Performance-Based Paving Concrete Mixture Design and Optimization

摘要

This paper describes an approach used in developing a performance-based mixture design and optimization system for paving concrete. This system is being developed as partofa Federal Highway Administration (FHWA) project entitled "Computer-Based Guidelines for Job-Specific Optimization of Paving Concrete." In this project, a new method of designing and optimizing concrete mixtures for pavement applications is being developed. The procedure includes two key elements: a knowledge base and mixture optimization routines. The former assists the user in selecting mixture design criteria based on site-specific conditions. It also allows forthe user to quickly identify what combinations of concrete-making materials may be a starting-point for their site-specific conditions. The second element allows the user to optimize numerous properties of their concrete mixture including: w/cm ratio, cement content, the use of chemical and mineral admixtures, and gradation of aggregates. The optimization can be based on a variety of targets including cost, strength, workability, durability, and numerous other concrete mixture properties - both fundamental and phenomenological. Overall optimization of the selected targets is achieved using concepts of utility theory. When combined, these methods represent a rational approach to quantifying subjective decision-making criteria that is used in findingthe optimum concrete mixture for specific conditions.