Controlled surface treatment of cementitious materials with modified lithium silicate solutions

Controlled surface treatment of cementitious materials with modified lithium silicate solutions

WoS Article

This study investigates the development of a surface treatment for cementitious materials based on lithium silicate solutions modified with hexylene glycol, aimed at achieving controlled gelation within the cement matrix to reduce water ingress. Rheological measurements identified an optimal hexylene glycol concentration of 0.90 M, enabling gelation within approximately 24 h. The structure and composition of gels formed in simulated pore solution were characterized using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and inductively coupled plasma optical emission spectroscopy (ICP-OES). The results indicate that hexylene glycol influences silicate condensation reactions and remains associated with the gel structure even after intensive washing. The resulting gel was dominated by Q3 silicate species with a minor contribution of Q4 units and incorporated lithium as the primary charge-balancing cation, while calcium was incorporated to a high extent (approximately 95%) despite its low overall concentration in the system. Microstructural analyses of treated mortar specimens using SEM-EDS and mercury intrusion porosimetry (MIP) revealed increased silicon content in the near-surface region together with significant pore structure refinement, including reduced critical pore entry diameters and total intrudable volume. Water absorption tests demonstrated a significant and long-term reduction in water uptake compared to untreated specimens and specimens treated with pure lithium silicate solutions, with the effect remaining evident even after 1 year of ageing. These findings suggest that the synergistic effect of lithium silicate and hexylene glycol promotes controlled gel formation and pore structure refinement, offering a promising approach for reducing water ingress through pore structure refinement.

This study investigates the development of a surface treatment for cementitious materials based on lithium silicate solutions modified with hexylene glycol, aimed at achieving controlled gelation within the cement matrix to reduce water ingress. Rheological measurements identified an optimal hexylene glycol concentration of 0.90 M, enabling gelation within approximately 24 h. The structure and composition of gels formed in simulated pore solution were characterized using X-ray photoelectron spectroscopy (XPS), Raman spectroscopy, and inductively coupled plasma optical emission spectroscopy (ICP-OES). The results indicate that hexylene glycol influences silicate condensation reactions and remains associated with the gel structure even after intensive washing. The resulting gel was dominated by Q3 silicate species with a minor contribution of Q4 units and incorporated lithium as the primary charge-balancing cation, while calcium was incorporated to a high extent (approximately 95%) despite its low overall concentration in the system. Microstructural analyses of treated mortar specimens using SEM-EDS and mercury intrusion porosimetry (MIP) revealed increased silicon content in the near-surface region together with significant pore structure refinement, including reduced critical pore entry diameters and total intrudable volume. Water absorption tests demonstrated a significant and long-term reduction in water uptake compared to untreated specimens and specimens treated with pure lithium silicate solutions, with the effect remaining evident even after 1 year of ageing. These findings suggest that the synergistic effect of lithium silicate and hexylene glycol promotes controlled gel formation and pore structure refinement, offering a promising approach for reducing water ingress through pore structure refinement.

Inorganic gel | Lithium silicate solution | Organic admixture | Surface treatment

Inorganic gel | Lithium silicate solution | Organic admixture | Surface treatment

MARKUSÍK, D.; KALINA, L.; SEDLAČÍK, M.; CÁBA, V.; PALOVČÍK, J.; HAJZLER, J.; BŘEZINA, M.; KOPLÍK, J.; BÍLEK, V.

15.06.2026

Elsevier Ltd

Journal of building engineering

128

United Kingdom of Great Britain and Northern Ireland

15

1

https://www.sciencedirect.com/science/article/pii/S2352710226015500