Get this simple Concrete Strength Generator - MRA is a common term used to describe the compressive strength relationship of a family of concrete mix designs. The chart shows two strength curves. The red lower curve is the strength measured at 7 days old. The upper blue curve is the concrete strength at 28 days old.

Concrete Main Relationship Analysis

We use the relationship between the 7 and 28 days strength. This is used for predicting what concrete strength will be at 28 days from the 7 day results. This means that concrete producers can control cement content in their concrete mix designs, which in turn alters the strength of a concrete mix. Using a prediction system reduces the risk of potential failure of ready mixed concrete and offers commercial benefits as well. Without a concrete strength prediction system concrete suppliers are open to 28 days worth of production risk. A construction site can build three concrete floors in a high rise building in a month and imagine how much it would cost to fix if the bottom floor failed in strength after the 28 days result came in!. No need to say any more...

Concrete Trial Mixes

Trial concrete mixes are carried at various cement contents, usually seven trials at equidistant cement content increments. At least 5 concrete cubes are made from each trial mix. Two are marked to be tested at 7 days and three are marked to be tested at 28 days.

The trial results are then plotted to produce the strength curves. The results are then used to create a complete strength table using a cement content range of between 50 and 550kg at 5kg increments.

Polynomial Regression Analysis

The standard method to do this is by using polynomial regression constants to the power of 3. There are usually refrenced as K3, k2, k1 and k0. These constants are then used to generate the MRA table.

Trendlines are used to graphically display trends in data and to analyze problems of prediction. Such analysis is also called regression analysis (regression analysis: A form of statistical analysis used for forecasting. Regression analysis estimates the relationship between variables so that a given variable can be predicted from one or more other variables.). By using regression analysis, you can extend a trendline in a chart beyond the actual data to predict future values.

We use regression analysis in concrete technology but do not extend analysis beyond the known variables.

	MRA Generator This pdf print is a sample of what can be produced from an MRA analysis. These tables can then be used to establish relationships between different concrete mixes.
	Excel Worksheet Use the excel macro buttons to generate extra worksheet to enable you to enter more mix desings and build up all your main relationship analysis family.

Please note*

If you are using our EN206 Conformity database you will need this MRA generator tool.

This Generator is available from Dataseen. Please use the contact facility to obtain it:
£15.00