Thermal conductivity of cement paste containing waste glass powder, metakaolin and limestone filler as supplementary cementitious material

The use of waste glass powder, metakaolin and limestone filler in cement-based materials is attractive for recycling the waste and reducing carbon dioxide emissions from cement factories. In this laboratory study, the effects of waste glass powder, metakaolin and limestone filler on the thermal conductivity, mechanical properties, hydration products and pore structures of cement paste were investigated. The results indicated that the addition 25% of metakaolin in cement paste increased the thermal conductivity by 54%. While, the addition 25% of waste glass powder and limestone filler decreased the thermal conductivity of cement paste by 24.05% and 36.26%, respectively. The cement paste containing meta kaolin exhibited lower porosity and higher compressive and flexural strength than pure cement paste. The incorporation of waste glass powder and limestone filler in cement paste decreased the compressive and flexural strength while increased the porosity. Under the same dosage conditions, the cement paste with limestone filler had a higher porosity than that with waste glass powder. This research provides the reference for application of waste glass powder, metakaolin and limestone filler to produce green building materials with excellent thermal conductivity. (C) 2020 Elsevier Ltd. All rights reserved.

Automated summary

The study found that adding metakaolin increased thermal conductivity in cement paste, while adding waste glass powder and limestone filler decreased thermal conductivity. Cement paste containing metakaolin exhibited lower porosity and higher compressive and flexural strength.