基于粗骨料含量的混凝土早龄期收缩调控
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摘要
试验研究了粗骨料体积分数在0~50%范围内增大时对混凝土早龄期收缩以及内部相对湿度的影响规律。试验结果显示:混凝土早龄期内部相对湿度和收缩发展均呈典型的两阶段发展特征。混凝土第I阶段收缩、自收缩和干燥收缩均随着粗骨料体积分数增大而减小,其中干燥收缩受粗骨料的约束程度最为明显。早期收缩中,低强混凝土以干燥收缩为主,高强混凝土以自收缩为主,中等强度混凝土的干燥收缩和自收缩二者相当。粗骨料含量对同水胶比系列混凝土的内部相对湿度发展的影响可以忽略。
Effect of volume fraction of coarse aggregate within the range of 0 to 50% on the development of internal relative humidity and shrinkage in early-age concrete was studied experimentally.The experimental results show that the development of internal relative humidity and shrinkage of early-age concrete follows a two-stage developing law respectively.The first stage shrinkage,autogenous shrinkage and drying shrinkage of concrete is decreased with the increase of coarse aggregate volume content.Drying shrinkage is more significantly influenced by the addition of coarse aggregate compared to that of autogenous shrinkage.Drying shrinkage for low-strength concrete,autogenous shrinkage for high-strength concrete,both drying and autogenous shrinkage for medium-strength concrete is individually found to be the principal part of early-age total shrinkage.The effect of coarse aggregate content on the internal relative humidity is ignorable.
Effect of volume fraction of coarse aggregate within the range of 0 to 50% on the development of internal relative humidity and shrinkage in early-age concrete was studied experimentally.The experimental results show that the development of internal relative humidity and shrinkage of early-age concrete follows a two-stage developing law respectively.The first stage shrinkage,autogenous shrinkage and drying shrinkage of concrete is decreased with the increase of coarse aggregate volume content.Drying shrinkage is more significantly influenced by the addition of coarse aggregate compared to that of autogenous shrinkage.Drying shrinkage for low-strength concrete,autogenous shrinkage for high-strength concrete,both drying and autogenous shrinkage for medium-strength concrete is individually found to be the principal part of early-age total shrinkage.The effect of coarse aggregate content on the internal relative humidity is ignorable.
引文
[1]BENTUR A.Overview of early age cracking[C]//BENTUR A ed.Early age cracking in cementitious systems-Report of RILEM Technical Committee 181-EAS.Cachan,France:RILEM Publications S A R L,2003:1-11.
[2]BENTA D P,WEISS W J.React:reducing early-age cracking today[J].Concrete Plant International,2008(3):56-61.
[3]ZHANG J,GAO Y,HAN Y D,et al.Shrinkage and interior humidity of concrete under dry-wet cycles[J].Drying Technology,2012,30(6):583-596.
[4]ZHANG J,HOU D W,HAN Y D.Micromechanical modeling on autogenous and drying shrinkages of concrete[J].Construct Build Mater,2012,29(3):230-240.
[5]韩宇栋,张君,王振波.粗骨料体积分数对混凝土弹模和抗压强度的影响[J].哈尔滨工业大学学报,2013,45(4):682-689.
[6]韩宇栋,张君,高原.粗骨料体积含量对混凝土断裂参数的影响[J].工程力学,2013,30(3):191-197.
[7]ZHANG J,HAN Y D,HAN J G,et al.Cement hydration based model to predict mechanical properties of precast concrete[J]..Magazine of concrete research,2014,66(12):603-617.
[8]韩宇栋,张君,罗孙一鸣.水胶比和粗骨料含量对混凝土内部湿度及扩散系数的影响[J].建筑材料学报,2014,17(2):193-240.
[9]侯东伟.混凝土自身与干燥收缩一体化及相关问题研究[D].北京:清华大学,2010.
[10]侯东伟,张君,孙伟.基于早期变形特征的混凝土凝结时间的确定[J].硅酸盐学报,2009,37(7):1079-1084.
[11]韩宇栋,张君,王振波.预吸水轻骨料对高强混凝土早期收缩的影响[J].硅酸盐学报,2013,41(8):1070-1078.
[12]张涛.混凝土早期开裂敏感性的影响因素研究[D].北京:清华大学,2006.
[13]ZHANG J,HAN Y D,GAO Y,et al.Integrative study on the effect of internal curing on autogenous and drying shrinkage of highstrength concrete[J].Drying Technology,2013,31(5):565-575.
[2]BENTA D P,WEISS W J.React:reducing early-age cracking today[J].Concrete Plant International,2008(3):56-61.
[3]ZHANG J,GAO Y,HAN Y D,et al.Shrinkage and interior humidity of concrete under dry-wet cycles[J].Drying Technology,2012,30(6):583-596.
[4]ZHANG J,HOU D W,HAN Y D.Micromechanical modeling on autogenous and drying shrinkages of concrete[J].Construct Build Mater,2012,29(3):230-240.
[5]韩宇栋,张君,王振波.粗骨料体积分数对混凝土弹模和抗压强度的影响[J].哈尔滨工业大学学报,2013,45(4):682-689.
[6]韩宇栋,张君,高原.粗骨料体积含量对混凝土断裂参数的影响[J].工程力学,2013,30(3):191-197.
[7]ZHANG J,HAN Y D,HAN J G,et al.Cement hydration based model to predict mechanical properties of precast concrete[J]..Magazine of concrete research,2014,66(12):603-617.
[8]韩宇栋,张君,罗孙一鸣.水胶比和粗骨料含量对混凝土内部湿度及扩散系数的影响[J].建筑材料学报,2014,17(2):193-240.
[9]侯东伟.混凝土自身与干燥收缩一体化及相关问题研究[D].北京:清华大学,2010.
[10]侯东伟,张君,孙伟.基于早期变形特征的混凝土凝结时间的确定[J].硅酸盐学报,2009,37(7):1079-1084.
[11]韩宇栋,张君,王振波.预吸水轻骨料对高强混凝土早期收缩的影响[J].硅酸盐学报,2013,41(8):1070-1078.
[12]张涛.混凝土早期开裂敏感性的影响因素研究[D].北京:清华大学,2006.
[13]ZHANG J,HAN Y D,GAO Y,et al.Integrative study on the effect of internal curing on autogenous and drying shrinkage of highstrength concrete[J].Drying Technology,2013,31(5):565-575.