ASTM C1381/C1381M-23 PDF

Full title and description

ASTM C1381/C1381M-23 — Standard Specification for Molded Glass Fiber Reinforced Gypsum Parts. This specification defines requirements for nonload-bearing, thin-shell, molded glass fiber reinforced gypsum (GRG) parts used as ornamental architectural interior components.

Abstract

This standard covers the materials, manufacture, dimensions, tolerances, and required mechanical properties for molded GRG parts. It requires manufacture from an alpha gypsum cement slurry (with potable water and permitted additives) containing glass fiber reinforcement (minimum specified content), produced by hand lay-up or spray-up in molds, and fabricated to approved shop drawings that specify dimensions, attachment points, embedments, reinforcements, and tolerances. The GRG parts are intended for interior architectural embellishment and are specified in both SI and inch‑pound units as independent systems.

General information

• Status: Active.
• Publication date: Current edition approved March 1, 2023 (published March 2023).
• Publisher: ASTM International (American Society for Testing and Materials).
• ICS / categories: 91.060.10 (Walls. Partitions. Facades); 91.100.10 (Cement. Gypsum. Lime. Mortar).
• Edition / version: C1381/C1381M-23. DOI: 10.1520/C1381_C1381M-23.
• Number of pages: 2 (document summary listing).

Scope

The specification applies to molded GRG parts that are nonload‑bearing, thin-shell ornamental shapes for interior architectural use. It addresses permitted materials, manufacture processes (hand lay-up or spray-up), minimum glass fiber reinforcement by weight, dimensional and tolerance requirements, mechanical property conformance (as referenced), and requirements for approved shop drawings and embedments for attachment. Both SI and inch‑pound units are provided and treated independently.

Key topics and requirements

• Materials: manufacture from alpha gypsum cement slurry with potable water and permitted additives; finished parts must use the same materials as the referenced GRG composite specification.
• Glass fiber reinforcement: minimum glass fiber content specified (not less than 5% by weight in the mixed slurry).
• Manufacture methods: parts may be produced by hand lay‑up or spray‑up processes in molds.
• Design documentation: parts shall be produced according to approved shop drawings that specify dimensions, quantities, recommended attachment points and methods, reinforcements, embedments, and tolerances.
• Dimensions and tolerances: minimum part thickness and control thickness are specified (typical minimum values in the standard: part thickness ≈ 5 mm; control thickness ≈ 8 mm — see the standard text for exact measured‑point definitions and tolerances).
• Mechanical properties: GRG parts must conform to mechanical property requirements consistent with the referenced GRG composite specification (C1355/C1355M).
• Units and measurement: SI units and inch‑pound units are both included and are to be used independently; combining values from the two systems may result in nonconformance.

Typical use and users

Intended users include architects and designers specifying decorative interior elements, GRG product manufacturers and fabricators, contract installers, quality control and inspection personnel, and spec writers preparing shop drawings and procurement documents for interior architectural ornamentation. The standard is used to ensure consistent material composition, fabrication processes, and dimensional/mechanical acceptance of GRG parts.

Related standards

Key referenced or related standards include ASTM C1355/C1355M (Specification for Glass Fiber Reinforced Gypsum Composites) for composite material properties and ASTM C11 (Terminology Relating to Gypsum and Related Building Materials and Systems) for definitions/terminology used in gypsum product standards. Other gypsum and gypsum‑product specifications and test methods published by Committee C11 may also be relevant for specific applications.

Keywords

glass fiber reinforced gypsum; GRG; molded GRG parts; gypsum composites; ornamental interior components; molded gypsum; shop drawings; glass fiber reinforcement; alpha gypsum cement; spray-up; hand lay-up.

FAQ

Q: What is this standard?

A: ASTM C1381/C1381M-23 is the ASTM specification that defines materials, manufacture, dimensional tolerances, and required properties for molded glass fiber reinforced gypsum (GRG) parts used as nonload‑bearing interior architectural ornamentation.

Q: What does it cover?

A: It covers permitted materials and composition, minimum glass fiber reinforcement, acceptable manufacture methods (hand lay‑up or spray‑up), shop‑drawing and embedment requirements, dimensional and tolerance limits, and mechanical property conformance (with reference to GRG composite requirements). Both SI and inch‑pound units are provided and must be treated independently.

Q: Who typically uses it?

A: Architects, GRG manufacturers and fabricators, contractors and installers, QA/QC personnel, and specification writers use this standard to ensure GRG parts meet consistent material, dimensional and performance requirements for interior architectural applications.

Q: Is it current or superseded?

A: The designation C1381/C1381M-23 is the current (2023) edition of this ASTM specification (active at time of publication). For confirmation of status or later revisions, consult ASTM publications or the ASTM store.

Q: Is it part of a series?

A: It is published under ASTM Committee C11 (Gypsum and Related Building Materials and Systems) and is directly related to ASTM C1355/C1355M (GRG composite specification) and to the C11 terminology standard; it is part of the group of gypsum product standards in Book of Standards volume 04.01.

Q: What are the key keywords?

A: Key keywords include: glass fiber reinforced gypsum, GRG, molded GRG parts, gypsum composites, alpha gypsum cement, hand lay-up, spray-up, shop drawings, embedments, dimensions, tolerances.