Effects of maximum size of brick aggregate on properties of concrete

Effects of maximum aggregate size (12.5mm, 19.0mm, 25.0mm, 37.5mm, and 50.0mm) on properties of concrete made with different sand to total aggregate volume ratio (0.40 and 0.45), W/C ratio (0.45, 0.50, and 0.55), and cement content (375kg/m3 and 400kg/m3) were investigated. Considering the variables, a total of 552 concrete cylinder specimens of diameter 100mm diameter and height 200mm were made for 52 numbers of independent cases. Brick aggregates were tested for specific gravity, absorption capacity, unit weight, and abrasion resistance. Concrete specimens were tested for compressive strength, stress-strain curve, splitting tensile strength, and Young's modulus. Results have revealed that for higher cement content (400kg/m3), concrete made with small aggregates give more compressive strength. However, for a cement content of 375kg/m3, and W/C ratio of 0.45, the compressive strength is increased with an increase in maximum aggregate size up to 37.5mm. The compressive strength of concrete increases with an increase in s/a ratio from 0.40 to 0.45. Relationships between mechanical properties of concrete, and stress-strain relationships are proposed for different maximum aggregate sizes.