Effect of carboxylic acids on the morphology, physical characteristics and hydration of <img src='/image/spc_char/alpha.gif' border=0>-hemihydrate plaster

Abstract

Hydration of <img src='/image/spc_char/alpha.gif' border=0>-hemihydrate in the presence of different concentrations of tartaric, succinic, malic and citric acids was studied. All the acids, except tartaric acid, retard the hydrations. <i style="">p</i>H measurements have shown that during hydration acids are adsorbed at solid surfaces, leading to the retardation of hydration. E-modulus of elasticity, tensile strengths, total porosity, compressive strength, morphological and temperature changes during hydration were studied. It is found that morphological changes control the strength properties.