Title: Recommendations for Unified Durability Guidance in ACI Documents

Author(s): Anthony Bentivegna;Thano Drimalas;Kimberley E. Kurtis;Jason H. Ideker;Michael D.A. Thomas;Scott H. Smith;Krishna Siva Teja Chopperla

Publication: CRC

Volume:

Issue:

Appears on pages(s):

Keywords: concrete,design,durability,ACI,documents,corrosion,resistance,freezing-thawing,resistance,sulfate,

DOI:

Date: 7/20/2020

Abstract:
The concrete design and construction industry needs uniform guidance on durability recommendations across ACI documents. As part of the preparation for this proposal, five ACI documents, where discrepancies exist, were examined: ACI 201.2R-16, 222R-19, 301-16, 318- 19, 350.5-12, and 350-06 [1-6]. These five documents contain the main guidance that informs our current concrete design and building practice regarding durability requirements and exposure category descriptions. Unfortunately, there is disagreement between these documents in providing 1) allowable chloride limits in new concrete for corrosion resistance; 2) water to cementitious material ratio (w/cm), strength requirements and air content (volume %) for freezing-thawing resistance; and 3) w/cm and strength requirements for resistance to sulfate attack. Further complicating matters there is no standard language to define the various exposure category descriptions for each deterioration mechanism. A systematic and rigorous statistical analysis of existing data is anticipated to provide an excellent resource to establish unified guidance by the aforementioned ACI Committees. This effort would represent an important clarification to our current code and guidance documents and would be a welcome and needed advancement for the concrete design and construction industry. Existing concrete durability data from field exposure sites, published literature, and Army Corps of Engineers infrastructure evaluations were analyzed to make recommendations on unified durability limits and exposure category descriptions. Project outcomes include: 1) Recommendations to ACI Committees 201, 222, 301, 318, and 350 on unified durability requirements and exposure category descriptions; 2) Identification of knowledge gaps and future studies to address deficiencies in existing data sets; and 3) A detailed research methodology that leverages modern field performance and lab testing to inform the development of performancebased standards. Furthermore, the completed work details the need for improved test methods to further validate the reliability of specified mixture proportions and material parameters for durability.