RT journal article
T1 Alkylsiloxane/alkoxysilane sols as hydrophobic treatments for concrete: A comparative study of bulk vs surface application
A1 González-Coneo, Jorge
A1 Zarzuela Sánchez, Rafael
A1 Elhaddad, Farid
A1 Martínez Carrascosa, Luis Antonio
A1 Gil Montero, María Luisa Almoraima
A1 Mosquera Díaz, María Jesús
A2 Ciencia de los Materiales e Ingeniería Metalúrgica y Química Inorgánica
A2 Química Física
K1 Hydrophobic
K1 Waterproofing
K1 Concrete
K1 Admixtures
K1 Silanes
K1 Surface treatment
AB Water and waterborne decay agents (e.g. salts, microorganisms) are commonly associated with undesired alterations and damages on concrete elements. A strategy to mitigate their impact is to decrease water retention in the material either by surface treatments or admixtures. In this work, hydrophobic concretes were developed by the addition of a hydrophobic sol containing TEOS and PDMS oligomers, synthetized by a surfactant-assisted sol-gel route, either as an admixture or as a surface treatment. The hydrophobic performance was similar for both application modes (>70% capillary absorption reduction) and higher than concrete containing a commercial (calcium stearate) admixture or a nanosilica-based hydrophobic coating. Addition as an admixture led to a higher durability in the rain and abrasion tests. The hydrophobic sol as an admixture promotes an increase of surface roughness and porosity, as well as the formation of C–S–H like reaction products with the cement matrix components, as evidenced by AFM, MIP, SEM and FTIR. Despite the higher porosity, impact resistance and material cohesion were not negatively affected respect to the plain concrete. Application as a surface treatment decreased porosity and led to a higher amorphous SiO2 content. The material cohesion and impact resistance was increased by this application, although penetration was limited to the first 4 mm and the hydrophobic properties were more susceptible to mechanical damages to the surface. © 2021 The Authors
PB ELSEVIER
SN 2352-7102
YR 2021
FD 2021
LK http://hdl.handle.net/10498/25916
UL http://hdl.handle.net/10498/25916
LA eng
NO This project has received funding from the European Union's Horizon 2020 - Research and Innovation Framework Programme under grant agreement No 760858; This work has been financed by the Spanish State Research Agency R&D program 2020 (Project reference: PID2020-115843RB-I00); This work has been co-financed by the European Union under the 2014-2020 ERDF Operational Programme and by the Department of Economic Transformation, Industry, Knowledge, and Universities of the Regional Government of Andalusia (Project reference: FEDER- UCA18-106613).
DS Repositorio Institucional de la Universidad de Cádiz
RD 06-nov-2026