تأثير الرماد المتطاير كبديل جزئي عن الرمل على خواص خرسانة الركام الخشن المعاد

Abstract

The research is deliberate each of characteristics (slump, Compressive, Splitting tensile,Water absorption, Density) in four different mixtures with 50% weight recycled coarse aggregate instead of natural coarse aggregate in all mixtures, one of them with natural sand considered referential mix , another three mixtures with fly ash class F as a partial replacement of sand with different weight ratios 15%, 30% , 45% , To know the effect of replacement on this properties in 7,14,28,and 90 day ages , Results show large favorable effect on increase Compressive strength with increasing replacement ratio of sand with fly ash and in oldness ages concrete to reach 48% over Compressive strength referential in 90 day age. Splitting tensile is favorable effected also increase with increasing replacement ratio and oldness ages concrete but with much little degree which in Compressive strength, maximum increasing tensile strength is 13.478% over tensile referential happened in 45% replacement in 90 day .Replacement is inconsiderable effect on dry density which maximum increasing 2.23% over referential density in 45% replacement, Water absorption and slump much lessen with increasing replacement ratio which maximum decrease 30.5% in water absorption, 29.88% in slump compare referential in 45% replacement .