Effect of Nominal Maximum Aggregate Size on Performance of Recycled Aggregate Self-Consolidating Concrete: Experimental and Numerical Investigation

Nominal maximum aggregate size (MAS) and particle distribution affect the performance of concrete significantly. However, their effect is influenced by the type of aggregate and the target concrete strength. This research investigates the effect of MAS on the mechanical performance of high-strength self-consolidating concrete (HSSCC). Two different types of coarse aggregates, natural quartz aggregate (NA) and recycled concrete aggregate (RA), were used in the evaluation. Compressive, splitting tensile, flexural, and shear strengths were tested and used as criteria for evaluation. Ultrasonic pulse velocity and rebound value were also used as nondestructive evaluation techniques. The results showed that compressive strength decreased when using a bigger MAS of NA, while it increased when using a bigger MAS of RA. However, this conclusion cannot be generalized to include all mechanical properties of concrete, as the failure mechanism for each test depends on the type and size of aggregate. In addition, finite and discrete element methods were applied to study the effect of MAS as well as to simulate the experimental performance of concrete. Following proper proportioning and mixing, RA could be used to produce HSSCC concrete. Keywords: coarse recycled concrete aggregate; discrete element modeling; finite element modeling; high-strength concrete; nominal maximum aggregate size; self-consolidating concrete.