摘要
为了研究生态型高延性水泥基复合材料(ECO-HDCC)在高温作用后的力学性能及损伤机理,研究了高温作用对混凝土抗压强度和对ECO-HDCC微观形貌和物相组成的影响。结果表明:300℃时ECO-HDCC抗压强度降低不明显;500℃时ECO-HDCC抗压强度损失率为32.6%～58.0%;800℃时ECO-HDCC抗压强度持续降低,损失率为58.9%～77.8%;1 100℃时ECO-HDCC无继续承载能力,损失率最高达92.5%。纤维熔化产生大量孔道和水化产物分解导致基体结构密实性降低,使ECO-HDCC抗压强度降低,也为ECO-HDCC在高温作用下形成的应力提供了释放通道,使ECO-HDCC在1 100℃高温作用下持续180min仍未发生爆裂。
In order to investigate the mechanical property and evolution mechanism of ecological high ductility cementitious com- posites （ECO-HDCC） after subjected to high temperature, the effect of temperature on the compressive strength of ECO-HD- CC was analyzed. The micro-morphology and phase composition of the ECO-HDCC subjected at various high temperatures were investigated by scanning electron microscopy, thermogravimetry-differential scanning calorimetry and X-ray diffraction, respec- tively. The experimental results show that the compressive strength of ECO-HDCC decreases after exposed to 300 ℃. After 500 ℃, the compressive strength loss ratio of ECO-HDCC increases from 32.6 % to 58.0%. The compressive strength loss ra- tio of ECO-HDCC after subjected to 800 ℃ increases from 58.9% to 77.8~. The ECO-HDCC has little load-bearing capacity, and the compressive strength loss ratio is up to 92.5%. It is revealed that the melting and evaporation of PVA fibers at high temperature have pathways for the vapor and the decomposition of hydration products coarsen the microstructure, resulting in the decrease of the compressive strength of ECO-HDCC, and the release of the internal stress of pores in the ECO-HDCC after heat treatment at 1 100 ℃ for 180 min.
出处
《硅酸盐学报》
EI
CAS
CSCD
北大核心
2014年第8期1018-1024,共7页
Journal of The Chinese Ceramic Society
基金
国家自然科学基金(51378113)
中央高校基本科研业务费专项资金(26220120012)资助
关键词
生态型高延性水泥基复合材料
高温
抗压强度
损伤机理
ecological high ductility cementitious composites
high temperature
compressive strength
damage theory
