One of the key goals of a materials Code or specification guide, in addition to representing state-of-the-art knowledge and application, is to foster communication among all of the parties subject to the Code. For structural concrete, these parties include licensed design professionals, engineers and architects, project managers, specifiers and others who prepare contract documents, insurers and building code officials, and the contractor who completes the project. All must be on the same page to create a safe, properly built structure that suits the needs of users, investors, and the community at large.
That objective was front-of-mind for ACI Committee 318 when reorganizing ACI 318, “Building Code Requirements for Structural Concrete and Commentary,” which was published as ACI 318-14 late last year. Special attention was paid to clearly delineating responsibilities and helping all parties bridge between ACI 318, which guides design, and ACI 301, “Specifications for Structural Concrete,” which guides construction. This was accomplished through a new Chapter 26 covering Construction Documents and Inspection.
In this article, we will review the thought processes that went into reorganizing the Code to improve communication between the licensed design professional (LDP) and the contractor community, and the anticipated results of this reorganization.
Implications for the construction industry
The reorganized ACI 318-14 follows the design process wherever possible, with a chapter for each type of concrete structural member. This more intuitive approach provides the designer with confidence that all provisions relevant to a particular design have been addressed. In 318-11, there was no internal road map to assure the user addressed all relevant provisions. That has been changed with the new 318-14.
In the past, the LDP, and to a lesser extent the contractor and supplier, would have to search throughout ACI 318 to find the required information needed to complete the design for each structural member. The absence of specific direction could potentially lead to an incomplete design. In practice, it was often assumed that the contractor would find the necessary information and requirements in the Code without any explicit instructions in the construction documents.
But with construction-related provisions collected into a single chapter, the new Chapter 26, it became clear that an overall organizational structure, unique to the construction chapter, had to be developed. Issues this approach raised and the way in which they were resolved include:
- There was some confusion over who needs to know and follow the guidelines of ACI 318, especially since some construction documents required the contractor and supplier to refer to the Code. Committee 318 decided that only licensed design professionals (including those on the staff of some contractors) are responsible for knowing and interpreting the provisions of the Code. This decision established the foundation for almost every other issue.
- All contractor provisions are now found in the construction chapter, which also includes the concrete proportioning provisions that were previously found elsewhere.
- For consistency and convenience, the 13 subchapters of Chapter 26 are organized along the lines of a typical construction specification. Subchapters of the new Chapter 26 follow an internal logic based on the character and end-user of the provisions. The three “groups of provisions” include:
- Design Information that is project-specific and is developed during the structural design and which must be included in the construction documents.
- Compliance Requirements, which are “general provisions that provide a minimum acceptable level of quality for construction of the Work.”
- Inspection Provisions, subchapter 13, which are directed to the inspector. The Inspection Provisions are formatted in code language that may be transferred directly to the construction documents with little to no change.
- While the inspection section of ACI 318-11 was moved to the construction chapter, it remains substantially as written in previous 318 codes and does not mirror the International Building Code. During the next code cycle, Committee 318 may be able to establish provisions acceptable to the International Code Council so that the IBC can reference ACI 318 directly.
- A large part of the reason for the reorganization of ACI 318 was to clearly assign responsibility among the design-build team and development contract. One new provision requires the LDP to identify work assigned to others and to include all of the information needed for another LDP to design a defined portion of the project.
- The Code now requires the LDP to assign the exposure classes and select the minimum concrete requirements associated with the assigned exposure class for use by the contractor or concrete supplier.