Title:
Effect of Using Unbonded Capping Systems on the Compressive Strength of Concrete cylinders
Author(s):
P. M. Carrasquillo and R. L. Carrasquillo
Publication:
Materials Journal
Volume:
85
Issue:
3
Appears on pages(s):
141-147
Keywords:
acceptability; capping; compressive strength; concretes; cylinders; high-strength concretes; quality control; tests; Materials Research
DOI:
10.14359/1799
Date:
5/1/1987
Abstract:
More than 500 6 x 12-in. (152 x 305-mm) cylinders from concretes having compressive strengths of from 2500 to 16,500 psi (17.2 to 113.8 MPa) were cast and tested using either unbonded caps or sulfur mortar caps, and the results were compared. Unbonded capping systems from two manufacturers were used. The effect of restraining ring dimensions on test results was also investigated. It was found that the use of unbonded caps could provide a cleaner, safer, and cost effective alternative to sulfur mortar for capping concrete cylinders. However, prior to the acceptance of each unbonded capping system, cylinders must be tested using the unbonded caps, and the results must be compared and correlated with results obtained from companion cylinders tested following current ASTM C 39 and C 617 procedures. This applies to all concrete strength levels to be tested.