Use of Particle Composite Theory to Model Concrete Asphalt Mixes

摘要

The main objective of this exploratory project was to evaluate the possibility of creating an accurate and flexible analytical model to predict the properties of Concrete Asphalt mixtures by the use of particle composite theory. The proposed work was to be a combination of tests performed at the materials laboratory of the Kansas Department of Transportation in Topeka, KS. The results of these tests were to be used as calibration data in the development of a model partially based on work performed by the researcher at the University of Kansas and a summary of work by others in the US and Europe. The main components of the experimental phase were to be the type of asphalt binder used and the size and composition of the particle reinforcement in the mix. The initial tests were planned with round glass beads to provide a mix where the particle was of geometric size, thus easy to model mathematically and where the particle composition were of lower modulus than the asphalt. From those tests, the initial calibration was planned to reduce the number of unknown constants in the model. Following the glass bead tests, specimens using irregular geometry and finally regular aggregate types were planned to be used in the testing of the calibrated model. Unfortunately, the tests at the experimental phase were not successful in providing a comprehensive data structure to develop the calibration of the models. Inconsistencies on air voids in specimens with the same variables and difficulties in achieving consistency in the mix at the mold make the calibration process unachievable at this time. Only one variable was able to be tabulated from tests at the loading machine and that was particle diameter, of this one only two sizes were tested, 3mm and 6mm, again creating a hard constraint in the process of comparing results for mathematical variable calibration and sensitivity studies. Following is a summary of the proposed model to be used in the initial steps and to be modified as needed from the results of the tests. In addition, results from the two series of compression tests for the 3mm and 6mm specimens are included for reference.