Analysis of Aggregate Aspect Ratio and Void Structure Within Bituminous Cement Matrices by use of a Neural Network

Aggregate shape and texture are the most important factors in determining the performance behavior of portland cement concrete and bituminous concrete. Currently it is difficult to determine these factors with precision. When a determination is made, a strong correlation with mix performance is rarely seen. What is needed is an accurate method for determining aggregate properties and a means of correlating these properties with mix performance. Studies have documented a relationship between specific aggregate properties (shape, texture, etc.) and mix performance. However, existing methods for determining aggregate properties are labor intensive and operator dependent. The goal of this project is to develop a method of automating the analysis of the mix matrix. For thousands of years, man has sought to understand how various parameters affect the performance of construction materials. In the late 1980's and early 1990's, the Strategic Highway Research Program (SHRP) developed design and test methods that attempted to relate material properties to performance. From this grew many of the specifications and methods now in use for mix design and materials testing. Little has been done to provide a forensic analysis of mix characteristics. In order to better ascertain how specific component properties affect the behavior of mixes in place, it is necessary to develop a method to quantify these characteristics. This method must be accurate, repeatable and able to be performed by trained technicians. Aggregate shape and texture are especially critical to the stability of bituminous mixes. Traditionally, rounded aggregate (coarse or fine) has been considered an unfavorable characteristic in hot mix asphalt. It tends to decrease the strength and stability of the mix. Since no standardized method is available of determining the in-situ characteristics of the mix, the matrix must be destroyed in order to reveal component aggregate characteristics. When the matrix is destroyed, nothing remains of the aggregate alignment, a potentially important concern in determining the affect of aggregate properties on mix performance. The goal of this study is to determine the affect of aggregate shape and texture on mix performance and to characterize the properties of the aggregate, both before and after incorporation in the mix.

Language

• English

Project

• Status: Active
• Funding: $60000.00
• Contract Numbers:

  SPR-2282 (268)

• Sponsor Organizations:

  Rhode Island Department of Transportation

  State Office Building, 2 Capitol Hill
  Providence, RI  United States  02903
• Project Managers:

  Franco, Collin

• Performing Organizations:

  Rhode Island Department of Transportation

  State Office Building, 2 Capitol Hill
  Providence, RI  United States  02903
• Principal Investigators:

  Sock, Michael

  Byrne, Michael

• Start Date: 20031215
• Expected Completion Date: 0
• Actual Completion Date: 0
• Source Data: RiP Project 9297

Subject/Index Terms

• TRT Terms: Aggregates; Asphalt mixtures; Bituminous mixtures; Hot mix asphalt; Materials; Mix design; Research projects; Stability (Mechanics); Void ratios
• Geographic Terms: Rhode Island
• Subject Areas: Design; Research; I30: Materials;

Filing Info

• Accession Number: 01458885
• Record Type: Research project
• Source Agency: Rhode Island Department of Transportation
• Contract Numbers: SPR-2282 (268)
• Files: RIP, STATEDOT
• Created Date: Jan 3 2013 12:52PM