Title:
Literature Review of Concrete Durability & Service Life Requirements in Global Codes and Standards
Author(s):
Tracy Marcotte - CVM Engineers, Inc.
Publication:
CRC
Volume:
Issue:
Appears on pages(s):
117
Keywords:
DOI:
Date:
1/1/2020
Abstract:
Durability design, as a framework for the construction of building structures to achieve an intentionally specified service life, is not well understood or comprehensively documented within the guides, standards and Codes developed by ACI. Globally, ACI 318 is the most commonly used code for design of new concrete structures. Use of ACI 318 for design of new concrete structures will result in concrete structural designs that can be economically constructed and have adequate strength to resist design loads. However, concerns exist about the effectiveness of the durability provisions in ACI 318 to produce structures that will perform successfully in aggressive environments and achieve longer term design service lives (i.e., the period of time before major repair or rehabilitation is necessary). These concerns were voiced by US practitioners that regularly use ACI 318, and people familiar with both ACI 318 and global design codes. To examine how ACI documents compare to globally developed codes, standards and guides, a literature review was completed that examined the durability provisions contained in over 50 documents. The overall impression from this literature review was, compared to global codes and standards, the durability provisions in ACI 318 do not approach durability in an integrated or systematic manner. Further, ACI 318 does not address concepts of design service life, future repairs, and maintenance of concrete structures. The ACI 318 approach to durability is limited to prescriptive requirements for concrete materials based upon exposure and cover requirements to provide for durability. Other ACI documents, and ACI documents the authors understand to be in development, address durability and design service life in a more integrated and comprehensive manner. These documents are not integrated with ACI 318, and therefore the information contained in the documents is unlikely to reach most US design professionals. Globally, other nations, regions and institutions have produced both consensus standards and best practice guides for both new and existing structures with both performance and prescriptive-based durability and service life requirements. Common features contained in the global codes, standards and guidelines include consideration of the design service life as a part of the design process, service life modeling, consideration of concrete cracking (spacing and width) in design, and more comprehensive concrete material performance requirements for concrete exposed to aggressive environments or structures with an extended design service life. Many of the global documents also integrated future repair and maintenance requirements into structural design codes. ACI 562 can be considered ACI 318’s counterpart in this respect, however, harmonization of the two Codes is limited. To maintain the long-standing prominence of ACI as the global leader in the development of concretebased knowledge, development of consensus guides and standards for durability design is essential. These documents can be developed within the framework of current ACI committees or by dedicated task groups. Critical documents include development of a planning guide for durability design and standards for durability design and service life modeling. The investigators acknowledge the generous financial support of the American Concrete Institute Foundation (ACIF) and technical guidance received via the Advisory Panel.