Improvement of Controlled Low-Strength Concrete Production Prepared with Fine Recycled Concrete Aggregate Using Lean Six Sigma DMAIC Methodology

Abstract

The recycled concrete aggregate applications in generating new concretes are established methods to enhance sustainability through minimizing construction wastes and the ecological impacts of utilizing natural concrete aggregates. Lean Six Sigma DMAIC methodology is a set of strategies and instruments for process improvements. The Six Sigma DMAIC method is used in this research to maximize the parameters of design to assure and improve the resulting recycled concrete aggregate (RCA) quality. Without applying additives, the project aimed to generate concretes with compressive strengths of 8.3 MPa (1200 psi). In the original analyses, five parameters were applied that were reduced to two parameters after refinements. The water/cement ratio and fine aggregate ratio are the refined parameters. For the two parameters, it was concluded that the optimal values are 0.5% and 30%, in order. In addition, it was founded on the facts that the setup of the existing plants is adjusted to produce controlled low-strength concrete production prepared with fine recycled concrete aggregate, and therefore zero based budgeting is ignored for plants of OB type