Properties of Asphaltic Paving Mixes Containing Hydrated Lime Waste

Abstract

This investigation presents the results of the study conducted to utilize carbide lime waste as a filler in asphaltic paving mixes, and to study the effect of the incorporation of the waste on the properties of asphaltic paving mixes. The waste, which consists mainly of calcium hydroxide, is generated from two acetylene plants in Bahrain, and the amount is estimated to be 5000 tonnes annually. Physical and chemical properties of the waste were studied. A total of 450 asphaltic concrete mixes were prepared at five different percentages by weight of the waste and the limestone (control). The percentages employed in the mixes were 2, 4, 6, 8, and 10 by weight of the aggregate. Marshall test methods were used to evaluate the compacted mix density, percent air voids, voids in mineral aggregate, stability, and flow. The Marshall stability was carried out at 40°C, 60°C, and 70°C. The results revealed that the minimum 8 KN criteria adopted by the Bahrain specifications was met by all the waste mixes. Also, the waste mixes had much better resistance to high temperatures compared with mixes using conventional limestone filler. The results of the investigation suggest that the incorporation of the waste in asphaltic concrete mixes improves some of its properties, and that it is especially advantageous for use in arid environments, such as Bahrain.