Behaviour of Cement Composites with Lightweight and Heavyweight Aggregates at High Temperatures

Abstract

This paper presents new results of the research of the influenceof individual input components done on the behaviour of cementbased composite materials exposed to high temperatures. Anew approach of this research lies in combining a fraction ofbasalt fine aggregate and an aggregate base on expanded clayfor a composite material with lower volume weight and higherstrengths and a resistance to high temperatures. In the field ofdispersed reinforcement, new polypropylene fibers treated bylow temperature plasma were tested. Degradation of the structureof designed mixtures was evaluated by comparing densitychanges, mechanical and acoustic properties before and afterexposure to high temperatures. An optical microscope was usedfor determining the width of cracks caused by a thermal load.The contribution of this research was the use of non-destructivemethods for diagnostics of quality and properties of designedconcrete mixtures exposed to high temperatures.