海工水泥原料组成的优化试验研究*

根据国家标准对海工水泥原材料组成的要求,本文以粉煤灰、矿粉、硅灰为混合材与硅酸盐水泥熟料、石膏复合,通过水泥砂浆物理性能试验、抗渗性能试验、抗硫酸盐侵蚀试验和混凝土氯离子扩散系数试验,优化、确定了海工水泥合理的原材料组成范围。试验结果表明,当熟料掺量≥33%,硅灰掺量≤3%时,所制备的海工水泥的力学性能满足国家标准42.5级海工水泥的要求;以33%的熟料、7%的石膏、17%的粉煤灰、40%的矿粉和3%的硅灰制备的海工水泥具有较好的早期、后期强度和良好的耐久性能。XRD和SEM分析结果表明,与普通硅酸盐水泥相比,海工水泥水化体系中AFt含量多,可提高水泥石的致密度,减小孔隙率,使水泥硬化体具有优异的力学性能和耐久性能。

Experimental study on reasonable composition of marine cement

According to the requirements of the composition of marine cement of the national standard, prepared cement mortar with fly ash, slag powder and silica fume as mixture and then mixed with Portland clinker and gypsum, and by physical performance test, penetration resistance test, sulfate resistance test and concrete chloride diffusion coefficient test, the reasonable range of raw material composition of marine cement is optimized and determined. The results show that when the clinker content is over 33% and the silica fume is lower than 3%, the prepared marine cement meets the requirements of 42.5 grade of marine cement national standard, and the marine cement prepared by 33% clinker, 7% gypsum, 17% fly ash, 40% slag and 3% silica fume has better early and late strength and good durability. The analysis results of XRD and SEM show that the AFt content in the hydraulic system of marine cement is more than that of Portland cement, which can increase the density of cement stone and reduce the porosity, which makes the hardened cement has excellent mechanical properties and durability.