Concevoir d'un polymère pour la cicatrisation et le scellement des fissures dans des dalles en béton.

Abstract

This thesis addresses the critical issue of concrete cracking, a fundamental material in civil engineering, whose low tensile strength compromises structural durability and promotes rebar corrosion. The study proposes an innovative repair approach using in- situ radical polymerization, aiming to restore the integrity and watertightness of cracked concrete.The first part of the work details cracking mechanisms and detection methods, including advanced techniques like ultrasound and the Water Permeability Test (WPT) based on Darcy's Law. The experimental methodology involved preparing Ordinary Concrete (BO) and Self-Compacting Concrete (BAP) samples of different ages, inducing controlled micro-cracks using the Brazilian test, and characterizing their opening. Permeability results quantitatively demonstrated the significant impact of cracks: they considerably increase water passage compared to sound matrices. Crack size is a dominant factor, with wider cracks leading to higher water flow. Interestingly, cracked BAP showed higher permeability than cracked BO for a finer crack, suggesting different crack morphologies. Concrete age also influences matrix permeability. This work highlights the urgency of controlling and repairing cracking, and the obtained data will serve as a reference for evaluating the future effectiveness of polymeric self- healing techniques. The goal is to validate the treatment's ability to significantly reduce water passage and restore an acceptable level of watertightness, opening new perspectives for the preventive maintenance of infrastructures.