矿物掺合料提升高强混凝土抗硫酸盐侵蚀性能的试验研究

Experimental Study on the Improvement of Sulfate Resistance of High-strength Concrete with Mineral Admixtures

在基础工程设施建设中,混凝土抵抗硫酸盐侵蚀的能力是保障在硫酸盐侵蚀环境下混凝土耐久性的基本性能指标。文中采用硅灰、Ⅱ级粉煤灰、S95级矿粉等矿物掺合料,通过改变它们被掺加的方式和掺量配制了不同水胶比的高强混凝土,并进行了高强混凝土抗压强度和抗硫酸盐侵蚀能力的试验研究。结果表明:保持水泥用量不变时,以增加矿物掺合料掺量的方式降低水胶比可提高混凝土的抗压强度,粉煤灰和硅灰复合掺加可提高混凝土抗硫酸盐侵蚀的能力;以矿粉等量替代水泥对混凝土抗压强度产生不利影响,但对混凝土的抗硫酸盐侵蚀能力影响较小。试验结果为高强混凝土在硫酸盐侵蚀环境下的使用和推广提供了理论依据。

In the infrastructure construction,the sulfate resistance of concrete is a basic performance index to ensure the durability of concrete under sulfate attack environment.By changing the type and dosage of mineral admixtures including silica fume,Ⅱ-class fly ash and S95-grade mineral powder,the high-strength concretes with the different ratio of water to binder were prepared to investigat the compressive strength experimentally and sulfate resistance.Results show that under the conditions without changing the dosage of cement,the compressive strength of high-strength concrete increases by increasing the dosage of mineral admixture to reduce the ratio of water to binder.The sulfate resistance of high-strength concrete increases by mixing with fly ash and silica fume.On the basis of adding fly ash and silica fume,the equal dosage of mineral powder replacing cement has adverse effect on the compressive strength,and has little influence on the sulfate resistance of concrete.These experimental results provide a basis of research for the application of high-strength concrete in sulfate attack conditions.