ABRASION RESISTANCE OF CONCRETE CONTAINING WOLLASTONITE MICRO-FIBER FOR PAVEMENT

Abstract

Roads are the life line of every nation. Deterioration of concrete Roads occurs due to various forms of wear such as erosion, cavitations, and abrasion due to varying degrees of exposures. Deterioration of concrete surfaces in concrete pavements is most significantly contributed by abrasion wear. Abrasion wear occurs due to repeated rubbing, scraping, skidding of wheel tyre on the concrete pavement surface. Concrete abrasion resistance is markedly influenced by a number of factors including concrete strength, aggregate properties, water-cement ratio, micro structural features of cement matrix, pore structure of surface zone and surface finishing. In this research Wollastonite Micro Fiber is used as a mineral admixture in concrete to improve its mechanical and durability characteristics as partial replacement of cement. Wollastonite is abundantly available in Rajasthan, Tamil Nadu, Uttarakhand, and Andhra Pradesh states of the Indian Union as a low-cost material. A concrete specimen of water-cement ratios of 0.4 was made for M-40 mix and 0.45 was made for M-30 using ordinary Portland cement (OPC), and OPC admixed with wollastonite micro-fibers. A total of ten concrete mixes were considered with varying proportions of wollastonite micro-fibers (10 %, 20 %, 30 % and 40 %). Admixing of wollastonite micro-fibers improves the flexural strength significantly up to 30% replacement levels irrespective of days of moist curing, but decreases the compressive strength beyond 20 percent replacement level are observed from the experimental tests. Marked improvement in resistance to abrasion was observed for wollastonite micro-fiber admixed concrete up to 20 percent of its admixing with OPC. The abrasion resistance is more pronounced for admixed concretes with Transportation Engineering Group, Department of Civil Engineering, IIT-Roorkee, Uttarakhand-247667. Page iii Abstract 2012 prolong curing duration. The abrasion resistance {cs Conventional method, the weight loss is more when compared to the abrasion resistance Of Sand balst mete. The strength and weight loss of PCC exposed to aggressive medium reduced significantly but the strength and weight loss of mixes M-2, M-3, P-2 and P-3 is less than the conventional mix. Because of high concrete strength and abrasion resistance, a better utilization of concrete cross section is possible. Alternatively, thickness of pavement slab can be reduced by incorporation of wollastonite micro fibers in concrete mixes. Key words: Wollastonite micro fibers, mechanical properties, abrasion resistance and aggressive mediums. Transportation