A limited Investigation of Capping Materials for Concrete Test Specimens
Thomas B. Kennedy
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An investigation was made of the influence of type and age of cap on the apparent strength of concrete cylinders. The capping materials tested consisted of two types of commercial sulfur-silica compounds and two commercial plasters which had been in general use for this purpose. A total of 252 tests were made of concrete ranging in strengths from 2800 to 7500 psi. The results indicate that the age of the caps has an important bearing on the apparent strength of the concrete with I hr being the minimum time re-quired for the best of the materials to develop the full strength of the concrete.