Evaluating the shear performance of reinforced concrete beams using waste glass powder as a sustainable cement substitute

Abstract

The scarcity of comprehensive data on the shear properties of reinforced GP‐concrete beams without shear reinforcement has hindered their widespread use, mainly due to challenges in predicting their shear performance. This study examines the influence of incorporating up to 15% waste glass powder (GP) with two separate particle size categories: GP‐A (55 to 135 μm) and GP‐B (finer than 55 μm) as a cement replacement on the 180‐day shear performance of reinforced concrete beams with varying cement content and without stirrups. To accomplish this, a total of 14 beams were used, all sharing identical dimensions measuring 200 mm × 250 mm × 2000 mm. The aforementioned parameters were investigated for their effects on the shear performance of beams, including crack patterns, modes of failure, load–deflection behavior, and strength capacities at different loading stages. Furthermore, this investigation explores the applicability of the most commonly used design codes of practice for predicting the shear strength of reinforced GP‐modified concrete beams. These codes are typically employed to design the shear strength of reinforced conventional concrete shallow beams without shear reinforcement. The study's findings indicate that the impact of GP particle size on the shear performance of beams with the same GP content is almost negligible. Additionally, the study found that incorporating GP into concrete beams does not have any negative effects on their cracking load capacity, shear strength, or flexural cracking load capacity. In fact, it can even improve the latter. A comparison of experimental results with predictions from the design codes revealed that both the CEB‐FIP (1990) equation and the ACI equations provided safe estimates of shear strength for the tested beams. However, the CEB‐FIP (1990) equation yielded predictions with a lower mean, standard deviation, and coefficient of variation compared with the ACI equations, suggesting a higher level of accuracy in its estimates. The findings affirm the suitability of GP‐concrete as a viable alternative in concrete structures specifically engineered to withstand shear forces.