Effects of aggregate flakiness on concrete

In this study, the effect of flakiness which is a geometric feature of crushed aggregate produced from Karaisalı limestone, on the physical properties of concrete was investigated. In this regard, the aggregate tests of flakiness index and sieve analysis accordance with Concrete aggregates standard of TS 706 EN 12620 +A1 in force in Turkey, and slump and concrete pressure strength tests accordance with respectively TS EN 12350-2 and TS EN 12390-3 standard were performed. In the experimental studies, aggregates which have different grain size distribution were separated from each other by geometry as flat or cubic. Using flat and cubic grains which have same mineralogical composition but different particle geometry, concrete samples including % 0, % 25, % 50 and % 100 flat particles were produced accordance with TS 802 standard. Aggregate geometry (percentage of flat particle) in concrete samples produced was used as variable parameter only, as the other components (water/cement ratio, the amount of contribution, etc.) were kept constant. The results indicate that the increase of the amount of flat grains in concrete mixture causes a particular decrease in strength of concrete and increase in slump.