ASTM C78/C78M-22 PDF
Name in English:
St ASTM C78/C78M-22
Name in Russian:
Ст ASTM C78/C78M-22
Original standard ASTM C78/C78M-22 in PDF full version. Additional info + preview on request
Full title and description
ASTM C78/C78M-22 — Standard Test Method for Flexural Strength of Concrete (Using Simple Beam with Third-Point Loading). This standard specifies the procedure, apparatus, specimen preparation, loading configuration and calculations used to determine the flexural strength (modulus of rupture) of concrete beams using a simply supported beam with third‑point loading. Results are reported in either SI or inch‑pound units (each system to be used independently).
Abstract
ASTM C78/C78M-22 defines a laboratory test for measuring the flexural strength of concrete by loading a simply supported beam at two third‑point loading positions until failure. The standard covers specimen dimensions and preparation, test-machine and loading-block requirements, measurement practices, calculation of the modulus of rupture, reporting requirements, and limitations and sources of variability. It is commonly used for slabs and pavement applications, mixture evaluation, and quality control.
General information
- Status: Active (current edition).
- Publication date: March 1, 2022.
- Publisher: ASTM International.
- ICS / categories: 91.100.30 (Concrete and concrete products).
- Edition / version: C78/C78M‑22 (2022 revision).
- Number of pages: 5 (standard document length).
Scope
This test method covers determination of the flexural strength of concrete by use of a simple beam with third‑point loading. It applies to specimens prepared and cured under the referenced specimen practices and test methods, and it provides procedures for both SI and inch‑pound units (each to be used independently). The standard notes safety and handling considerations are the user's responsibility and does not cover every possible safety concern.
Key topics and requirements
- Apparatus: requirements for testing machine, loading blocks, supports and fixtures that apply load without eccentricity.
- Specimens: recommended beam sizes, tolerances, molding or sawing practices and conditioning (references to specimen-making and curing practices).
- Loading configuration: simple beam with two equal loads placed at the thirds of the span (third‑point loading).
- Measurements: procedures for recording span, width, depth (typically averaged from multiple measurements), and load at failure.
- Calculation: modulus of rupture (flexural strength) computed from maximum load and specimen geometry; distinct formulae for third‑point loading and for when fracture is outside the middle third.
- Units: both SI and inch‑pound units are provided; the two systems are independent and not exact equivalents.
- Precision and limitations: discussion of variability sources (specimen size, curing, moisture condition, sawed vs molded beams) and comparability with other flexural tests (e.g., center‑point loading).
- Referenced practices and standards: requires or refers to specimen preparation and terminology standards for consistent testing and reporting.
Typical use and users
This standard is used by materials testing laboratories, DOT and transportation agencies, pavement and slab designers, concrete producers, quality control/assurance personnel, and research groups. Typical applications include routine QC testing of concrete for slabs and pavements, comparative testing of mix designs, and investigative or forensic testing where flexural behavior is of interest.
Related standards
Commonly referenced or complementary ASTM standards include: ASTM C293/C293M (flexural strength — center‑point loading), ASTM C31/C31M and C192/C192M (making and curing specimens in the field and laboratory), ASTM C42/C42M (obtaining and testing sawed beams and drilled cores), ASTM C125 (terminology relating to concrete and aggregates), ASTM E6 (general terminology for force/stress quantities), and other material‑specific standards for reporting and precision. Users should consult the referenced sections within C78/C78M-22 for the full list of referenced documents.
Keywords
flexural strength; modulus of rupture; third‑point loading; concrete beams; beam test; slab testing; pavement testing; specimen preparation; ASTM C78; bending test; quality control.
FAQ
Q: What is this standard?
A: ASTM C78/C78M-22 is the ASTM standard test method for determining the flexural strength (modulus of rupture) of concrete using a simple beam with third‑point loading.
Q: What does it cover?
A: It covers apparatus requirements, specimen dimensions and preparation, loading arrangement (third‑point), measurement and calculation methods for the modulus of rupture, reporting requirements, and limitations of the test. It provides procedures in both SI and inch‑pound units.
Q: Who typically uses it?
A: Laboratory technicians, materials engineers, concrete producers, transportation agencies, contractors, researchers, and anyone performing flexural testing of concrete for slabs, pavements or mix evaluation.
Q: Is it current or superseded?
A: The current published edition is C78/C78M‑22, published March 1, 2022. The standard is active. (Note: standards are periodically reviewed; revision work to update the method may be initiated from time to time.)
Q: Is it part of a series?
A: Yes — it is part of ASTM’s portfolio of concrete testing standards under Committee C09. It is related to other flexural and concrete specimen standards (for example C293 for center‑point loading and specimen‑preparation practices C31/C31M and C192/C192M).
Q: What are the key keywords?
A: Flexural strength, modulus of rupture, third‑point loading, concrete beam test, ASTM C78, slab and pavement testing, specimen preparation.