Effect of Silica Fume in Rubberized Concrete

Concrete is one of the most widely used construction materials in the world. The consistent increasing demand of raw materials used for concrete production paves the way for suitable recycled or waste materials instead of conventional materials which are likely to deplete in years ahead. In this present research, an attempt is made on the use of Crumb rubber from recycled rubber tyres through the cracker mill, granulator mill and micro mill and Silica fume from the byproduct of silicon metal or ferrosilicon alloys as a partial replacement of fine aggregates and cement respectively in concrete. The properties and suitability of the raw materials for the experiment were determined. A preliminary part of the programme constitutes the preparation of M30 grade of concrete mix design using IS method. The specimens (150 mm × 150 mm) were cast with optimum percentage (6%) replacements of the fine aggregate by crumb rubber. Then the Silica fume is partially replaced with cement as strength enhancer at various percentages (i.e. 0%, 5%, 10%, 15% and 20%) at the optimum percent of crumb rubber. The Silica fume is used to improve the strength properties of rubberized concrete up to some extent. The maximum compressive strength achieved at the age of 28 curing day is 35.5 N/mm² at 15% replacement of silica fume. The strength is increased to 5.07%, 23.94% compared to control concrete and rubberized concrete respectively.