冻融循环作用下不同含气量混凝土抗冻性研究
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摘要
冻融作用是影响混凝土耐久性的重要因素。本研究通过不同含气量混凝土的冻融循环试验,对冻融后混凝土的抗冻性能进行分析,采用质量损失与动弹性模量变化为抗冻指标对混凝土冻融循环结果进行评价。结果表明:引气剂的掺入可改善混凝土冻融循环条件下的抗冻性能。随冻融循环次数增加,混凝土的质量与动弹性模量均有所下降,掺有引气剂的混凝土下降幅度较小,质量与动弹性模量下降幅度随含气量增大而减小。通过研究引气剂对混凝土抗压强度的影响,发现含气量越高,混凝土抗压强度下降幅度越明显。从质量损失、动弹性模量变化与抗压强度三方面综合分析,得出使混凝土具有较好抗冻性能与较好力学性能的最佳含气量。
Freezing and thawing are important factors affecting the durability of concrete. The frost resistance of concrete with different air contents was analyzed by freeze-thaw cycle test. The mass loss and change of dynamic elastic modulus were used as anti-freeze indices to evaluate the results of the freeze-thaw cycle of concrete. The results showed that incorporation of air entraining agent can improve the frost resistance of concrete under freeze-thaw cycles. The mass and dynamic elastic modulus of concrete decreased with the increase of freeze-thaw cycles, while the concrete with air entraining agent decreased slightly. The mass loss and dynamic elastic modulus decreased with the increase of concrete gas content. By studying the influence of air entraining agent on the compressive strength of concrete, it is found that the higher the concrete air content is, the more obvious the concrete compressive strength decreases. The optimum gas content of concrete with better frost resistance and better mechanical properties is obtained by comprehensive analysis from mass loss,dynamic elastic modulus and compressive strength.
Freezing and thawing are important factors affecting the durability of concrete. The frost resistance of concrete with different air contents was analyzed by freeze-thaw cycle test. The mass loss and change of dynamic elastic modulus were used as anti-freeze indices to evaluate the results of the freeze-thaw cycle of concrete. The results showed that incorporation of air entraining agent can improve the frost resistance of concrete under freeze-thaw cycles. The mass and dynamic elastic modulus of concrete decreased with the increase of freeze-thaw cycles, while the concrete with air entraining agent decreased slightly. The mass loss and dynamic elastic modulus decreased with the increase of concrete gas content. By studying the influence of air entraining agent on the compressive strength of concrete, it is found that the higher the concrete air content is, the more obvious the concrete compressive strength decreases. The optimum gas content of concrete with better frost resistance and better mechanical properties is obtained by comprehensive analysis from mass loss,dynamic elastic modulus and compressive strength.
引文
[1]林跃忠,王铁成,杜喜凯.海水侵蚀混凝土强度的智能分析方法研究[J].河北农业大学学报,2008,31(1):107-109.
[2]龚洛书,刘春圃.混凝土结构耐久性设计与施工指南[M].北京:中国建筑工业出版社,2004.
[3]李金玉.冻融环境下混凝土结构的耐久性设计与施工[M].北京:中国建筑工业出版社,2004.
[4]张士萍,邓敏.孔结构对混凝土抗冻性的影响[J].武汉理工大学学报,2008,30(6):56-59.
[5]袁晓露,李北星.粉煤灰混凝土的抗冻性能及机理分析[J].混凝土,2008(12):43-45.
[6]周胜波,申爱琴.基于细观孔结构特征探讨矿渣微粉对混凝土抗冻性能的影响[J].混凝土,2012(10):94-96.
[7]张庆玲,刘燕,赵胜利.轴压荷载作用下粉煤灰混凝土抗冻性研究[J].河北农业大学学报,2017,40(5):115-119.
[8]陈聪.冻融循环作用下混凝土承载力劣化特性研究[D].重庆:重庆交通大学:2017.
[2]龚洛书,刘春圃.混凝土结构耐久性设计与施工指南[M].北京:中国建筑工业出版社,2004.
[3]李金玉.冻融环境下混凝土结构的耐久性设计与施工[M].北京:中国建筑工业出版社,2004.
[4]张士萍,邓敏.孔结构对混凝土抗冻性的影响[J].武汉理工大学学报,2008,30(6):56-59.
[5]袁晓露,李北星.粉煤灰混凝土的抗冻性能及机理分析[J].混凝土,2008(12):43-45.
[6]周胜波,申爱琴.基于细观孔结构特征探讨矿渣微粉对混凝土抗冻性能的影响[J].混凝土,2012(10):94-96.
[7]张庆玲,刘燕,赵胜利.轴压荷载作用下粉煤灰混凝土抗冻性研究[J].河北农业大学学报,2017,40(5):115-119.
[8]陈聪.冻融循环作用下混凝土承载力劣化特性研究[D].重庆:重庆交通大学:2017.