Performances of vermiculite and perlite based thermal insulation lightweight concretes

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.

Properties of Structural Lightweight Aggregate Concrete Based on Sintered Fly Ash and Modified with Exfoliated Vermiculite

“…The slump test results for SFA and SFA + EV mixes were equal to 45 mm and 35 mm, respectively. These results reflect the results achieved by Terzić et al [33] who described in details the influence of EV on the consistency of fresh concrete mix. The density of fresh SFA and SFA + EV fresh concrete mixes was equal to 1790 kg/m 3 and 1738 kg/m 3 , respectively.…”

Basalt fiber reinforced foam concrete with marble waste and calcium aluminate cement

“…Baradaran-Nasiri and Nematzadeh 35 explored the mechanical characteristics of concretes produced with CAC and fine recycled refractory brick aggregate at high temperatures. The authors showed that CAC and brick aggregate doubled the residual strength of concrete after 800 C. Terzic et al 36 studied the properties of concrete containing the vermiculite and perlite as aggregates and PC and CAC as binders to evaluate the influence of the high temperature in terms of thermal, microstructural, mechanical, and mineral phase composition. They indicated that compressive strength decreased at high temperatures but obtained lightweight concretes showed both thermal insulation and structural characteristics.…”