Flexural Behavior of GFRP-Reinforced Beams Made Of Recycled Coarse Aggregates from Waste Concrete

This paper reports the preliminary results from an experimental program aiming to gain a better understanding of the flexural behavior of GFRP-reinforced beams made of recycled aggregates concrete (RAC).Three 32 MPa concrete beams were designed to fail in flexure by concrete crushing before bar rupture and were tested in a four-point testing setup.The control beam was made of natural coarse aggregates (NCA).The second beam was reinforced similar to the control beam but was made of RAC.The third beam was made of RAC and contained a larger amount of longitudinal GFRP reinforcement.The behavior of the beams is reported.The compressive strength in the three beams was relatively similar.The RAC beam sustained noticeably larger deformation relative to the control beam made of NCA, but the ultimate flexural strength was relatively similar.The load-deflection response after cracking of the two RAC beams was relatively linear, which is typical behavior in GFRP-reinforced beams made using NCA.Hence, this property was not affected by the use of recycled aggregates.The calculations of the ACI 440.11 code for strength were conservative for the three beams.The calculations of this code for deflection at estimated service load level severely under-estimated the deflections.