Quality and timeliness in highway construction contracts: a new acceptance model based on both mechanical and surface performance of flexible pavements

Timely completion and high performance are becoming key factors in modern road projects, so research is needed to have reliable contracts and acceptance criteria. The goal of this paper is confined to the formalization and validation of a unique model for the determination of pay adjustment on the basis of both quality (mechanical and surface performance of road pavements) and timeliness. Three main topics are addressed. The first is the estimation of pay adjustment (PA, negative or positive) when both structural and non-structural deficiencies/surplus in characteristics are detected (e.g. low drainability in porous asphalt concretes). The second is the estimation of PA based on the quality of all the layers of the pavement. The third is the estimation of PA for early or late completion of the work. The formalized model is applied to an experimental case history. Analyses and validation demonstrate that the proposed model can efficiently solve typical problems in contract administration, in which decisions based upon objective criteria are needed.