Contrôle de la qualité en chantier des matériaux de fondation pulvérisés et stabilisés

Abstract

Full-depth reclamation (FDR) is a cold in-place rehabilitation method that has economic, environmental, and technical advantages as it allows to recycle 100% of the existing materials. The particularity of stabilisation with hydraulic and/or bituminous binders is that the physical structure and mechanical behaviour of the stabilised materials evolve over time. This phenomenon, known as curing, is of significant importance to the long-term performance of the stabilised materials, the reopening to traffic and the timing of the asphalt course placement over the stabilised base. However, in Quebec, road agencies do not have technical guidelines/requirements for quality control (QC) and monitoring of curing progress, which limits the use of this technique. In order to obtain quality works, a method for controlling the quality of pulverised and stabilised materials should be developed. For this purpose, it is essential to monitor and analyse the properties of the stabilised materials in situ in order to represent the real state of the materials and to avoid off-site testing due to curing. To this end, it was proposed to evaluate the applicability of the light-weight deflectometer (LWD) and the dynamic cone penetrometer (DCP) to measure certain properties of pulverised and stabilised materials in situ. Laboratory and in situ tests were carried out at different stages of a cement-foamed-bitumen recycling construction project. The study confirms the potential of using DCP at the reclamation stage as the dynamic resistance as a function of the penetration depth could help determine the quality and depth of the recycling zone. The results also highlight the significant decrease in dynamic resistance within the reclaimed layer compared to the DCP results in the initial pavement structure. The study also showed that LWD is a suitable and reliable tool after stabilisation to assess the in situ stiffness evolution of stabilised materials during curing between 24 and 48 h after placement. The use of in-situ and nondestructive tests, such as LWD and DCP, could therefore address the need for performancebased testing and ensure that reclaimed and stabilised materials meet the project specifications and pavement design criteria.

Date	19 May 2023
Original language	French
Awarding Institution	École de technologie supérieure
Supervisor	Éric Lachance-Tremblay (Supervisor) & Michel Vaillancourt (Co-supervisor)