Effects of maximum size of brick aggregate on properties of concrete

- Effects of maximum aggregate size (MAS) on brick aggregate concrete was studied.
- MAS was varied from 12.5 to 50.0 mm; cement contents from 375 to 400 kg/m3.
- Sand to total aggregate ratio was varied from 0.40 to 0.45; W/C from 0.45 to 0.55.
- Concrete compressive strength increases for lower MAS for a higher cement content.
- Compressive strength is increased up to MAS of 35 mm for lower cement content.

Effects of maximum aggregate size (12.5 mm, 19.0 mm, 25.0 mm, 37.5 mm, and 50.0 mm) 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 (375 kg/m3 and 400 kg/m3) were investigated. Considering the variables, a total of 552 concrete cylinder specimens of diameter 100 mm diameter and height 200 mm 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 (400 kg/m3), concrete made with small aggregates give more compressive strength. However, for a cement content of 375 kg/m3, and W/C ratio of 0.45, the compressive strength is increased with an increase in maximum aggregate size up to 37.5 mm. 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.