含石膏质岩集料混凝土内部硫酸盐侵蚀评估方法研究

Evaluation method of internal sulphate attack of concrete with gypseous rocks as aggregate

集料中掺杂过量的硫酸盐尤其是石膏会引起混凝土内部硫酸盐侵蚀,通过膨胀率和强度试验,研究了集料中掺杂石膏的粒径、掺合料种类和养护温度对混凝土抗内部硫酸盐侵蚀的影响,讨论了膨胀率、抗折强度和抗压强度这3个指标在评估混凝土内部硫酸盐侵蚀中的意义。结果表明:膨胀率能更好地反映混凝土内部硫酸盐侵蚀的大小,比较适合作为评价指标,而抗压强度和抗折强度因为存在数据跳差等问题,作为评价指标的参考性较差。

Contamination of aggregates with excess sulphate salts （ especially gypsum ） may result in internal sulphate attack （ISA） of concrete. Effects of gypsum aggregate particle size,mineral additive kinds and curing temperature on ISA of concrete was studied by the experiments of expan- sion ratio and strength, and the significance of the three evaluation indexes for ISA was discussed, such as expansion ratio, compressive strength and flexural strengthResults show that expansion ratio can objectively reflect the degree of ISA reaction and be more suitable for as evaluation index, and the compressive and flexural strengths as a reference of the evaluation indexes are poor because there exists data jump and errors in their tests.