The dynamic modulus ( E*) of asphalt mixtures correlates well with field performance. Studies have shown that in comparisons of dense-, gap-, and open-graded mixtures, confined E* ( C-E*) tests are recommended to rank and compare the expected field performance of the different mixtures. Unfortunately, C-E* tests are harder to perform than unconfined E* ( U-E*) tests. Factors such as time, availability of equipment, technical complexity, and financial needs must be carefully considered when a confined laboratory-testing program is being proposed. The objective of this study was to develop a simple method by which C-E* values could be predicted from U- E* results with a reduced number of C- E* tests. The methods analyzed were developed by using E* test results conducted on nine asphalt rubber mixtures at different confinement levels and were validated by using three conventional densegraded mixes previously tested at Arizona State University. The U- E* and C- E* test results generally showed a linear relationship with the applied bulk stress and were almost parallel regardless of the confinement level. An approach to predict a C- E* relationship from U- E* test data was developed by using one (or two) confined test(s) instead of the five required by current test protocols. The methods investigated potentially would provide a decrease in laboratory testing time of at least 50%. Because some level of laboratory confinement is recognized for gap- and open-graded mixes, the methods investigated in this study also may prove helpful in the development of more accurate pavement distress prediction models.
Reduced Confined Dynamic Modulus Testing Protocol for Asphalt Mixtures
Transportation Research Record: Journal of the Transportation Research Board
Transportation Research Record: Journal of the Transportation Research Board ; 1891 , 1 ; 153-162
2004-01-01
Article (Journal)
Electronic Resource
English
Reduced Confined Dynamic Modulus Testing Protocol for Asphalt Mixtures
Online Contents | 2004
|Reduced Testing Protocol for Measuring the Confined Dynamic Modulus of Asphalt Mixtures
Online Contents | 2011
|Reduced Testing Protocol for Measuring the Confined Dynamic Modulus of Asphalt Mixtures
Transportation Research Record | 2011
|Significance of Confined Dynamic Modulus Laboratory Testing for Asphalt Concrete
Transportation Research Record | 2011
|Dynamic Modulus of Asphalt Mixtures
Transportation Research Record | 2019
|