温变下不同含气量混凝土的力学性能

混凝土在温变疲劳作用下产生的温度应力对混凝土的抗压强度等力学性能均会产生一定的影响。本试验条件下:含气量2%混凝土,在温变循环(-20~15℃)50次后,抗压强度等力学指标损失率都在15%~35%之间;循环100次后均高于40%,而动弹性模量损失率高于25%;含气量4%以上的混凝土,在温变循环100次时抗压强度等力学指标的损失率在5%~10%之间;循环200次后混凝土各项力学指标损失在20%~30%间,动弹性模量损失率在10%左右。含气量相同的低水灰比混凝土受冻损伤程度小于高水灰比混凝土的受冻损伤程度。

MECHANICAL PROPERTIES OF CONCRETE WTH DIFFERENT AIR CONTENT UNDER VARIABLE TEMPERATURE

The compressive strength and other mechanical performance can be affected by temperature stress induced under variable temperature.For concrete with air content of 2%,15%～35% of compressive strength lost after 50 temperature shock cycles(-20℃～15℃).After 100 cycles,as high as 40% of compressive strength lost,and the dynamic modulus of elasticity lost 25%.For concrete with 4% air content,the compressive strength and other mechanical index lost 5%～10% after 100 temperature shock cycles;after 200 ycles,the mechanical index lost 20%～30%,and the dynamic modulus of elasticity lost 10% approximately.When air contents are the same,concrete with lower water cement ratio deterioraes more seriously than that with higher water cement ratio.