Functional characterization of a Cold-In place-Recycled pavement at different stages of the curing process

Abstract

Cold-In place-Recycled (CIR) pavements are an environmentally friendly option for road rehabilitation operations on aged pavements. These pavements are generally employed as base layers, and a surface treatment is performed on them. However, the design of new additives and enhancements in the technique for constructing CIR pavements have enabled such pavements to be used as wearing courses in some cases. In this context, research on the functional characteristics of CIR pavements is required for characterizing their performance and, therefore, broaden their knowledge and use as a noise mitigation measure. The aim of this study is to analyze some of these functional characteristics: tire/pavement sound levels, texture, and dynamic stiffness. An experimental test track section was evaluated during the pavement curing process (very short term) by means of laboratory and field auscultation. Different measurement campaigns were conducted at different stages of the pavement curing process. According to our results, the changes in the pavement during curing lead to higher tire/pavement sound levels due to the evolution of the dynamic stiffness of the pavement. The increase in tire/pavement noise levels is mainly located at the peak frequencies (800–1250 Hz) of the sound spectra, with values from 76.2 dB(A) to 81.5 dB(A) at 800 Hz. The differences among the mean values of the macrotexture (Mean Profile Depth — MPD) do not explain the different overall tire/pavement noise levels measured at the different stages of curing. However, the texture spectrum undergoes an evolution. The initial texture levels, with wavelengths between 100 mm and 500 mm decrease during the curing process.