Mechanism study on the effect of diammonium hydrogen phosphate on the setting time and micro-nanostructure of ordinary Portland cement paste

被引：6

作者：

Liu, Jianglin ^{[1
]}

Li, Yue ^{[1
]}

Jin, Caiyun ^{[2
]}

Li, Yaqiang ^{[3
]}

Lin, Hui ^{[1
]}

Shen, Jiale ^{[1
]}

机构：

[1] Beijing Univ Technol, Key Lab Urban Secur & Disaster Engn Minist Educ, Beijing Key Lab Earthquake Engn & Struct Retrofit, Beijing 100124, Peoples R China

[2] Beijing Univ Technol, Coll Appl Sci, 100 Pingleyuan, Beijing 100124, Peoples R China

[3] Beijing Forestry Univ, Coll Soil & Water Conservat, Dept Civil Engn, Beijing 100083, Peoples R China

来源：

CONSTRUCTION AND BUILDING MATERIALS | 2023年 / 407卷

基金：

国家重点研发计划; 中国国家自然科学基金;

关键词：

Diammonium hydrogen phosphate; Setting time; Micro-nanostructure; Mechanism study; Ordinary Portland cement; CALCIUM SILICATE HYDRATE; C-S-H; ATOMIC-FORCE; TARTARIC ACID; MICROSTRUCTURE; CONCRETE; PERFORMANCE; RETARDERS; CRACKING; MODEL;

D O I：

10.1016/j.conbuildmat.2023.133616

中图分类号：

TU [建筑科学];

学科分类号：

0813 ;

摘要：

The effect of diammonium hydrogen phosphate (DAP) on the setting time, mechanical properties and micro-nanostructure of cement paste is investigated. The results show that with an increase in DAP content, the peak value of hydration heat of cement is delayed, but the 3d cumulative hydration heat release of the cement is basically the same. The 3d compressive strength of cement paste is not significantly different, and the 28d compressive strength increases first and then decreases. When the DAP content is 0.5 wt%, the compressive strength of cement paste is most significantly improved, increasing by 38.5%. Meanwhile, the initial and final setting times of cement paste are extended by 74.0% and 73.2%, respectively. When the DAP content is 1.0 wt%, the cement paste has the longest setting time, with the initial and final setting times extended by 101.8% and 103.5%, respectively. However, the compressive strength of the cement paste can still be improved by 10.5%. It is mainly due to the change of pH value and calcium ion concentration of cement pore solution with different DAP content, which changes the micro-nanoscale morphology of C-S-H gel, Hamaker constant between globules, microscopic Young's modulus, and pore structure.

引用

页数：15