高温后石轻页岩陶粒混凝土性能试验研究

Experimental study on properties of stone shale ceramsite concrete after high temperature

为兼顾全轻混凝土和普通混凝土的优点,通过碎石按等体积取代率取代部分陶粒的方法,制成石轻页岩陶粒混凝土,依次进行不同高温后的表观变化、特征强度、弹性模量、应力-应变曲线试验。结果表明:随温度升高质量损失率逐渐增大;其立方体抗压强度在200℃时达到最大,随后一直减小;轴心抗压强度、劈裂抗拉强度、弹性模量均随温度的升高持续减小;应力-应变曲线随温度增加峰值点明显下降和右移,峰值应变越来越大,脆性增强,性能劣化越来越显著。给出的高温后石轻混凝土质量损失率、特征强度、弹性模量的数学表达式以及本构关系式均可较好反映其变化规律。

In order to give consideration to the advantages of both light and common concrete,lightweight shale ceramsite concrete is prepared by replacing part of ceramsite with crushed stones according to the equal volume substitution rate.The apparent change,characteristic strength,elastic modulus and stress-strain curve tests are carried out successively after different high temperatures.The results show that the mass loss rate gradually increases with the increase of temperature.The cube compressive strength reached its maximum at 200℃and then decreased all the time.The axial compressive strength,splitting tensile strength and elastic modulus decrease continuously with the increase of temperature.The peak point of stress-strain curve obviously decreases and moves to the right with the increase of temperature.The peak strain becomes larger and larger,the brittleness increases,and the performance deterioration becomes more and more obvious.The mathematical expressions and constitutive relations of mass loss rate,characteristic strength and elastic modulus of stone light concrete after high temperature can well reflect its change rule.