浇筑期温度对泡沫混凝土性能和微孔结构的影响  

Influence of Temperature on Performance and Microporous Structure of Foamed Concrete During Pouring Period

作　　者：刘鑫[1,2] 姚云龙 张思卿 史云强 洪宝宁[1,3] LIU Xin;YAO Yunlong;ZHANG Siqing;SHI Yunqiang;HONG Baoning(Key Laboratory of Ministry of Education for Geomechanics and Embankment Engineering,Hohai University,Nanjing 210098,China;Tunnel and Underground Engineering Institute,Hohai University,Nanjing 210098,China;Geotechnical Engineering Institute,Hohai University,Nanjing 210098,China)

机构地区：[1]河海大学岩土力学与堤坝工程教育部重点实验室,江苏南京210098 [2]河海大学隧道与地下工程研究所,江苏南京210098 [3]河海大学岩土工程科学研究所,江苏南京210098

出　　处：《西南交通大学学报》2024年第5期1123-1131,共9页Journal of Southwest Jiaotong University

基　　金：国家自然科学基金项目(51609071)。

摘　　要：泡沫混凝土在浇筑至固化成型这段时期内,易受温度等环境因素影响,不利环境因素会导致固化成型后泡沫混凝土的性能退化和劣化.为研究泡沫混凝土在浇筑期受温度(-15~70℃)影响后的性能和微孔结构,设计单因素室内试验方案,以干密度作为泡沫混凝土物理性质评价指标,抗压强度作为施工质量评价指标,吸水率用以评价泡沫混凝土的运营耐久性,并利用图像数据采集系统及Image J软件分析泡沫混凝土微孔结构的演变规律.结果表明:随着温度上升,泡沫混凝土干密度总体呈阶梯式下降,抗压强度先减小后增大再减小,吸水率以0℃为分界点,温度降低或升高均呈先增大后减小趋势;等效孔径先增大后减小再增大,孔隙圆度值先增大后减小,孔隙分布分维先减小后变大;从混凝土宏观性能和微孔结构的演变规律建议泡沫混凝土浇筑期施工的温度范围为-5~40℃.Foamed concrete is susceptible to environmental factors such as temperature during the period from pouring to curing and molding,and adverse environmental factors can lead to performance degradation and deterioration of foamed concrete after curing and molding.In order to study the performance and microporous structure of foamed concrete affected by temperature(-15 –70 ℃) during the pouring period,a single factor indoor test program was designed by using dry density,compressive strength,and water absorption to evaluate the physical property of foamed concrete,the construction quality,and the operational durability of foamed concrete,respectively.In addition,the evolution of the microporous structure of foamed concrete was analyzed by using an image data acquisition system and Image J software.The results show that the dry density of foamed concrete generally decreases in a stepwise manner as the temperature rises.The compressive strength first decreases,then increases,and finally decreases.The water absorption rate takes 0 ℃ as the cut-off point,and it tends to increase and then decrease when the temperature decreases or increases.The equivalent pore size shows a trend of increasing,decreasing,and increasing.The pore roundness value first increases and then decreases.The fractal dimension of pore distribution first decreases and then becomes larger.The results of macroscopic performance and microporous structure show that the recommended temperature range for the construction of foamed concrete during the pouring period is-5–40 ℃.

关 键 词：泡沫混凝土 浇筑期 温度 宏观性能 微孔结构 

分 类 号：TU528.2[建筑科学—建筑技术科学]