Impact of Rice Husk Ash on the Mechanical Characteristics and Freeze–Thaw Resistance of Recycled Aggregate Concrete

With the accelerating growth of infrastructure construction, carbon emission and environmental pollution problems have become increasingly severe. In order to promote sustainable development construction industry, using rice husk ash (RHA) in recycled aggregate concrete has aroused extensive interest. This study aims investigate impact partial replacement (0%, 10%, 20%, 30% binder) ordinary Portland cement (OPC) with RHA by equal mass on concrete’s mechanical characteristics freeze–thaw resistance. The workability, compressive strength, loss dynamic elastic modulus were tested, hydration products microstructure analyzed scanning electron microscope (SEM) tests. mechanism damage deterioration was revealed. results indicate that incorporation an adverse effect workability fresh concrete. Its high specific surface area will provide a large number nucleation sites for reaction, refining pore structure paste improving weak bonding interfacial transition zone (ITZ) enhancing matrix’s pozzolanic reaction filling effect, thus strength Furthermore, porous attached mortar mesoporous absorb lot water during cycles. continuous accumulation expansion pressure, interior pores cracks gradually expand extend, leading more severe concrete, degree grows as ratios increase.