Interaction of TEOS with cementitious materials: Chemical and physical effects

This study explored the effectiveness of tetraethyl orthosilicate (TEOS) as a Portland cement mortar consolidant to verify whether it meets the requirements for use in cultural assets. TEOS was found to raise cement mortar strength, lower its porosity and permeability and occasion minimal alteration in its appearance, an indication of its suitability to conserve heritage mortar works. FTIR and Si-29 MAS NMR studies supported the notion that TEOS interacts with the hydrated phases of the cement, portlandite and C-S-H gel. The reaction product between portlandite and TEOS was C-S-H gel and between TEOS and C-S-H gel was a gel with longer chain. (C) 2014 Elsevier Ltd. All rights reserved.