Abstract
This paper is to follow the previous part 1 in which basic properties of Gypsum were studied. In this paper experimental results and some considerations on the behaviour of cast Gypsum under several conditions of the environment are explained and concluded as follows. When cast Gypsum absorbs water the compressive, tensile, flexture strengths and young's modulus decrcase by considerable rate. Under wet condition the structure of cast Gypsum is destroyed as the age passing. Mixing and curing temperature influences the workability of the mixture and the strength of cast Gypsum. The higher the mixing temperature is, the more the workability of the mixture decreases. When the curing temperature is always over about 40℃, the strength of cast Gypsum clearly decreases. The strength of cast Gypsum made in the season when the monthly average temperature is higher than 18℃ and without controlling temperature, sometimes becomes smaller than intended. Gypsum has many strong points that are better ability on fireprevention, lighter weight for the compressive strength under dry condition and faster increase of strength than other inorganic cementing materials. Then it is possible and effective to use Gypsum as building materials in the form of composite materials expecting strength and durability by protecting from the action of water.
