Expert system for diagnosing hot mix asphalt segregation

Asphalt pavement segregation is a continuing, costly problem in the paving industry. The problem is complicated by the many sources of segregation found in typical paving jobs. This paper reviews the origins and remedies of segregation, emphasizing the complex nature of the problem. Because of the complexity of the problem and its remedies, an expert-system solution, SEG, is proposed. SEG is a computer program founded on a knowledge base taken from the literature, combined with current expert input. The system interactively interviews the nonexpert user, who answers questions about the paving operation exhibiting segregation. On the basis of the user's replies, the system suggests changes in the operation to eliminate segregation. The system is rapid, simple, and portable--it can be used in the field with a lap-top computer. Expert systems hold great potential for changing the way transportation engineering problems are solved. The introduction of SEG as a practical tool for analysis is expected to help reduce segregation, and consequently improve pavement quality.