Incorporation of finely ground waste cathode ray tube glass in concrete

Rapid increase in the use of flat screen image display devices in recent times has led to the replacement of cathode ray tube (CRT) image display devices. The environmental problems arising from CRT disposal is primarily due to the glass' high lead content. With landfilling being non-environmentally friendly, there is need to develop sustainable management methods. This study therefore investigated the incorporation of finely ground (< 0.6 mm) mixture of panel, funnel and neck CRT glass in concrete at 0%, 10%, 15%, 20% and 25% wt/wt replacement for sand, from where an optimum composition was obtained. The workability, compressive strength, elemental composition and lead leaching behaviour of concrete specimens were studied. The test results indicated that the workability of fresh concrete was negatively affected with increasing glass content. The compressive strength at 20% replacement level (29.4 MPa) was higher than the reference (20.3 MPa) by 44.8% after curing for 90 days. It was observed that lead concentration increased with increasing glass content but calcium decreased proportionally while lead leachability was within regulatory limits. This investigation thus revealed that finely ground CRT glass at 20% wt/wt replacement possesses the potential to be used in concrete as a partial replacement for fine aggregate.