Influence of Guar Gum Derivatives on Hardened Properties of Aerial Lime-Based Mortars

Influence of Guar Gum Derivatives on Hardened Properties of Aerial Lime-Based Mortars

en

This paper studies the possibility of usage of the guar gum and its derivatives (carboxymethylhydroxypropyl guar (CMHPG) and hydroxypropyl guar (HPG)) as admixtures for aerial lime-based mortars. The influence on the properties of mortars was studied on the aerial lime –based mortars prepared with quartz fine grained sand and doses of admixtures ranging between 0,5 and 10‰. The hardened bulk densities, flexural and compressive strength, porosity, water absorption coefficient due to capillarity action and carbonation rate were studied. The addition of the hydroxypropyl guar lowered the bulk density (due to an air intake), improved workability, slightly increased the strength, slowed carbonation rate, and nobbled the water transport in the mortar. The addition of carboxymethylhydroxypropyl guar does not impact the bulk density, the strengths were increased similarly to HPG: it does not impact carbonation rate significantly, so the long term strengths were comparative with the HPG. The water transport was slightly better in lower doses and slightly worse in larger doses in comparison with the reference mortar. The pure guaran was found not to be beneficial for the lime mortars for its only advantage is in the water transport, where in any dose the transport was better than any other mortar, but the benefit of this is questionable.

This paper studies the possibility of usage of the guar gum and its derivatives (carboxymethylhydroxypropyl guar (CMHPG) and hydroxypropyl guar (HPG)) as admixtures for aerial lime-based mortars. The influence on the properties of mortars was studied on the aerial lime –based mortars prepared with quartz fine grained sand and doses of admixtures ranging between 0,5 and 10‰. The hardened bulk densities, flexural and compressive strength, porosity, water absorption coefficient due to capillarity action and carbonation rate were studied. The addition of the hydroxypropyl guar lowered the bulk density (due to an air intake), improved workability, slightly increased the strength, slowed carbonation rate, and nobbled the water transport in the mortar. The addition of carboxymethylhydroxypropyl guar does not impact the bulk density, the strengths were increased similarly to HPG: it does not impact carbonation rate significantly, so the long term strengths were comparative with the HPG. The water transport was slightly better in lower doses and slightly worse in larger doses in comparison with the reference mortar. The pure guaran was found not to be beneficial for the lime mortars for its only advantage is in the water transport, where in any dose the transport was better than any other mortar, but the benefit of this is questionable.