Mechanical Properties of Concrete Mortar Based on Mixture of CRT Glass Cullet and Fluidized Fly Ash

The problem with the waste from electric and electronic equipment (WEEE), consisting of about 80% of television sets and computers containing a cathode ray tube (CRT) have just begun to deal with. Cathode ray tubes (CRTs) are the video display components of televisions and computer monitors (EPA, 1995). Arising problem related with recovery and recycling of CRT glass stimulates examinations aimed at making cullet-based ceramic materials of reinforced mechanical strength. Glasses as cone and neck contain principally different lead contents another dangerous elements instead panel glass has other heavy metals (Ba, Sr, etc.) that forbid their recycling in the glass industry for the production of containers, domestic glassware and glass fiber. As it is well known concrete is an excellent material for immobilization of these metals, what was the reason to undertake this research. The use of CRT (Cathode Ray tube) waste glasses in concrete has attracted a lot of interest worldwide due to the increased disposal costs and environmental concerns. Because of silica large quantities CRT glass in the theory is a pozzolanic in nature, thus it can be used as a sand replacement in light concrete. The research was performed with use of concrete mortars. As a reference concrete mortar a mix of cement, sand, expanded clay aggregate and water was used. The purpose of this work was to investigate the influence of additives e.g. CRT glass cullet as an aggregate, and fluidized fly ash on concrete properties. Based on obtained results both CRT glass cullet and fluidize fly ash improved compressive and flexural strength in respect of standard concrete mortar without these additives. The use of CRT glass as a sand replacement caused the increased of compressive strength of concrete mortar of about 16% and its flexural strength of about 14%.