DYNAMIC TESTING OF RIGID PAVEMENTS

Abstract

The dynamic behaviour, of pavement, layers can be completely. defined by three constants, namely density, Young's modulus of elasticity and Poisson's ratio. the measurements of the above parameters give complete descrip- tion of pavements. The value of Poisson's ratio for standard material is available in standardised form. The density can be easily found out. Even it has been shown (4) that the effect of Poisson's ratio and unit weight of material is 'not much significant in computing the Young's modulus of elasticity (E). No attempts, so far, have been made in India to find out the modulus of elasticity of cement concrete or rigid pavements except 'the work ,reported at CRRI (11). Work which has been reported, in India, is limited to flexible pavements (3,5,7). For the insitu evaluation of flexible pavements, the wave propagation technique, which is non-destructive in nature has been successfully developed and used. It has been tried to extend the technique for cement concrete pavements. An attempt has been made 'to evaluate cement concrete pavements and to determine the dynamic Young's modulus of elasticity by the equipment acquired by Transportation Engineering Division, Department of Civil Engineering, University of Roorkee, Roorkee. The above - indigenous equipment is easily 'transportable. Even in the absence or power 'supply, the equipment can be operated with generator. In the present study, four sections of rigid pave-ments were selected in the University of Roorkee, Roorkee. Dynamic modulus of elasticity was determined by dispersion curve technique. The elastic modulus was also compared for cement concrete pavement having a composition of 1:1.5:3. For this purpose a slab was carted. Keeping in the view the requirement of test the slab size was decided as 90 cm x 90 cm. Vibration test, using wave propogation technique, and plate load test were conducted on it.