养护龄期对粉煤灰混凝土高温性能的影响分析

Influence Laws of Curing Age on High Temperature Performance of Fly Ash Concrete

依据室内试验方法测试了粉煤灰混凝土高温后的抗压强度、动弹性模量、抗拉强度和内部损失量等基本使用性能,分析了养护龄期对各基本使用性能的影响规律。研究结果表明:(1)各基本使用性能均随温度的增大而弱化,温度大于450…℃时,高温弱化效果十分显著;(2)600…℃高温作用后,养护龄期为28～84…d的粉煤灰混凝土弹性模量和劈裂抗拉强度弱化了约48…%和28…%;(3)当养护龄期为28…d以上、温度超过300…℃时,粉煤灰混凝土的损伤量会随着温度的提高而逐渐增大且增大速率逐渐加快。

The high temperature basic performance of compressive strength, dynamic elastic modulus, tensile strength, internal loss of fly ash concrete are tested with the laboratory test method. And the influence law of curing age on the basic performance is analyzed. Research results show that:(1) The basic use performance are weakening along with the increase of temperature, even the temperature higher than 450 ℃.(2) After 600 ℃ high temperature effects, the elastic modulus and splitting tensile strength reduced about 48 % and 28 %, when the curing age is 28~ 84 d.(3) when the curing age is 28 d above, the temperature over 300 ℃, the amount of fly ash concrete damage will be increased gradually along with the increase of temperature and the increase rate was accelerated.