C60多孔粗骨料高性能混凝土配合比设计  

Mix design of C60 porous coarse aggregate high performance concrete

作　　者：孙婧[1,2] 洪俊哲 宋晓英 张少云 贾小静 刘宏波 Sun Jing;Hong Junzhe;Song Xiaoying;Zhang Shaoyun;Jia Xiaojing;Liu Hongbo(Hebei University of Architecture,Zhangjiakou 075000,China;Hebei Key Laboratory for Diagnosis,Reconstruction and Anti-disaster of Civil Engineering,Zhangjiakou 075000,China;Zhangjiakou construction engineering quality inspection center,Zhangjiakou 075000,China)

机构地区：[1]河北建筑工程学院,河北张家口075000 [2]河北土木工程诊断、重建与抗灾重点实验室,河北张家口075000 [3]张家口市建设工程质量检测中心,河北张家口075000

出　　处：《建筑科学》2024年第5期126-133,98,共9页Building Science

基　　金：河北省科技厅重点研发计划项目(20373802D);河北省建设科技研究计划项目(2020-266);张家口市科技局重点研发科技项目(2021012B);河北省高校2022年基本科研业务费项目(2022CXTD01)。

摘　　要：为了降低高性能混凝土(HPC)成本,目前常掺入不同种类的骨料部分或完全取代普通砂石,但利用多孔粗骨料制备HPC的研究极少。本文采用5~10mm多孔粗骨料全替代普通石子试制HPC,在低水胶比下,因其孔洞丰富导致拌合困难,因此提前用附加用水将粗骨料润湿;基于4因素4水平的正交试验,研究了不同因素对混凝土工作性能和力学性能的影响,利用Design-expert软件对多孔粗骨料HPC配合比进行设计。结果表明:当水胶比为0.28时,胶集比为0.51、砂率为42%、减水剂用量为0.2%且骨料附加用水量在7.618%~7.973%时,利用多孔粗骨料可制备出抗压强度≥60MPa且流动扩展度≥500mm的HPC;对抗压强度、扩展度影响最大的因素分别为砂率和骨料附加用水量;提出了抗压强度和扩展度经验计算公式;配比优化试件微观分析表明吸水后的多孔粗骨料有一定内固化作用,浆体和骨料结合程度较高,混凝土内部孔隙以无害、少害孔为主,保证了试件的强度。In order to reduce the cost of high performance concrete(HPC),different types of aggregates are often used to partially or completely replace ordinary sand and gravel.However,there are few studies on the preparation of HPC by porous coarse aggregate.In this paper,5~1Omm porous coarse aggregate is used to replace ordinary stone to produce HPC.Under low water-binder ratio,coarse aggregate was difficult to mix due to its rich pores,so additional water is used to wet coarse aggregate in advance.Based on the orthogonal test of 4 factors and 4 levels,the effects of different factors on the working performance and mechanical properties of concrete are studied.The mix ratio of porous coarse aggregate HPC is optimized by Design-expert software.The results show that When the water-binder ratio is 0.28,the binder-aggregate ratio is 0.51,the sand ratio is 42%,the amount of water reducing agent is 0.2%and the additional water consumption of aggregate is 7.618%~7.973%,HPC with compressive strength≥60MPa and flow expansion≥500mm can be prepared by using porous coarse aggregate.The most influential factors on compressive strength and expansion are sand ratio and aggregate additional water consumption.The empirical formulas of compressive strength and expansion degree are proposed.The microscopic analysis of the optimized specimen shows that the porous coarse aggregate after water absorption has a certain internal curing effect,the combination of slurry and aggregate is high,and the internal pores of concrete are mainly harmless and less harmful pores,which ensures the strength of the specimen.

关 键 词：多孔粗骨料 高性能混凝土 Design-expert 配比设计 响应曲面 孔结构 

分 类 号：TU528[建筑科学—建筑技术科学]