types and uses of concrete Test Specimens
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Concrete test specimens (concrete cylinders, beams, or cubes) are used for a variety of purposes on construction projects. Although all are intended to represent the strength of concrete used on the project, the break-result can be indicative of very different performance parameters depending on how each test specimen was cured.
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Concrete Cylinder and Cube Test Specimens.
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Standard (Lab) cured Test Specimens
Strength measurements from standard cured specimens are used for the following purposes:
Note that standard cured test specimens (e.g. lab cylinders) are NOT to be used to estimate in-place concrete strength, but rather to determine the potential strength and/or consistency of the represented concrete. or mix design
The key to making standard cured test specimens is that they are produced and cured in a defined, repeatable way. Standard cured test specimens are typically molded in the field, initially stored onsite in a controlled environment, then relocated to a lab where they continue to cure until reaching a specified age at which the strength is determined via destructive testing.
More about standard cured specimens
- Potential - Is the mix design able to achieve the specified strength
- Acceptance - Does a particular batch of concrete have the potential of achieving the specified strength
- Quality Control - Is the concrete consistent, batch to batch
- Concrete Maturity Validation - Does a particular batch of concrete match a specified concrete maturity curve
Note that standard cured test specimens (e.g. lab cylinders) are NOT to be used to estimate in-place concrete strength, but rather to determine the potential strength and/or consistency of the represented concrete. or mix design
The key to making standard cured test specimens is that they are produced and cured in a defined, repeatable way. Standard cured test specimens are typically molded in the field, initially stored onsite in a controlled environment, then relocated to a lab where they continue to cure until reaching a specified age at which the strength is determined via destructive testing.
More about standard cured specimens
field cured Test specimens
Field cured test specimens are used for the following purposes:
Field cured cylinders are NOT to be used for quality control or acceptance.
Field cured cylinders are molded and stored on, in, or as nearby the concrete placement as possible. The objective when curing field cured cylinders is to reproduce the effects of the environment as closely as possible such that the strength of the field cured test specimens closely approximates the actual strength of the concrete placement at any particular moment. Break-data from these cylinders are used to time critical operations, such as formwork removal, where the actual strength of the in-place concrete is critical.
More about field cured test specimens
- Estimating In-Place Strength - To determine if the placement is ready to be put into service, or formwork or shoring can be removed
- Comparison - How does the strength estimate from the field-cured specimen compare with the strength estimate from other in-place test methods
Field cured cylinders are NOT to be used for quality control or acceptance.
Field cured cylinders are molded and stored on, in, or as nearby the concrete placement as possible. The objective when curing field cured cylinders is to reproduce the effects of the environment as closely as possible such that the strength of the field cured test specimens closely approximates the actual strength of the concrete placement at any particular moment. Break-data from these cylinders are used to time critical operations, such as formwork removal, where the actual strength of the in-place concrete is critical.
More about field cured test specimens
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RESOURCES
CIP 35 - TESTING COMPRESSIVE STRENGTH OF CONCRETE
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