盐侵冻融作用下非饱和掺碱粉煤灰混凝土损伤研究
Damage of alkali-doped fly ash concrete with different saturation under combined action of sulfate erosion and freeze-thaw cycle
邵善庆 1龚爱民 1王福来 1屈宝莉2
作者信息
- 1. 云南农业大学水利学院,云南昆明 650201
- 2. 天启工程咨询有限公司,云南昆明 650201
- 折叠
摘要
为了让碱激发粉煤灰混凝土在工程中应用更为广泛,研究了碱性激发剂对粉煤灰混凝土耐久性的影响,以及碱激发粉煤灰混凝土在不同饱和度(30%,60%,100%)与不同硫酸盐溶液浓度(0%,5%,10%)耦合作用下的耐久性变化.从碱激发粉煤灰混凝土的外观损伤、质量损失、抗压强度损失、动弹性模量损失方面来评价试件损伤情况,并结合电子显微扫描技术分析试件在硫酸盐侵蚀-冻融耦合作用下的损伤机理.结果表明:100%饱和度的试件在浓度10%的硫酸钠溶液中抗冻性最差;碱激发粉煤灰混凝土的抗压强度损失和动弹性模量损失呈现为平稳下降和加速下降两个阶段;非饱和试件的劣化程度随试件饱和度降低而减少,因此非饱和条件下耐久性更好.最后通过理论分析和室内试验建立了精度较高的不同饱和度碱激发粉煤灰混凝土在硫酸盐侵蚀-冻融耦合作用下的损伤模型.
Abstract
In order to make alkali-activated fly ash concrete more widely used in engineering,the influence of alkaline activa-tor on the durability of fly ash concrete was studied,and the durability of alkali-activated fly ash concrete in different saturation(30%,60%,100%)and different sulfate solution concentration(0,5%,10%)were studied.The damage of specimens was evaluated from the aspects of appearance damage,mass loss,compressive strength loss and dynamic elastic modulus loss of alkali-activated fly ash concrete,and the erosion damage mechanism of specimens under sulfate erosion and freeze-thaw cycle cou-pling was analyzed by electron microscopy scanning technology.The results showed that the frost resistance of the specimens in 100%saturation was the worst in the 10%sodium sulfate solution.The compressive strength loss and dynamic elastic modulus loss of alkali-activated fly ash concrete had two stages of steady decline and accelerated decline.The deterioration degree of un-saturated specimens decreased with the decrease of saturation,so the durability under unsaturated conditions was better.Through theoretical analysis and laboratory test,a damage model of alkali-activated fly ash concrete with different saturations under sul-fate erosion and freeze-thaw cycle coupling was established.
关键词
碱激发粉煤灰混凝土/耐久性/饱和度/冻融循环/硫酸盐侵蚀Key words
alkali-activated fly ash concrete/durability/saturation/freeze-thaw cycle/sulfate erosion引用本文复制引用
基金项目
云南省教育厅科学研究基金(2022Y286)
出版年
2024
国家科技期刊平台
NSTL
维普
万方数据