掺氧化镁混凝土的安定性试验方法与判定准则

氧化镁水化时具有体积膨胀和水化速度较水泥矿物慢的特点,内掺或外掺氧化镁一直是解决混凝土后期收缩开裂问题的研究方向,但其延滞性膨胀可能影响混凝土体积的安定性。目前,掺氧化镁混凝土的安定性判定方法和判定准则决定了氧化镁的使用效果和安全性,基于氧化镁压蒸安定性试验,从安定性判定的目的出发,分析探讨了现有多种试验方法和判定准则的合理性,并指出后续研究的侧重点。

Discussion on soundness test method and judgment criteria for magnesium oxide's concrete

In the process of magnesium oxide hydration, the volume would expand and the hydration speed is slower than that of cement minerals.Adding magnesium oxide by internal mixing and external additive method are the research direction to solve the problem of concrete shrinkage cracking.However, the concrete volume would increase by hysteretic expansion of magnesium oxide.The judgment methods and criterion are used to evaluate the effect and soundness of magnesium oxide.Based on pressure-braise soundness test, the rationality of existing various experimental methods and judgment criterion are discussed from the aspect of soundness judgment object, and the future research emphasis is pointed out.