LABORATORY STUDY ON FIBROUS REINFORCEMENT IN PAVEMENT BASES/SUBBASES

Abstract

Base courses and subbases are used under flexible pavements primarily to increase the load supporting capacity of the pavement by distributing the load through a finite thickness of pavement. Since the base course lies close to the pavement surface, it must possess high resistance to deformation in order to withstand the high pressure imposed upon it. On the other hand, a subbase can be of a lower quality and generally consists of locally available materials. Base courses and subbases may be constructed using reinforced fly ash. If understood and used fly ash properly in road construction, it can result in protecting the environment and saving of the valuable resources. The present production of fly ash from thermal power plants in India is of the order of 80 million tonnes per year and it is expected to reach 100 million tonnes by 2000 A.D. Since this ash has become environmentally hazardous, there is an imperative need for better utilisation. This dissertation presents the effects of addition of cerrtent and.fibres to fly ash. This report deals with interpretation of Proctor's Test, Unconfined Compressive Strength Test, Triaxial Test, Plate Load test and Durability test to the effects of cement and fibre inclusion on the strength and durability of the fly ash so that it can be used in pavement bases and subbases. An attempt has been made to recommend a suitable fly ash-cement combination for practical applications which would create a confidence -amongst the construction agencies to adopt the new techniques. iii