Effects of Water and Compressed Air Pressure on the Adhesion of Na2SiO3 Binders on Silica sand Surface: Comparison of Experimental Data and Molecular Dynamics Simulation

In this study, the effects of different water amounts, compressed air blowing pressures were studied on the bonding strength of Na2SiO3 binders. It was concluded that the blowing pressure did not have a linear relationship with the bonding strength, but it was closely related to the diffusion coefficient of N-2. Based on scanning electron microscopic results, it was inferred that the low strength was caused by the formation of bond film and bond bridge crack after the adhesive was hardened. Based on molecular dynamics simulations, different pressures and water contents had a great influence on the diffusion coefficient of N-2 in the silicate binder system. This research provides an important theoretical background to improve the technology of CO2 + compressed air hardened Na2SiO3 bonded sands during the casting process.