Using Treated Recycled Demolition Aggregate in Concrete

The investigation focuses on the mechanical properties of treated recycled demolition aggregate, which was treated in two ways: one by immersing recycled demolition aggregate in NaOH solution for 24 hours and the other soaking in cement neat. The mixes were produced by substituting treated recycled demolition aggregate for 0%, 20%, 40%, and 60% of the coarse aggregate weight in both methods. The cement weight is replaced with 10% silica fume. The following tests were performed: compressive strength, splitting tensile strength, modulus of rupture, and density. Treated recycled demolition aggregate concrete compressive strength and modulus of rupture increased by 61% and 27%, respectively, as the treated recycled demolition aggregate ratio increased. Treated recycled demolition aggregate concrete has a lower tensile strength and density than normal concrete by 17 % and 12.5 %, respectively. Treated recycled demolition aggregate is appropriate for use in concrete and meets all criteria.