Performance evaluation of patch repairs on historic concrete structures (PEPS): Preliminary results from a selection of French case studies

Abstract

Within the frame of the international research project PEPS, ‘Performance Evaluation of Patch Repairs on Historic Concrete Structures (PEPS)’, dedicated to the durability of patch repairs in the context of culturally significant structure, a series of repaired monuments was examined in detail. Thus, the operational phases of the project are composed of in situ tests and laboratory analysis on samples performed on a selection of representative historic concrete structures in the three countries who are partners in the project: United States of America, United Kingdom and France. In this paper, cases studies and some results obtained on three of the five French sites will be presented: Le Raincy church built by Auguste Perret between 1920 and 1924, and Rezé housing unit and Jaoul houses built by Le Corbusier respectively in 1955 and in 1953. The assessment methodology followed is the one developed between the three institutions partners on the PEPS project: the Getty Conservation Institute (GCI), Historic England (HE) and Laboratory of Research in Historical Monuments (LRMH). All the selected French sites were repaired several decades ago. For Le Raincy church and the Jaoul houses, the conservation campaign of 1991 was considered, while for Rezé housing unit it was the 1995-1997 campaign. All the case study structures have different construction dates and concrete compositions. Various repair materials and application techniques were used. The conditions of exposure differ from one site to another. All these variations make the evaluation highly complex but also fully instructive, and able to meet the objectives of the project: producing practical guidance helpful for companies and conservators repairing historic concrete.