Influence of fly ash and decreasing water-powder ratio on performance of recycled aggregate concrete

U radu su prikazani rezultati ispitivanja zajedničkog učinka djelomične zamjene cementa s letećim pepelom i upotrebe recikliranog agregata s ciljem poboljšanja održivosti betona. Ispitivano je devet betonskih mješavina, u kojima su varirani količina letećeg pepela i vodovezivni omjer, analizirani su: tlačna čvrstoća, kapilarno upijanje, vodopropusnost i otpornost na prodor klorida. Dobiveno je da se povećanjem količine letećeg pepela neznatno smanjuje tlačna čvrstoća, ali da se smanjenjem vodovezivnog omjera to može nadomjestiti.Investigation results of the combined effect of partial cement replacement with fly ash, and the use of recycled concrete aggregate to improve the sustainability of concrete, are presented in this paper. The compressive strength, capillary water absorption, water permeability, and chloride ion penetration, are analysed by testing nine concrete mixtures, in which the fly ash content and water to powder ratio were varied. The results show that compressive strength slightly decreases as the fly ash content increases, but that this can be compensated by reducing the water to powder ratio