Pad Cap, 4 In (10.2 cm), 50 Durometer, Single

The Compression Pad Cap system consists of reusable Neoprene pads that are contained in steel retainer rings that fit upon the ends of concrete cylinders for compression testing. The Neoprene Compression Pad flows into irregularities and distributes the test load uniformly without creating air pockets to ensure consistent breaks. Pad Caps are made from neoprene and natural rubber and are 1/2 in (12.7 mm) thick.

ASTM C1231 states that unbonded caps are not to be used for acceptance testing of concrete with compressive strength below 1500 psi (10 MPa) or above 12,000 psi (85 MPa).

Choice of durometer (hardness) is determined by the amount of compression with which the cylinder will be tested. Compression pads are available in several hardnesses:

• 50 duro for design strength 1500 to 6000 psi.
• 60 duro for design strength 2500 to 7000 psi.
• 70 duro for design strength 4000 to 12,000 psi*

*Qualifying tests must be performed for strength over 7,000 psi per ASTM.

Pad Caps may be reused up to 100 times when testing in these ranges, however they should be discarded if they show excessive wear or cracking.

ASTM Standard C1231 and AASHTO Standard T22-851