Experimental study of mechanical properties and durability of green concrete containing slag, waste rubber powder and recycled aggregate with artificial neural network

In this experimental study, the impact of using waste materials such as ground granulated blast furnace slag (GGBFS), waste rubber powder (WRP), and recycled concrete aggregate (RCA) were evaluated on the compressive, tensile and, flexural strengths and durability test of rapid chloride migration test (RCMT) of concrete. It was observed that the mechanical properties of concrete decreased by raising the proportions of recycled materials in all replacement ratios. Because of the adverse effects of the WRP and RCA on the cement matrix and the interfacial transition zone, the reduction of the mechanical properties is higher for the concrete specimens with both recycled materials. In the case of durability, the migration rate of chloride ions in concrete is reduced by increasing the WRP rates due to the blockage of micro-pores connections. However, adding the RCA has a negative effect on the durability performance of concrete. Regarding the simultaneous effect of slag, rubber powder, and recycled aggregate on the migration of chloride ions, it can be derived that durability of samples containing 20% slag, 2.5% rubber powder, and 25% recycled aggregate at the age of 7 days on average is 14.8% higher compared to the reference sample. As the age of the samples increases to 28 days, the migration of chloride ions in the samples reduced 9.5% compared to 7 days.