摘要
采用溶胶凝胶法对硅藻土进行改性,然后研究改性前后的硅藻土对水泥净浆(标准稠度用水量、凝结时间)及砂浆性能(力学性能、调湿性能)的影响。研究结果表明:(1)经改性后的硅藻土比表面积由初始的2.76m^2/g增大到158.52m^2/g,平均孔径由初始的3.82nm减小到1.41nm。(2)改性前后的硅藻土水泥净浆标准稠度用水量均高于纯水泥的标准稠度用水量,且随着硅藻土掺量的增加而逐渐增大;随着改性前后硅藻土掺量的增加,水泥初凝时间延长,终凝时间缩短。另外,在硅藻土掺量相同的条件下,改性硅藻土时凝结时间较原状硅藻土水泥凝结时间短。(3)改性后硅藻土的水泥砂浆强度较原状硅藻土的水泥砂浆高;随着改性前后硅藻土掺量的增加,水泥砂浆的强度均逐渐降低,而水泥砂浆吸、放湿率逐渐增大。另外,改性前后的硅藻土掺量相同时,改性后硅藻土的水泥砂浆吸、放湿率大于改性前的硅藻土水泥砂浆的吸、放湿率。(4)X射线衍射(XRD)和扫描电镜(SEM)分析结果表明,改性硅藻土的水泥砂浆较原状硅藻土的水泥砂浆有更多的水化产物,且硬化体结构更加致密。
The impact of the diatomite before and after modified by sol-gel method on the properties of cement paste（setting time,water requirement of normal）and mortar（mechanical properties,humidity-performance）was studied.The results turned out that：（1）the surface area of the modified increased from the initial 2.76 m^2/g to158.52m^2/g,the average pore size decreased from the initial 3.82 nm to 1.41 nm.（2）The water requirement of normal consistency of the cement paste with diatomite before and after modified was higher than that of pure cement.It also gradually increased with the increase additon of diatomite.With increasing dosage of diatomite,the initial setting time of the cement extented and final setting time were shortened.In addition,the setting time of cement mixed with modified diatomite was shorter than that of cement mixed with raw diatomite under the same dosage.（3）The compressive strength of the mortar mixed with modified diatomite was higher than that of the mortar mixed with raw diatomite.With the increase of diatomite dosage,the strength of cement mortar was gradually reduced.The larger dosage of the diatomite before and after modified,the larger the moisture absorption and liberation ratio were.The moisture absorption and liberation ratio of the mortar mixed with modified diatomite were larger than that of the mortar mixed with raw diatomite.（4）X-ray diffraction（XRD）and scanning electron microscope（SEM）analysis showed that cement mortar mixed with modified diatomite had more hydration products than the cement mortar mixed with raw diatomite,and its hardened structure was more compact.
出处
《材料导报》
EI
CAS
CSCD
北大核心
2016年第16期120-126,共7页
Materials Reports
基金
天津市自然科学基金重点项目(14JCZDJC40800)
关键词
溶胶凝胶法
硅藻土
水泥基材料
调湿性能
sol-gel method
diatomite
cement-based materials
humidity performance
