ISSN: 1945-7553
CODEN: JTEVAB
Page Count: 8

Compaction of Asphalt Mixtures for Laboratory Testing: Evaluation Based on Density Profile

Fwa, TF
Senior lecturer, research assistant, and senior lecturer, National University of Singapore, Singapore,

Low, BH
Senior lecturer, research assistant, and senior lecturer, National University of Singapore, Singapore,

Tan, SA
Senior lecturer, research assistant, and senior lecturer, National University of Singapore, Singapore,

(Received 17 August 1992; accepted 19 January 1993)

Abstract

Cylindrical specimens are commonly used in laboratory testing of asphaltic paving mixtures. This paper describes a study that examined the influence of different compaction methods on the resulted density distributions of cylindrical specimens using a laboratory twin-probe nuclear density gage. Two common sizes of 102 mm (4 in.) cylindrical specimens, namely 64-mm (2.5-in.) high Marshall-size specimens, and 200-mm (7.87-in.) high triaxial test specimens, were considered in the test program. Four compaction methods were studied: drop-hammer compaction, kneading compactions, single-plunger compression, and double-plunger compression. In the case of 200-mm-tall specimens, the effect of compaction in layers was also examined. Test results show that, except for the kneading compaction method, the other three methods could all produce 64-mm-tall Marshall-size specimens of relatively uniform density distributions with density variation within 0.05 g/cm³. For 200-mm-tall specimens, only the double-plunger compression method was able to produce specimens with density distribution of similar uniformity.

Keywords:
density measurement, density profile, unclear density gage, asphalt mixtures, compaction methods, cylindrical specimens

Paper ID: JTE11786J
DOI: 10.1520/JTE11786J
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