Inhibition of alkali-silica reaction using tetraethyl orthosilicate silane (TEOS28 and TEOS40) for hardened cement-based materials

The alkali-silica reaction (ASR) is one of the main deleterious processes that affects concrete structures around the world. When it comes to the durability of large-scale projects, such as hydroelectric plants, predicting the performance of aggregates and materials throughout their useful life becomes an important factor.In recent decades, the use of surface treatments has become a good option among existing materials to help minimize the impacts of the alkali-aggregate reaction (AAR). Applications of silanes/siloxanes in real structures, diagnosed with alkali-aggregate reaction, have already yielded positive results from the point of view of reducing expansion kinetics. The use of inorganic materials with certain hydrophobic properties related to the crystallization of hydrated products, such as ethyl silicate, has aroused greater interest due to the entry of aggressive agents, such as chlorides and sulfates. We propose to characterize the impact of adding TEOS to cement paste. This characterization will contribute to the study of the control mechanisms of concrete expansion. Therefore, the objective of this study is to evaluate the effectiveness of two TEOS-based products containing different compositions of SiO2, through the analysis of hydration data from cement components using the quasiellastic and inelastic neutron scattering technique.