低温环境下全轻混凝土力学性能试验研究

Experimental study on mechanical properties of light-weight concrete under low temperature environment

为探讨低温环境对全轻混凝土(ALWC)的力学性能影响,本文以LC30为例,在混凝土试块制作完成后带模放进低温室,按照目标温度(-5℃、-10℃、-15℃)分别在低温室中养护3d、7d、14d、28d,并设置在20℃(常温)下养护3d、7d、14d、28d作为对照组,养护至目标龄期后再分别进行抗压强度、劈拉强度、轴心抗压强度、弹性模量、应力-应变曲线测试试验,分析混凝土的一般力学性能随温度、龄期的变化规律。结果表明:早期养护温度越低,混凝土抗压强度也随之降低,-5℃时28d的抗压强度与常温养护下28d的抗压强度接近,但-10℃和-15℃受冻的两组混凝土,抗压强度相对略低;应力-应变曲线上的峰值应力和峰值应变均减小,这些特征指标的变化规律均体现了混凝土更具脆性破坏的倾向。

In order to investigate the effect of low temperature environment on the mechanical properties of alllightweight concrete( ALWC),taking LC30 as an example,after the completion of the production of concrete specimens with a low greenhouse,in accordance with the target temperature(-5℃,-10℃,-15℃) in the low greenhouse for the maintenance of 3 d,7 d,14 d,28 d,and set at 20 ℃( room temperature) under the maintenance of 3 d,7 d,14 d and 28 d as control group,the compressive strength,splitting tensile strength,axial compressive strength,elastic modulus and stress-strain curve of the concrete were analyzed and the regularity of general mechanical properties with temperature and age was analyzed. The results show that the lower the early curing temperature,the compressive strength of concrete is also reduced,while the compression intensity of the-5℃ 28 d is close to the compressive strength of 28 d at ambient temperature,but 10 ℃ and-15℃ of thetwo groups of concrete have a relatively low compressive strength,and the peak stress and peak strain on the stress-strain curve decrease. The variation regularity of these characteristics reflects the tendency of the concrete to be more brittle and destructive.