Dynamic Cost Optimization Method of Concrete Mix Design

Abstract

As in the most practical problems, decisions have to be made sequentially at different points in time, place, and levels, dynamic programming as a mathematical technique is well suited for the optimization of these problems. Concrete mix design includes various parameters choosing each will have many direct effects on the others. Therefore, performing dynamic optimization in design process is essential to achieve the desired conditions. Cost optimization, is one of the most important aspects in the optimization problems especially in engineering ones. Cost optimization via dynamic programming is performed in the present study due to the effects of various parameters such as cement strength grade, water-cement ratio, maximum size of aggregate, amount of cement, concrete workability and other factors as decision variables. In this regard, a nonlinear dynamic model is used to study the behavior of variables; the model is validated using data presented in literature of this study. Since, the dynamic optimization method works as a decomposition technique, it requires the separability and monotonicity of the objective function. So, the objective function has been represented as the composition of the individual stage returns. The procedure then found the optimal profile modification that reduces the cost over a wide range of operating conditions. Dynamic optimization shows a good performance for the computational efficiency as well as the reliability of results. Finally, an application to air-entrained concrete curb is presented and an extremely good performance is obtained by optimization procedures and concrete properties.