Strength and fresh properties of borogypsum concrete

This paper reports on a comprehensive study on the properties of concrete containing borogypsum. Properties studied include setting time and volume expansion of paste, unit weight and consistency of fresh concrete, compressive and splitting tensile strength of hardened concrete. Potential use of borogypsum as a concrete admixture is discussed. Borogypsum contents of 0%, 3%, 5%, 10% and 15% by mass are used in the study. The strength results show that concrete mixtures containing 3% and 5% borogypsum developed higher strength values than those of control concrete mixtures. Based on strength properties, it is determined that 5-10% borogypsum may be used as a concrete additive. On the other hand, inclusion of borogypsum as a cement replacement reduced the consistency. Moreover, test results also showed that borogypsum delays setting time of paste made with cement and borogypsum. Thus, the use of borogypsum as a set retarder of Portland cement is recommended.