AASHTO R70
Full Name
AASHTO R70 – Standard Practice for Use of Apparatus for the Determination of Length Change of Hardened Cement Paste, Mortar, and Concrete
Scope
AASHTO R70 is a standard practice that outlines the requirements and procedures for using apparatus to measure length changes in hardened cement paste, mortar, and concrete. These length changes, which occur due to factors other than applied load, are crucial indicators of material performance and durability.
The standard covers the following aspects:
- Apparatus requirements: it details the specifications for equipment used in preparing test specimens, including molds, length comparators, and environmental chambers. It also specifies reference masses and devices for accurate mass and volume measurements.
- Specimen preparation: it outlines procedures for casting, curing, and storing test specimens to ensure consistent and representative results.
- Measurement procedures: it provides guidelines for accurately measuring length changes using dial gauges or digital length comparators under controlled conditions.
- Calculations and reporting: it specifies the calculations required to determine length changes and provides a standardized format for reporting results.
AASHTO R70 is essential for quality control and research in the construction industry. By standardizing the apparatus and procedures, it ensures reliable and comparable data across different laboratories and projects. The accurate measurement of length changes helps assess the potential for cracking, shrinkage, and other forms of deterioration in concrete structures.
The standard is applicable to a wide range of construction materials, including:
- Cement paste
- Mortar
- Concrete
By adhering to AASHTO R70, laboratories can confidently assess the dimensional stability of these materials, leading to informed decisions regarding mix design, curing practices, and material selection.
Key benefits:
- Standardized testing: ensures consistency and comparability of results.
- Reliable data: enables accurate assessment of material performance.
- Improved quality control: facilitates informed decision-making in construction projects.
- Enhanced durability: contributes to the longevity of concrete structures.
AASHTO R70 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO R70 standard.
Contact us for more information.
Resources
Keywords
length change; apparatus; hardened cement paste; mortar; concrete; measurement; specimen preparation; dial gauge; digital length comparator; reference bar; environmental chamber; mold; curing; storage; mass; volume; temperature; relative humidity; calculation; reporting