Impact of Guar Gum Derivatives on Properties of Freshly-Mixed Cement-Based Mortars

• 作 者: AlexandreGovin;Marie-ClaudeBartholin;PhilippeGrosseau;
• 机 构: SPIN-EMSE, CNRS: UMR5307, LGF, (E)cole des Mines de Saint-(E)tienne,42023 Saint-Etienne, France
• 出 处: The 14th International Congress on the Chemistry of Cement (
• 发表日期: 2015年期

　　Mortars are traditionally made from a mixture of sand, a binder and water.However, modern factory-made mortars are currently, very complex materials.Indeed, to exhibit various properties from the fresh paste to the hardened material, mortar formulations are composed of many mineral and organic admixtures.Among organic admixtures, polysaccharides, such as cellulose ethers (CE), are widely used into mortar formulation to improve water retention capacity of the freshly-mixed materials.The water retention capacity is an essential property of mortars leading to enhance the cement hydration and its adhesion to a substrate.Moreover, many polysaccharide admixtures, acting as viscosity-enhancing agents (VMA), prevent segregation and improve the homogeneity and workability of cement-based system.Indeed, the viscosity of the system strongly increases using polysaccharides and the rheological behavior of the cementitious paste may be completely modified and adapted to the application.Nevertheless, polysaccharides, as sugars, act on cement hydration.The main drawback is the retarding effect in hydration mechanism and setting-time of the cement.