碳酸钙晶须增强水泥基复合材料高温作用后的弯曲性能  

Flexural properties of calcium carbonate whisker reinforced cementitiouscomposites after exposed to elevated temperature

作　　者：陈泽辛 周宗伯 余志辉 张聪[1,2] CHEN Zexin;ZHOU Zongbo;YU Zhihui;ZHANG Cong(School of Environment and Civil Engineering,Jiangnan University,Wuxi 214000,China;Jiangsu Key Laboratory of Environment Impact and Structural Safety in Engineering,Xuzhou 221000,China)

机构地区：[1]江南大学环境与土木工程学院,江苏无锡214000 [2]江苏省土木工程环境灾变与结构可靠性重点实验室,江苏徐州221000

出　　处：《功能材料》2023年第9期9100-9106,共7页Journal of Functional Materials

基　　金：国家自然科学基金项目(51908247)。

摘　　要：对比研究了碳酸钙晶须增强水泥基复合材料(Calcium Carbonate Whisker Reinforced Cementitious Composites,CWRCC)和纯水泥砂浆的棱柱体试件(40mm×40mm×160mm)在常温下和200、400、600及800℃作用后的弯曲性能。研究结果表明:常温下试件的弯曲强度和弯曲韧性随碳酸钙晶须掺量的提高呈现先增大后减小的趋势,碳酸钙晶须的最优掺量为0.5%。高温作用对CWRCC和纯水泥砂浆的弯曲强度和弯曲韧性均有显著影响。各组试件的弯曲强度随温度升高呈现线性下降的趋势,而碳酸钙晶须的引入会增大高温对弯曲强度的劣化程度。各组试件的弯曲韧性随温度升高呈现先上升后下降的趋势,碳酸钙晶须的引入可以提升弯曲韧性在高温下下降的起始温度,但同时会减小弯曲韧性在高温下提升的幅度和增大其在高温下下降的幅度。在600℃前,相同温度下相较于纯水泥砂浆,碳酸钙晶须的引入可以提高试件的弯曲强度和弯曲韧性,而在800℃后,CWRCC的弯曲强度和弯曲韧性与纯水泥砂浆差别不大。The flexural properties of calcium carbonate whisker reinforced cementitious composites(CWRCC)and pure cement mortar at room temperature and after 200℃,400℃,600℃and 800℃elevated temperature exposure were investigated in comparison.The results indicate that the flexural strength and toughness of the specimens showed a trend of increasing first and then decreasing with the increase of calcium carbonate whisker volume fraction at room temperature,and the optimum volume fraction of calcium carbonate whisker was 0.5%.The effect of the elevated temperatures on the flexural strength and toughness of both CWRCC and pure cement mortar is significant.The flexural strength of each group of specimens showed a linear decrease with the increase of temperature,while the incorporation of calcium carbonate whisker increased the extent of deterioration of the flexural strength by elevated temperature.The flexural toughness of each group of specimens showed a trend of increasing first and then decreasing with the increase of temperature.The incorporation of calcium carbonate whisker increased the onset temperature of the decrease of the flexural toughness at elevated temperature,while it reduced the increase and increased the decrease of the flexural toughness at elevated temperature simultaneously.Compared to pure cement mortar,the incorporation of calcium carbonate whisker improved the flexural strength and toughness of specimens at the same temperature from 20℃to 600℃,while the flexural strength and toughness of CWRCC did not differ much from those of pure cement mortar after exposed to 800℃.

关 键 词：碳酸钙晶须 高温 弯曲性能 水泥基复合材料 

分 类 号：TU502[建筑科学—建筑技术科学]