CME Overview

CME is an application written in Microsoft Excel 2010, 2013, & 2016 + Office 365

Concrete mix design is no longer just a recipe of proportions of cement, sand, stone and water. Today the concrete supplier is held responsible for the performance of the in-place concrete. Curling, cracking, dusting, color variation, moisture transmission, and strength, are all concerns for the quality of the in-place concrete. Much of what happens is beyond the responsibility or control of the concrete producer. The concrete of good quality can become undesirable in the hands of an inexperienced finisher, but poor concrete, that of inappropriate proportions, will doom the final product regardless of the experience of the concrete finisher.

Changes in the American Concrete Institute, specifically ACI 302.1R, now discusses ranges of cementitious material contents, mortar fractions, coarseness / workability indexes, the total gradation of aggregates, as methods of evaluating concrete for potential in-place performance. The Concrete Mix Evaluator (CME) is a tool to help the concrete mix professional move from raw material selection to final job submittal letter.

CME is easy to use application that utilizes Microsoft Excel and VBA programming. This combination makes it possible to store up to 1500 concrete mixtures with material cost and provide Auto Blending features such as:

* Blend up to five (5) aggregates to fit within upper and lower gradation limits
* Blend aggregates to a specified Workability / Coarseness Index
* Yield a concrete mix to specified aggregate volume percentages
* Specify up to four cementitious percentages along with a W/C ratio and solve using water demand or cementitious content
* Blend using volume of a primary aggregate
* Sand to yield functions

CME contains three graphs:

* Total gradation of the concrete mix as percent retained and passing
* ACI 302 Coarseness Factor Chart
* Power of 45 curve

CME also calculates the concrete density and the following concrete ratios:

Water/Cementitious - Mortar and Paste fraction - Air Volume within the cement paste - Sand / Aggregate ratio by volume - w-Adjust factor - Volume of water to Volume of Cementitious - Omega-Index (OIF), and Modified Omega-Index (MOIF).

How the CME got started

Back in 1995, I took a job with a manufacturer of expanded clay lightweight in Southern Georgia. The product was used in the concrete block. Having worked for Besser Company (a manufacturer of concrete block equipment), I started writing a program to blend the aggregates for designing concrete block mixes using Microsoft Excel V. The lightweight aggregate was also used as structural lightweight in concrete. One day I was working at a precast plant, after putting up mixes and weighing and batching nine to ten mixes, I decided that I needed a more systematic approach. I went back to the hotel room and started working on an excel program that would become known as the "Concrete Solver." In the beginning, I did all the programming, It was quite fun and rewarding to see other concrete professionals use the program. With the changes in Excel V, Excel 97, Excel 2003, Excel 2007, and now Excel 2016 / Office 365 and updating of the Visual Basic (VBA) , I now hire the VBA programming out to a professional. The latest version is now the "Concrete Mix Evaluator." Your comments and suggestions are more than welcome as they help me continue to create an affordable tool for the concrete professional. Proportioning concrete has been my passion, as of this writing, I am the current Chair of ASTM C01.29 Sulfate Resistance and past Chair for ACI 211 on concrete mix proportioning, it has been fun.