Use of CRT funnel glass as a fine aggregate in self-compacting mortar: The effect of limestone on Pb immobilization
- Publication Type:
- Conference Proceeding
- Applied Mechanics and Materials, 2012, 193-194 pp. 513 - 516
- Issue Date:
End-of-life CRTs are classified as hazardous waste since the funnel glass component has a high Pb content. Alternative management of the glass is required due to the cessation of closedloop recycling of CRT glass. This study aims to compare the feasibility of using CRT funnel glass as fine aggregates in a self-compacting mortar by addition of limestone to enhance the Pb immobilization. Sample mixtures of self-compacting mortar were prepared from Ordinary Portland cement Type 1 (OPC) with water/cementitious (W/C) ratio of 0.38 by weight, which contained 0, 20 and 40 wt% of Samsung CRT funnel glass ground to sizes smaller than 595 μm as a sand replacement. The sample with glass mixtures contained additions of 5, 10 and 15 wt% of limestone, ground to sizes smaller than 297 μm as a viscosity modifying agent (VMA). The samples' flow ability was tested by V-funnel and Marsh cone. Pb-fixation in the samples was analysed by TCLP at 7 days and 14 days. The addition of limestone as a viscosity modifying agent improved flow ability in mixtures with CRT funnel glass, with the addition of 10 wt% limestone showing the highest flow improvement in V-funnel tests for both glass mixtures. CRT funnel glass utilized as sand replacement at 20 and 40 wt% showed Pb leaching results within the US EPA allowable limits. However, the addition of limestone reduced the Pb immobilization ability in mortars. A silica based VMA such as fly ash and rice husk ash should be used for these applications. © (2012) Trans Tech Publications, Switzerland.
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