Optimization of High-Performance-Concrete properties containing fine recycled aggregates using mixture design modeling

This investigation means to optimize the properties of High-Performance-Concrete (HPC) containing fine aggregates from concrete and brick wastes for different recycled aggregates substitution rates, using mixture design modeling. To succeed this, the design of experiments (DOE) method was used. It is observed that slump, flexural and compressive strength of recycled concrete are significantly influenced by the content of natural sand (NS), recycled concrete aggregates (RCA) and recycled brick aggregates (RBA). The experimentally measured responses were successfully studied to develop a polynomial model, which represents slump, flexural strength and compressive strength at 7 day and 28 day of HPC. The significance and accuracy of the model was confirmed by statistical analysis and experimental verification. Under optimal conditions, the maximum desirability is 0.65, which can be obtained by using only recycled sands, i.e. RBA (9.5%) and RCA (90.5%), and no natural sand. The statistical results show that the proposed models are well correlated with the experimental data