This study aims to present data from the literature that emphasize the influence of the polycarboxylate molecular structure on cement hydration, by isothermal calorimetry, setting times and thermogravimetric analysis of cement pastes. Using the same methodology, two Brazilian poly-carboxylates with different molecular structures, used on the production of Brazilian admixtures, were investigated. The literature data, as well as the test results, show that the main factor of the polycarboxylate molecular structure related to its retarding effect is the anionic charge density present in the system, which is higher when the side chain density is lower. In the case of polycarboxylates with equal side chain density, those with shorter side chains lead to higher retardation when used in the same mass quantity.
Polycarboxylate; Molecular structure; Hydration; Portland cement; Calorimetry; Thermogravimetric analysis
