摘要
本研究在考察混凝土中不同的含气量、纤维掺量和粉煤灰掺量对其早期抗裂性能的影响的前提下,同时探究了以这三种变量对强度的影响大小,结果显示:在所考察的水平范围内,三种因素均对混凝土早期抗裂性能具有不同程度的提升作用。随着含气量的增加,体系抗压强度只出现略微降低;纤维的掺入对混凝土早期抗裂性能具有显著提升作用,当纤维掺量达到0.1%时,C30和C60混凝土平均开裂面积均为6.6mm^(2),而对抗压强度并未造成明显影响;掺入粉煤灰后,C45混凝土平均开裂面积明显降低,且粉煤灰掺量与平均开裂面积的关系符合一次函数,与裂缝最大宽度的关系符合二次函数。当掺量为30%时,平均开裂面积降至7.0mm^(2),强度经养护28d后与不掺粉煤灰的混凝土基本持平。因此,以上三种因素对于混凝土体系综合性能的提升具有显著的效果。
In this study,the influence of different air content fiber content and fly ash content on the early crack resistance of concrete was investigated.At the same time,the influence of these three variables on the strength is explored.The results are as follows.In the range of the investigated levels,the three factors all have different degrees of improvement on the early crack resistance of concrete.With the increase of air content,the compressive strength of the system only slightly decreases.The addition of fiber can significantly improve the early crack resistance of concrete.When the fiber content reaches 0.1%,the average cracking area of C30 and C60 concrete is 6.6 mm^(2),but it has no obvious effect on the compressive strength.After adding fly ash,the average cracking area of C45 concrete decreases obviously.The relationship between the fly ash content and the average cracking area conforms to the first-order function,and the relationship between the fly ash content and the maximum crack width conforms to the second-order function.When its content is 30%,the average cracking area is reduced to 7.0 mm^(2),and the strength is basically the same as that of concrete without fly ash after curing for 28 days.Therefore,the above three factors have a significant effect on improving the comprehensive performance of concrete system.
作者
付士峰
刘东基
孔丽娟
FU Shifeng;LIU Dongji;KONG Lijuan(Hebei Academy of Building Research,Shijiazhuang 050021,China;Hebei Province Science and Technology Key Laboratory of Solid Waste for Building Materials,Shijiazhuang 050021,China;Shijiazhuang TieDao University,Shijiazhuang 050043,China)
出处
《建筑结构》
CSCD
北大核心
2021年第S01期1305-1310,共6页
Building Structure
关键词
高性能混凝土
抗裂性能
力学性能
含气量
纤维掺量
粉煤灰
high performance concrete
rupture resistance
mechanical property
air Content
fiber content
coal ash
