A solution for quarry limestone dust recycling

Abstract

In quarrying activities, rock is extracted and transformed into aggregate of various sizes for civil engineering applications. In this process waste fine aggregates (dust waste) are generated. The disposal of this type of waste is a further cost in the extraction process, but also a possible cause of environmental pollution. A strategy for the effective recycling of quarry dust, not only reduces waste generation and disposal but also addresses protection of the environment. Many researchers have tried to exploit quarry dust for the production of concrete and the quarry dust has been used as partial or full substitute of the sand. Rai et al (1) carried out an experimental investigation based on the substitution of the sand with quarry dust for the production of selfcompacting concrete. Prakash et al (2) assessed the use of dust for normal concrete, reporting that a 40% replacement of fine aggregate by quarry dust resulted in the highest compressive strength. In the study reported by Bahoria et al (3) sand was replaced with quarry dust in combination with waste plastic. Other researches have addressed the replacement of sand with quarry dust for the production of concrete (e. g. Jagadeesh et al (4) and Liebermann et al (5)). A literature review of the strategies used in the replacement of aggregate for concrete with waste is presented by Bahoria et al (3). However, some studies on the stress strain characteristics of concrete made using quarry dust waste are reported in literature (Kankam et al (6)). An interesting strategy refers to the use of quarry dust for the production of coarse aggregate through a cold bonding procedure as reported by Thomas et al (7). With regards marble quarries, different strategies have been employed for the use of coarse aggregate in concrete as reported by André et al (8). The Italian quarrying industry covers a relevant portion of global mineral extraction resulting in a significant production of fine waste are often located close to ecological sensitive and protected areas and to the coast with higher risks for biodiversity (an example is the limestone extraction industry in Trapani, Sicily). In this context, the paper discusses an experimental program intended to assess the mechanical properties of concrete made with the fine limestone waste produced in the area of Trapani, as a partial substitute of fine aggregate (sand).