The performance of an admixture for shotcrete in the field varies with the composition of the hydraulic cement and sand combination. Since this test method involves the determination of time of setting of a particular combination of hydraulic cement, sand and an admixture, it therefore provides information on the suitability for use of that particular combination in the field.

The time of setting of the combination established in the laboratory does not necessarily indicate the time of setting this combination will produce in actual shotcreting in the field.

This method is used to determine the effect on time of setting of mortars containing admixtures as compared to a control mortar.

The test method is used for comparison in laboratory pre-evaluation studies to demonstrate the effect of shotcrete admixtures in mortar compared with plain mortar and can be used to demonstrate or compare the performance of shotcrete admixtures which produce rapid setting or rapid rheological stiffening of shotcrete.

The test method is used to evaluate the relative performance of more than one shotcrete admixture for comparison of performance.

The test method is used to determine or verify that no adverse effects on setting time may be experienced with the use of admixtures that are not intended to accelerate or are used to produce stiffening of shotcrete mixtures.

Although specific environmental conditions are indicated, the testing environment can be varied to simulate the performance of admixtures in mortars at different temperatures. Such variations are reported as indicated in Section 11.