ASTM C617/C617M-23 PDF

Full title and description

ASTM C617/C617M-23 — Standard Practice for Capping Cylindrical Concrete Specimens. This practice describes apparatus, materials, and procedures for providing plane, perpendicular bearing surfaces on the ends of freshly molded concrete cylinders (using neat hydraulic cement paste) and on hardened cylinders or drilled concrete cores (using high‑strength gypsum paste or sulfur mortar) when end surfaces do not meet planeness and perpendicularity requirements for compressive testing. The practice also clarifies unit usage (SI and inch‑pound) and notes safety and handling considerations; Practice C1231/C1231M describes an alternative unbonded‑cap method.

Abstract

This standard establishes accepted methods for capping cylindrical concrete specimens to produce flat, perpendicular end surfaces required for valid compressive‑strength testing. It specifies acceptable capping materials (neat cement paste for fresh specimens; gypsum paste or sulfur mortar for hardened specimens and cores), basic apparatus and capping procedures, and considerations for specimen protection and measurement units. The practice is intended to ensure repeatable, reliable bearing conditions at load application.

General information

• Status: Active.
• Publication date: October 1, 2023 (current edition approved Oct 1, 2023).
• Publisher: ASTM International.
• ICS / categories: 91.100.30 — Concrete and concrete products.
• Edition / version: C617/C617M‑23.
• Number of pages: 6.

Scope

This practice covers the materials, equipment, and step‑by‑step procedures for capping freshly molded concrete cylinders with neat hydraulic cement paste and for capping hardened cylinders and drilled cores with high‑strength gypsum paste or sulfur mortar when end faces are not sufficiently plane or perpendicular for compressive testing. It defines unit conventions (SI and inch‑pound used separately), identifies notes and footnotes as informational rather than mandatory, and points users to Practice C1231/C1231M when unbonded caps are preferred. Safety and specimen‑handling precautions are also referenced.

Key topics and requirements

• Approved capping materials: neat hydraulic cement paste for fresh cylinders; high‑strength gypsum paste or sulfur mortar for hardened cylinders and cores.
• Apparatus and accessories: capping molds/retainers, plate thickness and flatness requirements, heating/melting equipment for sulfur mortar, and tools for applying and finishing caps.
• Procedural steps: surface preparation, mixing and conditioning of capping material, application and leveling of cap, curing/protection of caps prior to testing, and inspection for planeness and perpendicularity.
• Units and tolerances: SI and inch‑pound units are each regarded as independent standards (do not mix values from the two systems).
• When to use alternatives: reference to Practice C1231/C1231M for use of unbonded (pad) caps on hardened specimens.
• Safety and quality considerations: ventilation and PPE when using sulfur mortar, protection of capped specimens, and recordkeeping for cap material and application method.

Typical use and users

Used by concrete testing laboratories, materials engineers, construction quality‑control staff, forensic and research laboratories, and any organization performing compressive‑strength testing of molded cylinders or drilled cores. Typical applications include acceptance testing for construction projects, research and development, mix design verification, and compliance testing where reproducible end conditions are required for accurate compressive strength measurement.

Related standards

Commonly used alongside and referenced by other ASTM standards in concrete strength testing, including Practice C1231/C1231M (use of unbonded caps), Test Method C39/C39M (compressive strength of cylindrical specimens), Practices C31/C31M and C192/C192M (making and curing test specimens), Test Method C42/C42M (obtaining and testing drilled cores), and C873/C873M (compressive strength of cast‑in‑place cylinders). The 2023 revision of C617/C617M supersedes the 2015 edition.

Keywords

capping, concrete, cylindrical specimens, compressive strength, cores, cylinders, gypsum paste, sulfur mortar, neat hydraulic cement paste, planeness, perpendicularity, specimen preparation.

FAQ

Q: What is this standard?

A: ASTM C617/C617M‑23 is a practice that specifies materials, equipment, and procedures for capping cylindrical concrete specimens so their ends are plane and perpendicular to the cylinder axis for valid compressive‑strength testing.

Q: What does it cover?

A: It covers capping fresh molded cylinders with neat cement paste and capping hardened cylinders and drilled cores with high‑strength gypsum paste or sulfur mortar, plus apparatus, application procedures, curing/protection of caps, and unit conventions. It does not supplant safety responsibilities or other test method requirements.

Q: Who typically uses it?

A: Concrete testing laboratories, QC/QA teams on construction projects, materials engineers, contractors’ testing personnel, research labs, and forensic investigators performing compressive testing of cylinders or cores.

Q: Is it current or superseded?

A: Current (active). The C617/C617M‑23 edition approved October 1, 2023 supersedes the previous C617/C617M‑15 edition.

Q: Is it part of a series?

A: Yes. It is part of the suite of ASTM C09 committee standards dealing with concrete and concrete aggregates and is intended to be used with related standards for specimen production and testing such as C39, C31/C31M, C192/C192M, C42/C42M, and C1231/C1231M.

Q: What are the key keywords?

A: capping; concrete; compressive strength; cylinders; cores; gypsum cement paste; neat hydraulic cement paste; sulfur mortar; specimen preparation.