TESTING OF BITUMINOUS CONCRETE LAYER OVERLYING CEMENT CONCRETE SLABS

Abstract

The use of bituminous concrete overlays over existing cement concrete p1wnente is gaining considerable popularity those days. No rational oppxooch is yet available to define the structural behaviour of thin composite systems In this inueatigatioOt lood.deformation and load-* transmission characteristics of the bituminous concrete overlay over rigid pavements are studied,* For this#, precast cement concrete concteto base slabs of 14 metre square size were used« hose slabs were of two different thicknesses viz 5, and 7.5 an. Bituminous concrete o reriays of three different thicknesses via 2.5, 5 end 7„5 cm were laid separately over each base slab# Thus in all# nine, overlay al abs, each having constant mix gradation have been investigated. A relationship has been established to determine, the stress developed in the base slab of composite section. The equation involves various parameters of subgrade, base slab and overlay slab olongwith plate diameter and applied toad,. The equation has been used to determine the overlay thickness• over an existing rigid pavement, The results show a good agreement with the overlay thickness deigned from Corps of EnO nears method*