Effects of Aggregate Shape and Mineralogy on Relationships between Concrete Mechanical Properties

Aggregate mineralogy and shape effects on concrete mechanical property relationships were evaluated using 114 concrete mixtures that used rounded gravel, crushed gravel, and limestone. Mineralogy (that is, chert versus calcium carbonate) and shape (that is, crushed versus rounded) were found to have a meaningful effect on the relationships between compressive strength (f(c)), elastic modulus (E), and splitting tensile strength (St). These data sets were used to benchmark several empirical relationships found in the literature to determine their ability to predict E and St based on f(c). Most equations from the literature were conservative and did not consider aggregate type. A set of equations, following the form of ACI 318 and a power equation, are recommended by the authors for limestone, crushed gravel, and rounded gravel to realistically predict E and St based on f(c).