Document: NRC Regulatory Guide
Document ID: 3c238fa7-baa2-41c1-ac85-868fcda6b038
Document Type: regulatory_guide
Title: Design Limits, Loading Combinations, Materials, Construction, and Testing of Concrete Containments + HISTORY – HISTORY 07/2020 – DG-1372 , Proposed Revision 4 05/2019 – Periodic Review of Revision 3 – Revise 10/2015 – Periodic Review of Revision 3 – Reviewed with issues identified for future consideration 10/2006 – DG-1159, Proposed Revision 3 Prior to the issuance of DG-1159, RG 1.136 was entitled "Materials, Construction, and Testing of Concrete Containments (Rev. 4)
Source: NRC Regulatory Guide Division 1
Source URL: https://www.nrc.gov/docs/ML2010/ML20105A215.pdf
Revision Date: 2023-06
Chapter: 
Section ID: RG-1.136
CFR Part: 
CFR Title: 

Content:
0M-18 should be met for an obstruction to be considered not to detract from the net bearing area of the head. Accordingly, obstructions should be considered to not detract from the net bearing area of the head if (i) they do not extend from the bearing face of the head more than 0.6 nominal bar diameters (for No. 8 and larger bars), or smaller of 15 millimeters (0.6 inch) and the nominal bar diameter (for bars smaller than No. 8); and (ii) they do not have a diameter greater than 1.5 nominal bar diameters. Otherwise, consistent with Annex A1 to ASTM A970/A970M-18, the net bearing area of a bar with an obstruction meeting the requirements of Figure CC-2310-1 is the gross area of the head minus the maximum area of the obstruction and should not be less than four times the nominal cross-sectional area of the bar. DG-1372, Page 16 4. CC-2436.3 Acceptance Standards [Mechanical Tests] In addition to following CC-2436.3, “Acceptance Standards,” the maximum hardness for material of anchor head assemblies and wedge blocks shall not exceed that of Rockwell C40. To maintain uniformity in hardness, the tolerance on a designated hardness number shall not exceed ±2. 5. CC-2437 Hardness of Wedge Plates, Wedges and Anchor Nuts In addition to CC-2437, “Hardness of Wedge Plates, Wedges and Anchor Nuts,” the staff provides the guidance for protection of prestressing materials from low-temperature effects. Materials for all load-bearing components of prestressing systems should be selected so that they can withstand the anticipated low-temperature effects without loss in their ductility. Methods and procedures used for materials of liners in CC-2520, “Fracture Toughness Requirements for Materials,” are acceptable for qualifying the materials. Additionally, suitable tests should be conducted to demonstrate that with the maximum allowable flaw size (cracked button heads, wedge plates, wedges, and anchor nuts), the specific components will exhibit the required strength and