INFLUENCE OF COOLING METHODS ON THE COMPRESSIVE STRENGTH AND ABSORPTION FOR THERMOSTONE EXPOSED TO FIRE

Abstract

The research included two tests, compressive strength and absorption on two different types of thermostone ,first type without finishing , second with juss and gypsum finishing, tests were done on these samples under regular and high degree of temperature (300,400,500)C° as heated samples were tested and left to cool in air and then in water to simulate the fire condition. Results showed, compressive strength of thermostone reduce with the percentage of changes in temperature and the finishing layers depending on the changes of cooling condition as percentage of reducing in compressive strength increased with the increasement of temperature for the samples without finishing , the higher percentage was 29% at temperature 500 C° and the existence of finishing layers reduces the effect of heat on compressive strength the percentage reduction was (51.8,15,19.8)% for temperature (300,400,500) C° respectively ,for cooling condition , the thermostone samples exposed to high heat after cooling in water showed a specific reduce in compressive strength in high percent comparing with heated samples which cooled with air . the results also showed the absorption percent for samples without finishes is higher than those samples after removing finishing with temperature (,400,500)C° was (7.95,6.43)% respectively, the absorption percent of thermostone was only measured, so there was no possibility to measure it at (300)C° that means the presence of finishing reduces water absorption of thermostone .