C60低徐变混凝土的配制与徐变性能影响规律研究

3.佛山市公路桥梁工程监测站有限公司，广东 佛山  528000）

    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。

　　  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

    中图分类号：TU528        文献标识码：A        文章编号：1001-702X（2020）11-0103-04

 

Study on preparation and influence law of creep property of C60 low creep concrete

YANG Tengyu1，QIU Bing1，GUO Lixian1，SONG Putao2，WANG Liangbo3，WANG Jing2

（1.Foshan Transportation Science and Technology Co. Ltd.，Foshan 528300，China；

2.China Academy of Building Research，Beijing 100013，China；

3.Foshan Road and Bridge Supervision Station Co. Ltd.，Foshan 528000，China）

    Abstract：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.

    Key words：C60 low creep concrete，creep degree，type of coarse aggregate，air content of concrete，mix ratio parameter