西北大温差环境下温度对硫铝酸盐水泥砂浆抗压强度的影响
Effect of Temperature on Compressive Strength of Sulphoaluminate Cement Mortar in Large Temperature Difference of Northwest China
马继树 1杨淑雁1
作者信息
- 1. 宁夏大学土木与水利工程学院,银川 750021
- 折叠
摘要
为研究西北大温差环境下温度对硫铝酸盐水泥砂浆作为浅层病害混凝土修补材料的抗压强度影响规律,设计了改性前后三个不同配合比、三个温度梯度(-25、25和80℃)和三个时间长度(6、12和24 h)的试验,测试了试样的抗压强度,采用扫描电子显微镜(SEM)和X射线衍射(XRD)的方法测试了试样的微观性能.结果表明,改性后的试样破坏模式均优于未改性试样.-25℃时,随着时间延长,改性后试样的抗压强度增大幅度均大于未改性试样;25 ℃时,三个配合比试样抗压强度变化规律相似,均轻微下降;80 ℃时,掺入0.3％(质量分数)水玻璃、0.1％(质量分数)聚丙烯纤维和0.4％(质量分数)膨胀剂试样的抗压强度下降幅度最小.同时,本文还建立了该配合比试样在不同温度下,随时间延长的相对抗压强度变化率计算公式,可为西北大温差环境下硫铝酸盐水泥砂浆作为浅层病害混凝土修补材料提供参考.
Abstract
To study the effect of temperature on the compressive strength of sulphoaluminate cement mortar as a repair material for shallow decay concrete in large temperature difference of northwest China,three different mix proportions,three temperature gradients(-25,25 and 80 ℃)and three time lengths(6,12 and 24 h)before and after modification were designed.Compressive strength of samples were tested,and micro properties were tested by scanning electron microscopy(SEM)and X-ray diffraction(XRD)methods.The results show that the failure modes of modified samples are better than that of original sample.With the elongation of time,the growth rates of compressive strength of modified samples at-25℃are greater than that of original sample.At 25℃,the compressive strength of three groups samples are similar and have slight reductions.At 80 ℃,the compressive strength of modified sample with 0.3％(mass fraction)water glass,0.1％(mass fraction)PP fiber and 0.4％(mass fraction)expander has the least reduction rate.Meanwhile,the prediction formulas of relative variation rate of compressive strength for this sample with time at different temperatures are established,which can provide some references for sulphoaluminate cement mortar as a repairing material for shallow decay concrete in large temperature difference of northwest China.
关键词
硫铝酸盐水泥/水玻璃/聚丙烯纤维/UEA膨胀剂/西北大温差/温度/抗压强度Key words
sulphoaluminate cement/water glass/PP fiber/UEA expander/large temperature difference of northwest China/temperature/compressive strength引用本文复制引用
基金项目
宁夏自然科学基金(2023AAC03129)
出版年
2024
国家科技期刊平台
NSTL
万方数据