本文研究了在80℃水养护条件下,掺入不同掺量氧化镁膨胀剂、粉煤灰的混凝土试件的膨胀性能和劈拉强度。结果表明,适当的氧化镁掺量不仅使混凝土的膨胀值增大,而且对其劈拉、抗压强度均有一定的影响,粉煤灰对氧化镁的膨胀有明显的抑制作用。之后的实体工程质量跟踪中,工程实体外墙表面表明没有出现贯穿性裂缝,强度符合设计要求。 In this paper, the swelling properties and splitting tensile strength of concrete specimens with different dosages of magnesia expansive agent and fly ash were studied under water curing condition of 80 ℃. The results show that proper content of magnesia not only increases the swelling value of concrete, but also affects its splitting tensile strength and compressive strength. Fly ash obviously inhibits the expansion of magnesia. Subsequent physical project quality tracking, the engineering entity wall surface shows no penetration cracks, the strength meets the design requirements.