Impact of guar gum and chitosan ethers on physico-mechanical properties and durability of natural hydraulic lime mortars

Author(s): Tomáš Žižlavský, Martin Vyšvařil, Patrik Bayer, Pavla Rovnaníková
Paper category: Proceedings
Book title: Proceedings of the 5th Historic Mortars Conference
Editor(s):José Ignacio Álvarez, José María Fernández,Íńigo Navarro, Adrián Durán, Rafael Sirera
ISBN:978-2-35158-221-3
e-ISBN: 978-2-35158-222-0
Publisher: RILEM Publications SARL
Publication year: 2019
Pages: 1279-1290
Total Pages: 12
Language : English

Abstract: The addition of guar gum derivatives and chitosan ethers has been studied in the natural
hydraulic lime (NHL) mortars. These types of polysaccharides can be possibly used as
viscosity enhancing admixtures or water retaining agents for the mortars instead of cellulose
ethers. The water retention capacity is an essential property of the mortars to enhance the
hydration of NHL and mortar adhesion to the substrate. The main part of this study is
addressed to the physico-mechanical properties, microstructure, and durability of NHL
mortars. The hydroxypropyl- derivatives showed air-entraining function, which is beneficial
for the durability of mortars and affects porosity of mortars, as well as water absorption
coefficient. The biopolymer addition slightly improved initial flexural strength with the
increasing difference for later ages, the only exception being hydroxypropyl guar, which
showed slight decrease of flexural strength. Compressive strength decreased by the addition
of biopolymeric admixture in all cases; the degree of decrease was dependent on the type
and dosage of the admixture.

Online publication : 2019
Publication type : full_text
Public price (Euros) : 0.00