D-Optimal Criterion Application to Block Samo # 4 Manufacturing to Propose a Mixing Under Standards NTC4205-1

Abstract

The design of experiments is applied to find the optimum proportion of components for the samo # 4 block mix in the company Gres Caribe S.A. (Barranquilla, Colombia). The NTC 4205-1 standards for resistance to compression and water absorption were considered. Statistical analysis of collected data was assisted with Statgraphics Centurion XVI. Preliminary field tests established the limits of each component to determine the experimental region. The candidate points were selected under the D-optimal criterion and the regression model chosen. There are twenty points (o candidate mixtures) in total, thus twenty runs were required for the experiment. By maximizing the desirability function, the optimal mixture for the block was determined: 54.3091% clay, 37.5507% sand and 8.14017% water. Five field runs with this mixture showed that the property values of the new blocks exceeded the properties of the blocks manufactured with the old mixture. These blocks also meet the required standards. A savings of $ 9,606 / manufactured block is achieved, equivalent to a percentage decrease of 4.41%, quantified at COP 153'023,580 / year.