基于抗压强度的负温混凝土受冻临界强度研究
Research on the Critical Freezing Strengths of Subzero-temperature Concrete Based on Compressive Strength
关键词:
负温混凝土;抗压强度;受冻临界强度;预养护时间
Key words:
Subzero-temperature concrete; Ccompressive strength; Critical freezing strength; Pre-curing time
刊期:
2019年第10期
DOI:
10.19761/j.1000-4637.2019.10.024.03
文章编号:
基金项目:
“十三五”国家重点研发计划项目(2017YFB0309 900);黑龙江省科研机构创新能力提升专项计划项目(YC 2015D004)。
作者:
江守恒1,董淑慧2,朱卫中3,李鹤斌2,殷少辉1
单位:
1.黑龙江省寒地建筑科学研究院,哈尔滨 150083;2.哈尔滨工业大学交通科学与工程学院,150090;3. 黑龙江省城乡建设研究所,哈尔滨 150070
摘要
摘 要:研究了预养时间对掺与不掺防冻剂的C30、C40、C50、C60强度等级负温混凝土抗压强度的影响规律,得出了混凝土的受冻临界强度和相应预养时间。试验结果表明,受冻临界强度随混凝土强度等级的提高而提高;无论是掺加无机防冻剂还是有机防冻剂,均可以降低混凝土受冻临界强度、缩短混凝土达到受冻临界强度所需的预养时间,对C30、C40混凝土的作用效果尤为明显。
Abstract: In this paper, the influence law of pre-curing time on the compressive strength of subzero-temperature concrete whose strength grades are C30, C40, C50 and C60 with or without antifreeze was studied. The critical freezing strengths of concrete and the corresponding pre-curing time were obtained. The test results show that the critical freezing strength increases with the increase of concrete strength grades. Whether it is added with inorganic antifreeze or organic antifreeze, it can reduce the critical freezing strengths of concrete and shorten the pre-curing time of concrete that reaches the critical freezing strength, the effect of pre-curing time on C30 and C40 concrete is particularly obvious.
结论
(1)混凝土强度等级越高,受冻临界强度越高,掺无机或有机防冻剂均可降低混凝土受冻临界强度,对于C30、C40混凝土的作用效果更明显。
(2)使用防冻剂可明显缩短混凝土达到受冻临界强度所需的预养时间,对于预养4 h后受冻的C30、C40混凝土,在负温7 d+正温28 d龄期时的抗压强度即可达到试配强度的95%;受冻临界强度>5 MPa时,相应的预养时间分别为18 h、14 h,不掺加防冻剂混凝土则需48 h、36 h;不掺和掺加防冻剂的C50、C60混凝土的预养时间分别为36 h、24 h。
参考文献
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引用本文
江守恒,董淑慧,朱卫中,等.基于抗压强度的负温混凝土受冻临界强度研究[J].混凝土与水泥制品,2019(10):24-26.
JIANG S H,DONG S H,ZHU W Z,et al.Research on the Critical Freezing Strengths of Subzero-temperature Concrete Based on Compressive Strength[J].China Concrete and Cement Products,2019(10):24-26.
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