368 : ANNUAL REPORT 
CEMENT SPECIFICATIONS. 
In the following paragraphs the rules proposed by a committee of the 
American Society of Civil Engineers for the testing of Portland cement 
are given which were submitted to the society, January, 19023: 
On several matters which have been considered, such as the substi- 
tution of a natural sand for the standard quartz, and the tests for the 
normal consistency and constancy of volume, the committee has not 
reached final conclusions. 
SAMPLING. 
J. Selection of Sample.—The selection of the sample for testing 
is a detail that must be left to the discretion of the engineer; the number 
and the quantity to be taken from each package will depend largely on 
the importance of the work, the number of tests to be made and the facili- 
ties for making them. 
2. The sample shall be a fair average of the contents of the package ; 
it is recommended that, where conditions permit, one barrel in every ten 
be sampled. 
3. All samples should be passed through a sieve having twenty 
meshes per linear inch, in order to break up lumps and remove foreign 
material; this is also a very effective method for mixing them together 
in order to obtain an average. [For determining the characteristics of a 
shipment of cement, the individual samples may be mixed and the average 
tested; where time will permit, however, it 1s recommended that they be 
tested separately. 
4. Method of Sampling.—Cement in barrels should be sampled 
through a hole made in the center of one of the staves, midway between 
the heads, or in the head, by means of an auger or a sampling iron similar 
to that used by sugar inspectors. If in bags, it should be taken from 
surface to center. 
CHEMICAL ANALYSIS. 
5. Sitgnificance.—Chemical analysis may render valuable service in 
the detection of adulteration of cement with considerable amount of inert 
taaterial, such as slag or ground limestone. It is of use, also, in deter- 
termining whether certain constituents, believed to be harmful when in 
excess of a certain percentage, as magnesia and sulphuric anhydride, are 
present in inadmissible proportions. While not recommending a definite 
limit for these impurities, the committee would suggest that the most 
recent and reliable evidence appears to indicate that magnesia to the 
amount of 5 per cent. and sulphuric anhydride to the amount of 1.75 
per cent. may safely be considered harmless. 
6. The determination of the principal constituents of cement, silica, 
alumina, iron oxide and lime is not conclusive as an indication of quality. 
Faulty character of cement results more frequently from imperfect prep- 
aration of the raw material or defective burning than from incorrect pro- 
