ASTM C90-24a PDF

Full title and description

ASTM C90-24a — Standard Specification for Dry‑Cast Loadbearing Concrete Masonry Units. Defines the minimum physical and manufacturing requirements for machine‑made dry‑cast (low or zero‑slump) hollow and solid concrete masonry units used in loadbearing and nonloadbearing applications, including classification by unit weight (normal, medium, lightweight) and required material and dimensional characteristics.

Abstract

This standard covers dry‑cast hollow and solid concrete masonry units manufactured from hydraulic cement, water, and mineral aggregates (with or without other included materials). It establishes classes by unit weight, sets physical property requirements (e.g., compressive strength, water absorption, equivalent web thickness, face shell/web dimensions), and provides the basis for sampling, testing, and acceptance of units intended for both loadbearing and nonloadbearing construction.

General information

• Status: Active (current ASTM C90-24a version).
• Publication date: 2024 (current active revision/amendment C90‑24a; ASTM store shows the document active and last updated Jan 20, 2025).
• Publisher: ASTM International (formerly American Society for Testing and Materials).
• ICS / categories: 91.100.30 (Concrete and concrete products); Book of Standards Volume 04.05 (masonry/concrete products).
• Edition / version: C90‑24a (active revision of the C90 series).
• Number of pages: 5 pages (concise specification document).

Scope

Specifies requirements for dry‑cast (machine‑made) hollow and solid concrete masonry units produced from hydraulic cement, water, and mineral aggregates. Applies to units made with normal‑weight, medium‑weight, or lightweight aggregates and intended for loadbearing or nonloadbearing use. Notes address units’ manufacturing context, unit performance attributes, and the need to specify additional features (appearance, thermal, fire, acoustical properties) separately where required.

Key topics and requirements

• Classification by unit weight: normal, medium, and lightweight.
• Physical property limits: compressive strength, water absorption, equivalent web thickness, face shell and web dimensions and tolerances.
• Manufacturing method focus: dry‑cast (low/zero slump) concrete and machine production requirements.
• Sampling, testing, and acceptance criteria for production lots and individual units.
• Marking, packaging, and purchaser‑specified features (color, texture, special properties) to be agreed separately.
• Notes clarifying that the specification is unit‑level and that system or design performance should be assessed separately.

Typical use and users

Used by concrete masonry unit (CMU) manufacturers to establish production and QC criteria; by architects and specifiers to reference minimum unit properties in project specifications; by structural and materials engineers and testing laboratories for sampling and compliance testing; and by building officials and contractors for product acceptance and procurement. Manufacturers and suppliers commonly cite ASTM C90 when promoting compliance of CMU products.

Related standards

Commonly referenced alongside ASTM test and product standards for masonry and concrete units such as ASTM C140 (sampling and testing of concrete masonry units), C55 (concrete building brick), C129 (nonloadbearing CMU), C1372 (segmental retaining wall units), and other C‑series masonry standards used in design, testing, and installation; also referenced by building codes and industry guidance where unit properties are required.

Keywords

concrete masonry unit; CMU; dry‑cast; loadbearing; compressive strength; water absorption; face shell; web thickness; normal weight; lightweight; machine‑made; sampling; testing; ASTM C90.

FAQ

Q: What is this standard?

A: ASTM C90‑24a is the ASTM standard specification that defines minimum manufacturing and physical requirements for dry‑cast, machine‑made concrete masonry units intended for loadbearing (and nonloadbearing) use.

Q: What does it cover?

A: It covers hollow and solid dry‑cast concrete masonry units made from hydraulic cement, water, and mineral aggregates, specifying classifications by weight, physical property requirements, sampling/testing procedures, and acceptance criteria; purchaser‑specific features like color or enhanced thermal/fire performance must be specified separately.

Q: Who typically uses it?

A: CMU manufacturers, quality/control laboratories, architects and specifiers, structural engineers, contractors, and building officials use ASTM C90 to confirm unit compliance and to reference baseline material requirements in specifications and procurement.

Q: Is it current or superseded?

A: The C90‑24a edition is the active/current ASTM C90 version (designated C90‑24a); ASTM’s publications and store list the C90‑24a active and updated (ASTM store shows the document active and last updated Jan 20, 2025). Check ASTM or your organization’s standards subscription for any later amendments.

Q: Is it part of a series?

A: Yes — it belongs to the ASTM C90 family of specifications and sits within the broader ASTM C‑series masonry and concrete product standards (many related C‑standards govern testing, brick, facing units, and other masonry products).

Q: What are the key keywords?

A: Key keywords include: concrete masonry units, CMU, dry‑cast, loadbearing, compressive strength, absorption, face shell, web thickness, normal weight, lightweight, sampling, testing.