Application of pre-treated incineration fly ash (PIFA) in cement-stabilised macadam material: mechanism, mechanical and environmental considerations

This study comprehensively explored the feasibility of applying PIFA in roadbases from both technological and environmental perspectives. Firstly, by conducting macro-mechanical property tests and microscopic characterisations, it delved into the synergistic hydration behaviour of the cement-PIFA composite system, aiming to clarify the mechanism of how PIFA affects the strength development of cement-stabilised macadam. Then, the leaching toxicity of heavy metals in the whole life cycle of cement-stabilised macadam containing PIFA was simulated under unfavourable conditions such as crushing and acid rain. Meanwhile, water stability and frost resistance were also analysed. Results indicated that within a reasonable dosage range, PIFA could enhance the macro-mechanical properties, yet excessive dosage would have the opposite effect. The leaching concentration of heavy metals was far below the limit, making PIFA a feasible road-building alternative when used rationally.