Size Influence of Specimens and Maximum Aggregate on Dam Concrete: Compressive Strength

The compressive strength of mass concrete in dams is obtained from laboratory experiments of various cylindrical specimens with diameters of 150, 250, and 300 mm , and heights of 300, 500, and 450 mm , respectively. These specimens with 37.5, 75, and 150 mm maximum size of aggregate were investigated. The 7- and 90-day compressive strength of concrete was found to be between 20 and 58 MPa depending on the size of the specimens. The results reveal the existence of a significant size effect. Based on test results, relationships between the strength of mass concrete specimens and their size and shape are developed. Finally, results and a discussion are presented regarding compressive strength gain with time, effect of maximum aggregate size ( da ) , and specimen size effect.