The unbonded capping system is comprised of two plated alloy steel retainers and two tough 1/2in,(12.7mm) thick neoprene pads. The pads flow under compression to fill irregularities in cylinder ends and assure load uniformity. Pads are reusable up to 100 times or more with qualification testing. Retainers are permanent with normal use and care. Inside and outside bearing surface of the retainers are plane within 0.002in (0.05mm).
Order Retainer Sets and Pads separately. Pads and retainers for 4in (102mm) and 6in (152mm) diameter specimens comply with latest version of ASTM C 1231. The fifty durometer pads meet tensile strength and durometer requirements of AASHTO T 22 and are appropriate for ASTM C 1231 from 1,500-6,000psi (10-40mPa). Sixty durometer pads cover most common design strengths from 2,500-7,000psi (17-50mPa). Seventy durometer pads may be used for strength from 4,000-7,000psi (28-50mPa) and with qualification testing by user, up to 12,000psi (80mPa). The 6in retainer sets meet acceptable configuration of AASHTO T 22-92 and do not require acceptance testing as do alternative systems. 6in Steel Retainer Est. Ship Wt.: 25lb (11kg). 4in Steel Retainer Est. Ship Wt.: 18lb (8kg).
For quick release of pads from Unbonded Capping Set Caps, use Model HM-277 Quick Release Kit. Polysaccharide powder is a lubricant and bond breaker that extends pad life. Test results are also more consistent. Kit includes 8oz of powder in a Shaker Dispenser and 48oz of refill powder. Order additional filled Dispensers or Powder Refills in packs of two.
