Electrostatic properties of C–S–H and C-A-S-H for predicting calcium and chloride adsorption

The adsorption capacity of cement hydrates considerably affects the ionic ingress into cementitious materials. In this study, surface electrostatic properties calcium silicate hydrate (C–S–H) and aluminosilicate (C-A-S-H) were determined to understand effects on chloride adsorption. density functional groups was by analysing structure C–S–H C-A-S-H through 27Al 29Si MAS NMR. sites ?SiOH ?AlOH are available in whereas has for We found that incorporation aluminium decreases number total C-A-S-H. Furthermore, site increased with Ca/(Si + Al). To C-A-S-H/solution interface, a triple-layer complexation model developed associated equilibrium constants deprotonation, calcium, fitting experimental data potentiometric titration zeta potential measurement results. estimated modelling parameters verified predicting