AASHTO T 23 is a standard method of test used to make, cure, and transport concrete cylinder or flexural beam specimens prepared from representative samples of freshly mixed concrete under field conditions.
This standard is commonly referenced on transportation and heavy civil projects where field-cast specimens are later tested for compressive strength or flexural strength at specified ages. If you need help matching your curing setup, specimen molds, or transport approach to a specific project requirement, talk with our team.
AASHTO T 23 – Standard Method of Test for Making and Curing Concrete Test Specimens in the Field
AASHTO T 23 focuses on how test specimens are produced and protected so later strength results reflect the intended sampling and curing conditions. It is a specimen-preparation and curing method, not a strength test by itself.
Because specimen handling can materially affect results, labs and field crews typically treat T 23 as a “must-follow” reference whenever concrete acceptance cylinders or flexural beams are being cast on a project site.
Quick Definition
AASHTO T 23 describes procedures for making, curing, and transporting concrete cylinder and beam specimens made from representative samples of fresh concrete under field conditions.
What This Standard Covers
AASHTO T 23 is used when you need consistent, defensible field preparation of concrete specimens that will later be tested in a lab or at a jobsite testing location.
Typical coverage includes: specimen mold types (cylinders and beams), consolidation approach (rodding or vibration depending on the concrete), initial curing protection, transportation protection, and requirements for final curing conditions prior to testing.
Why This Standard Matters in Testing
Concrete strength test results are only as meaningful as the specimen quality and curing history. AASHTO T 23 helps reduce variability by controlling common field factors such as time to molding, disturbance during set, temperature exposure, moisture loss, and damage during transport.
When results are used for acceptance, pay factors, opening-to-traffic decisions, or troubleshooting low breaks, consistent T 23 practices help teams separate true material issues from specimen-handling artifacts.
Common Materials, Product Types, or Applications Covered
AASHTO T 23 is applied to freshly mixed hydraulic-cement concrete sampled during placement on construction projects.
Common applications: paving concrete, bridge and structural concrete elements, drilled shafts and foundations, and general DOT/agency concrete work where cylinders (compressive strength) and/or beams (flexural strength) are specified.
Common Test or Verification Workflow
AASHTO T 23 typically sits in the middle of the concrete QC/QA chain: sample fresh concrete, cast specimens, protect them through initial cure and transport, then complete final curing until the specified test age.
Common workflow: sample fresh concrete in the field, measure fresh properties as required by the project, mold cylinders or beams, maintain initial curing conditions, transport specimens without damage or moisture loss, then place specimens into final curing conditions until strength testing at the specified age.
Equipment Commonly Used for This Standard
AASHTO T 23 is equipment-light compared with many mechanical tests, but it is highly dependent on having the right molds, consolidation tools, and curing/transport controls.
Common equipment and accessories: cylinder molds and beam molds; tamping rods; internal vibrator (when required by the mixture/workability); strike-off tools (trowel/float) and mallet; a temperature-controlled curing box or enclosure for initial curing; max/min thermometer for initial cure monitoring; and final-curing equipment such as a moist room/cabinet or water storage tank consistent with curing requirements.
Practical quoting note: if your project includes both cylinders and flexural beams, it is often worth standardizing the specimen identification system and curing capacity (number of molds, curing box volume, and tank/rack space) so specimen turnaround does not bottleneck field operations.
How to Read This Designation or Revision
AASHTO standards are commonly cited as the designation plus a two-digit year suffix (for example, “T 23-18”). The suffix identifies the referenced edition year, and project specifications may require a particular edition.
Revision sensitivity: specimen curing, transport limits, and documentation requirements can vary by edition and by agency modifications, so equipment setups and checklists should be matched to the exact version cited in the contract documents.
Related Standards, Methods, or Frameworks
AASHTO T 23 is commonly used alongside other concrete field and strength-testing references, depending on what the project requires.
- AASHTO T 141 (sampling freshly mixed concrete)
- AASHTO T 119 (slump of hydraulic cement concrete)
- AASHTO T 309 (temperature of freshly mixed hydraulic-cement concrete)
- AASHTO T 152 (air content of freshly mixed concrete by pressure method)
- AASHTO T 22 (compressive strength of cylindrical concrete specimens)
- AASHTO M 201 (curing rooms/cabinets and water storage tanks used in testing)
Get help selecting a curing and specimen-handling setup
If you are building out a field curing kit or expanding lab curing capacity to support AASHTO T 23 workflows, you can request a detailed quote for molds, curing boxes, tanks, and accessories sized to your expected specimen volume and testing schedule.
