CAPÍTULO

Hydrophobized lime grouts prepared with microsilica and superplasticizers

Libro: Proceedings PRO 130 : 5th Historic Mortars Conference
Autores: González Sánchez, Jesús Fidel; Navarro Blasco, Íñigo; Durán Benito, Adrián; Sirera Bejarano, Rafael; Fernández Álvarez, José María; Álvarez Galindo, José Ignacio
Editorial: RILEM Publications S.a.r.l.
Localidad: Paris
ISBN: 978-235158-221-3
Página inicial-final: 330 - 345
Fecha de publicación: 2019
Resumen: This work reports the obtaining of lime-based grouts as repairing materials. Microsilica was added as pozzolanic additive to enhance the compressive strength of the hardened grouts. Sodium oleate, as water repellent admixture, and different superplasticizers (SPs) were also incorporated to reduce the water absorption and to enhance the injectability of the grouts. Polycarboxylate ether (PCE), polynaphthalene sulfonate (PNS), melamine sulfonate (MMS) and polyacrylic acid (PA) were tested as SPs. Regarding the fluidity of the grouts, PCE was seen to improve the injectability, followed by PNS, MMS and PA. However, PCE addition was also accompanied by a severe delay in the setting time. The other three superplasticizers did not provoke significant delays in the hardening of the samples. The water contact angle underwent an increase pointing to an effective hydrophobization of the surface as a consequence of the water repellent admixture. The combination with PCE was the most effective in keeping the water repellency in comparison with the control sample (lime grout + oleate). MMS yielded high compressive strengths and durability of the mortars, in the face of freezing-thawing cycles, was enhanced.