B2 and G1B3 reached 9,800 and 11,200 µɛ equal to (1,470 and 1,680 MPa), respectively, were greater than those of prestressed beams such as G2B3 of 10,930 µɛ equal to 1,640 MPa, which is represented as 82% of the ultimate stress of group two due to the location of CFRP in the center of cross section and was unbonded; therefore, the beam failed before reaching 100% of CFRP ultimate stress (2,000 MPa) through the extension of major cracks in upper and lower concrete fiber. Then the stress increased rapidly to reach the ultimate stress and the fiber was cut off. Otherwise, the prestressed CFRP bars had a great value reaching 12,970 µɛ in G5B1 which bonded by cement grout and 11,230 µɛ in G5B2 for epoxy resin as shown in Figure 11.

Figure 11 Behavior of CFRP Strand strain.
Figure 11

Behavior of CFRP Strand strain.

3.4.3 Load-strain in concrete

The mid-span concrete compressive strain peak values ranged from 1,730 to 7,750 µɛ for undammed portions at the failure stage in G1B1 and G2B3. Prestressed beams with ordinary steel rebar in the bottom layer increased compressive stress in the top extreme fiber of concrete, while those with ordinary CFRP bars decreased it and reduced concrete compressive strain. CFRP bars are used to endure high stress in the bottom layer and reduce concrete compression in the top layer.

The bottom strain-gauge showed a high tensile strain in G1B1 (19,030 µɛ) and decreased in G1B2 and G1B3 (8,686 and 9,570 µɛ, respectively) after replacing steel rebar with CFRP bars of the same radius (Ø12 mm) to increase participation in high stress. So, for the beam with prestressed CFRP, the tensile strain of concrete was approximately the same as for other prestressed beams, despite the 12 mm radius of the CFRP bar, which indicates that the prestressing technique pulls out the CFRP bar and causes axial compressive load that decreases the bottom layer’s tensile strain as shown in Figure 12.

Figure 12 Tension-compressive strain of concrete through depth for groups 1, 2, and 3.
Figure 12

Tension-compressive strain of concrete through depth for groups 1, 2, and 3.

Certain concrete strain distribution curves for the investigated members did not follow the Bernoulli–Navier hypothesis, which asserts that a bent plane section remains plane [18], for various reasons. Cracks may cause extremely high strain in certain members, but if they don’t travel through the strain gauge, its output value is correct. When the load increases, the neutral axis rises and shallowens the compression zone.

4 Conclusions and recommendations

After investigating six simply supported concrete beams experimentally, it is possible to conclude the following:

  1. The beams that had been strengthened with bonded CFRP bars in place of regular steel rebar had higher ultimate loads of 1.37 and 1.4 for G1B2 and G1B3, respectively, and larger first cracking, reaching 2.65 and 2.69, respectively.

  2. When comparing the epoxy resin bond to the cement grout bond, a slight increase in the bonding type was also seen in the ultimate and cracked load of beam G1B3 if compared with G1B2 contingent upon the bonding material used with the regular CFRP bars.

  3. Two steel rebars were swapped out for additional prestressed CFRP bars, which produced different measurements than that of the reference beam: 10.7 and 10.18 cracked load and 2.62 and 2.7 ultimate load for beams G5B1 and G5B2, respectively. This was the largest improvement among the experimental six beams.

  4. The bonding effect using epoxy resin was essential in postponing the onset of cracks by increasing the ultimate load strength and the size of the fractured area.

  5. The examined fracture patterns and failure mechanisms showed a variety of participating shear and flexural behaviors that were affected by the type of configured reinforcement. Diverse degrees of ductility and deformation were seen in the shear failure, mid-span deboning, and flexural cracking.

  6. Substituting the CFRP bars for the bottom steel rebar resulted in a maximum ductility of 2.49 in G1B2 but a reduction in ductility in G5B2, which agrees with many previous studies. Thus, this method is recommended for enhancing the flexural properties in general and the ductility in particular.

  7. Suggestions for Further Investigation and Design: The comprehensive experimental findings and analysis presented in our study establish a fundamental basis for subsequent investigations. Subsequent investigators may expand upon our discoveries to delve deeper into and refine CFRP reinforcement methodologies, whereas engineers may implement our understandings to design reinforced concrete structures that are more resilient and long-lasting.

  1. Funding information: The authors state no funding involved.

  2. Author contributions: All authors have accepted responsibility for the entire content of this manuscript and consented to its submission to the journal, reviewed all the results and approved the final version of the manuscript. ASE and WSA conceived and planned the experiments, and carried out the simulations. ASE carried out the experiments and contributed to sample preparation. ASE and WSA contributed to the interpretation of the results. ASE took the lead in writing the manuscript. Both authors provided critical feedback and helped shape the research, analysis, and manuscript.

  3. Conflict of interest: The authors state no conflict of interest.

  4. Data availability statement: The author datasets are available on reasonable request from the corresponding author with the attached information.

References

[1] Park SY, Naaman AE. Shear behavior of concrete beams prestressed with FRP tendons. PCI J. 1999 Jan;44:74–85. 10.15554/pcij.01011999.74.85.Search in Google Scholar

[2] Burgoyne CJ. Should FRP be bonded to concrete? Vol. 138, Frankfurt: ACI Special Publications; 1993 Mar. p. 367. Search in Google Scholar

[3] Maissen A, De Smet CA. Comparison of concrete beams prestressed with carbon fibre reinforced plastic and steel strands. InNon-Metallic (FRP) Reinforcement for Concrete Structures. Proceedings of the Second International RILEM Symposium. Vol. 29, London: United states; 1995 Aug. p. 430–439.Search in Google Scholar

[4] Warwaruk J, Sozen MA, Siess CP. Investigation of prestressed reinforced concrete for highway bridges, part III, strength and behavior in flexure of prestressed concrete beams. Engineering experiment station bulletin. Vol. 464, United states: University of Illinois; 1962.Search in Google Scholar

[5] Lees JM, Burgoyne CJ. Experimental study of influence of bond on flexural behavior of concrete beams pretensioned with aramid fiber reinforced plastics. ACI Struct J. 1999 May;96:377–85.10.14359/671Search in Google Scholar

[6] Belarbi A, Reda M, Poudel P, Tahsiri H, Dawood M, Gencturk B. Prestressing concrete with CFRP composites for sustainability and corrosion-free applications. InMATEC Web of Conferences. Vol. 149, EDP Sciences; 2018. p. 01010.10.1051/matecconf/201814901010Search in Google Scholar

[7] Abdelrahman AA, Tadros G, Rizkalla SH. Test model for first canadian smart highway bridge. ACI Struct J. 1995 Jul 1;92(4):451–8.10.14359/994Search in Google Scholar

[8] Heo S, Shin S, Lee C. Flexural behavior of concrete beams internally prestressed with unbonded carbon-fiber-reinforced polymer tendons. J Compos Constr. 2013 Apr;17(2):167–75. 10.1061/(ASCE)CC.1943-5614.0000306.Search in Google Scholar

[9] Kakizawa T, Ohno S, Yonezawa T. Flexural behavior and energy absorption of carbon FRP reinforced concrete beams. Spec Publ. 1993 Sep;138:585–98. 10.14359/3940.Search in Google Scholar

[10] Mertol HC, Rizkalla S, Scott P, Lees JM, El-Hacha R. Durability and fatigue behavior of high-strength concrete beams prestressed with CFRP bars. SP245-1, case histories and use of FRP for prestressing applications. Detroit, MI, USA: ACI Special Publication; 2006. p. 1–20.Search in Google Scholar

[11] Abdelrahman AA, Rizkalla SH. Serviceability of concrete beams prestressed by carbon. ACI Struct J. 1997 Jul;94(4):447–54.Search in Google Scholar

[12] Zou PX. Flexural behavior and deformability of fiber reinforced polymer prestressed concrete beams. J Compos Constr. 2003 Nov;7(4):275–84. 10.1061/(ASCE)1090-0268(2003)7:4(275) Search in Google Scholar

[13] Jeong SM. Evaluation of ductility in prestressed concrete beams using fiber-reinforced plastic tendons. United states: University of Michigan; 1994. https://www.proquest.com/openview/64880c828593a1989f1da034e50d3698/.Search in Google Scholar

[14] Abdelrahman AA. Serviceability of concrete beams prestressed by fibre reinforced plastic tendons. Ontario: National Library of Canada; 1995. https://mspace.lib.umanitoba.ca.Search in Google Scholar

[15] Forth JP, Beeby AW. Study of composite behavior of reinforcement and concrete in tension. ACI Struct J. 2014;111(2):397–406.Search in Google Scholar

[16] Saeed YM, Rad FN. Experimental investigation of CFRP prestressed concrete beams. Spec Publ. 2019 Feb;331:101–21.Search in Google Scholar

[17] Gerritse A. Specific features and properties of AFRP-bars. Advanced Composite Materials and Structures. Montreal. 1996 Aug 11;75–82.Search in Google Scholar

[18] Floris C, Paolo Lamacchia F. Analytic solution for the interaction between a viscoelastic Bernoulli-Navier beam and a winkler medium. Struct Eng Mech. 2011 Jan;38(5):593.10.12989/sem.2011.38.5.593Search in Google Scholar
Received: 2024-04-24
Revised: 2024-05-26
Accepted: 2024-06-12
Published Online: 2024-09-30

© 2024 the author(s), published by De Gruyter

This work is licensed under the Creative Commons Attribution 4.0 International License.

Articles in the same Issue

  1. Regular Articles
  2. Methodology of automated quality management
  3. Influence of vibratory conveyor design parameters on the trough motion and the self-synchronization of inertial vibrators
  4. Application of finite element method in industrial design, example of an electric motorcycle design project
  5. Correlative evaluation of the corrosion resilience and passivation properties of zinc and aluminum alloys in neutral chloride and acid-chloride solutions
  6. Will COVID “encourage” B2B and data exchange engineering in logistic firms?
  7. Influence of unsupported sleepers on flange climb derailment of two freight wagons
  8. A hybrid detection algorithm for 5G OTFS waveform for 64 and 256 QAM with Rayleigh and Rician channels
  9. Effect of short heat treatment on mechanical properties and shape memory properties of Cu–Al–Ni shape memory alloy
  10. Exploring the potential of ammonia and hydrogen as alternative fuels for transportation
  11. Impact of insulation on energy consumption and CO2 emissions in high-rise commercial buildings at various climate zones
  12. Advanced autopilot design with extremum-seeking control for aircraft control
  13. Adaptive multidimensional trust-based recommendation model for peer to peer applications
  14. Effects of CFRP sheets on the flexural behavior of high-strength concrete beam
  15. Enhancing urban sustainability through industrial synergy: A multidisciplinary framework for integrating sustainable industrial practices within urban settings – The case of Hamadan industrial city
  16. Advanced vibrant controller results of an energetic framework structure
  17. Application of the Taguchi method and RSM for process parameter optimization in AWSJ machining of CFRP composite-based orthopedic implants
  18. Improved correlation of soil modulus with SPT N values
  19. Technologies for high-temperature batch annealing of grain-oriented electrical steel: An overview
  20. Assessing the need for the adoption of digitalization in Indian small and medium enterprises
  21. A non-ideal hybridization issue for vertical TFET-based dielectric-modulated biosensor
  22. Optimizing data retrieval for enhanced data integrity verification in cloud environments
  23. Performance analysis of nonlinear crosstalk of WDM systems using modulation schemes criteria
  24. Nonlinear finite-element analysis of RC beams with various opening near supports
  25. Thermal analysis of Fe3O4–Cu/water over a cone: a fractional Maxwell model
  26. Radial–axial runner blade design using the coordinate slice technique
  27. Theoretical and experimental comparison between straight and curved continuous box girders
  28. Effect of the reinforcement ratio on the mechanical behaviour of textile-reinforced concrete composite: Experiment and numerical modeling
  29. Experimental and numerical investigation on composite beam–column joint connection behavior using different types of connection schemes
  30. Enhanced performance and robustness in anti-lock brake systems using barrier function-based integral sliding mode control
  31. Evaluation of the creep strength of samples produced by fused deposition modeling
  32. A combined feedforward-feedback controller design for nonlinear systems
  33. Effect of adjacent structures on footing settlement for different multi-building arrangements
  34. Analyzing the impact of curved tracks on wheel flange thickness reduction in railway systems
  35. Review Articles
  36. Mechanical and smart properties of cement nanocomposites containing nanomaterials: A brief review
  37. Applications of nanotechnology and nanoproduction techniques
  38. Relationship between indoor environmental quality and guests’ comfort and satisfaction at green hotels: A comprehensive review
  39. Communication
  40. Techniques to mitigate the admission of radon inside buildings
  41. Erratum
  42. Erratum to “Effect of short heat treatment on mechanical properties and shape memory properties of Cu–Al–Ni shape memory alloy”
  43. Special Issue: AESMT-3 - Part II
  44. Integrated fuzzy logic and multicriteria decision model methods for selecting suitable sites for wastewater treatment plant: A case study in the center of Basrah, Iraq
  45. Physical and mechanical response of porous metals composites with nano-natural additives
  46. Special Issue: AESMT-4 - Part II
  47. New recycling method of lubricant oil and the effect on the viscosity and viscous shear as an environmentally friendly
  48. Identify the effect of Fe2O3 nanoparticles on mechanical and microstructural characteristics of aluminum matrix composite produced by powder metallurgy technique
  49. Static behavior of piled raft foundation in clay
  50. Ultra-low-power CMOS ring oscillator with minimum power consumption of 2.9 pW using low-voltage biasing technique
  51. Using ANN for well type identifying and increasing production from Sa’di formation of Halfaya oil field – Iraq
  52. Optimizing the performance of concrete tiles using nano-papyrus and carbon fibers
  53. Special Issue: AESMT-5 - Part II
  54. Comparative the effect of distribution transformer coil shape on electromagnetic forces and their distribution using the FEM
  55. The complex of Weyl module in free characteristic in the event of a partition (7,5,3)
  56. Restrained captive domination number
  57. Experimental study of improving hot mix asphalt reinforced with carbon fibers
  58. Asphalt binder modified with recycled tyre rubber
  59. Thermal performance of radiant floor cooling with phase change material for energy-efficient buildings
  60. Surveying the prediction of risks in cryptocurrency investments using recurrent neural networks
  61. A deep reinforcement learning framework to modify LQR for an active vibration control applied to 2D building models
  62. Evaluation of mechanically stabilized earth retaining walls for different soil–structure interaction methods: A review
  63. Assessment of heat transfer in a triangular duct with different configurations of ribs using computational fluid dynamics
  64. Sulfate removal from wastewater by using waste material as an adsorbent
  65. Experimental investigation on strengthening lap joints subjected to bending in glulam timber beams using CFRP sheets
  66. A study of the vibrations of a rotor bearing suspended by a hybrid spring system of shape memory alloys
  67. Stability analysis of Hub dam under rapid drawdown
  68. Developing ANFIS-FMEA model for assessment and prioritization of potential trouble factors in Iraqi building projects
  69. Numerical and experimental comparison study of piled raft foundation
  70. Effect of asphalt modified with waste engine oil on the durability properties of hot asphalt mixtures with reclaimed asphalt pavement
  71. Hydraulic model for flood inundation in Diyala River Basin using HEC-RAS, PMP, and neural network
  72. Numerical study on discharge capacity of piano key side weir with various ratios of the crest length to the width
  73. The optimal allocation of thyristor-controlled series compensators for enhancement HVAC transmission lines Iraqi super grid by using seeker optimization algorithm
  74. Numerical and experimental study of the impact on aerodynamic characteristics of the NACA0012 airfoil
  75. Effect of nano-TiO2 on physical and rheological properties of asphalt cement
  76. Performance evolution of novel palm leaf powder used for enhancing hot mix asphalt
  77. Performance analysis, evaluation, and improvement of selected unsignalized intersection using SIDRA software – Case study
  78. Flexural behavior of RC beams externally reinforced with CFRP composites using various strategies
  79. Influence of fiber types on the properties of the artificial cold-bonded lightweight aggregates
  80. Experimental investigation of RC beams strengthened with externally bonded BFRP composites
  81. Generalized RKM methods for solving fifth-order quasi-linear fractional partial differential equation
  82. An experimental and numerical study investigating sediment transport position in the bed of sewer pipes in Karbala
  83. Role of individual component failure in the performance of a 1-out-of-3 cold standby system: A Markov model approach
  84. Implementation for the cases (5, 4) and (5, 4)/(2, 0)
  85. Center group actions and related concepts
  86. Experimental investigation of the effect of horizontal construction joints on the behavior of deep beams
  87. Deletion of a vertex in even sum domination
  88. Deep learning techniques in concrete powder mix designing
  89. Effect of loading type in concrete deep beam with strut reinforcement
  90. Studying the effect of using CFRP warping on strength of husk rice concrete columns
  91. Parametric analysis of the influence of climatic factors on the formation of traditional buildings in the city of Al Najaf
  92. Suitability location for landfill using a fuzzy-GIS model: A case study in Hillah, Iraq
  93. Hybrid approach for cost estimation of sustainable building projects using artificial neural networks
  94. Assessment of indirect tensile stress and tensile–strength ratio and creep compliance in HMA mixes with micro-silica and PMB
  95. Density functional theory to study stopping power of proton in water, lung, bladder, and intestine
  96. A review of single flow, flow boiling, and coating microchannel studies
  97. Effect of GFRP bar length on the flexural behavior of hybrid concrete beams strengthened with NSM bars
  98. Exploring the impact of parameters on flow boiling heat transfer in microchannels and coated microtubes: A comprehensive review
  99. Crumb rubber modification for enhanced rutting resistance in asphalt mixtures
  100. Special Issue: AESMT-6
  101. Design of a new sorting colors system based on PLC, TIA portal, and factory I/O programs
  102. Forecasting empirical formula for suspended sediment load prediction at upstream of Al-Kufa barrage, Kufa City, Iraq
  103. Optimization and characterization of sustainable geopolymer mortars based on palygorskite clay, water glass, and sodium hydroxide
  104. Sediment transport modelling upstream of Al Kufa Barrage
  105. Study of energy loss, range, and stopping time for proton in germanium and copper materials
  106. Effect of internal and external recycle ratios on the nutrient removal efficiency of anaerobic/anoxic/oxic (VIP) wastewater treatment plant
  107. Enhancing structural behaviour of polypropylene fibre concrete columns longitudinally reinforced with fibreglass bars
  108. Sustainable road paving: Enhancing concrete paver blocks with zeolite-enhanced cement
  109. Evaluation of the operational performance of Karbala waste water treatment plant under variable flow using GPS-X model
  110. Design and simulation of photonic crystal fiber for highly sensitive chemical sensing applications
  111. Optimization and design of a new column sequencing for crude oil distillation at Basrah refinery
  112. Inductive 3D numerical modelling of the tibia bone using MRI to examine von Mises stress and overall deformation
  113. An image encryption method based on modified elliptic curve Diffie-Hellman key exchange protocol and Hill Cipher
  114. Experimental investigation of generating superheated steam using a parabolic dish with a cylindrical cavity receiver: A case study
  115. Effect of surface roughness on the interface behavior of clayey soils
  116. Investigated of the optical properties for SiO2 by using Lorentz model
  117. Measurements of induced vibrations due to steel pipe pile driving in Al-Fao soil: Effect of partial end closure
  118. Experimental and numerical studies of ballistic resistance of hybrid sandwich composite body armor
  119. Evaluation of clay layer presence on shallow foundation settlement in dry sand under an earthquake
  120. Optimal design of mechanical performances of asphalt mixtures comprising nano-clay additives
  121. Advancing seismic performance: Isolators, TMDs, and multi-level strategies in reinforced concrete buildings
  122. Predicted evaporation in Basrah using artificial neural networks
  123. Energy management system for a small town to enhance quality of life
  124. Numerical study on entropy minimization in pipes with helical airfoil and CuO nanoparticle integration
  125. Equations and methodologies of inlet drainage system discharge coefficients: A review
  126. Thermal buckling analysis for hybrid and composite laminated plate by using new displacement function
  127. Investigation into the mechanical and thermal properties of lightweight mortar using commercial beads or recycled expanded polystyrene
  128. Experimental and theoretical analysis of single-jet column and concrete column using double-jet grouting technique applied at Al-Rashdia site
  129. The impact of incorporating waste materials on the mechanical and physical characteristics of tile adhesive materials
  130. Seismic resilience: Innovations in structural engineering for earthquake-prone areas
  131. Automatic human identification using fingerprint images based on Gabor filter and SIFT features fusion
  132. Performance of GRKM-method for solving classes of ordinary and partial differential equations of sixth-orders
  133. Visible light-boosted photodegradation activity of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 supported heterojunctions for effective degradation of organic contaminates
  134. Production of sustainable concrete with treated cement kiln dust and iron slag waste aggregate
  135. Key effects on the structural behavior of fiber-reinforced lightweight concrete-ribbed slabs: A review
  136. A comparative analysis of the energy dissipation efficiency of various piano key weir types
  137. Special Issue: Transport 2022 - Part II
  138. Variability in road surface temperature in urban road network – A case study making use of mobile measurements
  139. Special Issue: BCEE5-2023
  140. Evaluation of reclaimed asphalt mixtures rejuvenated with waste engine oil to resist rutting deformation
  141. Assessment of potential resistance to moisture damage and fatigue cracks of asphalt mixture modified with ground granulated blast furnace slag
  142. Investigating seismic response in adjacent structures: A study on the impact of buildings’ orientation and distance considering soil–structure interaction
  143. Improvement of porosity of mortar using polyethylene glycol pre-polymer-impregnated mortar
  144. Three-dimensional analysis of steel beam-column bolted connections
  145. Assessment of agricultural drought in Iraq employing Landsat and MODIS imagery
  146. Performance evaluation of grouted porous asphalt concrete
  147. Optimization of local modified metakaolin-based geopolymer concrete by Taguchi method
  148. Effect of waste tire products on some characteristics of roller-compacted concrete
  149. Studying the lateral displacement of retaining wall supporting sandy soil under dynamic loads
  150. Seismic performance evaluation of concrete buttress dram (Dynamic linear analysis)
  151. Behavior of soil reinforced with micropiles
  152. Possibility of production high strength lightweight concrete containing organic waste aggregate and recycled steel fibers
  153. An investigation of self-sensing and mechanical properties of smart engineered cementitious composites reinforced with functional materials
  154. Forecasting changes in precipitation and temperatures of a regional watershed in Northern Iraq using LARS-WG model
  155. Experimental investigation of dynamic soil properties for modeling energy-absorbing layers
  156. Numerical investigation of the effect of longitudinal steel reinforcement ratio on the ductility of concrete beams
  157. An experimental study on the tensile properties of reinforced asphalt pavement
  158. Self-sensing behavior of hot asphalt mixture with steel fiber-based additive
  159. Behavior of ultra-high-performance concrete deep beams reinforced by basalt fibers
  160. Optimizing asphalt binder performance with various PET types
  161. Investigation of the hydraulic characteristics and homogeneity of the microstructure of the air voids in the sustainable rigid pavement
  162. Enhanced biogas production from municipal solid waste via digestion with cow manure: A case study
  163. Special Issue: AESMT-7 - Part I
  164. Preparation and investigation of cobalt nanoparticles by laser ablation: Structure, linear, and nonlinear optical properties
  165. Seismic analysis of RC building with plan irregularity in Baghdad/Iraq to obtain the optimal behavior
  166. The effect of urban environment on large-scale path loss model’s main parameters for mmWave 5G mobile network in Iraq
  167. Formatting a questionnaire for the quality control of river bank roads
  168. Vibration suppression of smart composite beam using model predictive controller
  169. Machine learning-based compressive strength estimation in nanomaterial-modified lightweight concrete
  170. In-depth analysis of critical factors affecting Iraqi construction projects performance
  171. Behavior of container berth structure under the influence of environmental and operational loads
  172. Energy absorption and impact response of ballistic resistance laminate
  173. Effect of water-absorbent polymer balls in internal curing on punching shear behavior of bubble slabs
  174. Effect of surface roughness on interface shear strength parameters of sandy soils
  175. Evaluating the interaction for embedded H-steel section in normal concrete under monotonic and repeated loads
  176. Estimation of the settlement of pile head using ANN and multivariate linear regression based on the results of load transfer method
  177. Enhancing communication: Deep learning for Arabic sign language translation
  178. A review of recent studies of both heat pipe and evaporative cooling in passive heat recovery
  179. Effect of nano-silica on the mechanical properties of LWC
  180. An experimental study of some mechanical properties and absorption for polymer-modified cement mortar modified with superplasticizer
  181. Digital beamforming enhancement with LSTM-based deep learning for millimeter wave transmission
  182. Developing an efficient planning process for heritage buildings maintenance in Iraq
  183. Design and optimization of two-stage controller for three-phase multi-converter/multi-machine electric vehicle
  184. Evaluation of microstructure and mechanical properties of Al1050/Al2O3/Gr composite processed by forming operation ECAP
  185. Calculations of mass stopping power and range of protons in organic compounds (CH3OH, CH2O, and CO2) at energy range of 0.01–1,000 MeV
  186. Investigation of in vitro behavior of composite coating hydroxyapatite-nano silver on 316L stainless steel substrate by electrophoretic technic for biomedical tools
  187. A review: Enhancing tribological properties of journal bearings composite materials
  188. Improvements in the randomness and security of digital currency using the photon sponge hash function through Maiorana–McFarland S-box replacement
  189. Design a new scheme for image security using a deep learning technique of hierarchical parameters
  190. Special Issue: ICES 2023
  191. Comparative geotechnical analysis for ultimate bearing capacity of precast concrete piles using cone resistance measurements
  192. Visualizing sustainable rainwater harvesting: A case study of Karbala Province
  193. Geogrid reinforcement for improving bearing capacity and stability of square foundations
  194. Evaluation of the effluent concentrations of Karbala wastewater treatment plant using reliability analysis
  195. Adsorbent made with inexpensive, local resources
  196. Effect of drain pipes on seepage and slope stability through a zoned earth dam
  197. Sediment accumulation in an 8 inch sewer pipe for a sample of various particles obtained from the streets of Karbala city, Iraq
  198. Special Issue: IETAS 2024 - Part I
  199. Analyzing the impact of transfer learning on explanation accuracy in deep learning-based ECG recognition systems
  200. Effect of scale factor on the dynamic response of frame foundations
  201. Improving multi-object detection and tracking with deep learning, DeepSORT, and frame cancellation techniques
  202. The impact of using prestressed CFRP bars on the development of flexural strength
  203. Assessment of surface hardness and impact strength of denture base resins reinforced with silver–titanium dioxide and silver–zirconium dioxide nanoparticles: In vitro study
  204. A data augmentation approach to enhance breast cancer detection using generative adversarial and artificial neural networks
  205. Modification of the 5D Lorenz chaotic map with fuzzy numbers for video encryption in cloud computing
  206. Special Issue: 51st KKBN - Part I
  207. Evaluation of static bending caused damage of glass-fiber composite structure using terahertz inspection
https://doi.org/10.1515/eng-2024-0059
Keywords for this article
carbon fiber-reinforced polymer; flexural resistance; serviceability demands; prestressed concrete beams; steel strand; CFRP bond
Creative Commons
BY 4.0

Articles in the same Issue

  1. Regular Articles
  2. Methodology of automated quality management
  3. Influence of vibratory conveyor design parameters on the trough motion and the self-synchronization of inertial vibrators
  4. Application of finite element method in industrial design, example of an electric motorcycle design project
  5. Correlative evaluation of the corrosion resilience and passivation properties of zinc and aluminum alloys in neutral chloride and acid-chloride solutions
  6. Will COVID “encourage” B2B and data exchange engineering in logistic firms?
  7. Influence of unsupported sleepers on flange climb derailment of two freight wagons
  8. A hybrid detection algorithm for 5G OTFS waveform for 64 and 256 QAM with Rayleigh and Rician channels
  9. Effect of short heat treatment on mechanical properties and shape memory properties of Cu–Al–Ni shape memory alloy
  10. Exploring the potential of ammonia and hydrogen as alternative fuels for transportation
  11. Impact of insulation on energy consumption and CO2 emissions in high-rise commercial buildings at various climate zones
  12. Advanced autopilot design with extremum-seeking control for aircraft control
  13. Adaptive multidimensional trust-based recommendation model for peer to peer applications
  14. Effects of CFRP sheets on the flexural behavior of high-strength concrete beam
  15. Enhancing urban sustainability through industrial synergy: A multidisciplinary framework for integrating sustainable industrial practices within urban settings – The case of Hamadan industrial city
  16. Advanced vibrant controller results of an energetic framework structure
  17. Application of the Taguchi method and RSM for process parameter optimization in AWSJ machining of CFRP composite-based orthopedic implants
  18. Improved correlation of soil modulus with SPT N values
  19. Technologies for high-temperature batch annealing of grain-oriented electrical steel: An overview
  20. Assessing the need for the adoption of digitalization in Indian small and medium enterprises
  21. A non-ideal hybridization issue for vertical TFET-based dielectric-modulated biosensor
  22. Optimizing data retrieval for enhanced data integrity verification in cloud environments
  23. Performance analysis of nonlinear crosstalk of WDM systems using modulation schemes criteria
  24. Nonlinear finite-element analysis of RC beams with various opening near supports
  25. Thermal analysis of Fe3O4–Cu/water over a cone: a fractional Maxwell model
  26. Radial–axial runner blade design using the coordinate slice technique
  27. Theoretical and experimental comparison between straight and curved continuous box girders
  28. Effect of the reinforcement ratio on the mechanical behaviour of textile-reinforced concrete composite: Experiment and numerical modeling
  29. Experimental and numerical investigation on composite beam–column joint connection behavior using different types of connection schemes
  30. Enhanced performance and robustness in anti-lock brake systems using barrier function-based integral sliding mode control
  31. Evaluation of the creep strength of samples produced by fused deposition modeling
  32. A combined feedforward-feedback controller design for nonlinear systems
  33. Effect of adjacent structures on footing settlement for different multi-building arrangements
  34. Analyzing the impact of curved tracks on wheel flange thickness reduction in railway systems
  35. Review Articles
  36. Mechanical and smart properties of cement nanocomposites containing nanomaterials: A brief review
  37. Applications of nanotechnology and nanoproduction techniques
  38. Relationship between indoor environmental quality and guests’ comfort and satisfaction at green hotels: A comprehensive review
  39. Communication
  40. Techniques to mitigate the admission of radon inside buildings
  41. Erratum
  42. Erratum to “Effect of short heat treatment on mechanical properties and shape memory properties of Cu–Al–Ni shape memory alloy”
  43. Special Issue: AESMT-3 - Part II
  44. Integrated fuzzy logic and multicriteria decision model methods for selecting suitable sites for wastewater treatment plant: A case study in the center of Basrah, Iraq
  45. Physical and mechanical response of porous metals composites with nano-natural additives
  46. Special Issue: AESMT-4 - Part II
  47. New recycling method of lubricant oil and the effect on the viscosity and viscous shear as an environmentally friendly
  48. Identify the effect of Fe2O3 nanoparticles on mechanical and microstructural characteristics of aluminum matrix composite produced by powder metallurgy technique
  49. Static behavior of piled raft foundation in clay
  50. Ultra-low-power CMOS ring oscillator with minimum power consumption of 2.9 pW using low-voltage biasing technique
  51. Using ANN for well type identifying and increasing production from Sa’di formation of Halfaya oil field – Iraq
  52. Optimizing the performance of concrete tiles using nano-papyrus and carbon fibers
  53. Special Issue: AESMT-5 - Part II
  54. Comparative the effect of distribution transformer coil shape on electromagnetic forces and their distribution using the FEM
  55. The complex of Weyl module in free characteristic in the event of a partition (7,5,3)
  56. Restrained captive domination number
  57. Experimental study of improving hot mix asphalt reinforced with carbon fibers
  58. Asphalt binder modified with recycled tyre rubber
  59. Thermal performance of radiant floor cooling with phase change material for energy-efficient buildings
  60. Surveying the prediction of risks in cryptocurrency investments using recurrent neural networks
  61. A deep reinforcement learning framework to modify LQR for an active vibration control applied to 2D building models
  62. Evaluation of mechanically stabilized earth retaining walls for different soil–structure interaction methods: A review
  63. Assessment of heat transfer in a triangular duct with different configurations of ribs using computational fluid dynamics
  64. Sulfate removal from wastewater by using waste material as an adsorbent
  65. Experimental investigation on strengthening lap joints subjected to bending in glulam timber beams using CFRP sheets
  66. A study of the vibrations of a rotor bearing suspended by a hybrid spring system of shape memory alloys
  67. Stability analysis of Hub dam under rapid drawdown
  68. Developing ANFIS-FMEA model for assessment and prioritization of potential trouble factors in Iraqi building projects
  69. Numerical and experimental comparison study of piled raft foundation
  70. Effect of asphalt modified with waste engine oil on the durability properties of hot asphalt mixtures with reclaimed asphalt pavement
  71. Hydraulic model for flood inundation in Diyala River Basin using HEC-RAS, PMP, and neural network
  72. Numerical study on discharge capacity of piano key side weir with various ratios of the crest length to the width
  73. The optimal allocation of thyristor-controlled series compensators for enhancement HVAC transmission lines Iraqi super grid by using seeker optimization algorithm
  74. Numerical and experimental study of the impact on aerodynamic characteristics of the NACA0012 airfoil
  75. Effect of nano-TiO2 on physical and rheological properties of asphalt cement
  76. Performance evolution of novel palm leaf powder used for enhancing hot mix asphalt
  77. Performance analysis, evaluation, and improvement of selected unsignalized intersection using SIDRA software – Case study
  78. Flexural behavior of RC beams externally reinforced with CFRP composites using various strategies
  79. Influence of fiber types on the properties of the artificial cold-bonded lightweight aggregates
  80. Experimental investigation of RC beams strengthened with externally bonded BFRP composites
  81. Generalized RKM methods for solving fifth-order quasi-linear fractional partial differential equation
  82. An experimental and numerical study investigating sediment transport position in the bed of sewer pipes in Karbala
  83. Role of individual component failure in the performance of a 1-out-of-3 cold standby system: A Markov model approach
  84. Implementation for the cases (5, 4) and (5, 4)/(2, 0)
  85. Center group actions and related concepts
  86. Experimental investigation of the effect of horizontal construction joints on the behavior of deep beams
  87. Deletion of a vertex in even sum domination
  88. Deep learning techniques in concrete powder mix designing
  89. Effect of loading type in concrete deep beam with strut reinforcement
  90. Studying the effect of using CFRP warping on strength of husk rice concrete columns
  91. Parametric analysis of the influence of climatic factors on the formation of traditional buildings in the city of Al Najaf
  92. Suitability location for landfill using a fuzzy-GIS model: A case study in Hillah, Iraq
  93. Hybrid approach for cost estimation of sustainable building projects using artificial neural networks
  94. Assessment of indirect tensile stress and tensile–strength ratio and creep compliance in HMA mixes with micro-silica and PMB
  95. Density functional theory to study stopping power of proton in water, lung, bladder, and intestine
  96. A review of single flow, flow boiling, and coating microchannel studies
  97. Effect of GFRP bar length on the flexural behavior of hybrid concrete beams strengthened with NSM bars
  98. Exploring the impact of parameters on flow boiling heat transfer in microchannels and coated microtubes: A comprehensive review
  99. Crumb rubber modification for enhanced rutting resistance in asphalt mixtures
  100. Special Issue: AESMT-6
  101. Design of a new sorting colors system based on PLC, TIA portal, and factory I/O programs
  102. Forecasting empirical formula for suspended sediment load prediction at upstream of Al-Kufa barrage, Kufa City, Iraq
  103. Optimization and characterization of sustainable geopolymer mortars based on palygorskite clay, water glass, and sodium hydroxide
  104. Sediment transport modelling upstream of Al Kufa Barrage
  105. Study of energy loss, range, and stopping time for proton in germanium and copper materials
  106. Effect of internal and external recycle ratios on the nutrient removal efficiency of anaerobic/anoxic/oxic (VIP) wastewater treatment plant
  107. Enhancing structural behaviour of polypropylene fibre concrete columns longitudinally reinforced with fibreglass bars
  108. Sustainable road paving: Enhancing concrete paver blocks with zeolite-enhanced cement
  109. Evaluation of the operational performance of Karbala waste water treatment plant under variable flow using GPS-X model
  110. Design and simulation of photonic crystal fiber for highly sensitive chemical sensing applications
  111. Optimization and design of a new column sequencing for crude oil distillation at Basrah refinery
  112. Inductive 3D numerical modelling of the tibia bone using MRI to examine von Mises stress and overall deformation
  113. An image encryption method based on modified elliptic curve Diffie-Hellman key exchange protocol and Hill Cipher
  114. Experimental investigation of generating superheated steam using a parabolic dish with a cylindrical cavity receiver: A case study
  115. Effect of surface roughness on the interface behavior of clayey soils
  116. Investigated of the optical properties for SiO2 by using Lorentz model
  117. Measurements of induced vibrations due to steel pipe pile driving in Al-Fao soil: Effect of partial end closure
  118. Experimental and numerical studies of ballistic resistance of hybrid sandwich composite body armor
  119. Evaluation of clay layer presence on shallow foundation settlement in dry sand under an earthquake
  120. Optimal design of mechanical performances of asphalt mixtures comprising nano-clay additives
  121. Advancing seismic performance: Isolators, TMDs, and multi-level strategies in reinforced concrete buildings
  122. Predicted evaporation in Basrah using artificial neural networks
  123. Energy management system for a small town to enhance quality of life
  124. Numerical study on entropy minimization in pipes with helical airfoil and CuO nanoparticle integration
  125. Equations and methodologies of inlet drainage system discharge coefficients: A review
  126. Thermal buckling analysis for hybrid and composite laminated plate by using new displacement function
  127. Investigation into the mechanical and thermal properties of lightweight mortar using commercial beads or recycled expanded polystyrene
  128. Experimental and theoretical analysis of single-jet column and concrete column using double-jet grouting technique applied at Al-Rashdia site
  129. The impact of incorporating waste materials on the mechanical and physical characteristics of tile adhesive materials
  130. Seismic resilience: Innovations in structural engineering for earthquake-prone areas
  131. Automatic human identification using fingerprint images based on Gabor filter and SIFT features fusion
  132. Performance of GRKM-method for solving classes of ordinary and partial differential equations of sixth-orders
  133. Visible light-boosted photodegradation activity of Ag–AgVO3/Zn0.5Mn0.5Fe2O4 supported heterojunctions for effective degradation of organic contaminates
  134. Production of sustainable concrete with treated cement kiln dust and iron slag waste aggregate
  135. Key effects on the structural behavior of fiber-reinforced lightweight concrete-ribbed slabs: A review
  136. A comparative analysis of the energy dissipation efficiency of various piano key weir types
  137. Special Issue: Transport 2022 - Part II
  138. Variability in road surface temperature in urban road network – A case study making use of mobile measurements
  139. Special Issue: BCEE5-2023
  140. Evaluation of reclaimed asphalt mixtures rejuvenated with waste engine oil to resist rutting deformation
  141. Assessment of potential resistance to moisture damage and fatigue cracks of asphalt mixture modified with ground granulated blast furnace slag
  142. Investigating seismic response in adjacent structures: A study on the impact of buildings’ orientation and distance considering soil–structure interaction
  143. Improvement of porosity of mortar using polyethylene glycol pre-polymer-impregnated mortar
  144. Three-dimensional analysis of steel beam-column bolted connections
  145. Assessment of agricultural drought in Iraq employing Landsat and MODIS imagery
  146. Performance evaluation of grouted porous asphalt concrete
  147. Optimization of local modified metakaolin-based geopolymer concrete by Taguchi method
  148. Effect of waste tire products on some characteristics of roller-compacted concrete
  149. Studying the lateral displacement of retaining wall supporting sandy soil under dynamic loads
  150. Seismic performance evaluation of concrete buttress dram (Dynamic linear analysis)
  151. Behavior of soil reinforced with micropiles
  152. Possibility of production high strength lightweight concrete containing organic waste aggregate and recycled steel fibers
  153. An investigation of self-sensing and mechanical properties of smart engineered cementitious composites reinforced with functional materials
  154. Forecasting changes in precipitation and temperatures of a regional watershed in Northern Iraq using LARS-WG model
  155. Experimental investigation of dynamic soil properties for modeling energy-absorbing layers
  156. Numerical investigation of the effect of longitudinal steel reinforcement ratio on the ductility of concrete beams
  157. An experimental study on the tensile properties of reinforced asphalt pavement
  158. Self-sensing behavior of hot asphalt mixture with steel fiber-based additive
  159. Behavior of ultra-high-performance concrete deep beams reinforced by basalt fibers
  160. Optimizing asphalt binder performance with various PET types
  161. Investigation of the hydraulic characteristics and homogeneity of the microstructure of the air voids in the sustainable rigid pavement
  162. Enhanced biogas production from municipal solid waste via digestion with cow manure: A case study
  163. Special Issue: AESMT-7 - Part I
  164. Preparation and investigation of cobalt nanoparticles by laser ablation: Structure, linear, and nonlinear optical properties
  165. Seismic analysis of RC building with plan irregularity in Baghdad/Iraq to obtain the optimal behavior
  166. The effect of urban environment on large-scale path loss model’s main parameters for mmWave 5G mobile network in Iraq
  167. Formatting a questionnaire for the quality control of river bank roads
  168. Vibration suppression of smart composite beam using model predictive controller
  169. Machine learning-based compressive strength estimation in nanomaterial-modified lightweight concrete
  170. In-depth analysis of critical factors affecting Iraqi construction projects performance
  171. Behavior of container berth structure under the influence of environmental and operational loads
  172. Energy absorption and impact response of ballistic resistance laminate
  173. Effect of water-absorbent polymer balls in internal curing on punching shear behavior of bubble slabs
  174. Effect of surface roughness on interface shear strength parameters of sandy soils
  175. Evaluating the interaction for embedded H-steel section in normal concrete under monotonic and repeated loads
  176. Estimation of the settlement of pile head using ANN and multivariate linear regression based on the results of load transfer method
  177. Enhancing communication: Deep learning for Arabic sign language translation
  178. A review of recent studies of both heat pipe and evaporative cooling in passive heat recovery
  179. Effect of nano-silica on the mechanical properties of LWC
  180. An experimental study of some mechanical properties and absorption for polymer-modified cement mortar modified with superplasticizer
  181. Digital beamforming enhancement with LSTM-based deep learning for millimeter wave transmission
  182. Developing an efficient planning process for heritage buildings maintenance in Iraq
  183. Design and optimization of two-stage controller for three-phase multi-converter/multi-machine electric vehicle
  184. Evaluation of microstructure and mechanical properties of Al1050/Al2O3/Gr composite processed by forming operation ECAP
  185. Calculations of mass stopping power and range of protons in organic compounds (CH3OH, CH2O, and CO2) at energy range of 0.01–1,000 MeV
  186. Investigation of in vitro behavior of composite coating hydroxyapatite-nano silver on 316L stainless steel substrate by electrophoretic technic for biomedical tools
  187. A review: Enhancing tribological properties of journal bearings composite materials
  188. Improvements in the randomness and security of digital currency using the photon sponge hash function through Maiorana–McFarland S-box replacement
  189. Design a new scheme for image security using a deep learning technique of hierarchical parameters
  190. Special Issue: ICES 2023
  191. Comparative geotechnical analysis for ultimate bearing capacity of precast concrete piles using cone resistance measurements
  192. Visualizing sustainable rainwater harvesting: A case study of Karbala Province
  193. Geogrid reinforcement for improving bearing capacity and stability of square foundations
  194. Evaluation of the effluent concentrations of Karbala wastewater treatment plant using reliability analysis
  195. Adsorbent made with inexpensive, local resources
  196. Effect of drain pipes on seepage and slope stability through a zoned earth dam
  197. Sediment accumulation in an 8 inch sewer pipe for a sample of various particles obtained from the streets of Karbala city, Iraq
  198. Special Issue: IETAS 2024 - Part I
  199. Analyzing the impact of transfer learning on explanation accuracy in deep learning-based ECG recognition systems
  200. Effect of scale factor on the dynamic response of frame foundations
  201. Improving multi-object detection and tracking with deep learning, DeepSORT, and frame cancellation techniques
  202. The impact of using prestressed CFRP bars on the development of flexural strength
  203. Assessment of surface hardness and impact strength of denture base resins reinforced with silver–titanium dioxide and silver–zirconium dioxide nanoparticles: In vitro study
  204. A data augmentation approach to enhance breast cancer detection using generative adversarial and artificial neural networks
  205. Modification of the 5D Lorenz chaotic map with fuzzy numbers for video encryption in cloud computing
  206. Special Issue: 51st KKBN - Part I
  207. Evaluation of static bending caused damage of glass-fiber composite structure using terahertz inspection
Sign up now to receive a 20% welcome discount
Institutional Access
How does access work?
Have an idea on how to improve our website?
Please write us.
© 2025 De Gruyter Brill
Downloaded on 4.11.2025 from https://www.degruyterbrill.com/document/doi/10.1515/eng-2024-0059/html
Scroll to top button