污泥热处理产物对水泥水化和强度演化的影响

Effect of Sludge Thermal Treatment Products on Hydration Mechanism and Strength Evolution of Cement

摘要:

探究了市政污泥生物炭（SBC）和污泥焚烧灰（ISSA）协同取代普通硅酸盐水泥时复合浆体的强度演化规律和水化机制。结果表明：2%SBC和10%ISSA的协同取代使复合净浆的28 d抗压强度提高了17.5%；在新拌净浆水化方面，生物炭能够促进高取代量焚烧灰的早期水化，而焚烧灰能够在水化中后期通过火山灰反应大幅提升体系强度；在水化产物方面，生物炭和焚烧灰能够促进复合净浆中碳铝酸盐和高聚合度水化硅（铝）酸钙凝胶的形成，有助于填充浆体中的纳米孔隙。

Abstract:

The strength evolution and hydration mechanism of composite paste were explored when municipal sludge biochar（SBC） and incinerated sewage sludge ash（ISSA） were synergistically used to replace ordinary Portland cement. The results show that the synergistic replacement of 2% SBC and 10% ISSA increases the 28 d compressive strength of the composite paste by 17.5%. In terms of fresh paste hydration， SBC enhances the early hydration of ISSA at high replacement levels， while ISSA significantly improves the system’s strength in the middle and late stages through pozzolanic reactions. Regarding hydration products， SBC and ISSA promotes the formation of carboaluminate phases and highly polymerizes hydrated calcium silicate（aluminate） gels in the composite paste， which effectively filles the nanopores within the matrix.