Synthesis of low carbon cement from local reject brine

• Main Author: Teng, Bryon Yi Xiu
• Other Authors: En-Hua Yang
• Format: Final Year Project
• Language: English
• Published: Nanyang Technological University 2023
• Subjects: Engineering::Civil engineering
• Online Access: https://hdl.handle.net/10356/167271
• Institution: Nanyang Technological University

This project serves to explore more sustainable ways to synthesize magnesium cement from wastewater and develop high performance magnesium concrete in various ways. This project was brought forth due to global cement sustainability challenge to reduce carbon emissions produced during the production of cement. Magnesium is a more sustainable material for cement hence, this project aims to create Magnesium cement from the precipitation of mixing brine with curing water or the precipitation of mixing brine with soaking water. The curing water is made by casting different cement ratios and curing the dried cement in water. Similarly soaking water is made by soaking recycled concrete fines in water. Both waters will be left untouched until the pH is suitably high enough to react with factory reject brine to form brucite in the form of precipitate. During this study the half of brucite produced are burnt at 500℃ to form Magnesium Oxide, MgO. Both brucite and MgO are mixed with similar ratios of mixtures to compare compressive strength of the casted Magnesium cement. Subsequently to determine the contents in the sample when mixing brine with curing and soaking water, several tests are conducted. Tests includes, Thermogravimetric analysis tests, Field emission scanning electron microscopy (FE-SEM) tests, EDX tests, X-Ray Diffraction tests and BET analysis. Other compressive tests to compare curing methods such as, using a critical point dryer were also conducted to compare to using a carbon chamber for 28 days. This was to find the difference in compressive strength.