- 目录
- 混凝土与制品
- 首页
（1.武汉三源特种建材有限责任公司，湖北 武汉 430070；
2.武汉轻工大学，湖北 武汉 430070）
2.武汉轻工大学，湖北 武汉 430070）
摘要：通过研究氧化镁掺量为0、4%、6%、8%混凝土的劈裂抗拉强度、变温历程下的约束应力发展，并结合成熟度理论和数据拟合计算混凝土变温历程下的等效龄期，评价混凝土的开裂敏感性。结果表明，掺4%、6%氧化镁可提高混凝土的劈裂抗拉强度，掺8%氧化镁可提高混凝土的早期劈裂抗拉强度，但不利于后期劈裂抗拉强度发展；温度-应力试验表明，掺氧化镁可以提高混凝土的抗裂性能，但开裂温度和开裂应力的定量评价结果存在差异；开裂敏感度综合考虑了混凝土温度历程和劈裂抗拉强度发展，其作为评价指标更加准确，氧化镁掺量为4%、6%、8%的混凝土开裂敏感度较基准组分别减小了4.6、5.0、1.8个百分点。
关键词：成熟度理论；等效龄期；劈裂抗拉强度；温度应力试验机；开裂敏感度
中图分类号：TU528.01 文献标识码：A 文章编号：1001-702X（2023）02-0011-04
Evaluation of cracking sensitivity of MgO-doped concrete based on maturity theory
QIN Zhehuan1，ZHU Guojun1，LIU Jiesheng2，JI Xiankun1，LIU Pin1
（1.Wuhan Sanyuan Special Building Materials Co. Ltd.，Wuhan 430070，China；
2.Wuhan Polytechnic University，Wuhan 430070，China）
Abstract：By adding 0，4%，6%，8% magnesium oxide to concrete，splitting tensile strength and restraint stress development under varying temperature history were studied. Combined with maturity theory and data fitting，the equivalent age of concrete under changing temperature history was calculated. It evaluated the cracking susceptibility of concrete. The results showed that the splitting tensile strength of concrete can be improved by adding 4% and 6% magnesium oxide. The early tensile strength of concrete could be improved by adding 8% magnesium oxide. However，it is not conducive to the development of later splitting tensile strength. The evaluation index of temperature-stress test showed that adding magnesium oxide could improve the crack resistance of concrete. There were differences in the quantitative evaluation results of cracking temperature and cracking stress. Cracking susceptibility considering concrete temperature history and tensile strength development. It was more accurate as an evaluation index. Compared with the reference group，the cracking sensitivity of concrete with 4%，6% and 8% MgO decreased by 4.6，5.0 and 1.8 percentage points respectively.
Key words：maturity theory，equivalent age，splitting tensile strength，temperature stress testing machine，cracking sensitivity