METHODS OF SAMPLING AND TESTING HIGHWAY MATERIALS 7 
36. In making the determination. 500 grams of cement, with a measured quan- 
tity of water, shall be kneaded into a paste, as described in section 33. and 
quickly formed into a ball with the hands, completing the operation by tossing 
it six times from one hand to the other, maintained about 6 inches apart: the 
ball resting in the palm of one hand shall be pressed into the larger end of the 
conical ring held in the other hand, completely filling the ring with paste : the 
excess at the larger end shall then be removed by a single movement of the 
palm of the hand : the ring shall then be placed on its larger end on a glass 
plate and the excess paste at the smaller end sliced off at the top of the ring 
by a single oblique stroke of a trowel held at a slight angle with the top of the 
ring, and the top smoothed, if necessary, with a few liiiht touches of the pointed 
end of the trowel. During these operations care shall be taken not to compress 
the paste. The paste confined in the ring, resting on the plate, shall be placed 
under the rod. the larger end of which shall be brought in contact with the sur- 
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face of the paste ; the scale shall then be read, and the rod quickly released. 
The paste shall be of normal consistency when the rod settles to a point 10 
millimeters below the original surface in one-half minute after being released. 
The apparatus shall be free from all vibrations during the test. Trial pastes 
shall be made with varying percentages of water until the normal consistency 
is obtained. Each trial shall be made with fresh cement. The amount of water 
required shall be expressed in percentage by weight of the dry cement. 
37. The consistency of standard mortar shall depend on the amount of water 
required to produce a paste of normal consistency from the same sample of 
cement. Having determined the normal consistency of the sample, the consist- 
ency of standard mortar made from the same sample shall be as indicated in 
Table 1, the values being in percentage of the combined dry weights of the 
cement and standard sand. 
