不同类型混凝土冻融损伤比较研究

Comparative Research on the Freeze-thaw Damage for Different Types of Concrete

抗冻性差是混凝土在低温工程实践中破坏的主要原因,为研究混凝土冻融损伤特性,文章对素混凝土、钢纤维混凝土、钢-聚丙烯混杂纤维混凝土、矿渣粉煤灰混凝土以及矿渣粉煤灰钢纤维混凝土进行了快速冻融循环试验,并测量了冻融后混凝土的质量损失率、抗压强度和相对动弹性模量。并比较了基于以抗压强度和相当动弹模衰减作为损伤变量的冻融损伤模型,数据表明以相对动弹模为损伤变量建立的模型能更好的表征混凝土的冻融损伤程度。

Concrete will be damaged due to poor frost resistance in low temperature engineering practice.In order to research the damage characteristics of concrete during freeze-thaw and improve the frost resistance of concrete,the rapid freeze-thaw cycle test of plain concrete,steel fiber concrete,steel polypropylene hybrid fiber concrete,slag fly ash concrete and slag fly ash steel fiber concrete were conducted in this paper.The quality loss rate,compressive strength and dynamic modulus of elasticity were measured.Two different freeze-thaw damage model of concrete were ompared.One was based on the changes of dynamic elastic modulus,and the other was based on the changes of compressive strength.Rresults show that the quadratic polynomial damage model based on relative dynamic modulus of elasticity can better reflect the freeze-thaw damage degree of concrete.