Document: NUREG-0800
Document ID: 072325a8-02ea-4d59-bb3f-06592c340804
Document Type: srp
Title: The Aluminum Association, Specification for Aluminum Structures
Source: NUREG-0800
Source URL: https://www.nrc.gov/docs/ML0520/ML052070327.pdf
Revision Date: 2023-06
Chapter: 3
Section ID: 3.4
CFR Part: 
CFR Title: 

Content:
tion The American Concrete Institute (ACI) 349 Code has been developed by the professional community for the design of seismic Category I structures. The staff reviewed Appendix B to ACI 349-85, "Code Requirements for Nuclear Safety Related Concrete Structures," and foreign and domestic test data for anchor bolts. On the basis of that review, the staff has taken exceptions to Appendix B to the ACI 349 Code as detailed below. This position has been developed as an aid for the review of applications. The staff's primary concerns regarding Appendix B to the ACI 349 Code are discussed below and exceptions to the use of Appendix B are noted. The staff's primary concern with Appendix B to the ACI 349 Code is the use of a basic assumption of the 45-degree concrete-failure cone. This assumption may have been chosen for convenience. However, tests have not confirmed this assumption even for single anchors. The assumption becomes even less conservative when an anchor is located near the free edge of the concrete or when anchors are closely spaced. Appendix B to the ACI 349 Code is deficient because it has no provisions for reduced anchor strength when the anchor is located in cracked concrete, such as in the tension zone of a concrete slab. DRAFT Rev. 2 - April 1996 3.8.4-44 STAFF'S EXCEPTIONS TO APPENDIX B TO THE ACI 349 CODE Section B.4.2 - Tension and Figures B.4.1 and B.4.2 In this section and the figures, ACI specifies that the tensile strength of concrete for any anchorage can be calculated by a 45-degree failure-cone theory. The staff disseminated the German test data questioning the validity of the 45-degree failure-cone theory to licensees, architect-engineers, bolt manufacturers, and the code committee members when it met with them. The data showed that the actual failure cone was about 35 degrees and the use of the 45-degree cone theory could be unconservative for anchorages of deep embedment, and for the anchorage of groups of bolts. The code committee, having