Foam glass gravel made from glass waste by microwave irradiation

Abstract

The experimental results of the manufacturing process of foam glass gravel using recycled glass waste (in very high ratio) are presented in the paper. The technique used for heating at 815-837 ºC of the raw material, composed of a powder mixture of glass, calcium carbonate (between 3-5%) as a foaming agent and borax (between 4.5-5.3%) as a fluxing agent, is unconventional based on microwave irradiation. The main physical, mechanical and morphological characteristics of the glass foam (low thermal conductivity between 0.087-0.110 W/ m•K, very high compressive strength up to 6.3 MPa, practically zero water absorption, pore size between 0.7-1.7 mm), similar to those industrially manufactured by conventional methods, are suitable for load-bearing thermal insulation under foundations or floorings, for insulation around the perimeter of buildings, underground heating pipes, underground tanks, as well as a filling material in the structure of road and railway constructions.

Keywords

• foam glass gravel
• microwave irradiation
• calcium carbonate
• borax
• compressive strength