Behaviour of cement composites with lightweight and heavyweight aggregates at high temperatures

Abstract

This paper presents new results of the research of the influence of individual input components done on the behaviour of cement based composite materials exposed to high temperatures. A new approach of this research lies in combining a fraction of basalt fine aggregate and an aggregate base on expanded clay for a composite material with lower volume weight and higher strengths and a resistance to high temperatures. In the field of dispersed reinforcement, new polypropylene fibers treated by low temperature plasma were tested. Degradation of the structure of designed mixtures was evaluated by comparing density changes, mechanical and acoustic properties before and after exposure to high temperatures. An optical microscope was used for determining the width of cracks caused by a thermal load. The contribution of this research was the use of non-destructive methods for diagnostics of quality and properties of designed concrete mixtures exposed to high temperatures.