Investigation into the thermal performance of recycled glass screed for construction purposes

Thermal properties of five screed specimens were evaluated by four different thermal analysis methods. Thermal conductivity results showed that samples with recycled glass aggregate had a substantially lower thermal conductivity compared with those of sand screeds. Variation of heat capacity between the glass and sand screed mixtures increased with elevated temperature to a significant extent; the glass screeds seemed to show the highest heat capacities at these increased levels. The 100% glass aggregate specimens exhibited a lower thermal expansion at higher temperatures showing a higher dimensional stability. From the results a model was created to assess some realistic scenarios which the screeds may be presented with. A comparison of the screeds over different temperature ranges was produced. Glass screeds were shown to save approximately three times the energy of conventional sand counterparts due to good thermal insulation. When compared, the 100% glass with rapid cementations provided the best possibility for financial savings. The study demonstrated that glass aggregate screeds could be used as a cost effective and environmentally friendly building material that superseded sand alternatives dramatically in thermal retention.