ASTM C956-04

Standard Specification for Installation of Cast-In-Place Reinforced Gypsum Concrete

ABSTRACT
This specification covers the minimum requirements for the installation of cast-in-place reinforced gypsum concrete over permanent formboard. Subpurlins shall be designed to support live and dead loads of the roof deck. Got-rolled and cold-rolled steel shapes other than bulb trees or truss tees shall meet the requirements of this specification. Mineral fiber formborad shall be tested in accordance with the transverse loading test. Hexagonal reinforcing mesh, rectangular reinforcing fabric, gypsum concrete, and expansion filler strip shall be fabricated in accordance to the specification. The subpurlins shall be placed transversely to the purlins and primary framing and shall be spaced to suit the size of the formboards. Cross tees shall be provided where formboard ends are supported by purlins or the primary framing. Formboards shall be located face down on the flanges of the supporting members and with the ends on top of the purlins. The mesh of wire fabric shall be located with the main longitudinal wires at right angles to the subpurlins and adjacent to the formboard at midspan between the purlins. Expansion filler strips shall be placed continuously against the walls, curbs, nailers, or other rigid surfaces that gypsum concrete will abut. Gypsum concrete mixing and placement shall be performed. Mixing shall be thorough but not overmixed.
SCOPE
1.1 This specification covers the minimum requirements for the installation of cast-in-place reinforced gypsum concrete over permanent formboard.  
1.2 The values stated in inch-pound units are to be regarded as the standard. The values given in parentheses are for information only.  
1.3 The text of this standard references notes and footnotes which provide explanatory material. These notes shall not be considered requirements of the standard.

General Information

• Status: Historical
• Publication Date: 30-Apr-2004
• ICS: 91.100.10 - Cement. Gypsum. Lime. Mortar
• ICS: 91.100.30 - Concrete and concrete products
• Technical Committee: C11 - Gypsum and Related Building Materials and Systems
• Drafting Committee: C11.03 - Specifications for the Application of Gypsum and Other Products in Assemblies

Relations

• Replaces: ASTM C956-97(2002)e1 - Standard Specification for Installation of Cast-In-Place Reinforced Gypsum Concrete
• Effective Date: 01-May-2004
• Replaced By: ASTM C956-04(2010) - Standard Specification for Installation of Cast-In-Place Reinforced Gypsum Concrete
• Effective Date: 15-May-2010

Standards Content (Sample)

NOTICE: This standard has either been superseded and replaced by a new version or withdrawn.
Contact ASTM International (www.astm.org) for the latest information
Designation: C956 – 04
Standard Specification for
1
Installation of Cast-In-Place Reinforced Gypsum Concrete
This standard is issued under the fixed designation C956; the number immediately following the designation indicates the year of
original adoption or, in the case of revision, the year of last revision.Anumber in parentheses indicates the year of last reapproval.A
superscript epsilon (´) indicates an editorial change since the last revision or reapproval.
1. Scope ACI 318 Building Code Requirements for Reinforced Con-
3
crete
1.1 This specification covers the minimum requirements for
2.3 American Welding Society Standard:
the installation of cast-in-place reinforced gypsum concrete
4
D1.1 Structural Welding Code Steel
over permanent formboard.
1.2 The values stated in inch-pound units are to be regarded
3. Terminology
as the standard. The values given in parentheses are for
3.1 Definitions shall be in accordance with Terminology
information only.
C11.
1.3 The text of this standard references notes and footnotes
3.2 Definitions:
which provide explanatory material.These notes and footnotes
3.2.1 primary framing, n—structural members provided to
(excluding those in tables and figures) shall not be considered
support the reinforced gypsum concrete roof deck assembly.
requirements of the standard.
3.2.1.1 purlin, n—asecondarystructuralmemberthatspans
2. Referenced Documents the primary framing members and provides support for sub-
2
purlins.
2.1 ASTM Standards:
3.2.2 subpurlin, n—a steel member applied transversely to
A82/A82M SpecificationforSteelWire,Plain,forConcrete
the primary framing and purlins to support the formboards and
Reinforcement
to transmit the dead and live loads from the gypsum concrete
A185/A185M Specification for Steel Welded Wire Rein-
slab to the primary framing.
forcement, Plain, for Concrete
3.2.2.1 bulb tee, n—a subpurlin, hot-rolled formed steel,
A568/A568M Specification for Steel, Sheet, Carbon, Struc-
rail-shaped section.
tural, and High-Strength, Low-Alloy, Hot-Rolled and
3.2.2.2 truss tee, n—a subpurlin fabricated from steel wire
Cold-Rolled, General Requirements for
and strip, tee-shaped section.
A653/A653M Specification for Steel Sheet, Zinc-Coated
3.2.3 crosstee,n—asteeltee-shapedsectionusedtosupport
(Galvanized) or Zinc-Iron Alloy-Coated (Galvannealed)
a formboard end at right angles to the subpurlins where a
by the Hot-Dip Process
formboard end does not occur over the purlin or primary
C11 TerminologyRelatingtoGypsumandRelatedBuilding
framing.
Materials and Systems
3.2.4 formboard, n—sheet material used as a permanent
C317/C317M Specification for Gypsum Concrete
form to support the gypsum concrete.
C726 SpecificationforMineralFiberRoofInsulationBoard
3.2.5 reinforcement, n—steel wire mesh or fabric used
E72 Test Methods of Conducting Strength Tests of Panels
within the gypsum concrete slab to provide longitudinal and
for Building Construction
transverse strength.
2.2 American Concrete Institute Standard:
3.2.6 double-pouring, n—the application of gypsum con-
creteinmorethanonelayertocompletethefullslabthickness.
See 8.7.4.3.
3.2.7 ribbon-pouringorstrip-pouring,n—theapplicationof
1
This specification is under the jurisdiction of ASTM Committee C11 on
narrow ribbons of gypsum concrete, about 10 to 12 in. (254 to
GypsumandRelatedBuildingMaterialsandSystemsandisthedirectresponsibility
1
ofSubcommitteeC11.03onSpecificationsfortheApplicationofGypsumandOther
305 mm) wide by 1 to 1 ⁄2 in. (25.4 to 38.1 mm) deep, across
Products in Assemblies.
the width of the formboard at center of span between purlins.
Current edition approved May 1, 2004. Published May 2004. Originally
´1
approved in 1981. Last previous edition C956–97(2002) . DOI: 10.1520/C0956-
04.
2 3
For referenced ASTM standards, visit the ASTM website, www.astm.org, or Available from the American Concrete Institute, P.O. Box 19150, Detroit, MI
contact ASTM Customer Service at [e-mail]. For Annual Book of ASTM 48219.
4
Standards volume information, refer to the standard’s Document Summary page on Available from the American Welding Society, 550 N.W. La Jeune Rd., P.O.
the ASTM website. Box 351040, Miami, FL 33135.
Copyright © ASTM International, 100 Barr Harbor Drive, PO Box C700, West Conshohocken, PA 19428-2959, United States.
1

---------------------- Page: 1 ----------------------
C956 – 04
4. Delivery of Materials Reinforcement shall be free of rust, scale, or other materials
that reduce bond to the gypsum concrete.
4.1 Materials shall be delivered in original packages, con-
7.4.1 Hexagonal Reinforcing Mesh,shallbefabricatedfrom
tainers, or bundles bearing the brand name and name of
2in.(50.8mm)hexagonalmeshformedofnotlessthan0.0410
producer or seller. Bulk materials shall be delivered with the
in. (1.04 mm) diameter wires with longitudinal wires not less
bran
...