Experimental study of concrete mixes using crushed and uncrushed coarse aggregates by adopting ACI and DoE methods

Abstract

The main objective of this research is to investigate experimentally the effect of crushed and uncrushed coarse aggregate on the properties of hardened concrete (compressive strength) by adopting the American Concrete Institute (ACI) and the British Department of Environment (DoE) methods. Concrete mixes were designed, concrete cubes and cylinders were prepared and casted by using DoE and ACI respectively. DoE concrete design method considers both types of aggregates; crushed and uncrushed, while the ACI method does not take into account the effect of uncrushed coarse aggregate in design provisions. Then compressive strength tests of concrete samples were determined at ages of 7 and 28 days full curing period. The results obtained show that ACI gave higher values of compressive strength than that obtained by DoE for M30 and M40 except M25, which resulted in lower values than that obtained by DoE for crushed coarse aggregates. The 7-day compressive strength represents 75% of the 28-day compressive strength for ACI method, whereas in DoE reaching up to 73% and 77% for crushed and uncrushed coarse aggregate, respectively.