Durham Geo Capping Compounds are specially formulated powders. They are melted and then formed over the ends of the test cylinders to provide a smooth and level surface. Melting point is 240 degrees F (115 degrees C), best flow at 260-280F (126-137C). Made in two formulations with two hour setting time giving compressive strengths of: 550 psi (38 MPa) or 8000 psi (55 MPa).
ASTM C 617