Concrete with biofuel fly ash freezing - thawing resistance

Abstract

Biofuel combustion ash is one concrete mineral additives. Materials used for the research Portland cement CEM I 42.5 R, sand of 0/4 fraction, gravel of 4/16 fraction, biofuel fly ash, superplasticizer and water. Seven compositions of concrete mix were designed by replacing 0 %, 5 %, 10 %, 15 %, 20 %, 25 % and 30 % of cement with biofuel fly ash. The article analyses the effect of biofuel ash content on the properties of concrete. The tests revealed that the increase of biofuel ash content up to 5 % increases concrete density and compressive strength after 28 days of curing and decreases water absorption. It was found that concrete where 5 % of cement is replaced with biofuel ash has higher frost resistance in comparison with concrete without fly ash.