The conservation of heritage concrete structures requires an approach that embraces the structure’s cultural and technical significance. Repair design is based on assessment of the structure and materials, characteristics of the concrete, and conditions and deterioration mechanisms present. The repair design needs to be technically compatible with the original concrete, match the original concrete in color, texture, and finish, and provide a durable solution that extends the service life of the concrete element or structure. Conservation of architectural or heritage concrete requires similar techniques as repair of conventional concrete, guided by conservation and preservation precepts. For example, work on architectural or heritage concrete includes careful matching of character-defining features and materials. As a result, the repair process can be challenging, especially depending on the conservation approach, existing conditions, and level of craftsmanship available. This paper will discuss factors to be considered in developing a conservation approach; the methods and techniques required to apply and implement repairs, as well as mix design development, trial repairs and mock-ups; technical characteristics of repair materials; and aesthetic matching.
Harrer et al. (2025) studied this question.