基于温控型氧化镁膨胀剂的混凝土抗裂性能研究  

Crack resistance of concrete based on temperature-controlled magnesium oxide expansion agent

作　　者：王丙垒 张登科 王海龙 纪宪坤 辜振睿 程福星 WANG Binglei;ZHANG Dengke;WANG Hailong;JI Xiankun;GU Zhenrui;CHENG Fuxing(Wuhan Sanyuan Special Building Materials Co.Ltd.,Wuhan 430083,China;Wuhan Yuanjin Building Materials TechnologyCo.Ltd.,Wuhan 430083,China;China General Research Institute of Building Materials Co.Ltd.,Beijing 100024,China)

机构地区：[1]武汉三源特种建材有限责任公司,湖北武汉430083 [2]武汉源锦建材科技有限公司,湖北武汉430083 [3]中国建筑材料科学研究总院有限公司,北京100024

出　　处：《新型建筑材料》2024年第3期104-110,共7页New Building Materials

摘　　要：研究了温控型氧化镁膨胀剂(TME)对混凝土和易性、凝结时间、抗压强度、胶砂限制膨胀率、水化热降低率和工程结构抗裂性的影响。结果表明,外掺TME提高了混凝土的粘聚性,延长了凝结时间,对抗压强度的影响集中在7 d内,对28 d强度无影响;TME对40℃水养胶砂限制膨胀率的影响集中在28 d内,随TME掺量增加而增大;TME能明显降低水泥水化放热率和水泥胶砂温升;掺6%TME显著降低了混凝土裂缝数量,与空白段相比,结构温升降低了5.0℃,14 d膨胀历程终值133.9με,降低开裂温度14.4℃,提高抗裂安全系数62%,对于施工不连续引起的早期裂缝也有显著效果。The effects of temperature-controlled magnesium oxide expansion agent(TME)on workability,setting time,compressive strength,limited expansion rate of mortar,heat reduction rate of hydration and cracking resistance of engineering structures were studied.The results show that the addition of TME improves the cohesiveness of concrete,prolongs the setting time of concrete,and the influence on the compressive strength of concrete is concentrated within 7 days,but has no effect on the strength of concrete at 28 days.The effect of TME on the limited expansion rate of water-cured mortar at 40℃was concentrated within 28 days and increased with the increase of TME content.TME can obviously reduce the heat release rate of cement hydration and the temperature appreciation of cement mortar.The 6%TME content significantly reduces the number of cracks in concrete,reduces the structural temperature appreciation by 5.0℃,the final value of the 14 day expansion process is 133.9με,reduces the cracking temperature by 14.4℃,and improves the anti-cracking safety factor by 62%.It also has a significant effect on the early cracks caused by construction discontinuity.

关 键 词：温控型氧化镁膨胀剂 混凝土裂缝 结构自防水 等效龄期 抗裂安全系数 

分 类 号：TU528.32[建筑科学—建筑技术科学]