碱激发生活垃圾焚烧炉渣底灰泡沫混凝土制备及性能研究

Investigation on Preparation and Performance of Alkali-activated Municipal Waste Incineration Bottom Ash(MIBA)Foam Concrete

泡沫混凝土因其较低的自重、良好的隔音隔热和抗震性能在建筑行业应用广泛。传统泡沫混凝土使用水泥作为胶凝材料,碳排放量较大。为减少碳排放,使用城市生活垃圾焚烧炉渣底灰(MIBA)部分替代水泥制备生活垃圾焚烧炉渣泡沫混凝土(MIBAFC),在优选发泡剂的基础上,采用碱激发技术进一步改进泡沫混凝土性能,研究不同类型激发剂对MIBAFC力学性能、吸水率、干燥收缩的影响,并采用BSE、SEM、TG-DTG、XRD测试碱激发MIBAFC的微观结构和水化特性。结果表明:CaO+Na_(2)CO_(3)(CN)、NaOH(NH)、水玻璃+K_(2)CO_(3)(SK)、水玻璃(NS)这四种激发剂均可与MIBA中的SiO_(2)、Al_(2)O_(3)等活性组分发生聚合反应,提高水化反应程度,改善硬化浆体的气孔结构,从而对MIBAFC的凝结时间、吸水率、力学性能、干燥收缩均有显著改善作用,对比四种激发剂的激发效果,NS综合改性效果最佳,CN效果不显著。

Foam concrete is widely used in the construction industry due to its low weight,good sound insulation,heat insulation,and seismic perfor-mance.Traditional foam concrete uses cement as the binder,which results in high carbon emissions.To reduce carbon emissions,municipal solid waste incineration bottom ash(MIBA)is partially used to replace cement to prepare MIBA foam concrete(MIBAFC).Based on the optimal foaming agent,alkali-activated technology is further used to improve the performance of foam concrete.The effects of different types of activators on the mechanical properties,water absorption rate,and drying shrinkage of MIBAFC were studied,and the microstructure and hydration characteristics of alkali-activated MIBAFC were tested using BSE,SEM,TG-DTG,and XRD.The results show that CaO+Na_(2)CO_(3)(CN),NaOH(NH),water glass+K_(2)CO_(3)(SK),and water glass(NS)can all undergo polymerization reaction with the active components such as SiO_(2)and Al_(2)O_(3)in MIBA,which improves the degree of hydration reaction and the pore structure of the hardened slurry.This significantly improves the setting time,water absorption rate,mechanical properties,and drying shrinkage of MIBAFC.Among the four activators,NS has the best overall modification effect,while CN has no significant effect.