USACE / NAVFAC / AFCESA / NASA UFGS-03 52 16 (April 2008) ---------------------------- Preparing Activity: USACE Superseding UFGS-03 51 00 (October 2007) UNIFIED FACILITIES GUIDE SPECIFICATIONS References are in agreement with UMRL dated October 2007 SECTION 03 52 16 LIGHTWEIGHT INSULATING CONCRETE 04/08 NOTE: This guide specification covers the requirements for low density cast-in-place concrete roof decking. Edit this guide specification for project specific requirements by adding, deleting, or revising text. For bracketed items, choose applicable items(s) or insert appropriate information. Remove information and requirements not required in respective project, whether or not brackets are present. Comments and suggestions on this guide specification are welcome and should be directed to the technical proponent of the specification. A listing of technical proponents, including their organization designation and telephone number, is on the Internet. Recommended changes to a UFGS should be submitted as a Criteria Change Request (CCR). PART 1 GENERAL 1.1 REFERENCES NOTE: This paragraph is used to list the publications cited in the text of the guide specification. The publications are referred to in the text by basic designation only and listed in this paragraph by organization, designation, date, and title. Use the Reference Wizard's Check Reference feature when you add a RID outside of the Section's Reference Article to automatically place the reference in the Reference Article. Also use the Reference Wizard's Check Reference feature to update the issue dates. References not used in the text will automatically be deleted from this section of the project specification when you choose to reconcile references in the publish print process. The publications listed below form a part of this specification to the extent referenced. The publications are referred to within the text by the basic designation only. AMERICAN IRON AND STEEL INSTITUTE (AISI)AISI SG03-3(2002) Cold-Formed Steel Design Manual SetAMERICAN SOCIETY OF HEATING, REFRIGERATING AND AIR-CONDITIONING ENGINEERS (ASHRAE)ASHRAE FUN IP(2005) Fundamentals Handbook, I-P EditionASHRAE FUN SI(2005) Fundamentals Handbook, SI EditionAMERICAN WELDING SOCIETY (AWS)AWS A2.4(2007) Standard Symbols for Welding, Brazing and Nondestructive ExaminationASTM INTERNATIONAL (ASTM)ASTM A 185/A 185M(2007) Standard Specification for Steel Welded Wire Reinforcement, Plain, for ConcreteASTM A 653/A 653M(2008) Standard Specification for Steel Sheet, Zinc-Coated (Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed) by the Hot-Dip ProcessASTM A 82/A 82M(2007) Standard Specification for Steel Wire, Plain, for Concrete ReinforcementASTM C 150(2007) Standard Specification for Portland CementASTM C 260(2006) Standard Specification for Air-Entraining Admixtures for ConcreteASTM C 332(2007) Lightweight Aggregates for Insulating ConcreteASTM C 495(2007) Compressive Strength of Lightweight Insulating ConcreteASTM C 578(2008b) Standard Specification for Rigid, Cellular Polystyrene Thermal InsulationASTM C 595(2008) Standard Specification for Blended Hydraulic CementsASTM C 796(2004) Foaming Agents for Use in Producing Cellular Concrete Using Preformed FoamASTM C 869(1991; R 2006) Foaming Agents Used in Making Preformed Foam for Cellular Concrete1.2 DESIGN REQUIREMENTS Provide services of a firm experienced in the installation of cast-in-place _{low density roof systems}. A representative of the firm shall supervise the mixing, transporting, placing, finishing, and testing the low density concrete. 1.2.1 Concrete NOTE: Oven-dry unit weight of low density concrete should not exceed 800 kg/cubic meter (50 pcf); nor should the compressive strength exceed 3100 kPa (450 psi). Insulation value decreases with high unit weights. Unit weight of 400 kg/cubic meter (25 pcf) with a minimum compressive strength of 862 kPa (125 psi) will normally be specified. Manufacture of this type of concrete is specialized and manufacturer's data should be relied on to establish mixture proportions. See ACI 523.1R for additional information. Establish the strength qualities of the low density concrete proposed for use from manufacturer's submitted data prior to the beginning of construction operations. Perform the preparation of the _{design mix} and subsequent testing through an approved testing laboratory capable of performing such services or, if approved, by the manufacturer of the low density concrete. Prepare trial design batches with the same materials proposed for use in the work. Make and test Test Cylinders in accordance with ASTM C 495 for perlite and vermiculite concrete and ASTM C 796 for cellular concrete. Proportion low density concrete for a minimum oven-dry unit weight of [400] [_____] kg/cubic meter [25] [_____] pcf and the minimum average compressive strengths at 28 days of [862] [_____] kPa [125] [_____] psi. 1.2.2 Required U-Value The actual average installed thickness of concrete, forms, and insulation, if used, shall be sufficient to provide a coefficient of heat transmission, or U-value, based on winter conditions, through the affected construction, not in excess of [_____] W per square meter, per degree K Btu per hour, per square foot, per degree F temperature difference, when determined in accordance with recognized methods set forth in the ASHRAE FUN SI ASHRAE FUN IP . Determine the U-value from inside air to outside air. 1.2.3 Steel Forms Design of steel forms shall conform to AISI SG03-3. Design units for attachment to the structural supports by welding or by a special system of clips as recommended by the manufacturer. The deflection of the steel forms under the design live load indicated shall not exceed 1/240 of the clear span. 1.3 SUBMITTALS NOTE: Review submittal description (SD) definitions in Section 01 33 00 SUBMITTAL PROCEDURES and edit the following list to reflect only the submittals required for the project. Submittals should be kept to the minimum required for adequate quality control. A “G” following a submittal item indicates that the submittal requires Government approval. Some submittals are already marked with a “G”. Only delete an existing “G” if the submittal item is not complex and can be reviewed through the Contractor’s Quality Control system. Only add a “G” if the submittal is sufficiently important or complex in context of the project. For submittals requiring Government approval on Army projects, a code of up to three characters within the submittal tags may be used following the "G" designation to indicate the approving authority. Codes for Army projects using the Resident Management System (RMS) are: "AE" for Architect-Engineer; "DO" for District Office (Engineering Division or other organization in the District Office); "AO" for Area Office; "RO" for Resident Office; and "PO" for Project Office. Codes following the "G" typically are not used for Navy, Air Force, and NASA projects. Choose the first bracketed item for Navy, Air Force and NASA projects, or choose the second bracketed item for Army projects. Government approval is required for submittals with a "G" designation; submittals not having a "G" designation are for [Contractor Quality Control approval.][information only. When used, a designation following the "G" designation identifies the office that will review the submittal for the Government.] Submit the following in accordance with Section 01 33 00 SUBMITTAL PROCEDURES: _{SD-02 Shop Drawings Low Density Roof Systems}[; _G][; _{G, [_____]}] Drawings indicating shop and erection details for form systems proposed to be used. Show on the drawings cuts, vent holes, cut-outs for other trades, connections, and welds. Indicate welds in accordance with AWS A2.4. _{SD-06 Test Reports Design Mix} Certified copies of the design mix report for low density concrete indicating mixture proportions, average compressive strength in MPa psi, and wet unit weight at point of placement for the type proposed for the project. Make allowances for any unit weight changes resulting from handling and placing methods. PART 2 PRODUCTS 2.1 MATERIALS 2.1.1 Admixtures Provide air-entraining admixtures conforming to ASTM C 260. Do not use admixtures containing chloride ions. 2.1.2 Aggregate Provide light weight aggregate free of asbestos and conforming to ASTM C 332, Group I. 2.1.3 Foaming Agent Provide foaming agents, for making cellular concrete, conforming to ASTM C 869. 2.1.4 Cementitious Material Provide portland cement conforming to ASTM C 150, Type I, III; or ASTM C 595, Type IS. 2.1.5 Wire Reinforcement Provide reinforcement consisting of either wire mesh or welded wire fabric. Mesh shall be 50 mm 2 inch hexagonal, woven from 19 gauge 19 gauge steel wire and reinforced with 16 gauge 16 gauge longitudinal steel wire spaced on 75 mm 3 inch maximum centers. Wires forming common sides of mesh spaces that are adjacent to longitudinal wires shall be woven around longitudinal wires. Wire shall be galvanized conforming to ASTM A 82/A 82M. Welded wire fabric shall conform to ASTM A 185/A 185M, galvanized, 12 gauge 12 gauge longitudinal wires spaced on 100 mm 4 inchmaximum centers with 14 gauge 14 gauge transverse wires spaced on 200 mm 8 inch maximum centers. 2.1.6 Steel Forms Forms shall be galvanized corrugated steel conforming to ASTM A 653/A 653M, Grade A or E, with coating Class G 90. Provide forms with side lap venting clips, formed in side lap vents, or vent slots in the corrugation. Vent area shall be at least 700 square mm per square m 0.10 square inch per square foot of roof deck area. 2.1.7 Rigid Insulation Provide insulation conforming to ASTM C 578, Type as recommended by the manufacturer. 2.1.8 Expansion Joint Materials Expansion joint material shall be compressible up to at least 50 percent under 172 kPa 25 psi of pressure. Material shall be weather resistant and compatible with the roofing system used. 2.2 MIXING PROCEDURE Mechanically mix concrete ingredients to produce low density concrete of uniform consistency and a wet unit weight at point of placement required to obtain the compressive strength specified. Mixing and transporting operation shall be in accordance with the low density concrete material manufacturer's recommendation. PART 3 EXECUTION 3.1 FORMWORK Attach forms to structural members by plug welding or special clips furnished by the manufacturer. Welding or the use of clips shall be in conformance with recommendations of the manufacturer. Sheets shall be placed with edge-corrugation lips pointing upward and shall be lapped not less than one full corrugation. End laps shall be located over permanent supports and shall be a minimum of 50 mm 2 inches. Venting shall be as recommended by the manufacturer. Prior to placing low density concrete, areas of coating that have been damaged by welding or other operations shall have welding flux, spatter, and slag removed, shall be cleaned of loose rust and other foreign matter by wire brushing, and then coated with zinc-rich paint. 3.2 WIRE REINFORCEMENT Unroll and place wire reinforcement so that the long dimension is perpendicular with the corrugation in the steel forms. Location of reinforcement shall be approximately in the center of the lower one-third of the slab in which it is placed; however, minimum cover for reinforcement shall be 19 mm 3/4 inch. 3.3 LOW DENSITY CONCRETE CONVEYING AND PLACEMENT Conveying of low density concrete from the mixer to place of deposit shall be by methods that will prevent segregation and loss of material. Equipment for conveying concrete shall be of such size and design to ensure uniform, continuous placement of concrete. Deposit and screed low density concrete in a continuous operation until the placing of a panel or section is completed. Do not use rodding, tamping, vibrating, or steel troweling. Use temporary runways during placement. The actual thickness of the roof system shall be that required to obtain the U-value specified; however, the minimum thickness of the top-most layer of low-density concrete shall not be less than 50 mm 2 inches. Rigid insulation, if used to obtain the required U-value, shall be encapsulated in low density concrete as recommended by the manufacturer. 3.4 EXPANSION JOINTS NOTE: Expansion joints will be as required by normal building design and construction. Perlite systems require expansion joints at all intersections with vertical surfaces except where designed as diaphragms in seismic design. Use 40 mm (1-1/2 inch) joints when roof exceeds 30 m (100 feet) in length. Locate expansion joints as indicated. In addition, where perlite aggregate is used [25] [40] mm [1] [1-1/2] inch expansion joints shall be installed at junctions of roof and vertical surfaces. Joints shall extend the full depth of the roof system. 3.5 COLD WEATHER PLACEMENT Reinforcement, forms, fillers, and other materials that will come in contact with the low density mixture shall be free of frost, snow, or ice. Do not place low density concrete at temperatures below 4 degrees C 40 degrees F or when temperatures are predicted to fall below 4 degrees C 40 degrees F during placement, unless precautions recommended by the manufacturer are employed and such placement is approved. 3.6 CURING Cure low density concrete in accordance with the manufacturer's recommendation. Curing operations shall commence at initial set of the concrete. After curing, allow surfaces to dry to permit subsequent application of roofing system, as determined by installation firm. 3.7 FIELD-CONTROL TESTS Field-control tests shall be performed by an approved commercial testing laboratory and consist of wet-density at time of placement and compressive strength tests. If the specimens tested fail to meet the compressive-strength requirements, remove and replace the portion of roof decking represented by the specimens. 3.7.1 Wet-Density Tests Wet-density tests shall be made as required, but shall be not less than twice during each day's pour. Samples for wet-density tests shall be taken at the point of placement. A variation in excess of 5 percent under the laboratory-established design wet density after discharge at point of placement shall require a modification of mix proportions or changes in mixing procedure, or both. 3.7.2 Compressive Strength Tests The preparation of cylinders and testing shall be in accordance with ASTM C 495, or ASTM C 796 as applicable except that samples shall be obtained at the point of placement. Take samples at least once a day and for each 60 cubic meters 75 cubic yards of low density concrete placed. The area of roof decking represented by the sample shall be properly identified. One sample shall be sufficient to make at least four cylinders. 3.8 CLEANING AND PROTECTION Upon completion of the roof deck, sweep the roof surfaces clean of debris and left ready to receive the roofing. Protect the finished deck from damage by weather and construction operations prior to installation of roofing.