摘要
研究了2%掺量纳米二氧化硅(Nano-silica,NS)对纯水泥体系和矿粉-水泥体系抗压强度和凝结时间的影响,并利用X射线衍射分析(XRD)、差热分析(DSC-TG)、扫描电镜(SEM)、压汞法(MIP)等测试手段探究其作用机理。结果表明,由于NS表面活性较高,其掺入可显著促进两种胶凝体系早期水化,明显缩短凝结时间并提高早期强度,且NS对矿粉-水泥体系1、3、7 d强度的提升效果均优于纯水泥体系。矿粉的微填充效应和活性效应可显著提高胶凝体系28 d的致密度,进而提升其28 d强度。矿粉与NS二者复合可有效弥补单掺矿粉带来的早期强度损失。
The effects of 2%nano-silica on the compressive strength and setting time of pure cement system and slag powder-cement system were studied,and the mechanism of action was explored by means of XRD,DSC-TG,SEM,MIP,etc.Results show that the addition of nano-silica could significantly promote the hydration,obviously shorten the setting time and increase the early strength of both systems due to the high surface activity of nano-silica,and the effects of nano-silica on the early strength improvement of the slag powder-cement system at 1 d,3 d and 7 d were greater than those of the pure cement system.The micro-filling effect and activity effect of slag powder can remarkably improve the density of cementitious system,and thus increase the strength at 28 d.Moreover,the combination of nano-silica and slag powder can make up for the early strength loss caused by slag powder alone.
作者
徐智东
梅军鹏
王智鑫
李海南
文江涛
牛寅龙
XU Zhidong;MEI Junpeng;WANG Zhixin;LI Hainan;WEN Jiangtao;NIU Yinlong(School of Urban Construction,Wuhan University of Science and Technology,Wuhan 430065,China;Department of Construction Cost,Wuhan Textile University,Wuhan 430200,China;China Construction Third Bureau First Engineering Co,Ltd.,Wuhan 430040,China)
出处
《混凝土》
CAS
北大核心
2023年第4期69-73,77,共6页
Concrete
基金
国家自然科学基金(51908434)
湖北省自然科学基金(2020CFB799)。
关键词
矿粉
纳米二氧化硅
早期强度
孔结构
slag powder
nano-silica
early strength
pore structure
