Question

What would be the maximum aggregate size used for the given mixture properties by using ACI Method of Mix Design. 28-day specified concrete strength is 3b Mpa, standard deviation is choosen as 3.a Mpa and it is required that no more than 1 test result in 200 will fall below the specified strength. Project Title: Detoration of wood column of a commercial building Project summary: Wood deterioration at the lower level of a heavy timber column, which supports five floor levels, was remedied by removing a section of column and the construction of a new concrete pier and footing.

For Coarse Aggregate (Uncrushed): SSD Bulk Specific Gravity: 2.60, Absorption Capacity: 1.8 %, Total Moisture: 2.3 % and Dry Rodded Unit Weight: 1430 kg/m3.

For Fine Aggregate (Crushed): SSD Bulk Specific Gravity: 2.70, Total Moisture: 3.c % and Free Moisture: 1.d %. FM= 2.65, Zone II.

Cement: Portland Composite Cement, Specific Gravity: 3.01. For 0.2a m3 cement is calculated as 12b kg.

Hint ( dot mean simple dot; not multiplication i.e 3.a mean 3.7 and 3b mean 34)

A=7,B=4,C=8,D=1,E=2