The effect of sand addition on the properties of grc

Abstract

The properties of spray-dewatered grc composites in which upto 50% by weight of the cement has been replaced by sand are described in terms of three storage conditions and age. The initial strength values of grc show a slight decrease with increasing proportions of sand due to the dilution of the cement matrix. Conversely, the Young's modulus and density show an increase. The addition of sand reduces the drying shrinkage of the composites and allows the LOP (in bending) values to be stable in a relatively dry environment. In wet environments LOP values increase with age. The weatherability of grc composites containing sand is significantly improved when the matrix is modified by a suitable polymer. The 10 year strength properties of grc containing varying amounts of sand are very similar to those of ordinary grc made from neat cement paste.