n. masne

In the past two decade, researchers have studied the flexural, shear and bond behaviour of recycled aggregate concrete (RAC) beams. This work intends to analyze the behaviour of RAC beams under pure torsion, despite the lack of information on its behaviour under pure torsion. The coarse recycled concrete aggregates (RCA) extracted from construction and demolition (C & D) waste was used to replace natural coarse aggregates (NCA) in 0 %, 50 %, and 100 % ratio. Their recycling could help preserve the environment and promote sustainability through solid waste management. Six beams, each of size 150 x 250 x 1800 mm were prepared and tested. To detects minor deformation and to achieve the same strength through the out-of-plane direction, 250 mm inbuilt cantilever projections were provided on opposite faces of the beams at a span of 1000 mm along the longitudinal axis. The ultimate torsional capacity of tested beams was lower by 7.41 %, 8.60 % and 13.58 % than ATENA-3D (FEM) for 0 %, 50 % and 100 % RCA. The change in the replacement ratio of aggregate has a low impact on the ultimate torque and angle of twist. Based on the experimental and analytical results, it was established that the torque resistance capacity of the RAC beam was reduced as the % of RCA increased. Similar crack patterns and failure behaviour were observed in RAC and NAC beams in both studies. Therefore, it is practically possible to apply RAC in structural applications under pure torsional loading.

In this study, natural coarse aggregates were replaced with coarse recycled concrete aggregate (RCA) in 0 %, 50 %, and 100 % extracted from construction and demolition wastes. Their recycling could lead to a greener resolution for preserving the environment and paving the way for sustainability through solid waste management. The compressive strength of 0 %, 50 % and 100 % RCA at 365 days was reduced by 3.97 %, 4.88 %, 6.81 %, respectively, compared to the compressive strength at 28 days. Tensile strength at 365 days was reduced by 4.31 %, 6.50 % and 9.83 % compared to tensile strength at 28 days. There was no discernible effect of water type on the strength properties of concrete. Compared to other combinations, 100 % RCA concrete experiences a greater percentage of weight loss owing to evaporation of free water. When temperature was elevated, the concrete matrix expands and deep cracks were observed on the concrete surface. The overall performance of recycled aggregate concrete was not much influenced by the use of such aggregates, so these findings will add a new achievement to a sustainable construction through solid waste management.

This study presents the ATENA-3D simulation of natural aggregate concrete (NAC) and recycled aggregate concrete (RAC) beams subjected to pure torsion and the beam was validated by the experimental results with corresponding outputs. All the test specimens were 150 mm wide, 250 mm, deep and 1800 mm long. The natural coarse aggregate (NCA) were replaced by coarse recycled concrete aggregate (RCA) at three replacement ratios of 0 %, 50 %, and 100 % to prepare concrete. All the beam specimens were simulated and tested to assess the parameters like torque, twist, crack pattern, stiffness, and toughness in pure torsion. The comparison of ATENA-3D and experimental results showed that torque resistance capacity, stiffness, and toughness of beams decreased as the % of RCA increased in the concrete. A similar torque-twist curve pattern was observed in simulation and experimental studies. All the specimens failed due to torsional cracking. The torsional capacity of the beams in ATENA-3D software was higher by 9.80 %, 10.67 %, and 12.80 % than the experimental results. The results reveal that varying the quantity of RCA in RAC does not compromise the pure torsional behavior of the beam in both methods. Also, it can be concluded that the use of RCA in RAC is acceptable for structural concrete beams in pure torsion.