不同水灰比条件下碳酸钙晶须对水泥净浆收缩性能的影响  

Influence of calcium carbonate whiskers on shrinkage performance of cement paste with different water cement ratios

作　　者：郑忠良 尤博 张兆彪 李宇翔 曹明莉[2] ZHENG Zhongliang;YOU Bo;ZHANG Zhaobiao;LI Yuxiang;CAO Mingli(China Mcc22 Group Corporation Ltd.,Tangshan 064000,China;School of Civil Engineering,Dalian University of Technology,Dalian 116024,China)

机构地区：[1]中国二十二冶集团有限公司,河北唐山064000 [2]大连理工大学土木工程学院,辽宁大连116024

出　　处：《水利水电科技进展》2024年第1期66-72,共7页Advances in Science and Technology of Water Resources

基　　金：国家自然科学基金项目(51678111);大连理工大学-中国二十二冶集团有限公司校企合作项目(HX20200728)。

摘　　要：为探究碳酸钙晶须对水泥净浆收缩性能的影响,分别测试了3种水灰比试样在不同龄期的干燥收缩、化学收缩和自收缩,并采用X射线衍射(XRD)和压汞法(MIP)分别分析了自收缩试样的物相和孔隙结构变化特性。结果表明:碳酸钙晶须在水泥基体中具有吸附和转移自由水的特性;在不同水灰比条件下,碳酸钙晶须对干燥收缩的影响不同,且影响程度与其掺量呈正相关关系;化学收缩随碳酸钙晶须掺量呈先升后降的变化趋势;碳酸钙晶须对自收缩具有明显的改善作用,尤其是早期自收缩,且水灰比的提高使碳酸钙晶须对早期自收缩的改善效果更加显著;碳酸钙晶须细化了孔隙结构,且未生成新的水化产物。To investigate the effect of calcium carbonate whiskers on the shrinkage properties of cement paste,dry shrinkage,chemical shrinkage and autogenous shrinkage of specimens with three kinds of water cement ratios were tested at different ages,respectively.The phase composition and pore structure changes of the autogenous shrinkage specimens were characterized using X-ray diffraction(XRD)and mercury intrusion porosimetry(MIP),respectively.The results show that calcium carbonate whiskers have the characteristics of adsorbing and transferring free water in cementitious materials.Under different water cement ratios,calcium carbonate whiskers exhibit different effects on drying shrinkage,and the degree of influence shows a trend of initially increasing and then decreasing with the dosage of calcium carbonate whiskers.The chemical shrinkage shows a tendency of increasing and then decreasing with its dosage.Calcium carbonate whiskers can significantly improve the self-shrinkage,especially the early autogenous shrinkage,and the increase of the water cement ratio makes the improvement of the early autogenous shrinkage by calcium carbonate whiskers more significant.The whiskers refine the pore structure without generating new hydration products.

关 键 词：水泥净浆 碳酸钙晶须 水灰比 干燥收缩 化学收缩 自收缩 

分 类 号：TU528.58[建筑科学—建筑技术科学]