Experimental investigation of hollow-core reinforced concrete T-beams

Hollow-core reinforced concrete beams are structural members that incorporate continuous longitudinal voids along their length. These internal cavities offer multiple advantages over conventional solid beams. By reducing the volume of concrete, the overall dead load is decreased, leading to lower construction costs, accelerated building processes, and the ability to span longer distances. Moreover, these voids can serve as integrated pathways for electrical and mechanical installations. Environmentally, the reduced use of concrete also contributes to sustainability by limiting CO₂ emissions associated with cement production. This research presents an experimental investigation into the structural performance of hollow-core reinforced concrete Tee beams (HRCTBs). The study involved casting and testing seven T-shaped reinforced concrete beams, each with a total length of 2000 mm. Among these, six were designed with hollow longitudinal cavities, while one solid beam served as a control specimen for comparison. The investigation focused on two primary parameters: the number of longitudinal cavities (one, two, and three) and their diameters (25 mm, 32 mm, and 50 mm). The test outcomes revealed that the introduction of hollow circular cavities significantly influenced the initial cracking load. However, their impact on yield load and ultimate load capacity was relatively minor. More specifically, increasing the number of cavities from one to three led to a reduction in the first crack load by approximately 7.14% to 14.27%, and a decrease in ultimate load capacity by about 1.67% to 3.60%. Similarly, enlarging the cavity diameter from 25 mm to 50 mm resulted in a drop in the initial cracking load by around 10.71% to 17.86%, and a reduction in the ultimate strength ranging from 1.03% to 3.60%.