June 22, 2009 TO: SUBJECT: PARTIES INTERESTED IN EVALUATION REPORTS ON COMPOSITE COLD-FORMED LIGHT GAGE STEEL AND CONCRETE MASONRY LINTELS Acceptance Criteria for Composite Cold-formed Light Gage Steel and Concrete Masonry Lintels, Subject AC409-0609-R1 (ME/BG) Dear Madam or Sir: Enclosed is a copy of the subject new acceptance criteria approved by the ICC-ES Evaluation Committee on June 4, 2009, effective July 1, 2009. This acceptance criteria applies to cold-formed light gage steel shapes installed over openings of masonry wall construction to reinforce the masonry lintel, with the masonry and steel shapes compositely resisting gravity loads. Such installation would be an alternative to the requirements for reinforced masonry lintels in the 2009 International Building Code (IBC) and the 2009 International Residential Code (IRC). During the hearing, the Evaluation Committee approved all the revisions proposed in the staff memo dated May 29, 2009. Based on the discussions during the hearing, a revision was also approved by the committee to the statement in Section 6.4 as set forth in item no. 7 of the staff memo dated May 29, 2009:...and/or out-of-plane loads, depending on the qualification data submitted. ICC-ES evaluation reports issued on or after the effective date noted above, both new reports and conversions of legacy reports, must comply with this criteria if they fall within its scope. If you have any questions, please contact Mahmut Ekenel, Ph.D., P.E., Staff Engineer, at (800) 423-6587, extension 3260. You may also reach us by e-mail at es@icces.org. Yours very truly, KS/gh:raf Enclosure Kurt Stochlia, P.E. Vice President cc: Evaluation Committee
www.icc-es.org (800) 423-6587 (562) 699-0543 A Subsidiary of the International Code Council ACCEPTANCE CRITERIA FOR COMPOSITE COLD-FORMED LIGHT GAGE STEEL AND CONCRETE MASONRY LINTELS AC409 Approved June 2009 Effective July 1, 2009 PREFACE Evaluation reports issued by ICC Evaluation Service, Inc. (ICC-ES), are based upon performance features of the International family of codes and other widely adopted code families, including the Uniform Codes, the BOCA National Codes, and the SBCCI Standard Codes. Section 104.11 of the International Building Code reads as follows: The provisions of this code are not intended to prevent the installation of any materials or to prohibit any design or method of construction not specifically prescribed by this code, provided that any such alternative has been approved. An alternative material, design or method of construction shall be approved where the building official finds that the proposed design is satisfactory and complies with the intent of the provisions of this code, and that the material, method or work offered is, for the purpose intended, at least the equivalent of that prescribed in this code in quality, strength, effectiveness, fire resistance, durability and safety. Similar provisions are contained in the Uniform Codes, the National Codes, and the Standard Codes. This acceptance criteria has been issued to provide all interested parties with guidelines for demonstrating compliance with performance features of the applicable code(s) referenced in the acceptance criteria. The criteria was developed and adopted following public hearings conducted by the ICC-ES Evaluation Committee, and is effective on the date shown above. All reports issued or reissued on or after the effective date must comply with this criteria, while reports issued prior to this date may be in compliance with this criteria or with the previous edition. If the criteria is an updated version from the previous edition, a solid vertical line ( ) in the margin within the criteria indicates a technical change, addition, or deletion from the previous edition. A deletion indicator ( ) is provided in the margin where a paragraph has been deleted if the deletion involved a technical change. This criteria may be further revised as the need dictates. ICC-ES may consider alternate criteria, provided the report applicant submits valid data demonstrating that the alternate criteria are at least equivalent to the criteria set forth in this document, and otherwise demonstrate compliance with the performance features of the codes. Notwithstanding that a product, material, or type or method of construction meets the requirements of the criteria set forth in this document, or that it can be demonstrated that valid alternate criteria are equivalent to the criteria in this document and otherwise demonstrate compliance with the performance features of the codes, ICC-ES retains the right to refuse to issue or renew an evaluation report, if the product, material, or type or method of construction is such that either unusual care with its installation or use must be exercised for satisfactory performance, or if malfunctioning is apt to cause unreasonable property damage or personal injury or sickness relative to the benefits to be achieved by the use of the product, material, or type or method of construction. Acceptance criteria are developed for use solely by ICC-ES for purposes of issuing ICC-ES evaluation reports. Copyright 2009
ACCEPTANCE CRITERIA FOR COMPOSITE COLD-FORMED LIGHT GAGE STEEL AND CONCRETE MASONRY LINTELS (AC409) 1.0 INTRODUCTION 1.1 Purpose: The purpose of this acceptance criteria is to establish requirements for composite cold-formed light gage steel and concrete masonry lintels to be recognized in an ICC Evaluation Service, Inc. (ICC-ES), evaluation report under the 2009 International Building Code (IBC) and the 2009 International Residential Code (IRC). Bases of recognition are IBC Section 104.11 and IRC Section R104.11. The reason for the development of this criteria is to provide a guideline for the evaluation of composite coldformed light gage steel and concrete masonry lintel systems, since these systems are alternatives to the reinforced masonry lintels defined in the IBC and IRC. 1.2 Scope: This acceptance criteria applies to composite lintels over masonry wall openings supporting gravity loads. The lintels are composed of solid grouted concrete masonry units, a cold-formed light gage steel shape and, if used, steel reinforcing bars. This acceptance criteria emphasizes the structural design characteristics and requires verification of design equations and assumptions used in the structural analysis of the coldformed light gage steel/masonry composite lintel. The concrete masonry shall have a specified compressive strength (fn m ) as determined in accordance with the IBC. This criteria is applicable to load-bearing and nonloadbearing walls of residential and nonresidential buildings. Composite cold-formed light gage steel/masonry lintels used with the masonry walls shall be designed and constructed in accordance with the applicable sections of the IBC and IRC. Use of the composite cold-formed light gage steel/masonry lintel system is applicable under the IRC, when an engineered design is submitted to the code official in accordance with Section R301.1.3 of the IRC for each project. 1.3 Codes and Referenced Standards: 1.3.1 2009 International Building Code (IBC), International Code Council. 1.3.2 2009 International Residential Code (IRC). International Code Council. 1.3.3 ASTM A 1003/1003M-08, Standard Specification for Steel Sheet, Carbon, Metallic- and Nonmetallic-Coated for Cold-Formed Framing Members, ASTM International. 1.3.4 ASTM C 90-06b, Specification for Loadbearing Concrete Masonry Units, ASTM International. 1.3.5 ASTM C 1314-07, Test Method for Compressive Strength of Masonry Prisms, ASTM International. 1.3.6 AISI-NAS, North American Specification for Design of Cold-formed Steel Structural Members, 2007. 1.3.7 ANSI/ASCE 3-91, Standard for the Structural Design of Composite Slabs, American Society of Civil Engineers. 1.4 Definitions: 1.4.1 Composite Lintel: A lintel formed from the following parts: solid grouted concrete masonry units, a 2 cold-formed light gage steel shape, and, if used, steel reinforcing bars. The parts act compositely to resist gravity loads as a unit. 1.4.2 Grout: Grout is defined in, and shall comply with, IBC Section 2103.12. 1.4.3 Mortar: Mortar is defined in Section 2102 of the IBC, and shall comply as Type M, N or S in accordance with IBC Section 2103.8. 1.4.4 Concrete Masonry Unit: A concrete masonry unit (CMU) is defined in Section 2102 of the IBC, and shall comply with ASTM C 90. 1.4.5 Cold-formed Light Gage Steel Shape Basemetal Thickness: Thickness of the steel of cold-formed light gage steel shapes, exclusive of all coating and galvanization thicknesses in accordance with AISI-NAS. 1.4.6 Five Percent Fractile: A statistical term meaning 90 percent confidence that there is 95 percent probability of the actual strength exceeding the nominal strength. 2.0 BASIC INFORMATION 2.1 General: The following information shall be submitted: 2.1.1 Product Description: Complete information concerning the composite masonry lintel system, including lintel configurations, material specifications for all components, manufacturing process for the cold-formed light gage steel shapes, fully dimensioned drawings of steel shapes with tolerances, and cold-formed light gage steel shape base-metal thickness. 2.1.2 Installation Instructions: Installation instructions and engineered drawings shall accompany the cold-formed light gage steel shape to the jobsite. The instructions shall include any special instructions required for the cold-formed light gage steel/masonry composite lintel, as well as handling requirements. 2.1.3 Identification: Cold-formed light gage steel shapes shall be identified by visible labels bearing the ICC-ES evaluation report number, manufacturer s name and address, product designation, and notice of any product installation limitations. Labels shall be placed on each cold-formed light gage steel shape. 2.1.4 Field Preparation: A description of the methods of field-cutting components and masonry, and placing cold-formed light gage steel shape. 2.2 Testing Laboratories: Testing laboratories shall comply with Section 2.0 of the ICC-ES Acceptance Criteria for Test Reports (AC85) and Section 4.2 of the ICC-ES Rules of Procedure for Evaluation Reports. 2.3 Test Reports: Test reports shall comply with AC85. The test reports shall be in sufficient detail to identify specimen properties that might affect system performance. 2.4 Product Sampling: Sampling of the cold-formed light gage steel shapes, masonry units, mortar and grout used in the qualification tests shall comply with Section 3.1 of AC85. Cold-formed light gage steel shapes shall be sampled from each manufacturing facility for which
ACCEPTANCE CRITERIA FOR COMPOSITE COLD-FORMED LIGHT GAGE STEEL AND CONCRETE MASONRY LINTELS (AC409) recognition is sought. Assembly of the composite lintel test assemblies shall be witnessed in accordance with Section 3.3 of AC85. 3.0 TEST AND PERFORMANCE REQUIREMENTS 3.1 Initial Submittal: The initial submittal shall include the following: 3.1.1 Composite Lintel Load Resistance Capacities: Details and examples of the design of the composite lintel to resist gravity loads, including equations with procedures (engineering analysis), and properties needed for design and analysis, shall be submitted. The engineering analysis shall consider failure modes or limit states, deflections and creep. The engineering analysis shall comply with the applicable sections of the IBC. 3.1.2 Qualification Test Plan: The qualification test plan shall specify the qualification tests described in Section 4.0. Qualification tests shall provide data on material properties, including stresses, deformations and/or ductility, creep, and limit states or failure modes to support the rational analysis procedure. The test plan and preliminary analysis shall be submitted to ICC-ES for review prior to the commencement of any testing. Tests shall simulate the anticipated loading conditions and load levels. The testing details noted in Section 4.0 are intended for verification of the structural analysis procedures, not for establishment of design stresses. 3.2 Final Submittal: The final submittal shall include the following: 3.2.1 Steel: The steel used in the production of the steel shapes shall comply with AISI-NAS. The steel shall have a minimum galvanization coating weight complying with ASTM A 1003. 3.2.2 Test Report: The testing laboratory shall report on the qualification testing performed in accordance with the approved test plan. Any deviations from the test plan shall be noted and explained. In addition to the information required by Section 2.0 of this criteria, the test report shall include the following: 1. Description of test specimens. 2. Description of test setup. 3. Rate and method of loading. 4. Deformation measurements. 5. Modes of failure. 6. Failure loads. 7. Properties of test specimen components (steel, masonry, etc.). 8. In addition to the standard reporting and certification of test results, observations shall be reported, and photographs shall be taken and submitted, of specimen response at significant stages of the loading process. 3.2.3 Design Criteria Report: A design criteria report shall be submitted and shall include a complete analysis and interpretation of the qualification test results presented in the independent laboratory test report. The actual material strengths for the cold-formed light gage 3 steel, masonry, masonry units, mortar and grout used in the test specimens shall be used in the design equations in the analysis, to verify that the design stresses or characteristic strengths used in the analysis and design are qualified by the test data. Provisions are outlined in the IBC concerning strength reduction factors to be used in the design. A minimum safety factor of 2.5 shall be applied to the test results as determined in accordance with Section 4.2.2 of this criteria. An appropriate design analysis shall be used to assign design stresses that provide the degree of safety required by the IBC. 3.2.4 Design Value: The predicted design capacity for the composite lintel system, based on working stress or strength methods, shall be derived using the appropriate provisions cited in the IBC. 4.0 QUALIFICATION TESTS AND ENGINEERING ANALYSIS 4.1 Lintel Load Tests: 4.1.1 General: Tests shall demonstrate the applicability of the design provisions to representative configurations consisting of various lintel widths, depths and masonry units, and for anticipated uses with design procedures as noted in the IBC. Extrapolation of the tested representative configurations is prohibited. 4.1.2 Test Methods: 1. A minimum of three lintel load test specimens shall be tested for each selected lintel configuration, with minimum and maximum span to be recognized in the ICC- ES ESR report and for each wall thickness. The test program shall be submitted to the ICC-ES staff for review and acceptace prior to any testing being performed. 2. Coupon tests or mill certificates shall be provided to establish the base-metal thickness and actual physical properties of the steel of the steel shapes used in the lintel tests. 3. The mortar and grout mix design(s) shall be documented in the test report. A minimum of three mortar tests in accordance with ASTM C 270, and a minimum of three grout tests in accordance with ASTM C 1019, shall be done for each selected wall configuration tested, to be used in the design and analysis. 4. Concrete masonry units used in the lintel tests shall be verified as complying with ASTM C 90. 5. Compressive strength of masonry prism specimens shall be tested in accordance with IBC Section 2105.2.2.2 and ASTM C 1314. Masonry prism compressive strength tests shall be conducted within 24 hours of the lintel load tests. 6. Masonry shall be constructed over the coldformed light gage steel shape in accordance with the manufacturer s published installation instructions and the IBC. Lintels shall be constructed so that the minimum bearing length provided at each end of the cold-formed light gage steel shape is as specified in the published installation instructions. The solid grouted composite section shall be provided with a minimum bearing length at each end of the lintel span as specified in the published installation instructions and the IBC. 7. The lintel load tests shall be conducted as fourpoint bending (third-point loading). A pinned end condition
ACCEPTANCE CRITERIA FOR COMPOSITE COLD-FORMED LIGHT GAGE STEEL AND CONCRETE MASONRY LINTELS (AC409) (i.e., no restraint to rotation at the end bearings) shall be used. 8. Loading shall start with P 1 equal to 500 pounds (2225 N). The load shall be held for one full minute. Load, P 1, shall be increased by 200 pounds (890 N) and the new load held for another full minute. This loading regime shall be continued until failure. Failure is defined as the inability to support additional load. 9. Tests shall be done in a manner that will provide a load-deflection curve. Tests shall be closely observed, for crack formation and failure mode recorded. Mid-span deflections and end-slip between steel shape and masonry shall be recorded and documented for each increment of load. 4.2 Engineering Analysis: 4.2.1 An engineering analysis, prepared and signed by a registered design professional, shall be submitted and shall include a complete analysis and interpretation of the qualification test results presented in the independent laboratory test report. The analysis shall consider the recommendations cited in Section 3.2.4 of ASCE 3. Design stresses (shear and moment capacities) or characteristic strengths used in the analysis and design shall be qualified by the test data. Procedures or provisions cited in the IBC, and an appropriate design analysis, shall be used to assign design capacities that provide the degree of safety required by the IBC. A minimum safety factor of 2.5 shall be applied to the test results as deteremined in accordance with Section 4.2.2 of this criteria. 4.2.2 Where three specimens are tested the lowest peak test value shall be used in the data analysis. As an alternative, the five percent fractile value may be used in the data analysis where the number of tested specimens is four or more. 5.0 QUALITY CONTROL 5.1 Quality documentation complying with the ICC-ES Acceptance Criteria for Quality Documentation (AC10) shall be submitted for the manufacturer of the cold-formed steel shapes. 5.2 Third-party follow-up inspections are not required for the manufacturing of the cold-formed light gage steel shapes under this acceptance criteria. 5.3 Installation of elements requiring special inspection under the IBC shall comply with the IBC Section 1704 and other applicable sections of that code. 6.0 EVALUATION REPORT RECOGNITION The evaluation report shall include the following: 6.1 Basic information required by Section 2.0, including a description of the cold-formed steel shapes, installation procedures, and packaging and identification information. 6.2 Design loads and deflections for each assembly, based on analysis of data as provided in Section 4.2. 6.3 A statement that the use of composite lintels where coupling beams are used is outside the scope of the evaluation report. 6.4 A statement that this evaluation report is for composite cold-formed light gage steel and concrete masonry lintels supporting gravity loads and/or out-ofplace loads, depending on the qualification data submitted. 6.5 Statements regarding any limitations on design based on the submitted qualifications. 4