22 
The proper method of handling the cement is sometimes con- 
siderably affected by the requirements which the specifications pro- 
vide regarding tests. Some specifications require that the cement 
shall be held until the results of the 28-day test are reported, while 
others permit its use as soon as it has satisfactorily passed such 
tests as may be made within seven days. If any tests of consequence 
are required and the sampling is not done until the cement arrives at 
the nearest railroad station, it will be necessary either to unload and 
store it or pay demurrage charges. This difficulty may be overcome to 
some extent by placing an inspector at the cement plant to collect and 
forward samples to the testing laboratory as soon as the cars are 
loaded. The testing may then be begun while the cars are en route. 
Another plan sometimes employed to lessen the demurrage and 
avoid rehandling is to purchase bin-tested cement and have the cars 
loaded under the supervision of an inspector. "When this is clone, the 
cement may be used as soon as it" arrives on the work, but the custom 
of cement manufacturers to make a slight additional charge for bin- 
tested cement may entirely offset the economical advantages gained by 
its use. 
Xo matter what the arrangements for testing the cement may be, 
provision should usually be made for storing near the work sufficient 
cement to keep the mixer going for four or five days, in case that 
shipments are delayed, as frequently happens. 
In general, the most. satisfactory method of hauling the materials 
for the concrete is by means of an industrial railway constructed 
along one shoulder of the road, though this method is not always the 
most economical. Teams, traction engines with trailers, and motor 
trucks with or without trailers have each been frequently used for 
this purpose, and are no doubt each economically best adapted to 
certain sets of conditions. But all of these are objectionable from a 
construction standpoint on account of the damage which they usually 
do to the subgrade. 
Among the advantages possessed by an industrial railway for haul- 
ing the concrete materials are : 
(1) Materials may be delivered without disturbing the subgrade. 
(2) The railway may be readily operated along the shoulder of a 
newly laid pavement, which makes it practicable to prosecute the 
work at any desired point. 
(3) Hauling is affected comparatively little by weather conditions. 
(4) Where there is sufficient work to keep an industrial railway 
outfit busy, it is usually economical, especially where the size of 
the projects is such that the railway can be operated continuously 
throughout a season on the same project. The purchase of an indus- 
trial railway outfit, however, usually involves a greater outlay of 
capital than is desirable for a single project. 
