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"Sixty years ago I knew everything; now I know nothing; education is a
progressive
discovery of our own ignorance." - Will Durant
Objective
This assignment's purpose is twofold: (1) use the ACI concrete
mix design procedure, and (2) continue to develop your spreadsheet skills.
You must hand in the cover
sheet for the assignment, your
calculation for Parts 1 and 2, and a printout of
your spreadsheet for Part 2. Also, submit
your spreadsheets for Part 2 to Canvas. You
must follow the Excel format.
Part 1: Use the ACI method for concrete mix
design to proportion a 1 yd3 of concrete. Compute the weight of
each mix component by hand to meet the following specifications.
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 inches, and the maximum aggregate size should not exceed 1 inch. The properties of the
materials are as follows:
- Cement: Type I, specific gravity = 3.15
- Coarse
Aggregate: Bulk specific gravity (SSD) = 2.72;
absorption capacity = 1.3%;
dry-rodded unit weight = 103 lb/ft3;
surface moisture = 1%
- Fine
Aggregate: Bulk specific gravity (SSD) = 2.67;
absorption capacity = 1.5%;
fineness modulus = 2.70
surface moisture = 2%
Follow the
homework format given in class and report the weight of
cement, water, coarse aggregate, and fine aggregate required per yd3 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.
Concrete is required for an interior
column. The 28-day compressive strength should be 5,000 psi. The slump should be between
1
and 2 inches, and the maximum aggregate size should not exceed
¾ inch. The properties of the
materials are as follows:
- Cement: Type I, specific gravity = 3.15
- Coarse
Aggregate: Bulk specific gravity (SSD) = 2.70;
absorption capacity = 0.5%;
dry-rodded unit weight = 96 lb/ft3;
surface
moisture = 1%
- Fine
Aggregate: Bulk specific gravity (SSD) = 2.67;
absorption capacity = 1.1%;
fineness modulus = 2.70
surface
moisture = 1.5%
Your Excel spreadsheet should be configured similarly 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 should be rounded to the nearest
integer in both the Volume Calculation and Moisture Adjustment sections. 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.
Part 3. Read Chapters 9 and 10 in "A Mind for
Numbers" by Barbara Oakley.
Additional Resources
Microsoft Excel includes a built-in user manual and tutorial. They are
available through the Help option at the right end of Excel's main command line.
A web page describing the CIVL 1112
Excel Homework
Policy is available. Please read it before you turn in each assignment
this semester.
Cover sheet for homework
This website was originally
developed by
Charles Camp for
CIVL
1112.
This site is maintained by the
Department of Civil Engineering
at the University of Memphis.
Your comments and questions are welcomed.
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