Combining pozzolanic material as ternary binder in Recycled Aggregate Concrete (RAC) to develop a new sustainable concrete

The demand for a sustainable concrete has increasing due to the effect of conventional concrete that led to many environmental problems such as carbon dioxide emission and depletion of natural resources. Hence, this paper discusses about the usage of ternary binder in recycled aggregate concrete (RAC). Ternary binder was developed from combination of palm oil fuel ash (POFA) Class C and rice husk ash (RHA) Class F as partial cement replacement. This study consists of two (2) phases that are; phase 1 to determine the optimum percentage of ternary binder and phase 2 to determine the compressive strength of recycled aggregate concrete with ternary binder system. Compressive test was conducted for 7 and 28 days to determine the compressive strength. The results show that existence of POFA and RHA as pozzolan for ternary binder help to improved strength of RAC. Combinations of 10% POFA + 15% RHA + 20% RA produce a compressive strength up to 32.8 MPa at 28 days. Increasing of RA content up to 20% will reduce the compressive strength. Overall it can be concluded that combination of POFA and RHA as ternary binder in RAC can produce a concrete with satisfactory strength for structural purposed.