ASTM C926-23a PDF

ABSTRACT This specification covers the standard requirements for the application of full thickness Portland cement-based plaster for exterior (stucco) and interior work. It also sets forth tables for proportioning of various plaster mixes and plaster thickness. The materials used shall consist of the following: cement which shall be a Portland cement, air-entraining Portland cement, masonry cement, blended hydraulic cement, air-entraining blended hydraulic cement, or plastic cement; Type S hydrated lime; aggregates such as perlite and sand for base and job-mixed finish coats; water to be used in mixing; admixtures; and fibers. Surfaces of solid bases such as masonry, stone, cast-in-place or precast concrete shall be prepared either by sandblasting, wire brushing, acid etching, chipping, or a combination thereof. Details on curing to resist cracking; materials protection and storage; environmental conditions; and application of plaster, finish-coat, and fog-coat, which shall be done by hand or machine up to the specified nominal thickness on metal and solid plaster bases are discussed. SCOPE 1.1 This specification covers the minimum technical requirements for the application of full thickness portland cement-based plaster for exterior (stucco) and interior work. These requirements do not by default define a unit of work or assign responsibility for contractual purposes, which is the purview of a contract or contracts made between contracting entities. 1.2 This specification sets forth tables for proportioning of various plaster mixes and plaster thickness. Note 1: General information is found in Annex A1. Design considerations are found in Annex A2. 1.3 The text of this specification references notes and footnotes that provide explanatory material. These notes and footnotes (excluding those in tables and figures) shall not be considered as requirements of the specification. 1.4 Details of construction for a specific assembly to achieve the required fire resistance shall be obtained from reports of fire-resistance tests, engineering evaluations, or listings from recognized fire testing laboratories. 1.5 The values stated in inch-pound units are to be regarded as standard. The values given in parentheses are mathematical conversions to SI units that are provided for information only and are not considered standard. 1.6 This international standard was developed in accordance with internationally recognized principles on standardization established in the Decision on Principles for the Development of International Standards, Guides and Recommendations issued by the World Trade Organization Technical Barriers to Trade (TBT) Committee.