Development of sepiolite doped materials in cement mortar adhesive

This project comprises the studies to develop a national source based on material that can be used as an alternative material to one of the most critical additives used in cement based construction chemical products, which is "water retaining additive". Water retaining additives are the compounds that greatly affect hydration reaction, which occurs between cement and water and determine the mechanical performance in cement based on construction materials. Today, cellulose ethers are commoly used as water retaining agents in cement based on adhesive mortars. Moreve even though the amount of cellulose ether in a standart adhesive formulation is less than 1 %wt, it comprises approximately 25% of the total cost of the recipe. Sepiolite, a natural clay, has the ability to retain high level of water due to its microfiber bundles, structure with channels, and silanol and hydroxyl groups on its surface. Therefore, it is an appropriate candidate to be used as a water retaining agent in cementitious products, but it has to be purified from its impurities, disintegrated from its agglomerates of bundles and surface modified with suitable chemicals (e.g. silane compounds, guar gums, etc.). The experimental studies are grouped under four main headings: 1) Physical and chemical characterization of commercially available sepiolite products, and their performans tests in cementitous products, 2) Investigation of appropriate sepiolite source, and removal of the impurities coming from this source, 3) according to the results of the first two stages, physical and/or chemical modification studies of raw sepiolite, 4) Otimization of the recipe of cementitious products, which is developed using the modified sepiolite.