Experimental study and comparison between the use of natural and artificial coarse aggregate in concrete mixture

摘要

There is a general belief that crushed aggregates contribute higher strength in concreting compared to rounded aggregates. Contrary to this belief, our study revealed: rounded aggregates perform better than crushed aggregates because the rounded shape which considered as a negative characteristic is compensated by improving the workability and reducing the need of mixing water, thus; the water/cement ratio, these essential parameters leads to gaining strengths in concrete. From the laboratory test of strength determination it was explored that rounded aggregate provide more compressive, flexural tensile and splitting tensile strengths (26%, 46% and 38% at 28 days) than crushed aggregates. Relevant to mention: uncrushed aggregate is cheaper than crushed aggregate. Consequently, concrete with uncrushed aggregates will be cheaper. It can be concluded that uncrushed aggregates are appropriate for medium grade concrete for better performance in terms of workability, strength and economy. Future study is required on testing other artificial aggregate with different mineralogy characteristics and different type of crusher rather than gyrator crusher.