蒸养条件下钢渣粗骨料对混凝土的破坏作用
Destructive effect of steel slag coarse aggregate on the concrete under autoclaved condition

为了揭示钢渣粗骨料因安定性不良问题而对混凝土造成破坏的规律, 将钢渣粗骨料和含钢渣粗骨料的混凝土进行了压蒸试验, 研究了钢渣粗骨料含量对不同强度的混凝土的破坏规律。所用钢渣的游离CaO和MgO质量百分数分别为4.83%和4.76%。研究结果显示: 压蒸条件下, 游离CaO和MgO矿物会加速反应使钢渣粗骨料发生膨胀破坏, 含钢渣粗骨料的混凝土可能会因钢渣产生的内部膨胀应力而产生损伤; 钢渣粗骨料占粗骨料的比例越大, 对混凝土造成的损伤越严重; 混凝土的强度越高, 抵抗钢渣粗骨料造成内部膨胀应力的能力越强, 但钢渣粗骨料的含量仍需严格控制, 就该文采用的钢渣而言, 钢渣粗骨料质量百分数不能超过40%。
Abstract：This study analyzes the destructive effect of steel slag coarse aggregate on concrete with bad steel slag. The destructive effect of steel slag coarse aggregate on different strength concrete samples was investigated by autoclave tests of the steel slag coarse aggregate and the concrete containing the steel slag coarse aggregate. The free CaO and MgO mass ratios of the steel slag were 4.83% and 4.76%. The results show that the free CaO and the minerals containing MgO react rapidly at high temperatures, which crushes the steel slag aggregate due to the interior expansion stresses. The concrete containing the steel slag coarse aggregate might be damaged by the expansion stresses caused by the steel slag. The concrete damage is more severe with higher steel slag coarse aggregate mass ratios. Though the higher strength concrete can resist higher interior expansion stresses caused by the steel aggregate, the aggregate content should still be strictly controlled. For the steel slag used in this paper, the steel slag coarse aggregate mass ratios should be less than 40%.