Another significant section deals with reinforcement and reinforcement supports, with a focus on cutting and/or bending existing reinforcing materials and connecting them with new ones, covering splices, length of splice laps, and details of any mechanical and welded splices. As with mating new concrete surfaces to existing ones, mating new concrete to existing steel reinforcement requires the metal to be free of contaminants deleterious to the bond. When it is necessary to move the reinforcement beyond specified placing tolerances to avoid interference with other reinforcements, conduits, or embedded items, a proposed plan must be submitted to and then approved by the architect/engineer. In general, if concrete cover over reinforcing materials (or other existing conditions) is inadequate when compared to new-build codes, engineers should make owners aware of these pre-existing conditions.
Another important portion of ACI 563-18 is “Proprietary Cementitious and Polymer Repair Materials.” This section addresses properties, proportioning, mixing, and use of proprietary cementitious and polymer repair materials. In addition to requiring architects/engineers work with manufacturers’ representatives in the field, it states submittals must include:
- repair material manufacturer (RMM) product data sheets and certifications with performance data (collected in accordance with nationally standardized test methods whenever possible);
- material safety data sheets (MSDS) or safety data sheets (SDS);
- product samples; and
Supplemental testing data and mockups are also required. RMM sheets and other supplied data must be followed throughout the application process and through inspection of post-repair material installation. Manufacturer-supplied data includes information on equilibrating the repair materials and substrate to the proper temperature, controlling moisture conditions, preparing surfaces, and adhering to batching, mixing, placing, and curing requirements.
ACI 563-18 is also one of the few specifications to address workflows including the use of proprietary materials, which are common during any repair project. For example, it requires a manufacturer’s field representative be onsite before proprietary materials or components are mixed or installed. The representative is responsible for training site personnel on product use and is generally required to remain at the jobsite to observe work being performed until such time as the contractor and/or owner is satisfied the crew has mastered the technique of preparing and installing the products acceptably. After that time, the field representative is expected to make periodic visits to review completed work and distribute reports describing workmanship and conformance with the manufacturer’s requirements.
Addressing two other situations unique to concrete repair, ACI 563-18 refers to ACI 503.7, Specification for Crack Repair by Epoxy Injection, and ACI 506.2, Specification for Shotcrete. Remaining sections and paragraphs of the new standard discuss:
- materials and proportioning of concrete;
- formwork performance criteria and construction;
- treatment of joints;
- repair of surface defects;
- mockups; and
- finishing of formed and unformed surfaces.
Checklists on mandatory as well as any optional requirements are provided to assist the architect/engineer in supplementing the provisions of this specification, as required or needed, by designating or specifying individual project requirements.
ACI 563-18 leaves room for adaptation to individual project circumstances while providing a much-needed framework for design teams faced with concrete repair. As SDC committees and others continue to make progress on Vision 2020’s list of stated goals, codes and specifications will continue to develop, addressing repair materials, performance prediction, education, and more.
Tracy D. Marcotte, FACI, PE, is an expert in the metallurgical and materials engineering field with CVM, based in King of Prussia, Pennsylvania. With more than 25 years of laboratory as well as professional practice, she is past chair of American Concrete Institute (ACI) Committee 563, Specifications for Repair of Structural Concrete in Buildings, and an active member of multiple ACI committees related to corrosion, durability, sustainability, service life, and repair. Marcotte also serves on ACI’s Technical Activities Committee as well as its Board of Directors. She holds degrees in materials and metallurgical engineering from Queen’s University and the University of Waterloo in Canada, with graduate research focused on steel corrosion in concrete. Marcotte can be reached at firstname.lastname@example.org.