掺MgO膨胀剂的侧墙混凝土体积变形趋势和膨胀量  

Volume Deformation Trend and Expansion Calculation of Micro-expansion Side Wall Concrete Mixed with MgO

作　　者：占文 谭刚 孙钰秋 

机构地区：[1]中交武汉港湾工程设计研究院有限公司,湖北武汉430040 [2]海工结构新材料及维护加固技术湖北省重点实验室,湖北武汉430040 [3]中交二航武汉港湾新材料有限公司,湖北武汉430040

出　　处：《混凝土世界》2024年第8期55-58,共4页China Concrete

基　　金：宁波市科技计划项目(2019C50019)。

摘　　要：为分析掺MgO膨胀剂的轨道交通侧墙C35混凝土的体积变形趋势,准确控制MgO膨胀剂掺量并指导现场施工和裂缝修补,本文根据不同掺量MgO膨胀剂混凝土的长龄期体积变形数据,推算用于某轨道交通工程侧墙的MgO膨胀剂混凝土收缩变形计算模型和公式,计算混凝土的最终体积膨胀量。结果表明:MgO膨胀剂可实现较长龄期混凝土的微膨胀;在试验配合比体系下,计算出抵消混凝土自收缩的MgO膨胀剂掺量为13.6 kg/m^(3);当MgO膨胀剂掺量为40 kg/m^(3)且龄期超过120 d时,混凝土的体积变形基本趋于稳定,可开展裂缝修补工作;长期来看,掺入MgO膨胀剂一年后,混凝土的体积变形量趋于稳定,体积变形差异小于0.001 mm。In order to analyze the volume deformation trend of C35 rail transit side wall concrete with MgO expander,accurately control the amount of MgO expander,and guide on-site construction and crack repair,This article uses long-term volume deformation data of MgO expander concrete with different dosages to calculate the shrinkage deformation calculation model and formula of MgO expander concrete used for side wall conditions in rail transit engineering,and to calculate the final volume expansion of concrete.The results indicate that MgO expander can achieve micro expansion of concrete with longer age;under the experimental mix proportion system,the amount of MgO expander that can counteract the self shrinkage of concrete is 13.6 kg/m^(3);when the dosage of MgO expansion agent is 40 kg/m^(3)and the age exceeds 120 days,the volume deformation of concrete tends to stabilize and crack repair work can be carried out;in the long run,after adding MgO expansion agent for one year,the volume deformation of concrete remains stable,and the difference in volume deformation is less than 0.001 mm.

关 键 词：MGO膨胀剂 体积变形 膨胀量 

分 类 号：TU528.042.4[建筑科学—建筑技术科学]