ASTM C1231/C1231M-23 PDF
Name in English:
St ASTM C1231/C1231M-23
Name in Russian:
Ст ASTM C1231/C1231M-23
Original standard ASTM C1231/C1231M-23 in PDF full version. Additional info + preview on request
Full title and description
Standard Practice for Use of Unbonded Caps in Determination of Compressive Strength of Hardened Cylindrical Concrete Specimens — practice that specifies use, limitations, and qualification requirements for unbonded elastomeric capping systems (neoprene and other elastomers) used when testing hardened concrete cylinders or cores to determine compressive strength.
Abstract
This practice describes the use of unbonded caps (elastomeric pads restrained by plates and rings) as an alternative to bonded capping systems for compressive-strength testing of cylindrical concrete specimens and cores. It defines allowable material types, reuse and qualification requirements, and the compressive-strength range for which unbonded caps are appropriate. The practice warns about more violent ruptures with unbonded caps and references safety guidance.
General information
- Status: Active / Published.
- Publication date: October 2023 (designation -23; issued October 1, 2023 in the ASTM/standards listings).
- Publisher: ASTM International.
- ICS / categories: 91.100.30 — Concrete and concrete products (Construction materials / concrete testing).
- Edition / version: C1231/C1231M-23 (revises C1231/C1231M-15).
- Number of pages: 5.
Scope
This practice covers requirements for a capping system using unbonded caps for testing concrete cylinders molded in accordance with Practices C31/C31M or C192/C192M, or cores obtained in accordance with Test Method C42/C42M. It permits unbonded neoprene caps of defined hardness to be used up to specified reuse and strength limits, requires qualification testing for elastomeric materials other than neoprene, and restricts use for acceptance testing to specimens with compressive strength between 10 MPa (1500 psi) and 80 MPa (12 000 psi). The practice also notes unit conventions and safety considerations.
Key topics and requirements
- Definition and components of an unbonded capping system (elastomeric pads, restraint plates, metal rings) and how they transfer load to specimen ends.
- Material and hardness criteria for neoprene caps and reuse limits without qualification testing.
- Requirement for qualification testing of non-neoprene elastomeric caps regardless of concrete strength.
- Permitted compressive-strength range for acceptance testing: not below 10 MPa (1500 psi) and not above 80 MPa (12 000 psi).
- Warning and recommended safety precautions (concrete specimens tested with unbonded caps can rupture more violently than with bonded caps).
- References to related ASTM practices and test methods used in specimen production and coring (C31/C31M, C192/C192M, C42/C42M, and comparison to Practice C617/C617M).
Typical use and users
Laboratories performing compressive-strength testing of hardened concrete cylinders or cores, quality-control personnel on construction projects, materials testing laboratories, testing equipment manufacturers, and specifying engineers who need standardized procedures for using unbonded caps where bonded capping is impractical. Users rely on this practice to ensure consistent test results, to qualify cap materials, and to apply appropriate safety measures.
Related standards
Commonly used alongside or referenced with ASTM Practice C31/C31M (making and curing cylinders in the field), C192/C192M (laboratory molding and curing), Test Method C42/C42M (obtaining and testing cores), Practice C617/C617M (bonded capping), and the Manual of Aggregate and Concrete Testing for safety guidance. This practice explicitly revises the C1231/C1231M-15 edition.
Keywords
unbonded caps, neoprene cap, elastomeric cap, compressive strength, concrete cylinder, concrete core, capping system, ASTM C1231, specimen preparation, qualification testing, concrete testing, laboratory practice.
FAQ
Q: What is this standard?
A: ASTM C1231/C1231M-23 is a practice that specifies the use, limitations, and qualification requirements for unbonded elastomeric caps used when determining the compressive strength of hardened cylindrical concrete specimens and cores.
Q: What does it cover?
A: It covers material and hardness criteria for unbonded caps, reuse and qualification rules (neoprene vs. other elastomers), the safe and permitted compressive-strength range for acceptance testing (10 MPa to 80 MPa), and the apparatus restraint arrangement to ensure uniform load distribution.
Q: Who typically uses it?
A: Materials testing laboratories, third-party testing agencies, construction quality-control teams, equipment manufacturers, and engineers specifying or interpreting compressive-strength test results.
Q: Is it current or superseded?
A: Current — the active edition is C1231/C1231M-23 (published October 2023), which revises the prior 2015 edition.
Q: Is it part of a series?
A: It is part of ASTM's concrete testing practices and is typically used in conjunction with related standards (C31/C31M, C192/C192M, C42/C42M, C617/C617M) found in ASTM Book of Standards Volume 04.02.
Q: What are the key keywords?
A: Unbonded caps, neoprene, elastomeric pads, compressive strength, concrete cylinders, cores, qualification testing, specimen capping.