Mechanical property, nanopore structure and drying shrinkage of metakaolin-based geopolymer with waste glass powder

This paper investigates the mechanical properties, nanopore structure and drying shrinkage behavior of the metakaolin-based geopolymer mixtures containing 0%-20% waste glass powder. The prepared samples were cured under ambient temperature and high temperature (60 degrees C), respectively. The mechanical properties of the samples can be improved by introducing the low content of glass powder (5%-10%). Microstructure and nanopore structure analysis indicated that a denser gel phase was formed in the glass powder modified geopolymer samples. The added glass powder reduced the water loss rate of the samples under drying condition, leading to a reduction of drying shrinkage at early ages. The capillary stress in the prepared geopolymer samples was analyzed based on the pore size distribution of the mixtures. The magnitude of capillary stress generated in glass powder containing samples was similar to that of geopolymers without glass powder. The improved creep modulus with added glass powder facilitated the reduction of the shrinkage of the samples at later ages. This study can facilitate the recycling of waste glass into geopolymer for sustainable construction applications. (c) 2019 Elsevier Ltd. All rights reserved.