Comparative Experimental Investigation of Flexure and Shear Strength in Hybrid - Trapezoidal Reinforced Concrete Sections

The structural behavior of the hybrid reinforced concrete beams of the trapezoidal section is investigated in this paper. This study aims mainly to investigate the interaction effect of hybrid concrete compressive strength for section has geometry variation upon beam strength characteristics. Throughout the considered experimental program, 10 simply supported reinforced concrete beams were prepared and tested using a four-point load setting. All specimens had equal cross-sectional area. These specimens were divided into two groups, each group contain 5 beams. The first group deals with flexural behavior and the second group concerned with shear behavior. In addition to hybrid compressive strength considerations, two types of concrete with different compressive strengths of (25 and 50 MPa) were used and three trapezoidal geometries with different alignment side angles (75, 80, and 85) are adopted. The experimental testing showed that the effectiveness of the hybrid trapezoidal force formation maintained the strength of the samples decreased more than the hybrid effect force. As for the flexural behavior, the ultimate strength decreased by (2.82%) and the deflection increased by (56.81%) with respect to rectangular specimens. For shear behavior, the ultimate load was close or identical to the control specimens with deflection increment ranging from (9% to 60%) with respect rectangular specimen. The effect of area distribution within section (section shape sides orientation) was clearly on the first crack load where the angle (80) recorded a highest value of crack load.