ASTM C243
Overview of ASTM C243 standard for Bleeding of Cement Pastes and Mortars
1. Overview
1.1 Purpose: This method measures the rate and total amount of bleeding in cement paste and mortar.
1.2 Measurement Units: SI units are the primary standard; other units are supplementary.
1.3 Safety and Compliance: The standard doesn't cover all safety concerns. Users must ensure safety and compliance with relevant regulations. Refer to Section 5 for hazard information.
2. Referenced Standards
2.1 Associated ASTM Standards: Includes C 109 (Compressive Strength of Hydraulic Cement Mortars), C 230 (Flow Table for Hydraulic Cement), C 305 (Mechanical Mixing of Hydraulic Cement Pastes and Mortars), C 778 (Standard Sand), and C 1005 (Weights and Weighing Devices for Testing Hydraulic Cements).
3. Application
3.1 Use Case: Primarily for research into the bleeding behaviour of cement pastes and mortars.
4. Required Equipment
4.1 Scales and Balances: Must comply with ASTM C 1005, with a minimum capacity of 5000 g.
4.2 Tamper: Made from nonabsorptive, nonabrasive material, sized and shaped as specified.
4.3 Bleeding Measurement Device: Includes a noncorroding metal container and a calibrated liquid displacement setup with specific dimensions.
4.4 Mixer: A mechanical mixer that meets ASTM C 305 standards.
4.5 Flow Table and Mold: Should conform to ASTM C 230 specifications.
5. Safety Precautions
5.1 Handling Hazards: Caution with chlorinated hydrocarbons; use in ventilated areas.
5.2 Equipment Setup: Minimize vibration and use appropriate cushioning under the bleeding apparatus.
6. Environmental Conditions
6.1 Temperature Control: Maintain a specific temperature range for the test environment and materials.
6.2 Humidity Requirements: Ensure a minimum relative humidity in the testing area.
7. Testing Cement Pastes
7.1 Composition: Specific cement and water proportions.
7.2 Mixing Process: Detailed steps for mixing, resting, and further mixing of the paste.
7.3 Test Execution: Instructions for filling the container, starting the test, and conducting measurements.
8. Testing Cement Mortars
8.1 Composition: Defined ratios of cement, sand, and water.
8.2 Mixing Process: Sequential steps for adding and mixing materials.
8.3 Flow Determination: Adjustments to the standard flow test method.
8.4 Test Execution: Detailed procedure for mortar testing, similar to paste testing.
9. Data Analysis
9.1 Bleeding Rate Calculation: Formula and variables for calculating the rate of bleeding.
9.2 Bleeding Capacity Calculation: Method for determining the total bleeding capacity.
10. Reporting Results
10.1 Documentation: Report bleeding rate and capacity with specified precision.
11. Method Precision
11.1 Limitations: Acknowledges the challenges in specifying the precision of the test method.
12. Key Terms
12.1 Definitions: Includes terms like bleeding capacity, bleeding rate, cement mortar, and cement paste.
This reworded description of ASTM Standard C 243 outlines the methodology for assessing the bleeding characteristics of cement paste and mortar, including equipment requirements, safety measures, test procedures, and reporting standards.