Commercial testing of concrete

<p>The material included within this report is the result of a series of tests of concrete specimens taken during the construction of various buildings in the cities of Pasadena and Los Angeles over a period of eight months.</p> <p>The object of the problem is to determine the effect of the water ratio on the ultimate strength of the concrete as obtained from data observed and recorded from specimens taken from actual building practice rather than that from laboratory specimens made under ideal, or at least more nearly standard conditions.</p>