PARAMETRIC STUDY ON SEMI-RIGID PAVEMENT MODEL SLABS USING CALCITIC/DOLOMITIC LIME

Abstract

Huge deposits of calcitic and dolomitic lime exist in India. The calcitic lime has been extensively used both for buildings and roads but the dolomitic lime is generally unfit for use in the buildings due tb its slow rate of hydration and accompanied volume change.Dolomi-tic lime, available in plenty, has not yet been used in road construction. In the present work comparative study has been made on two types of limes namely calcitic and dolomitic. fly-ash was used as a pozzolana and the brick ballast as the coarse aggregate. from the laboratory investigations the suitable per-centage of lime and fly ash in the total mix was determined by carrying out unconfined compressive strength tests. With this percentage of lime and fly ash, specimen were carted to find modulus of elasticity and flexural strength of the mix. To evaluate the structural behaviour of this mixture six model slabs, three for each material, with varying thicknesses were dasted and cured for 28 days. The slabs were tested for their edge loading using 30 cm.diameter 4. iv MI= plate. Deflections were measured at 10 positions at top surface of the slab. Finally the ultimate load capacity of of slab was determined. Results of tests were analysed and discussed in the form of graphs and tables and experimental values were compared with theoretical values. Finally economic analysis of two mixes was carried-out taking unit cost and strength into account and the most economic mix was recommended.