SAMPLING AND TESTING HIGHWAY MATERIALS. 
67 
In making the slump test in the laboratory or in the field it is recommended that 
the form be filled immediately after mixing and withdrawn three minutes after 
mixing has been completed . 
When central mixing plants are used slump tests shall be made at the plant and 
at the end of the haul . At the plant the sample or concrete shall be taken after the 
h 4-" 
PLAM 
Fig. 35. — Cone for concrete slump test. 
entire batch has been discharged from the mixer. At the end of the haul the slump 
sample shall be taken from the batch after it has been dumped on the subgrade. 
The slump at the points of deposition shall be suitable for the particular type of 
finish employed. 
