摘要
以北江大桥为项目背景,配制出徐变性能满足项目要求的C60低徐变混凝土。重点研究了水胶比、胶凝材料用量、砂率、掺合料的掺用比例、混凝土含气量、骨料种类对混凝土徐变性能的影响规律。结果表明,各因素对90 d徐变度影响顺序为:不掺掺合料>增加胶凝材料用量>单掺粉煤灰>采用砂岩骨料>低胶凝材料用量=降低砂率>提高混凝土含气量。在水胶比为0.30,胶凝材料总量490 kg/m3,砂率37%,粉煤灰及矿渣粉占胶凝材料比例分别为15%及10%时90 d徐变度相对最低,其它性能也相对较优,此时混凝土坍落度为225 mm,含气量为1.2%,倒筒时间为14 s,7 d抗压强度为77.1 MPa,28 d抗压强度为90.1 MPa,7 d弹性模量为3.82 GPa,90 d徐变度为10×10-6 MPa-1。
C60 low creep concrete with creep performance meeting the project requirements is prepared for Beijiang Bridge Project of Guangdong Province.The effects of water-binder ratio,binder content,sand ratio,admixture ratio,air content of concrete and aggregate type on creep properties of concrete are studied.It is found that the influence sequence on 90 d creep degree is:No Admixture>Increase the dosage of cementitious material>Single application of Fly Ash>Adopt sandstone aggregate>Low dosage of cementitious Material=Reduce the sand rate>increase the air content of concrete.The 90 d creep degree is the lowest,and other properties are also relatively better when the ratio of water to binder is 0.30,the amount of cementitious material is 490 kg/m3,the sand ratio is 37%,the ratio of fly ash and slag powder to cementitious material is 15%and 10%.At this time,the concrete slump is 225 mm,the air content is 1.2%,the pouring time is 14 s,the 7 d compressive strength is 77.1 MPa,the 28 d compressive strength is 90.1 MPa,the 7 d elastic modulus is 3.82 GPa and the 90 d creep degree 10×10-6 MPa-1.
作者
杨腾宇
邱冰
郭立贤
宋普涛
王良波
王晶
YANG Tengyu;QIU Bing;GUO Lixian;SONG Putao;WANG Liangbo;WANG Jing(Foshan Transportation Science and Technology Co.Ltd.,Foshan 528300,China;China Academy of Building Research,Beijing 100013,China;Foshan Road and Bridge Supervision Station Co.Ltd.,Foshan 528000,China)
出处
《新型建筑材料》
北大核心
2020年第11期103-106,共4页
New Building Materials
基金
佛山市科技创新项目(1920001001168)。
关键词
C60低徐变混凝土
徐变度
粗骨料种类
混凝土含气量
配合比参数
C60 low creep concrete
creep degree
type of coarse aggregate
air content of concrete
mix ratio parameter
