Study the Impacts of Aggregate’s Geometry and Cement Contents on Fresh and Hardened Properties of Concrete

Abstract

The effects of gravel’s geometry and cement content are one of the most important parameters in the construction industry. Two types of aggregates, sharp corners and rounded corners with different sizes, and several samples of various cement contents were prepared. Then the workability, strength, and elastic modulus tests were performed. Experimental results indicate that workability and compressive strength increase with increasing cement content as expected (12% and 22% for workability and 64% and 69% for compressive strength with regard to sharp and rounded aggregate, respectively). Also, in most cases, seismic parameters improve too (maximum of 120% and 107% for energy absorption regarding sharp and rounded aggregate, respectively). The results demonstrate that concrete samples with the largest grain size of 12.5 mm have the most compressive strength, elastic modulus, energy absorption, and ductility in comparison with other samples (maximum 24% and 18% for elastic modulus with reference to sharp and rounded aggregate, respectively). Finally, the results show that the sharp corner aggregates have greater strength and better seismic parameters in comparison with rounded corner (maximum 16% for energy absorption). In contradiction to the above statement, the rounded corners aggregates have more workability than sharp corner ones (up to 18%), and also the workability increases by reducing the gravel size (26% and 19% for sharp and rounded aggregate, respectively). A statistical approach was used to determine the optimal shape and size of aggregate and organize the results scattering.