It was believed that the pH of concrete would affectthe workability. The effect of pH on the workability wasdetermined experimentally by adding chemical admixturesto a cement mortar mix, measuring the pH and workability.
pH was measured by a Beckman Glass Electrode pHMeter 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 inwet 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 workabilityhas a linear relationship to that measured by the slump test.
From these tests it was found that the pH has no effecton the workability of cement mortar. The admixtures changedboth the pH and the workability, however, the variations in pHand workability were independent of each other. It is believedthat the major factor which affects the workability of concreteis the dispersing effect of the admixture on the cement.
