The Effect of pH on the Workability of Concrete

Citation

Linderman, Robert Bruce (1952) The Effect of pH on the Workability of Concrete. Engineer's thesis, California Institute of Technology. doi:10.7907/C141-5S39. https://resolver.caltech.edu/CaltechTHESIS:12042017-111708147

Abstract

It was believed that the pH of concrete would affect the workability. The effect of pH on the workability was determined experimentally by adding chemical admixtures to a cement mortar mix, measuring the pH and workability.

pH was measured by a Beckman Glass Electrode pH Meter equipped with a standard Calomel electrode and a special type "42" glass electrode. The use of the type "42" glass electrode made it possible to place the electrodes in wet cement mortar without damage.

The workability was determined by measuring the penetration of a three inch diameter cylinder with a hemispherical tip. This ball penetration measure of workability has a linear relationship to that measured by the slump test.

From these tests it was found that the pH has no effect on the workability of cement mortar. The admixtures changed both the pH and the workability, however, the variations in pH and workability were independent of each other. It is believed that the major factor which affects the workability of concrete is the dispersing effect of the admixture on the cement.

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