In today’s complex construction environment, as knowledge, experience and uses of structural concrete continues to grow, it is extremely important that all construction disciplines work in synergy with one another.
That is why the reorganized and recently published ACI 318, “Building Code Requirements for Structural Concrete and Commentary,” pays special attention to helping all parties bridge between ACI 318, which guides design, and ACI 301, “Specifications for Structural Concrete,” which guides construction. This was accomplished through an all-new Construction Chapter 26 in ACI 318-14 covering Construction Documents and Inspection. All of this was done with the goal of improving communication between the licensed design professional (LDP) and the contractor community.
Implications of a reorganized Code for the construction industry.
The reorganized ACI 318-14 follows the design process wherever possible, with a chapter for each type of member. This more intuitive approach provides the designer with confidence that all provisions relevant to a particular design have been addressed.
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 possibly lead to an incomplete design. In practice, it was also often assumed the contractor would find the necessary information and requirements in the Code without any explicit instructions in the construction documents.
Importantly, as construction-related provisions were collected into a single chapter, the new Chapter 26, it became clear an overall organizational structure, unique to the construction chapter, had to be developed. Questions this approach raised and the manner they were addressed include:
- ACI determined that only licensed design professionals (including those on staff of some contractors) are responsible for knowing and interpreting the provisions of ACI 318. This decision established the foundation for nearly every other issue.
- For consistency and convenience, the 13 subchapters were organized along the lines of a typical construction specification and all contractor provisions, including concrete proportioning provisions, are now found in the construction chapter.
- Subchapters of the new Chapter 26 follow an internal logic based on the character and end-user of referred to provisions, assigned as Design Information, Compliance Requirements or Inspection Provisions. These latter provisions are formatted in code language that may be transferred directly to the construction documents with minor or no change.
- A large part of the ACI 318 reorganization has the intent of more clearly assigning responsibility among the design-build team and development contract. A new provision requires the LDP to identify work assigned to others and include all necessary information needed for another LDP to design a definable portion of the project.
Impact for the construction industry
The assignment of duties and responsibilities on a complex project and job site can sometimes become problematic. Often, this only becomes germane much later if a lawsuit or inspection issue arises. Therefore, distinguishing between these responsibilities became a priority and directive of the ACI 318 committee.
Chapter 26.1 makes it explicit with respect to Contractor Responsibility that “it is not intended that the Contractor will need to read and interpret the Code,” plus “a general reference in the construction documents requiring compliance with this Code is to be avoided.” Furthermore, Chapter 26.1 specifies: “This chapter is directed to the LDP responsible for incorporating project requirements into the construction documents.”
The most likely way the LDP will satisfy this requirement is to copy the “compliance requirement” provisions directly into the construction documents as applicable, but the LDP is not required to use the wording in the Code verbatim in construction documents.
At the same time, it has been made clear that “Compliance requirement” provisions transferred to the construction documents are the responsibility of the contractor.
The Code will require the LDP to assign the Exposure Classes and select the minimum concrete requirements associated with the assigned exposure class in the construction documents.
The contractor/concrete supplier will use the minimum requirements to proportion the concrete mixtures. The 318 committee members made the decision not to accept a pure performance specification for concrete proportioning. If the LDP wants the concrete supplier to select the minimum concrete requirements, the contractor must be instructed to do so and the exposure classes must be explicitly stated in the construction documents.
It is the belief of ACI Committee 318 the reorganized ACI 318-14 reflects the real world design process as much as possible. It is easier to understand by students and others new to the construction industry, and will be adaptable as advances are made in the use of structural concrete.
Specifically, the new construction chapter of ACI 318-14 provides contractors with the information, direction and clarity needed to fulfill their responsibilities on any project.
Ed. Note: For more information, visit www.concrete.org/ACI318.