Two-point Loading Research Articles

Influence of water-absorbent polymer balls on the structural performance of reinforced concrete beam: An experimental investigation

Abstract This research investigated the influence of water-absorbent polymer balls (WAPB) on reinforced concrete beams’ structural behavior experimentally. Four self-compacted reinforced concrete beams of identical geometric layouts 150 mm × 200 mm × 1,500 mm, reinforcement details, and compressive strength f c ′ {f}_{\text{c}}^{^{\prime} } ≈ 50 MPa were castellated. Each beam contained a volume percentage of WAPB that differed from the others, and the considered percentages were V b = 0, 1, 2, and 3%. A static test under two-point loads was adopted to evaluate the structural behavior of the tested beams. The results indicated that the maximum load capacity of the tested beams was increased by 2.0, 3.0, and 7.14% for the volume percentages of 1, 2, and 3%, respectively, as compared to the reference beam (V b = 0%). It was also observed that the impact of V b = 3% was higher than that of the other percentages. For all the tested beams, the mode of failure was a flexural failure that is compatible with the considered preliminary design. The results showed that increasing the percentage of polymer to 3% had a significant effect on the deflection, as the deflection was directly proportioned to the percentage of WAPB.

Minimum weight design of reinforced concrete beams utilizing grey wolf and backtracking search optimization algorithms

In this study, optimal weight design of a reinforced concrete beam subjected to various loading conditions is investigated. The purpose of the optimization is to attain the minimum weight design of the reinforced concrete beam under distributed and two-point loads. The design problem is handled under three different design load cases. The two-point loads are affected on beam-to-beam connection nodes of reinforced concrete beams. Thus, while the magnitudes of distributed load and two-points load are remained constant, the distances between two-points loads are taken as 2m, 3m and 4m, respectively. The width and height of the rectangular cross-section of the concrete beam, and the diameters of the longitudinal and confinement steel rebars are treated as design variables of the optimum design problem. The design constraints of the optimization problem consist of the geometric constraints and necessities of the Turkish Requirements for Design and Construction of Reinforced Concrete Structures (TS500), and Turkish Building Earthquake Code (TBEC). As two novel metaheuristics, grey wolf (GW) and backtracking search (BS) optimization algorithms are selected as optimizers. Both algorithms are independently operated five times for three different design problems. Thus, the obtained results are examined statistically to compare in accordance with algorithmic performances. The optimal findings from optimization algorithms show that the GW algorithm is a little bit more robust on the exploitation phase, while the BS algorithm is stronger on the exploration phase. Moreover, it can be deducted from optimal beam designs that the GW algorithm is more viable to minimize reinforced concrete beam design.

Karakteristike posmične veze u spregnutoj ploči od čelika i betona

Steel-concrete composite slabs with cold-formed, profiled steel deck sheets are popularly used in steel-framed buildings. In these slabs, the deck platform acts as a working platform during construction and also as tensile reinforcement under in-service load conditions. The shear bond capacity of the composite slab is evaluated in this study for two different profile steel deck sheets. Specifically, their composite behaviour is investigated by casting and testing twelve full-scale composite deck slab specimens using the two-point loading system. In addition, based on the shear span length and profile height, the structural performance of the composite deck slab is analysed in terms of load-displacement response, shear bond capacity, ductility index, and load-slip behaviour. The results show that the most common failure of all tested specimens occurs due to the longitudinal shear failure between the concrete and profile deck sheets. As the longitudinal shear is a complex phenomenon, empirical approaches are used to evaluate the shear bond mechanism between the concrete and profile deck. The verification and comparison of experimental test results are performed with conventional and simplified m-k models based on the profile deck depth. The validated results reveal an acceptable level of reliability for prediction of each profile height based on the m and k interaction values.

Evaluation and Prediction of the Bending Behavior of Circular Hollow Steel Tube Sections Using Finite Element Analysis.

Circular hollow steel tube columns are widely used in high-rise buildings and bridges due to their ductility and lower weight compared to reinforced concrete. The use of this type of steel section has several advantages over using reinforced concrete members. The present study investigates the bending behavior of steel circular hollow sections when subjected to bending loads. The variations in material characteristics with regard to position along the cross-section of a steel tube member is first considered in this experimental study, providing for a more accurate definition of the material behavior in the model. A supported beam tested by two-point loads is the loading type that is used to study the bending performance of steel tubes. Ten circular hollow beam specimens were prepared and tested up to and post the failure stage with the following dimensions: thickness (2, 3, and 6 mm), diameter (76.2, 101.6, and 219 mm), and span (1000, 1500, and 2000 mm). A finite element analysis has been conducted for these ten specimens using the ANSYS program. The finite element model is compared to experimentally obtained data to verify that both local and global behaviors are correctly considered. The load-deflection results of this analysis showed a good agreement with the experimental results. A parametric study also was performed that considered two variables, which were the effect of the presence of circular rings and the change of opening location in the length direction on the specimens’ behavior. This study showed that the presence of the circular rings in the specimen led to an increase in its ultimate strength (of 53.24%) compared with the non-presence of these rings. In contrast, the presence of openings at 30, 40, and 50% from the specimen length reduced the strength capacity by 8.76, 14.23, and 17.88%, respectively.

Numerical Investigation on Shear Performance of Reinforced Concrete Beam by Using Ferrocement Composite

This study presents an extensive analytical investigation of the shear performance of reinforced concrete beams by using ferrocement composite as transverse reinforcement. Nonlinear finite element simulation was conducted in Abaqus 6.14 software package. Fifteen beam models were selected under two-point loading. The main parameters considered includes the diameter, spacing, number of layers of wire mesh, and its combination with stirrups. The results testified that as the diameter and number of layers of wire mesh increased, the ultimate failure load, shear capacity, and stiffness of the model specimen also increased. However, as the number of layers becomes greater than three, no significant change happens in the shear performance of the beam. In another way, the failure load, shear capacity, and stiffness of the beam models are decreased, as the spacing between wire mesh is increased. Furthermore, the study confirmed that under the same weight criteria, the shear performance of RC beam specimens with wire mesh and its combination with stirrups as shear reinforcement is greater than specimens with stirrups only. Finally, the sensitivity analysis is conducted in MS excel to access the effect of each independent variable on the ultimate failure load of the RC beam.

Double skin composite beams at Arctic low temperatures: Numerical and analytical studies

This paper focused on the developments of numerical and analytical models for double skin composite beams (DSCBs) subjected to low-temperature loadings. Firstly, ten two-point loading tests on DSCBs at varying low temperatures (T) were reported. Followed, a detailed 3D finite element model (FEM) based on ABAQUS was built for simulating ultimate strength behaviours of DSCBs at low temperatures. This FEM fully considered low-temperature influences on material properties, built detailed connector-concrete interactions, and material/geometry nonlinearities. Validations of FEM simulations by ten-test results confirmed the capabilities of the proposed FEM on simulating low-temperature structural behaviours of DSCBs. Parametric studies with 64 cases were performed with the validated FEM to make in-depth investigations on influences of T, steel-faceplate thickness (t), shear span ratio (λ), spacing of headed studs (S), and grade of concrete core (fc). The parametric studies showed that decreasing T from 20 to −80 has significantly improved the ultimate strength of DSCBs; varying shear span ratio (λ = 2.8–5.7) did not change the flexural failure mode of DSCBs; increasing fc marginally changed the ultimate strength behaviour of DSCBs. Corresponding discussions and considerations of these influencing parameters were also given. Analytical models were proposed for estimations of strength and stiffness of DSCBs under low-temperature loadings. Followed validations proved their successful predictions on the strength and stiffness of DSCBs under low-temperature loadings.

Structural Behavior of High Strength Arched Reinforced Concrete Slabs

In the past, the arch represented one of the few structural systems which provide a possibility to cover large spans. Nowadays, the same importance is presented as the need increased with the increase of construction with large spans and with arched structures which are constructed in different shapes and from various materials such as brick, steel and reinforced concrete. The main aim of this study was to investigate the behavior and ultimate strength of concrete arched slab under flexural load. The main parameters considered in the present investigation are, concrete mix compressive strength, thickness of slab, area of steel, curvature and support conditions. A total of fourteen samples of the arched slab are constructed and tested under two-point load. The behavior of the samples is observed by reading the deflection at mid-span and observing the crack patterns and strains at top and bottom fibers. The behavior of arched slab samples is linear up to first cracking load and still linear up to (35% - 55%) from the ultimate load. The load-deflection curve at mid span of the arched slab may be idealized by bilinear curve. The increasing of compressive strength by 116% leads to increase the ultimate load by (15% - 25%). Increasing the slab thickness by 43% leads to increase the ultimate load by (6% -17%). Increasing the area of steel by 45% leads to increase the ultimate load by (29% - 34%). Increasing the curvature by 200% leads to increase the ultimate load by (6% - 28%). Changing the support from simply support to pin-pin leads to increase the ultimate load by (200% - 245%).

Novel hybrid informational model for predicting the creep and shrinkage deflection of reinforced concrete beams containing GGBFS

This study investigates a Novel Hybrid Informational model for the prediction of creep and shrinkage deflection of reinforced concrete (RC) beams containing different percentages of ground granulated blast furnace slag (GGBFS) at different ages, varying from 1 to 150 days. The percentage of cement replacement by GGBFS varies from 20 to 60%. In order to examine the effects of the applied load and tensile reinforcement on creep behavior, the magnitude of two-point loading was varied from 200 kg to a maximum of 350 kg while the percentage of tensile reinforcement (ρ) was selected as either 0.77% or 1.2%. The current situation about short-term and long-term deflections due to creep and shrinkage available in the international standards, including ACI, BS and Eurocode 2, is discussed. The results indicate that RC beams containing GGBFS have larger deflections than the ones with conventional concrete (i.e., ordinary Portland cement concrete). After 150 days, the average creep deflection of RC beams containing 20, 40, and 60% GGBFS was 30, 70, and 100% higher than the ones for conventional concrete beams, respectively. A hybrid artificial neural network coupled with a metaheuristic Whale optimization algorithm has been developed to estimate the overall deflection of concrete beams due to creep and shrinkage. Several statistical metrics, including the root mean square error and the coefficient of variation, revealed that the generalized model achieved the most reliable and accurate prediction of the concrete beam’s deflection in comparison with international standards and other models. This novel informational model can simplify the design processes in computational intelligence structural design platforms in future.

Shear strengthening of RC deep beams using glass chopped strand mat (GCSM) composite

This paper presents an easy and effective technique for shear strengthening of reinforced concrete (RC) deep beams using the glass chopped strand mat (GCSM) composite. Based on the previous research, the RC deep beams may fail because of the de-bonding of the GCSM composite from the concrete surface. To prevent this de-bonding failure and to use the GCSM composite to its full potential, two different anchoring systems were investigated and proposed. A total of twenty RC deep beams were tested to failure subjected to one-point and two-point loading systems. The effects of several important parameters, such as GCSM composite layer, strengthening configuration, anchoring system, loading system, and concrete strength, on the ultimate loading capacity and failure modes of the RC deep beams were investigated. The experimental results revealed that the GCSM composite enhanced the ductility and the ultimate loading capacity of the RC deep beams. To confirm the experimental findings, finite element analysis (FEA) of the RC deep beams strengthened with the GCSM composite was also carried out employing the FEA software VecTor2. The FEA results were found to be in good agreement with experimental results for the RC deep beams with and without strengthening.

Structural Performance of Reinforced Concrete Beams with Various Cross-Section

The deflection of reinforced concrete beams with various cross-sections was investigated in this work. The experimental program comprised of four reinforced concrete beams that were simply supported. They were put through a two-point load test. High to width ratio (h/b) was (0.36, 0.64, 1, and1.56), concrete compressive strength was from 27 MPa. The gradual increase in the (h/b) ratio (from 0.36 to 0.64, 1 and 1.56) with (27 MPa) compressive strength of concrete leads to increase the first crack load for the (N2, N3 and N4) by (74%, 111% and 122%) respectively as compared with (N1), the beams (N2, N3 and N4) exhibits an increase in the yielding load by (41.2%, 70.6% and 64.7%) respectively as compared with (N1), increase the ultimate load by (25% - 130%). The ductility index is reduced with gradual increase in the (h/b) ratio (from 0.36 to 0.64, 1 and 1.56) for (27 MPa) concrete compressive strength by (1.2% - 25.5%). For the beams (N1, N2, N3 and N4) it is noticed that the central deflection of the four beams reduced gradually at the same load with increase in the (h/b) ratio from (0.36 to 0.64, 1 and 1.56) with constant (27 MPa) compressive strength concrete. The maximum crack width decreases gradually with gradual increase in the (h/b) ratio (from 0.36 to 0.64, 1 and 1.56) for constant (27 MPa).

Reliability and validity of the multi-point method and the 2-point method's variations of estimating the one-repetition maximum for deadlift and back squat exercises.

This study aimed at examining the concurrent validity and reliability of the multi-point method and the two-point method’s variations for estimating the one-repetition maximum (1RM) in the deadlift and squat exercises and to determine the accuracy of which optimal two loads can be used for the two-point method protocol. Thirteen resistance-trained men performed six sessions that consisted of two incremental loading tests (multi-point method: 20–40–60–80–90% and two-point method variations: 40–60%, 40–80%, 40–90%,60–80%, 60–90%) followed by 1RM tests. Both the multi-point method and the two-point method load variations showed reliable results for 1RM estimation (CV < 10%) squat and deadlift exercises. Session-session reliability was found to be low in deadlift (ICC: 0.171–0.335) and squat exercises (ICC: 0.235–0.479) of 40–60% and 60–80% in two-point methods. Deadlift (ICC: 0.815–0.996) and squat (ICC: 0.817–0.988) had high session-to-session reliability in all other methods. Regarding the validity of deadlift exercise, the multipoint method (R2 = 0.864) and two variations of the two-point method (R2 = 0.816 for 40–80%, R2 = 0.732 for 60–80%) showed very large correlations, whereas other two variations of the two-point method (R2 = 0.945 for 40–90%, R2 = 0.914 for 60–90%) showed almost perfect correlations with the actual 1RM. Regarding the validity of squat exercise, the multi-point method (R2 = 0.773) and two variations of the two-point method (R2 = 0.0847 for 60–80%, R2 = 0.705 for 40–90%) showed very large correlations, whereas 40–60% variation showed almost perfect correlation (R2 = 0.962) with the actual 1RM. In conclusion, whereas both the multi-point method and the two-point method load variations showed reliable results, the multiple-point method and most of the two-point methods’ load variations examined in this research provided an accurate (from large-moderate to perfect) estimate of the 1RM. Therefore, we recommend using the multi-point method and especially the two-point methods variations including higher relative loads to estimate 1RM.

Experimental study on bearing capacity of steel and steel fiber reinforced concrete composite beams without rebar cages

In consideration of the interference between H-shaped steel and rebars and the difficulty of concrete pouring in SRC structure, steel fibers rather than the rebar cage in SRC beam are used to form the steel and steel fiber reinforced concrete (SSFRC) beams. Based on the two-point symmetrical loading experiments of 18 SSFRC specimens without rebar cages, the failure mode and load–deflection curve of each specimen were obtained. Thus, the effects of shear span ratio, H-shaped steel ratio and steel fiber volume ratio on the mechanical properties of beams were investigated. With the increase of the shear span ratio, the bearing capacity of the specimens presented a decreasing trend. Benefitting from the “bridging” effect of steel fibers, the failure mode of the specimen was less affected by the shear span ratio. When H-shaped steel ratio was greater, the bending and shear resistance of H-shaped steel could be fully utilized. Additionally, the composite action between materials was weakened when the thickness of concrete cover decreased. Increases in the steel fiber volume ratio could delay the elongation of cracks and reduce the sudden decrease of bearing capacity caused by the damage of the bonding interface between H-shaped steel and SFRC, therefore improving the bearing capacity. According to the superposition principle, the shearing capacity formula of SSFRC beam was proposed. By introducing the bond coefficient and considering the coupling effect of different parameters on the collaborative work of H-shaped steel and SFRC, the calculation formula of bending capacity with high accuracy was obtained. The coefficient could be used to objectively and quantitatively identify or predict the failure type of specimens, providing reference for engineering design.

Numerical study of RC slabs under two-point contact explosion load

As an important bearing component of bridge, bridge deck is the key to bridge passage. In this paper, a solid model of reinforced concrete slab is established in LS-DYNA software, and the parameters are designed as the amount of explosive and the distance between explosives. The numerical simulation of two-point explosion test is carried out, and the damage mechanism and dynamic response of reinforced concrete slab under two-point explosion load are proposed. The results show that there is a phenomenon of energy accumulation in two-point contact explosion. At the same charge, the failure characteristics and dynamic response of RC slabs are related to the distance between the blast points. When the distance is small (30cm), the stress wave encounters and superposition strengthens between the blast points. When the spacing is large (60cm), the stress waves do not meet between the burst points, but reach the back burst surface and the side of the plate at the same time, and the damage is serious near the side of the plate, and the peak acceleration is small.

Effect of Pumice Stone and Sugar Molasses on the Behavior of Reinforced Concrete One-Way Ribbed Slabs

The world is currently heading towards sustainability by reducing the amount of concrete, thus reducing the total unit weight. Moreover, design construction requires materials with a higher strength-to-weight ratio. Ribbed slabs and lightweight concrete (LWC) are considered two leading sustainability facilities. This research developed an experimental study to evaluate the effects of concrete type, steel reinforcement ratio, the geometry of ribs, voiding ratio, and slab type on the structural behavior of one-way ribbed slabs. Eight of the one-way slabs were constructed using pumice stone and by-product material sugar molasses (SM), and one slab was constructed using gravel and SM. These slabs were tested under a static two-point load and simply supported until failure. The results showed that using SM with pumice stone instead of gravel led to high strength-lightweight concrete (HSLWC), with a cylinder compressive strength of 42.2 MPa and a density of 1943 kg/m3, which meets the requirements of HSLWC codes. Using HSLWC instead of high-strength normal-weight concrete (HSNWC) decreased the thermal conductivity by 43.55% and the unit weight by 19.31%. Moreover, the ultimate strength of the HSLWC one-way ribbed slab decreased by 17.70%. Overcoming this strength reduction necessitated increasing the steel reinforcement ratio of the ribs from 0.28 to 0.44% in the HSLWC ribbed slab. Changing the number of ribs at the same amount of HSLWC showed a minor effect on the strength capacity of slabs but showed an economic benefit. However, increasing the rib width to reduce the voiding ratio from 44 to 40% resulted in a greater improvement in structural efficiency (SE) of one-way ribbed slab than reducing it from 44 to 33%. Consequently, the optimum rib width was 120 mm. Moreover, using a ribbed slab instead of a solid slab of HSLWC at the same amount of concrete increased the ultimate strength by 130.37%, decreased deflection by 3.99%, and improved SE by 126.46%. Furthermore, experimental results of ultimate load were compared with the ACI 318-19 code design equation. Doi: 10.28991/CEJ-2022-08-02-011 Full Text: PDF

EFFECTS OF WEB OPENINGS ON SHEAR BEHAVIOUR OF NORMAL AND INTERNALLY STRENGTHENED CONCRETE BEAMS

Web openings in reinforced concrete (RC) beams are provided to pass utility pipes and ducts through them. This causes high stresses (with local cracking) around the transverse web openings, which may lead to reduction in ultimate strength and stiffness of RC beams. Internal strengthening with shear reinforcement can increase ultimate strength of the beam with web openings. This paper presents an experimental study which was conducted to investigate load carrying capacity, mid-span deflection and failure modes of beams with web openings. A total of eighteen RC beams were included in the testing programme, which were tested under two-point loading. The beams contained both pre-planned and post-planned web openings. Experimental results showed that ultimate load of the beams decreased from forty-two to sixty-seven percent due to the presence of web openings in the shear zones. Shear strength of the beams with pre-planned web openings increased by thirty-six percent and one-hundred two percent as compared to the reference beam due to the increase of shear reinforcement by one-hundred twenty-two percent and three-hundred three percent, respectively. Similarly, increase in shear capacity up to six percent and fourteen percent was found for the beams with post-planned web openings due to the aforementioned increase in the area of shear reinforcement, respectively. The ultimate load carrying capacity was also compared with the theoretical models. Internal strengthening and pre planned opening were found effective for providing web openings in the beams.

Developments of prefabricated steel-concrete composite beams with novel steel-yielding demountable bolt connectors

This paper developed prefabricated steel-concrete composite beams (PSCCBs) with novel steel-yielding demountable bolt connectors (SYDBCs). This new connecting system adopted the post-installed bolts and concrete plug blocks to interlock the prefabricated concrete slab and underneath I-beam, which significantly improves the construction efficiency. The concept design of the PSCCBs with SYDBCs was firstly introduced. Followed, four push-out tests with PSCCBs using SYDBCs were tested to investigate their shear behaviours at the component level. Push-out test results showed that compared with the casted-in bolt connectors, the developed SYDBCs slightly reduces the shear stiffness (about 20%) and yielding load, but does not affect their ultimate shear strength. Moreover, the SYDBCs exhibit better shear ductility than the casted-in bolt connectors with the same size. Two PSCCBs designed with post-installed normal bolts (NBs) and SYDBCs were also tested under two-point loading to study their ultimate strength behaviour. Test results showed that PSCCBs using SYDBCs exhibited reduced elastic stiffness (by about 22%), but equivalent ultimate strength (difference is 3%) to those PSCCBs using casted-in bolt connectors. Finally, two T-joints using the casted-in steel-concrete composite beams and PSCCBs with SYDBCs were tested under cyclic loading to study their seismic performances. Using SYDBCs has quite limited influences on the stiffness, ultimate bending resistance, and energy dissipation of the T-joint with composite beams (reductions equal to about 10%). This further confirms the applicability of the developed SYDBCs for the PSCCBs in steel framed buildings.

Experimental investigation of composite steel–concrete beams using symmetrical and asymmetrical castellated beams

Abstract This study aims to investigate the behavior of concrete slabs acting compositely with symmetrical and asymmetrical castellated beams. Stud connectors are used to connect the concrete slab and steel section. The use of castellated steel beams to build up composite steel-concrete beams is now common practice in building construction. Five simply supported composite beams were examined under two-point loading. Two specimens built up from standard steel beams were used as control specimens and three specimens were built up from castellated steel beams. One of these specimens was built up using a castellated steel beam with an asymmetrical cross-section fabricated from two different standard sections (IPE120/HEA120). The concrete slab of all composite specimens had the same dimensions and properties. The experimental results showed that strength and rigidity were considerably greater for composite castellated steel beams compared to composite beams built up from the parent sections. The ultimate load capacity of a composite castellated beam fabricated from an IPE120 section was 46% greater than that of a composite beam built up using the parent beam, and the ultimate load capacity of a composite castellated beam fabricated from a wide-flanged HEA120 section resulted in an increase of 21% over the parent beam control specimen. The ultimate load capacity of the composite specimen built up using the asymmetrical castellated beam (IPE120/HEA120) achieved increases of 69% and 12%, respectively, compared to the control specimens built up from standard sections.

Static and Dynamic Behavior of High-strength Lightweight Reinforced Concrete One-way Ribbed Slabs

Nowadays, reducing the self-weight of structures and vibration problems is the primary goal for design requirements in most civil constructions. Two-point loading and harmonic loading tests were conducted to examine the strength and serviceability of high-strength reinforced concrete one-way ribbed slabs. Six slabs were cast and tested. The behavior of cracking, deflection, and vibration was investigated. The experimental results showed that using high strength-lightweight concrete (HSLWC) instead of high strength-normal weight concrete (HSNWC) in constructed one-way ribbed slab led to a decrease in the density by 19.31%, the strength by 17.70%, and ultimate deflection by 17.33%. Although the addition of steel fibers to HSLWC led to an increase in the density of concrete its addition enhances the load-deflection relationship and ultimate load for slab specimen which reduced the reduction in strength by 14.49%. Furthermore, ductility index, stiffness, and toughness index for ribbed slab specimens with steel fibers showed better behavior than those without steel fibers. The HSNWC gave a negative impact on the vibration of the one-way ribbed slab at both operation frequencies (25 and 50) Hz, while using HSLWC with and without steel fibers, led to reducing the vibration effect by (30.11and 30.68) % and (15.26 and 20.25) % at 25Hz and 50Hz, respectively.

Rehabilitation of Hybrid RC-I Beams with Openings Using CFRP Sheets

This research presents an experimental investigation of the rehabilitation efficiency of the damaged hybrid reinforced concrete beams with openings in the shear region. The study investigates the difference in retrofitting ability of hybrid beams compared to traditional beams and the effect of two openings compared with one opening equalized to two holes in the area. Five RC beams classified into two groups, A and B, were primarily tested to full-failure under two-point loads. The first group (A) contained beams with normal weight concrete. The second group (hybrid) included beams with lightweight concrete for web and bottom flange, whereas the top flange was made from normal concrete. Two types of openings were considered in this study, rectangular, with dimensions of 100×200 mm, and two square openings with a side dimension of 100 mm. A full wrapping configuration system for the shear region (failure zone) was adopted in this research. Based on the test results, the repaired beams managed to recover their load carrying capacity, stiffness, and structural performance in different degrees. The normal concrete beam regains its total capacity for all types of openings, while the hybrid beams gain 84% of their strength. The strength of hybrid concrete members compared with normal concrete is 81 and 88% for beams of one opening and two openings, respectively. Doi: 10.28991/CEJ-2022-08-01-012 Full Text: PDF

Strength performance of deep beam with embedded side plates as shear reinforcement: A numerical analysis

The major design criteria in deep beam is shear failure, as it is brittle in nature and causes sudden damage or collapse. Hence, research had investigated the effect of their shear strengthening method on the load carrying capacity of deep beam. This study proposed a method which replace the shear link with mild steel plate as an alternative shear reinforcement that reduce steel congestion in deep beam. Three numerical specimens were modelled using ABAQUS. The specimens were simply supported at both end and two-point loads were gradually acting on the specimens in the mode of monotonic loading condition. The results obtained from the numerical control specimen was validated with the experimental results done by other researchers. The numerical results show that the load bearing capacity of proposed deep beams were lower than the conventional specimen. The mild steel plates in proposed beams demonstrated tendency of side concrete cover separation from the main concrete body. Hence, it caused delamination of concrete leading to lower load carrying capacity.