This video shows the tensile strength test for chemical-resistant mortars and surfacings using the ASTM C307 method — with a special focus on the briquette-style grips required to hold the cured specimens securely during testing.

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ASTM C307 uses a molded specimen, often cast in a dumbbell or briquette shape to prevent slippage under load. These samples are tested in a universal testing machine fitted with curved, self-aligning grips that match the concave profile of the specimen ends.

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The grips are crucial for accurate results, allowing the load to be applied evenly across the entire cross-section. Improper grips can cause premature failure or invalid results.

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Tensile Strength = Max Load / Cross-Sectional Area

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This test is commonly used for epoxy grout, vinyl ester toppings, and other industrial floor coatings. It complements standards like ASTM C579 (compressive) and ASTM C581 (chemical resistance).

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Watch the video to see how the custom grips work in action and ensure compliance with ASTM C307.