粉煤灰混凝土早期热膨胀系数试验研究及预测模型构建
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摘要
热膨胀系数是混凝土结构早龄期开裂计算的重要热学参数,对不同粉煤灰掺量混凝土早期热膨胀系数进行了试验研究,得到了混凝土早期热膨胀系数的变化规律,分析了粉煤灰掺量变化的影响机理,提出了考虑粉煤灰掺量变化的混凝土早期热膨胀系数预测模型。研究表明:粉煤灰掺量增加,混凝土早期热膨胀系数先增大后减小,且在掺量为30%时有最大值。研究结果可为混凝土结构早期开裂计算提供试验依据和参数选取。
Thermal expansion coefficient (TEC) is an important thermal parameter in cracking computing of concrete structures at early age. The TEC of concrete with different contents of fly ash at early age is studied by experiments. The change law of concrete's TEC is obtained. The influence mechanism of the fly ash contents on TEC of concrete is analyzed. The calculation model which considering fly ash contents of concrete's TEC at early age is suggested. The results show that the early TEC of concrete increases first and then decreases when the fly ash content increased. It has a maximum value when the fly ash content is 30%. The results can provide experimental basis and parameter selection for the calculation of concrete structure cracking at early age.
Thermal expansion coefficient (TEC) is an important thermal parameter in cracking computing of concrete structures at early age. The TEC of concrete with different contents of fly ash at early age is studied by experiments. The change law of concrete's TEC is obtained. The influence mechanism of the fly ash contents on TEC of concrete is analyzed. The calculation model which considering fly ash contents of concrete's TEC at early age is suggested. The results show that the early TEC of concrete increases first and then decreases when the fly ash content increased. It has a maximum value when the fly ash content is 30%. The results can provide experimental basis and parameter selection for the calculation of concrete structure cracking at early age.
引文
[1]赵志方,李超,张振宇,等.超高掺量粉煤灰大坝混凝土早龄期抗裂性研究[J].水利发电学报,2016,35(7):112-119.
[2]崔溦,冀天竹,吴甲一.热膨胀系数对早期混凝土性态影响试验及数值模拟[J].同济大学学报(自然科学版),2016,44(3):355-361,401.
[3]黄杰,袁学锋,帅映勇,等.不同水灰比混凝土早期热膨胀系数试验研究[J].工业建筑,2017,47(4):127-129,147.
[4]高桂波,钱春香,朱晨峰,等.粉煤灰对混凝土热膨胀系数的影响[J].东南大学学报(自然科学版),2006,36(SⅡ):185-190.
[5]GB/T50146-2014.粉煤灰混凝土应用技术规范[S].2014.
[6]陈波,丁建彤,蔡跃波,等.基于温度-应力试验的混凝土早龄期应变分离及热膨胀系数计算[J].水利学报,2016,47(4):560-565.
[7]Powers T C,Brownyard T L.Studies of the physical properties of hardened portland cement paste-Part 4:the thermodynamics of adsorption of water on hardened paste[J].Journal of the American Concrete Institute,1947,18(5):549-595.
[8]Berwanger C,Sarkar A F.Thermal expansion of concrete and reinforced concrete[J].Journal of the American Concrete Institute,1976,73(11):618-621.
[9]Emanuel J H,Hulsy J L.Prediction of the thermal coefficient of expansion of concrete[J].ACI Journal,1977,74(4):149-155.
[2]崔溦,冀天竹,吴甲一.热膨胀系数对早期混凝土性态影响试验及数值模拟[J].同济大学学报(自然科学版),2016,44(3):355-361,401.
[3]黄杰,袁学锋,帅映勇,等.不同水灰比混凝土早期热膨胀系数试验研究[J].工业建筑,2017,47(4):127-129,147.
[4]高桂波,钱春香,朱晨峰,等.粉煤灰对混凝土热膨胀系数的影响[J].东南大学学报(自然科学版),2006,36(SⅡ):185-190.
[5]GB/T50146-2014.粉煤灰混凝土应用技术规范[S].2014.
[6]陈波,丁建彤,蔡跃波,等.基于温度-应力试验的混凝土早龄期应变分离及热膨胀系数计算[J].水利学报,2016,47(4):560-565.
[7]Powers T C,Brownyard T L.Studies of the physical properties of hardened portland cement paste-Part 4:the thermodynamics of adsorption of water on hardened paste[J].Journal of the American Concrete Institute,1947,18(5):549-595.
[8]Berwanger C,Sarkar A F.Thermal expansion of concrete and reinforced concrete[J].Journal of the American Concrete Institute,1976,73(11):618-621.
[9]Emanuel J H,Hulsy J L.Prediction of the thermal coefficient of expansion of concrete[J].ACI Journal,1977,74(4):149-155.