MECHANICAL CHARACTERISTICS OF FIBER REINFORCED SELFCOMPACTING CONCRETES EXPOSED TO ELEVATED TEMPERATURES

摘要

In this paper, the studies concern the influence that polypropylene fibres have on thernproperties of SCC of different strength classes when exposed to elevated temperatures. Arntotal of four different SCC and two normal concrete mixtures were produced. The strengthrnclasses of the mixtures were C25/30 and C30/37.rnThe specimens produced were placed at the age of 180 days in an electrical furnace whichrnis capable to reach 300 ℃ at 30 minutes and 600 ℃ at 70 minutes. When the maximumrntemperature was reached, it was maintained for one hour. Then the specimens were let to coolrnin the furnace. The properties measured after fire exposures were the compressive strength,rnsplitting tensile strength and water capillary absorption.rnIt was noticed that, the spalling tendency was increased for specimens of higher strengthrnclass C30/37 irrespective of the mixture type (SCC or NC). Such an explosive behavior wasrnnot observed when polypropylene fibers were added in the mixtures; however, in this case thernresidual mechanical characteristics of concretes were significantly reduced.