CIVL 1112 - Assignment #5

 Name: ________________________

 

"Sixty years ago, I knew everything; now I know nothing; education is a progressive discovery of our own ignorance."  -  Will Durant

Objective

The purpose of this assignment is twofold: (1) to use the ACI concrete mix design procedure and (2) to continue to develop your spreadsheet skills. 

You must hand in the cover sheet for the assignment, your calculations for Parts 1 and 2, and printouts of your spreadsheet for Part 2. Also, submit your spreadsheet for Part 2 to Canvas.

Part 1: Use the ACI method for concrete mix design to proportion a 1 yd.3 of concrete. Compute the weight of each mix component by hand to meet the following specifications:

The concrete is required for an interior column. The 28-day compressive strength should be 6,000 psi. The slump should be between 1 and 2 in. and the maximum aggregate size should not exceed 1 in. The properties of the materials are as follows:

  • Cement: Type I, specific gravity = 3.15
     
  • Coarse Aggregate: Bulk specific gravity (SSD) = 2.65
    absorption capacity = 0.5%
    dry-rodded unit weight = 96 lb./ft.3
    surface moisture = 0.5%
     
  • Fine Aggregate: Bulk specific gravity (SSD) = 2.60
    absorption capacity = 1.1%
    fineness modulus = 2.70
    surface moisture = 1%

Follow the homework format given in class and report the weight of cement, water, coarse aggregate, and fine aggregate required per cubic yard for this application.  If we were to mix this concrete in the lab using the yellow mixer (about 1 ft3 in volume), what would be the required weight of cement, water, coarse aggregate, and fine aggregate?

Part 2: Develop an Excel spreadsheet that computes the amount of fine aggregate using the ACI Mix Design volume method, given the amounts of water, cement, and coarse aggregate and then adjusts each mix component for moisture content. 

The concrete is required for an interior column. The 28-day compressive strength should be 4,000 psi. The slump should be between 3 and 4 in. and the maximum aggregate size should not exceed 1.5 in. The properties of the materials are as follows:

  • Cement: Type I, specific gravity = 3.15
     
  • Coarse Aggregate: Bulk specific gravity (SSD) = 2.65
    absorption capacity = 0.5%
    dry-rodded unit weight = 96 lb./ft.3
    surface moisture = 0.5%
     
  • Fine Aggregate: Bulk specific gravity (SSD) = 2.60
    absorption capacity = 1.1%
    fineness modulus = 2.70
    surface moisture = 1%

Your Excel spreadsheet should be configured similar to the one shown below. The data in the yellow boxes are computed using steps 1-7 of the ACI Mix Design procedure. The data in the gray boxes are the material parameters. The values in the green boxes are the results of embedded Excel functions you should program. 

In the Volume Calculation section, round your results to two decimal places. The final component weights in the Volume Calculation and Moisture Adjustment sections should be rounded to the nearest integer. The calculations in the spreadsheet below are the same as an example problem in the ACI Mix Design notes. Click here to download a template copy of the following spreadsheet.