钢渣粉和粉煤灰对硫铝酸盐水泥砂浆性能的影响试验研究

Experimental investigation on the effect of steel slag and fly ash on the properties of sulphoaluminate cement mortar

硫铝酸盐水泥(SAC)具有速凝早强、抗渗性好和耐化学腐蚀等优点,广泛应用于快速抢修、水利水电、地下管网和海洋工程等环境中;但是高昂的使用成本限制了SAC的进一步发展和应用。利用工业废弃物少量取代SAC,可在改善水泥性能的同时降低材料成本。研究了钢渣和粉煤灰对硫铝酸盐水泥砂浆(SACM)的工作性能、力学强度和抗渗性能的影响,并通过SEM和XRD分析了微观结构和水化产物。结果表明:钢渣掺量30%时,砂浆的终凝时间仅70 min,相比纯SACM缩短了28.5%;粉煤灰因“滚珠效应”显著提高了砂浆的扩展度;2种掺合料提高了SACM的吸水率;因为活性低,钢渣和粉煤灰均在不同程度上不利于砂浆的力学性能和抗渗性能。单掺10%钢渣的砂浆能最大程度保持纯SACM的基本性能,且凝结时间更短;该组砂浆综合性能最优,具有一定环保和经济价值。

Sulphoaluminate cement(SAC)is characterized of rapid setting,early strength development,good permeability resistance and chemical corrosion resistance,for which SAC is widely used in practical engineerings like rapid repair,water conservancy and hydropower,underground pipe network and marine environment.However,the high cost of SAC limits its further development.It is reported that cement replaced with industrial wastes have desirable performance and economic benefits.The effects of steel slag and fly ash on the workablility,mechanical strength and impermeability of sulphoaluminate cement mortar(SACM)were studied.Then hydration products and microstructure of SACM were analyzed by means of SEM and XRD.The results show when steel slag content reaches 30%,the final setting time of mortar is 70 min,which is 28.5%shorter than the pure SACM.Fly ash significantly improves the fluidity due to its“ball effect”.The two admixtures will increase the water absorption of SACM.And the two admixtures are also detrimental to the mechanical properties and impermeability,for their low reactivity.The mechanical properties and impermeability of SACM can be maximally maintained,but with shorter setting time,by incorporating 10%steel slag.The experimental group with 10%steel slag has the best comprehensive performance,as well as certain environmental protection and economic value.