ASTM C940 is the standard test method for measuring expansion and bleeding of freshly mixed grouts used in preplaced-aggregate concrete in the laboratory. It gives a practical way to evaluate how grout behaves while still fresh, which can help with mix verification, quality control, and performance consistency. By focusing on these key properties, the standard supports more reliable testing and better comparison of grout mixtures before placement in concrete work.

What is ASTM C940?

ASTM C940 provides a laboratory test method for assessing the expansion and bleeding characteristics of freshly mixed grout intended for preplaced-aggregate concrete. Its purpose is to offer a consistent technical approach for observing early behavior of the grout before it hardens. As an ASTM standard, it is commonly used to support product evaluation and compliance checks where fresh grout performance matters. ASTM C940 is especially relevant when controlled test results are needed for comparing mixtures.

Where is ASTM C940 used?

This standard is used in laboratory testing environments that work with grouts for preplaced-aggregate concrete. It is most relevant for mix development, quality control programs, and technical review of grout materials before field use. Laboratories, concrete material suppliers, and engineering teams may use ASTM C940 when they need a repeatable method to measure fresh grout behavior under controlled conditions. The test supports decisions made during product qualification and specification review.

Why is ASTM C940 important?

ASTM C940 helps users evaluate fresh grout behavior in a consistent way, which is important for comparing materials and checking whether a mix meets project expectations. Measuring expansion and bleeding can reduce uncertainty during testing and support more dependable procurement and quality control decisions. For products used in preplaced-aggregate concrete, this standard helps identify potential performance issues early, before the material is placed in service. That makes it a useful tool for technical review and risk reduction.

• Laboratory test method for fresh grout
• Measures expansion and bleeding
• Applies to preplaced-aggregate concrete grout
• Supports mix evaluation and quality control
• Useful for technical and compliance review