铝冶炼硅钙渣基生态混凝土的性能研究

硅钙渣是高铝粉煤灰提取氧化铝过程中排放的固体废弃物。为揭示以其为主要原料制备的硅钙渣基生态水泥的性能,以32.5#普通硅酸盐水泥为参照对象,以天然砂石为骨料、液态聚羧酸为减水剂,分别制备了等级为C30和C40的混凝土,比较了同等级的2种混凝土的力学性能和耐久性能。结果表明:1硅钙渣基生态混凝土的早期力学性能高于相同标号的普通混凝土,后期力学性能则发展缓慢,胶砂28 d的抗折、抗压强度分别达到8 MPa和40MPa以上。2硅钙渣基生态混凝土与普通混凝土相比具有优异的抗硫酸盐侵蚀性能和抗氯离子渗透性能;硅钙渣基生态混凝土14 d前(含14 d)的收缩率与普通混凝土相当,14 d后收缩率小于普通混凝土;C40硅钙渣基生态混凝土具有优异的抗碱骨料反应性能,其余耐久性能与普通混凝土相当。3硅钙渣基生态水泥对于Cr离子具有优异的固化特性。因此,硅钙渣基生态水泥总体性能优于32.5#普通硅酸盐水泥。

Study on the Performance of Eco-concrete with Calcium-silicate Slag from Alumina Metallurgy

Calcium-silicate slag is a kind of solid waste,which is discharged during alumina extraction from high alumina content fly ash.To reveal the performance of calcium-silicate slag based eco-cement,regarding 32.5# ordinary Portland cement as a reference object,natural sandstone as aggregate,and liquid polyethylene acid as reducing agent,concrete at the degree of C30 & C40 were produced,and also its mechanical properties and durable performance were investigated.The results show that ①the mechanical properties of the calcium-silicate slag based eco-concrete at early age are better than those of the ordinary Portland concrete,but at slow growth in the late.The flexural strength and the compressive strength of the eco-cement mortar cured at 28d reach more than 8 MPa and 40 MPa,respectively.②Compared with ordinary concrete,eco-concrete confers excellent properties of the resistance to sulfate attack and chloride penetration.Eco-concrete cured at 14 d (including 14 d)is about the same to ordinary Portland concrete,but its shrinkage is less than ordinary Portland concrete after 14 d.Eco-cement C40 has excellent resistance to alkali-aggregate reaction.The remaining durable performance of eco-concrete is fairly the same as that of ordinary Portland concrete.③Eco-cement has excellent solidification characteristics for Cr ions.Therefore,eco-cement is superior to the ordinary Portland concrete.