DFT Study on the Compatibility Between Bentonite Clay Mineral and Hydration Products With the Polycarboxylate Water Reducer in the Cement Hydration Process

Huang Teng, Huang Teng, Zhihao He, Zhihao He, Zhihao He, Gao Meiben, Jiaxing Zhang, Jiaxing Zhang
2022 Frontiers in Earth Science  
As one of the most used grouting materials, cement has the characteristics of low price and a wide resource of raw material. With the in-depth research and application of cement admixture, the compatibility between different water-reducing agents and clay has become one of the critical factors that affects the cement hydration process. Due to the adsorption of clay on cement additives, the dispersion efficiency of the water reducer will be reduced, also the strength and impermeability of
more » ... on products will be adversely affected. This paper studies the adsorption characteristics of different PCE superplasticizers on bentonite clay minerals and hydration products using a molecular simulation technique. Results showed that there is competitive adsorption between the clay and hydration products when the admixture participates in the hydration reaction, the additives are likely to adsorb on the CH rather than the clay minerals, while the adsorption energy of the hydration product C-S-H is the highest, thus the preferential adsorption order and compatibility between clay minerals and hydration products on admixtures could also be obtained. PDOS (partial density of states) analysis concluded that some new characteristic peaks and rearrangement of the bonding orbitals may appear after the adsorption, with the peak value of the minerals higher than that of jennite, which is also consistent with the adsorption energy. This study aims to reveal the interaction mechanism and compatibility between the hydration product and clay minerals, hoping to fully utilize the advantages of both clay minerals and admixtures in the cement hydration process.
doi:10.3389/feart.2022.890968 doaj:a395553a8c234aeda72ee8a105269ce6 fatcat:4cdhz5n7p5dgbizhtbpkl4vpaa