AASHTO T131
Full Name
AASHTO T131 – Standard Method of Test for Time of Setting of Hydraulic Cement by Vicat Needle
Scope
AASHTO T131 is a standard test method used to determine the time of setting of hydraulic cement, such as Portland cement, by using a Vicat needle apparatus. This test is essential for assessing the rate at which cement paste stiffens and hardens, providing valuable information for concrete mix design, construction scheduling, and quality control.
Key aspects of AASHTO T131:
- Purpose: the primary objective of this test is to determine the initial and final setting times of hydraulic cement paste. The initial setting time is the time elapsed between the initial contact of cement and water and the time when the Vicat needle penetrates the paste to a specified depth. The final setting time is the time when the Vicat needle no longer makes an indentation on the paste surface.
- Vicat apparatus: the test utilizes a Vicat apparatus, which consists of a needle with a defined diameter and weight, a frame to hold the needle, and a scale to measure the penetration depth.
- Procedure: a cement paste of normal consistency is prepared and placed in a mold. The Vicat needle is then lowered onto the surface of the paste at regular intervals until it reaches the specified penetration depth for the initial setting time. The test is continued until the needle no longer makes an indentation, indicating the final setting time.
- Significance: the setting time of cement is a critical parameter that influences the workability, strength development, and overall performance of concrete. Knowing the setting time helps in determining the appropriate time for concrete placement, finishing, and formwork removal.
Applications of AASHTO T131:
- Quality control: cement manufacturers and testing laboratories use this test to ensure that the cement meets the specified setting time requirements.
- Mix design: the setting time information is used in concrete mix design to select the appropriate type of cement and adjust the admixture dosage to achieve the desired setting time and workability.
- Construction: contractors use the setting time information to plan and schedule their construction activities, ensuring that the concrete is placed and finished before it sets.
AASHTO T131 Accredited Laboratory
Applied Testing & Geosciences, LLC is accredited for performing tests using the AASHTO T131 standard.
Our laboratory offers comprehensive cement testing services, including the determination of setting time by Vicat needle according to AASHTO T131. Our experienced technicians utilize standardized procedures and calibrated equipment to ensure accurate and reliable results.
Contact us for more information.
Resources
Keywords
setting time; Vicat needle; hydraulic cement; cement paste; initial setting time; final setting time; penetration resistance; normal consistency; Vicat apparatus