Performances of Vermiculite and Perlite Based Thermal Insulation Lightweight Concretes

  • Anja Terzić Institute for Testing of Materials - IMS
  • Jovica Stojanović Institute for Technology of Nuclear and other Mineral Raw Materials
  • Ljubiša Andrić Institute for Technology of Nuclear and other Mineral Raw Materials
  • Ljiljana Miličić Institute for Testing of Materials - IMS
  • Zagorka Radojević Institute for Testing of Materials - IMS

Abstract

This experimental study was conducted with an aim to investigate the effect of the elevated temperature on the mineral phase composition, microstructure and mechanical properties of the thermal insulation lightweight concretes. The first group of experimental concretes was based on the expanded vermiculite and expanded perlite used as lightweight aggregates (in 65 wt%) in combination with either ordinary Portland cement or refractory calcium aluminate cement. The mix-design of the second group of concretes comprised standard quartz aggregate, vermiculite or perlite as aggregate replacement (25 wt%) and binder (PC or CAC). A total of 10 concrete mix-designs were fabricated in form of 40×40×160 mm samples which were submitted to heat-treatment at 400, 600, 800 and 1000 C upon standard 28-days period of curing and hardening. The changes in crystallinity and mineral phase composition induced by temperature were monitored by X-ray diffraction technique. Microstructural visualizations of the non-fired and fired concrete samples were conducted by scanning electron microscopy accompanied with EDX analysis. The results indicated that despite the decrease in compressive strengths upon firing, investigated lightweight concretes can be categorized both as thermal insulators and structural materials.

Published
2020-04-05
Section
Articles