DURABILITY AND CONSERVATION OF TWENTIETH-CENTURY CONCRETE

In many countries, structures in reinforced concrete “of historical interest” are covered by preservation legislation. In striving to restore them, scholars make use of knowledge accumulated over time. Less well known is the technological research that was part of the production and use of cements and concrete mixtures for reinforced concretes, whose durability has always been a prime concern. Historic works bear witness to their ability to last over time and to the ways in which structures and materials age and deteriorate, thus providing evidence as to the validity of the expectations of durability which existed when the work was designed. The systematic collation of data relating to such artefacts and the repairs they have undergone would be of great use (e.g. with regard to the components used in the original work and in the repairs). Furthermore, collaboration with manufacturing companies and research laboratories should allow us to make use of recently developed prepacked mortars and concrete in new repair work, assessing their compatibility with old materials and monitoring their performance over time. The resultant database and experimental results would provide clues useful in moving beyond current rudimentary practices, laying the basis for a shift from “concrete repair to concrete conservation”