冻融循环后泡沫混凝土的强度研究

复杂寒区隧道填充材料要兼具防寒保温,还需要有一定的强度和抗震性能,常规的泡沫混凝土往往只能有保温效果,但是强度方面有较大的不足。为了解决这一不足,研究制备了一种新配合比的泡沫混凝土,通过添加不同长度的纤维和减水剂等外加剂,研制一种高强度防寒保温泡沫混凝土,通过交叉对比试验,结果得出当水灰比为0.5时,在掺加19mm的聚丙烯纤维和减水剂时,泡沫混凝土的抗压强度能提高427%,在经过25次冻融循环后,强度损失最低,损失幅度为10.4%。

Tunnel filling materials in complex cold regions should be both cold proof and thermal insulation. They also need a certain de gree of strength and seismic performance. Conventional foam concrete can only have thermal insulation effect, but there is a large deficiency in strength. In order to solve this problem, a new proportion of foam concrete was prepared. By adding different lengths of fibers and water reducing agents, a high strength cold proof and thermal insulation foam concrete was developed. Through cross comparison test, it was found that when the water cement ratio was 0.5, the foam was mixed when 19mm polypropylene fiber and water reducing agent were added. The compressive strength of the concrete can be increased by 427%. After 25 freeze-thaw cycles, the strength loss is the lowest, and the loss range is 10.4%.