An Investigation of the Effectiveness of Asphalt Durability Tests: Fid-Bau Portal

An Investigation of the Effectiveness of Asphalt Durability Tests

N. H. Predoehl / G. R. Kemp

This is the final report of an asphalt durability project which involved weathering laboratory fabricated briquettes at four different climatic weathering sites within California and subsequent comparison of the effect of this weathering with the results of several laboratory tests of the asphalts used for the briquettes. The analysis of the test results presents a startling picture of extreme weathering at a hot desert site and the realization that thermal oxidation is the most significant factor affecting asphalt durability. Included are analyses which show that the effects of voids and aggregate porosity are less severe than the thermal oxidation effect in hot desert climates. A comparison of the results of laboratory tests for predicting asphalt hardening with the results for the field weathered briquettes show that none of the procedures is capable of adequately predicting asphalt weathering in a hot weathering site such as Indio. A new procedure (California Tilt-oven Asphalt Durability Test) was developed to approximate the effect produced at Indio in two years. Some correlation to briquette results was obtained. A climatic specification to control asphalt hardening in the hot climatic areas is proposed.