Capping Fixtures

Capping fixtures are used when applying capping compound to the ends of concrete cylinders in preparation for compression testing.

Melted capping compound is poured into the ring portion of the capping fixture base and the cylinder is placed in the fixture. The vertical arms keep the cylinder in vertical orientation so that the top and bottom surfaces remain parallel.
The capping fixture consists of a 1 inch (25.4 mm) thick base plate ground to maintain planeness within 0.002 inch (0.05 mm) in 6 inch (152 mm); a 3, 4 or 6 inch (76, 102 or 152) mm retainer ring; and a heavy-duty vertical arm assembly for centering cylinders.
Our customers relate that the temperature of the workspace can affect how quickly the capping compound hardens. Make sure that you are ready to put the cylinder into the capping fixture quickly if you are working in a cold room!
Capped specimens are ready for compression testing in as little as 2 hours, though many sources recommend waiting up to 24 hours for optimum compound strength.
Meets ASTM C31, C39, C192, C617, AASHTO T22, T23, T126, T231 , EN 12390-3.