The Thermal Insulating Properties of Vermiculite

Abstract

A study has been carried out to determine the thermal insulating properties of expanded vermiculite mineral in the form of loose particles and in the form of compressed vermiculite boards. Measurements show that the thermal con ductivity of the loose vermiculite particles is in the range of 0.0633-0.0738 w/(m °C) and these values were found to vary with the pouring density of the loose particles and also with the size of the particles. Studies also show that loose vermiculite particles can be readily compacted into rigid and densified board with the addition of an external bonding medium. A phosphate-based cementitious material was found to be an effective bonding medium. Com pressed vermiculite boards containing the phosphate-based cementitious material exhibit a thermal conductivity in the range of 0.1040-0.1530 W/(m°C), a compressive strength of about 20 MN/m2 and a transverse strength of about 9 MN/m2. The compressed and bonded vermiculite boards are found to have good potential as a building material for construction applications.