Recycled Portland Cement Concrete Pavement Modulus Evaluation Using Surface Waves

Abstract

The rubblization of severely deteriorated Portland cement concrete (PCC) pavements involves breaking the concrete slabs into smaller fragments that are then compacted and overlaid with Hot Mixed Asphalt. The rubblized slabs are left in-place and therefore recycled into the new pavement as a base layer. Rubblization is becoming an attractive alternative to traditional methods of rehabilitation of PCC pavements because of the speed of construction, sustainable practices, and potential cost savings. However, one of the challenges of rubblization is estimating the modulus of the rubblized PCC pavement concrete to ensure adequate structural stability of the rehabilitated pavement. The Spectral Analysis of Surface Wave (SASW) technique was recently used to evaluate the moduli on several PCC pavement rubblization projects in New Jersey and compare them to those of typical dense graded aggregate base material. In general, the results indicate that the modulus of rubblized PCC is higher than the modulus of typical unbound granular base. Although there is a wide spread in the computed moduli, the average values correlate well with moduli backcalculated from Falling Weight Deflectometer testing.