CME is an Application Written in Microsoft Excel 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. Concrete of good quality can become undesirable in the hands of an inexperienced finisher. Still, poor concrete 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, now discuss ranges of cementitious material contents, mortar fractions, coarseness/workability indexes, and 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 the final job submittal letter.
CME is an easy-to-use application that utilizes Microsoft Excel and VBA programming. This combination makes it possible to store up to 1,500 concrete mixtures with material cost. It provides Auto-blending features, such as blending up to five (5) aggregates to fit within upper and lower gradation limits (Tarantula Curve). 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 the volume of primary aggregate sand to yield functions. CME contains the Coarseness Factor Chart, the Power of 45 curves, and the Total gradation of the concrete mix as percent retained and passing.
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).