（西安建筑科技大学土木工程学院， 西安 710055）

［摘要］试验研究不同水胶比(0-34，0-4，0-5)、不同粉煤灰掺量(0%，30%，50%)混凝土试件，经不同温度(20，200，400，600℃)作用后抗压强度的变化规律。结果表明：200℃时低水胶比(0-34)混凝土抗压强度损失率相对较小，600℃时高水胶比(0-5)混凝土抗压强度损失率相对较小；对于大掺量粉煤灰混凝土试件，混凝土抗压强度随粉煤灰掺量的增大而减小；粉煤灰掺量为30%时，高温导致的强度损失相对较小。研究结果可为混凝土结构火灾后的损伤评估和维修加固提供参考。

［关键词］水胶比； 粉煤灰； 高温； 抗压强度； 损伤评估； 维修加固

中图分类号：TU502-6文献标识码：A文章编号：1002-848X(2019)22-0093-04

Influences of water-binder ratio and fly-ash replacement level on compressive strength of concrete after high temperature

Wu Yaopeng, Li Yanhao, Zhang Xu, Wang Yonghui

(School of Civil Engineering, Xi′an University of Architecture and Technology, Xi′an 710055, China)

Abstract:The compressive strengths of concrete specimens with different water-binder ratios (0-34, 0-4 and 0-5) and different fly-ash replacement levels (0%, 30% and 50%) after different temperatures (20, 200, 400 and 600 ℃) had been experimentally investigated. The results showed that the compressive strength loss rate of the concrete with low water-binder ratio (0-34) after 200℃ was relatively small, and the compressive strength loss rate of the concrete with high water-binder ratio (0-5) after 600℃ was relatively small; for high volume fly-ash concrete, the compressive strength of the concrete decreased with the increasing fly-ash replacement level; for the concrete with the fly-ash replacement level of 30%, the compressive strength loss caused by high temperature was relatively small. The results can provide references for the damage evaluation and maintenance and  reinforcement of concrete structure after fire.

Keywords:water-binder ratio; fly ash; high temperature; compressive strength; damage evaluation;  maintenance and  reinforcement

*国家自然科学基金项目（51108371），陕西省教育厅重点实验室科研计划项目（16JS050）。

作者简介：吴耀鹏，博士，副教授，硕士生导师，Email: wyp@xauat.edu.cn。