蒸养混凝土中GFRP筋微观结构与抗拉性能分析

为了研究服役前蒸养养护过程对混凝土中玻璃纤维材料(glassfiber reinforced plastic,GFRP)筋抗拉强度的劣化程度,减小不同养护制度下混凝土中GFRP筋抗拉性能设计的误差,本文从微观与宏观角度分析标准养护制度(20℃)、蒸养养护制度(40℃、60℃、80℃)对混凝土中GFRP筋微观结构及抗拉性能的影响。并为减小混凝土中GFRP筋抗拉性能测试的难度及对GFRP筋裸筋耐久性研究成果的拓展,同时针对裸筋与混凝土包裹两种试验方法中的GFRP筋微观及抗拉性能进行研究。研究结果表明:不同养护制度对混凝土中GFRP筋的微观结构与抗拉强度的劣化程度随养护温度的提高而不断增大;不同养护制度对混凝土中GFRP筋抗拉强度的劣化影响与裸筋有所不同;并且不论是养护制度的影响还是试验方法的影响,都随直径的增大而有所降低。基于GFRP筋抗拉试验数据建立了与养护温度、直径同时相关的不同试验方法差异性方程,实现通过裸筋养护试验预测不同养护制度下混凝土中GFRP筋抗拉强度的衰减率。

Similarities and Differences Between Freundlich Kinetic Equation and Two-Constant Equation

A mathematical expression of Freundlich kinetic equation, 1nS=A'+B'1nt, is presented, and the physical meanings of its parameters are indicated. Although the Freundlich kinetic equation and the two-constant equation are the same in the form, the derivation of the Freundlich kinetic equation is precise, while the deriVation of the two-constant equation has some contradictions and is unreasonable. And it is suggested that the Freundlich kinetic equation should have priority over the two-constant equation to be used.