Effect of Curing Temperature on the Morphology and Hydration of Mg O Expansive Material in Paste
The morphologies and hydration properties of Mg O expansive material at different curing temperatures were investigated. When the curing temperature varies from 25 ℃ to 50 ℃,the conductivity of Mg O rises from 40 to80 μs/cm,the hydration product of Mg O expansive material curing in water for 28 days is from 1.5—2 mm to 2—2.5 μm in length through SEM observation,and the expansion of pastes with 5% of the magnesium oxide is from0.36% up to 1.01%,it is increased by 2.78 times. When the content of cement paste increases to 95% and cured in water for 90 days,the brucite forms as hexaflaggy-shaped crystal,which is less than 0.1 μm and tends to aggregates.The effect of curing temperature on the hydration of Mg O expansive material is obvious.
the Research Center on Levee Safety Disaster Prevention, MWR (No. 2019004)； High-level Talent Project Funding Scheme of Jiangsu (No. XCL-CXTD-007)； China Postdoctoral Science Foundation (No. 2018M630559)； the National Natural Science Foundation of China (No. 51908285)； the Fundamental Research Nantong Metro Group Co., Ltd； the traffic construction science and technology project of Shanxi (No. 16-2-08) for its financial support in this project；