Combined Effect of Glycerol and Calcium Carbonate as Expanding Agents for Manufacturing Foam Glass Gravel on a Pilot Microwave Oven

Foam glass gravel, a building material with excellent load-bearing and insulation properties, has become very attractive in recent decades due to its low production costs and its environmental friendliness. Used in construction, especially in harsher climates, this product uses recycled residual glass as a raw material. The authors of current paper have recently approached this field using electromagnetic waves as energy carriers converting microwave power into heat. Raw material was recycled post-consumer glass and the combination of a liquid agent (glycerol) and a solid agent (calcium carbonate) was used as the glass powder foaming agents. The experiment took place in a modified 10 kW-oven, much larger than the 800 W-microwave oven used previously. Glass foam gravel had excellent thermal insulation properties and very good compressive strength being at the qualitative level of industrial products manufactured by conventional methods