摘要
无砂混凝土是一种重要的绿色生态护坡建筑材料,具有良好的透水性和透气性,但强度普遍偏低。无砂混凝土透水系数与抗压强度为负相关关系,同时满足高强度、高透水性有难度。基于某泵站工程现场用原材料,深入研究目标孔隙率P、水灰比W/C、骨料粒径、水泥种类等因素对无砂混凝土性能的影响,在此基础上提出高强度、高透水系数无砂混凝土的制备方案。结果表明:插捣成型条件下,实测连续孔隙率C_(void)均大于设计的目标孔隙率P。P一定时,存在最优W/C,使无砂混凝土透水系数最大;28 d抗压强度则随W/C(0.21~0.33范围内)的增大而提高。推荐采用工地现场所用5~16 mm连续级配骨料、P·O 52.5水泥制备无砂混凝土,P宜取15%,W/C宜取0.27或0.30;制备的无砂混凝土综合性能良好,可同时满足透水系数k_(T)≥1 mm/s、28 d抗压强度f_(cc)≥25 MPa的要求。
No-fines concrete is an important green ecological slope protection construction material,which has good water permeability and air permeability,but the strength is generally low.There is a negative correlation between the permeability coefficient and the compressive strength of no-fines concrete,and it is difficult to meet high strength and high permeability at the same time.Based on the raw materials used in a pumping station project,this paper deeply studies the impact of factors such as goal porosity(P),water to cement ratio(W/C),aggregate particle size and cement type on the performance of no-fines concrete,and proposes a preparation scheme for the no-fines concrete with high strength and high permeability coefficient.The results show that,measured continuous porosity(C_(void))is greater than designed goal porosity(P)under the conditions of plug-in molding.When P is constant,there is an optimal W/C to maximize the permeability coefficient of no-fines concrete,and the 28 d compressive strength increases with the increase of W/C(within the range of 0.21 to 0.33).It is recommended to prepare no-fines concrete with 5~16 mm continuous graded aggregate and P·O 52.5 cement at the construction site,with the goal porosity(P)of 15%and the W/C of 0.27 or 0.30.The prepared no-fines concrete has a good comprehensive performance,which can meet the requirements of permeability coefficient(k_(T))not less than 1 mm/s and the 28 d compressive strength(f_(cc))more than 25 MPa at the same time.
作者
凌国栋
丁平
周斌
张丰
陈波
吕乐乐
胡海明
LING Guodong;DING Ping;ZHOU Bin;ZHANG Feng;CHEN Bo;LYU Lele;HU Haiming(Yangzhou Water Resources Bureau,Yangzhou 225200,Jiangsu,China;Yangzhou Water Conservancy Engineering Construction Center,Yangzhou 225200,Jiangsu,China;Project Construction Department of Yangzhou Guazhou Pump Station,Yangzhou 225200,Jiangsu,China;State Key Laboratory of Hydrology-Water Resources and Hydraulic Engineering,Nanjing Hydraulic Research Institute,Nanjing 210029,Jiangsu,China)
出处
《水利水电技术（中英文）》
北大核心
2022年第4期192-200,共9页
Water Resources and Hydropower Engineering
基金
国家重点研发计划(2018YFC0406702)
国家自然科学基金项目(51739008)
中央级公益性科研院所基本科研业务费专项(Y419004)。
关键词
无砂混凝土
配合比设计
孔隙率
透水系数
抗压强度
no-fines concrete
mix proportions design
porosity
permeability coefficient
compressive strength
