Anthony Berg

Date of Award

January 2016

Document Type

Thesis

Degree Name

Master of Science (MS)

Department

Civil Engineering

First Advisor

Daba Gedafa

Abstract

The ability to create a hot-mix asphalt (HMA) design in a laboratory setting that matches the HMA mix that was done in a field setting is important to ensure proper mixing techniques are being done in both situations. A laboratory setting is a more controlled environment compared to the field where the environment can be more complicated with heat and weather control. Doing performance measures such as rutting and cracking resistance are viable tests to see the effect of lab versus field mix. The research was done to compare laboratory and field mix when it came to rutting resistance and cracking performance of HMA mixes. Performance grade (PG) 58-28 and PG64-28 were considered for testing. Both performance grades were taken from highways in North Dakota with separate mix designs. The nominal maximum aggregate side (NMAS) for all mixes was 12.5mm. Ten specimens for both lab and field (mixes 150 mm diameter and 75 mm high) were compacted to a target of 7% air voids using a gyratory compactor. Six were used for the Asphalt Pavement Analyzer (APA), which measured rutting resistance of the specimens. The remaining four were used to find cracking resistance using the Disk-Shaped Compact Tension (DCT) test. The DCT was performed at 10ᵒC above the PG lower limit of the asphalt binders in the mixes. Cracking resistance was measured in terms of fracture energy. The results showed that for PG58-28 the lab mix rutted less than field mix whereas PG64-28 showed field mix rutting less than lab mix. The lab mix performed better than field mix in cracking resistance for both performance grades.

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