Overview
ASTM C940-22: Standard Test Method for Expansion and Bleeding of Freshly Mixed Grouts for Preplaced-Aggregate Concrete in the Laboratory provides a reliable laboratory method for assessing the expansion and bleeding characteristics of freshly mixed fluid hydraulic cement grout. This standard is essential for quality control and mix design verification in preplaced-aggregate (PA) concrete and cementitious post-tensioning tendon grout applications. By measuring both the expansion and the accumulation of bleed water, the method helps ensure mixture performance, stability, and long-term durability in the field.
Key Topics
- Grout Performance Evaluation: Determines expansion and bleeding, which are critical to the performance of hydraulic cement grouts used in PA concrete and post-tensioning systems.
- Testing Applicability: Covers grouts with or without fine aggregate and supplemental cementitious materials.
- Laboratory Procedures: Details the placement of grout in graduated cylinders, measurement of volume changes, and tracking of bleed water over time under controlled conditions.
- Measurement Precision: Includes specific procedures for consistent temperature control and sample handling to ensure reliable, reproducible results.
- Reporting Requirements: Specifies reporting expansion, bleeding, combined expansion, and temperature measurements at defined intervals for comprehensive documentation.
Applications
ASTM C940-22 is widely used in laboratory settings for:
- Mix Design Verification: Ensuring hydraulic cement grouts meet project requirements for expansion and minimize unwanted bleeding before field application.
- Admixture Qualification: Comparing and qualifying grout fluidifiers and other admixtures used in preplaced-aggregate concrete or post-tensioning grouts.
- Quality Control: Assessing batch-to-batch consistency and conformity to specifications prior to field placement, which is vital for construction quality assurance.
- Research and Development: Supporting innovation in grout formulations by providing standardized methods for evaluating performance characteristics.
Practitioners such as materials engineers, laboratory technicians, and quality control managers frequently use this test method within segments of the construction, infrastructure, and precast concrete industries that rely on high-performance cement grouts.
Related Standards
For broader testing and specification compliance in concrete and grout applications, the following ASTM standards are closely associated with ASTM C940-22:
- ASTM C125 - Terminology Relating to Concrete and Concrete Aggregates
- ASTM C219 - Terminology Relating to Hydraulic and Other Inorganic Cements
- ASTM C937 - Specification for Grout Fluidifier for Preplaced-Aggregate Concrete
- ASTM C1064/C1064M - Test Method for Temperature of Freshly Mixed Hydraulic-Cement Concrete
- ASTM E1272 - Specification for Laboratory Glass Graduated Cylinders
By integrating ASTM C940-22 with these related standards, organizations ensure precise evaluation, improved material performance, and adherence to industry best practices when working with hydraulic cementitious grouts, preplaced-aggregate concrete, and post-tensioning systems.
Keywords: ASTM C940-22, grout expansion, grout bleeding, preplaced-aggregate concrete, hydraulic cement grout, laboratory testing, quality control, post-tensioning grouts, concrete standards.