RT journal article
T1 Effect of alkoxysilane on early age hydration in portland cement pastes
A1 Husillos-Rodríguez, N.
A1 Martínez-Ramírez, S.
A1 Zarzuela Sánchez, Rafael
A1 Mosquera Díaz, María Jesús
A1 Blanco-Varela, María Teresa
A1 Garcia-Lodeiro, Inés
A2 Química Física
K1 Consolidants
K1 Alkoxysilanes
K1 Silica oligomers
K1 C–S–H
K1 Hydration kinetics
AB Silanes added during mortar or concrete preparation, may modify the fresh state properties, hydration kinetics and mechanical strength of the final product. The effects of silanes on cement hydration have been widely studied in the literature, however, there is some controversy about its effect at short ages. The present study was undertaken to determine the effect of a TEOS-based alkoxysilane (UCA-T), produced by ultrasound-assisted pre-hydrolysis of an oligomeric precursor, on early age cement paste hydration. The nature of the processes modifying the various stages of cement hydration kinetics in the presence of the alkoxysilane was ascertained by analysing paste composition at several ages (defined on the grounds of calorimetric curve results) using XRD, TG-DTG, FTIR and Raman spectroscopy. The calorimetric curve of pastes containing UCA-T exhibited a new early age, pre-induction period exothermal peak, indicative of UCA-T hydrolysis, C(3)A and C3S dissolution and ettringite and C-S-H gel precipitation. Portlandite, however, did not precipitate but reacts with the Si(OH)(4) sourced from UCA-T hydrolysis to generate further C-S-H gel. The induction period following on that new exothermal peak was considerably longer than the period observed in the reference cement, an effect that intensified at higher UCA-T content.
PB ELSEVIER
SN 2352-7102
YR 2022
FD 2022-06
LK http://hdl.handle.net/10498/26914
UL http://hdl.handle.net/10498/26914
LA eng
DS Repositorio Institucional de la Universidad de Cádiz
RD 07-nov-2026