Analysis of flexural behaviour of steel reinforced cement-less concrete beam

Limited information exists in the scientific literature on the structural performance of reinforced elements using cement-less concrete mixes. To address this gap, an experimental investigation was conducted to evaluate the structural behavior of reinforced geopolymer concrete (GPC) beam elements. This study specifically examines the bending performance of GPC beams compared to Ordinary Portland Cement Concrete (OPCC) beams, focusing on failure loads, deflections, strains, and crack patterns. Three beams were tested under four-point bending: two with GPC mixes and one with OPCC as a reference. The maximum loads achieved by the GPC beams were 14 % and 9 % higher than the OPCC reference beam, while the OPCC beam failure load was 9 % above its expected maximum. Maximum strains of 4.3 ‰ and 3.7 ‰ were recorded for the GPC beams, closely aligning with the 3.5 ‰ design value for OPCC. Load-displacement analysis revealed negligible differences in the elastic behavior for all beams, as well as for ductility and deformation at service load. On the other hand, Cracking moments for GPC beams were observed to be up to 34 % lower than OPCC, likely due to differences in tensile strength and microstructural composition. Overall, the experimental results demonstrated that GPC beams can be designed using OPCC structural provisions with comparable accuracy, as evidenced by the alignment of experimental and theoretical moment-curvature curves. Finally, an experimental-analytical comparison according to the existing standards suggestions was carried out.