AASHTO T197
Full Name
AASHTO T197 – Standard Method of Test for Time of Setting of Concrete Mixtures by Penetration Resistance
Scope
AASHTO T197 is a standard test method used to determine the time of setting of concrete mixtures by measuring the penetration resistance of mortar sieved from the concrete. This test is crucial for evaluating the setting behavior of concrete, providing valuable information for construction scheduling, quality control, and mix design optimization.
Key aspects of AASHTO T197:
- Purpose: the primary objective of this test is to determine the initial and final setting times of concrete. The initial setting time is the time elapsed from the start of mixing until the mortar fraction of the concrete reaches a specified penetration resistance. The final setting time is the time when the penetration resistance exceeds a higher specified value, indicating that the concrete has hardened significantly.
- Test apparatus: the test utilizes a penetration resistance apparatus, which consists of a penetration probe with a defined tip area and a device to measure the force required to penetrate the mortar to a specified depth.
- Procedure: freshly mixed concrete is sampled and sieved to obtain the mortar fraction. The mortar is then placed in a container, and the penetration resistance is measured at regular intervals until the initial and final setting times are reached.
- Significance: the setting time of concrete is a critical parameter that affects construction operations, such as placing, finishing, and formwork removal. It also provides an indication of the rate of strength development in the early stages of curing.
Applications of AASHTO T197:
- Quality control: this test is used to ensure that the concrete mix meets the specified setting time requirements, ensuring proper workability and adequate time for construction activities.
- Mix design optimization: by evaluating the setting time of different concrete mixtures, engineers can optimize the mix design by adjusting the proportions of cement, water, aggregates, and admixtures.
- Troubleshooting: the test can be used to diagnose setting problems in concrete, such as delayed or accelerated setting, and to identify potential causes, such as variations in materials or environmental conditions.
AASHTO T197 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T197 standard.
Our laboratory offers comprehensive concrete testing services, including the determination of setting time by penetration resistance according to AASHTO T197. Our experienced technicians utilize standardized procedures and calibrated equipment to ensure accurate and reliable results.
Contact us for more information.
Resources
Keywords
setting time; penetration resistance; concrete; mortar; initial setting time; final setting time; penetration probe; penetration resistance apparatus