不同强度等级铁矿废石骨料混凝土抗氯离子渗透性能

Chloride ion penetration resistance of iron ore waste rock aggregate concrete with different strength grade

在固废资源化发展背景下,利用铁矿废石骨料生产混凝土可以有效缓解天然砂石资源面临枯竭的困境。为研究不同强度等级铁矿废石骨料混凝土的抗氯离子渗透性能,设计了水胶比分别为0.59、0.35和0.23的混凝土,进行了立方体抗压强度试验,并采用电通量法分别测试了养护28 d和56 d混凝土的抗氯离子渗透性能。试验结果表明:养护28 d后,3种混凝土立方体抗压强度分别为25.3 MPa、54.6 MPa和79.9 MPa,渗透性评价依次为低、很低和极低;养护56 d后,3种混凝土的抗压强度分别增长16.9%、9.4%和7.4%,且电通量明显降低,说明养护龄期对渗透性的影响显著;混凝土的电通量与抗压强度具有极强相关性,呈线性递减关系。

In the context of the development of solid waste recycling,using aggregates produced from iron ore waste rock to prepare concrete can effectively alleviate the dilemma of depletion of natural sand and gravel.In order to study the chloride ion penetration resis-tance of iron ore waste rock aggregate concrete with different strength grade,concrete with water-binder ratios of 0.59,0.35 and 0.23 were designed.Cubic compressive strength tests were carried out and the electric flux method was used to test the chloride ion penetration resis-tance of the cured concrete for 28 d and 56 d.The test results show that after 28 days of curing,the compressive strengths of the three con-crete cubes are 25.3 MPa,54.6 MPa,and 79.9 MPa,respectively,and the permeability evaluations are in order of low,very low,and negli-gible.After 56 days of curing,the compressive strengths of the three types of concrete increased by 16.9%,9.4%,and 7.4%,and the electri-cal flux was significantly reduced,indicating that the curing age has a significant impact on the permeability.The electric flux and compres-sive strength of concrete have a very strong correlation,showing a linear decreasing relationship.