고강도 콘크리트 원주형 공시체의 압축강도 시험을 위한 Unbonded Cap의 사용

Use of Unbonded Caps in Determination of Compressive Strength for High Strength Concrete Cylinders

The effect of unbonded capping system on high strength concrete(400~600kgf/$\textrm{cm}^2$), with respect to both ø10$\times$20 and ø15$\times$30cm specimens, has been investigated in accordance with ASTM C 1231 and our procedures based on the existing studies. Tests show that the ratios of test results obtained using unbonded cap to grinding system are 1.02 in both cylinder sizes. Also, based on the results of ø10$\times$20cm specimens using unbonded cap and ø15$\times$30cm specimens using grinding system, it has been proposed that the use of the former has to spread throughout whole laboratories in field.