粉煤灰掺量对引气混凝土抗硫酸盐侵蚀能力的影响

Effect of Fly Ash Content on the Sulfate Corrosion Resistance of Air Entrained Concrete

为了提高引气混凝土在硫酸盐干湿循环环境下的抗侵蚀能力,采用粉煤灰等量替代水泥的方式,以混凝土试件的质量损失率和抗压强度值为评价指标,考察了不同粉煤灰掺量对不同强度等级引气混凝土抗硫酸盐干湿循环侵蚀能力的影响。试验结果表明:粉煤灰的掺入能够有效降低三种不同强度等级引气混凝土在硫酸盐干湿循环试验后的质量损失率,并能有效提高引气混凝土试件的抗压强度值;当粉煤灰的掺量达到20%时,三种不同强度等级(C30、C35和C40)的引气混凝土试件质量损失率均可以达到最低(分别为1.23%、1.16%和1.05%),而抗压强度值均可以达到最大(分别为45.8 MPa、50.6 MPa和61.8 MPa),有效提高了混凝土试件的抗硫酸盐侵蚀能力。研究结果表明,粉煤灰的掺入可以有效降低引气混凝土硫酸盐侵蚀的损害程度,延长混凝土试件的使用寿命。

In order to improve the corrosion resistance of air entrained concrete under sulfate dry wet cycle environment,the method of replacing cement with equal amount of fly ash is adopted,and the impact of different fly ash content on the sulfate dry wet cycle corrosion resistance of air entrained concrete with different strength grades is investigated by taking the mass loss rate and compressive strength value of concrete specimens as evaluation indicators.The test results show that the addition of fly ash can effectively reduce the mass loss rate of three different strength grades of air entrained concrete after sulfate dry wet cycle test,and can effectively improve the compressive strength of air entrained concrete specimens;When the content of fly ash reaches 20%,the mass loss rate of air entrained concrete specimens with three different strength grades(C30,C35 and C40)can reach the lowest(1.23%,1.16%and 1.05%respectively),while the compressive strength value can reach the maximum(45.8 MPa,50.6 MPa and 61.8 MPa respectively),it is indicated that the sulfate resistance of concrete specimens is effectively improved.The results show that the addition of fly ash can effectively reduce the degree of sulfate corrosion for air entrained concrete,and prolong the service life of concrete specimens.