As is well known, in the current design codes, the shear strength of beams is calculated based on the modified truss theory, which does not consider the effects of the flange area of T-beams. The main objective of this paper was to gain a better understanding and enhance the experimental database of the shear behavior of RC T-beams and illustrate the contribution of the flange to the shear capacity of T-beams. To accomplish this aim, a specially designed experimental program was executed, and its test results were analyzed. The main investigated variables were flange dimensions (thickness and width) and its reinforcement (longitudinal and/or vertical). Nineteen simply supported beam specimens were tested to failure under a load configuration made of two concentrated loads. Eighteen specimens had T-shaped cross-sections, while one specimen had a rectangular cross-section for comparison purposes. The items monitored during testing included the development of diagonal cracks, concrete strains, reinforcement strains, maximum loads, and deflections. Test results showed a notable increase in the shear strength of T-beams compared to rectangular beams with the same web size. For the range of variables investigated, increasing the flange thickness-to-beam depth ratio (ρ_t) from 0.3 to 0.5 increased the shear capacity by up to 54%. In addition, increasing the flange width-to-web width ratio (ρ_b) from 3 to 5 increased the shear capacity by up to 19%. It was also shown that the results of three-dimensional finite element (FE) analyses using ANSYS compared reasonably well with the test results for all specimens. Finally, based on the test and FE results, a simplified method that accounts for the contribution of the flange to shear capacity was proposed.

Hazardous blast loads pose significant structural challenges to buildings and infrastructure.Masonry walls, widely used in commercial, manufacturing, and residential constructions are susceptible to blast loads due to their rigidity and limited energy dissipation capacity. Understanding the effects of blast loads on masonry walls is essential for designing structures capable of withstanding such forces, thereby minimizing structural damage and ensuring occupant safety. This study investigates the impact of explosive loading on masonry walls, encompassing failure mechanisms, and strategies to evaluate and mitigate blast damage. ABAQUS/Explicit 2017 was used for a numerical evolution to assess eight masonry wall cases, comparing the performance of clay- brick masonry walls including as well as without a core made of reinforced concrete under blast loads and to figure out the importance of lateral wall support. The outcomes demonstrated that the resistance throughout clay-brick masonry walls to explosions decreases in terms of maximum displacement, stresses, and damage patterns as wall thickness increases. Conversely, walls with thicker RC cores demonstrated significantly improved performance by absorbing most of the energy from the air blast. Furthermore, side-supported walls outperformed free-standing walls in terms of displacement, stress distribution, and overall damage resistance, with the latter experiencing total collapse in several scenarios.

The present study concerned with studying the flexural behavior of RC beams with stay in place (SIP) forms, which can be used as a novel construction technology. Eight specimens were prepared, five of them with SIP form and three specimens were prepared conventionally. The specimens were tested in flexure under four-point bending loads. All the specimens had hollow unreinforced longitudinal PVC tube, located at tension side to reduce specimen weight. The used SIP forms were made from glass fiber reinforced polymer (GFRP). The GFRP forms were extended at compressive side forming hooks in order to enhance their bond with concrete and, also, to avoid a premature lateral local buckling. The forms were provided, also, with lateral clips GFRP to improve their bond with concrete, and to avoid a premature lateral buckling. The tested specimens can be divided into three groups. The first group contains three specimens, which prepared conventionally (without SIP forms) with different reinforcement steel bars (10, 12 or 16 mm diameter) at tension side. The second group includes three specimens similar to those of the first group but with SIP forms. The third group contains two specimens similar to the first specimen of the second group but they were strengthened at tension side with additional longitudinal sheets of carbon fiber reinforced polymer (CFRP) or glass fiber reinforced polymer (GFRP) in order to increase their flexural resistance. The experimental results included ultimate load, load-deflection and load-strain relationships. The cracking behavior and failure mode were observed and recorded. The experimental results showed a significant improvement in the flexural behavior of the tested specimens with SIP forms compared to the corresponding conventional ones. The tested specimens were simulated numerically using ANSYS (version 15). The numerical values of ultimate load were almost higher than the corresponding experimental value; up to 18%.

The present work studies the flexural behavior of a new type of staying in place (SIP) forms which could be used for beams in future buildings. Six specimens were prepared with (SIP) and tested under four points bending loads. The first group contains two specimens; both of them are supplied with inverted FRP U shape strips to improve the bond between FRP form and concrete. The first specimen contains a PVC tube without reinforcing while the second specimen contains a PVC tube wrapped by three layers of GFRP sheets. The second group contains two specimens; both of them are prepared with upper FRP hooks to improve the bond between FRP form and concrete. Also, the first specimen of the second group contains a PVC tube without reinforcing while the second specimen contains a PVC tube wrapped by three layers of GFRP sheets. The third group contains two specimens; both of them are prepared with upper FRP hook and have three layers of CFRP in the bottom inner face of the form. Both specimens contain unreinforced PVC tube, and the second specimen is prepared with transversal FRP links to improve the bond between FRP form and concrete. The experimental results included ultimate load, load-deflection and load-strain relationships, also; the cracking behavior and failure mode were observed and recorded. The experimental results showed an improvement in the flexural strength of the tested specimens as FRP reinforcement is added to PVC tube or to the form. Also, using FRP hook was the best technique to improve the bond between FRP form and concrete. Moreover, the tested specimens were simulated numerically using ANSYS (version 15). The ultimate loads according to the numerical simulation were higher than the corresponding experimental results by 5% to 38%.