I From Cement and Concrete (a general reference book), Portland Cement Association
,1929.2 Shipments in 1928; Bureau of Mines statistics, 175,838,332 barrels.
568 MINERALS YEAREOOK


probably is slightly higher than it might have been if they had been built
in a period of economy and conservatism.
 The third class of plants includes those built primarily for economy of
operation and low unit cost regardless of ultimate output. Developments in
Europe are characteristic of this trend.
 The obvious procedure would seem to include wholesale replacement of existing
plants with more modem equipment designed to reduce production costs. The
solution, however, is not so simple. As depreciation, interest, and tax charges
make up a considerable part of the final production costs, any contemplated
new venture or modernizing. program, unless carefully planned, may increase
overhead charges enough to more than offset savings in actual manufacturing
costs. Continuation of adverse economic conditions such as prevailed in 1932
tend to force an adjustment of the situation. Furthermore, agitation among
architects and engineers for cement approaching high-early-strength properties
but at no increase in price may encourage producers to rebuild obsolescent
plants.
 New developments.—Although no new cement plants were built in 1932,
persistent rumors of piomotional activities were prevalent, and stock in
a company proposing to build a plant in the Lehigh district was offered for
sale during the year. Remodeling and modernizing construction was reduced
to a minimum due to the curtailed income of virtually all cement companies.
Despite the drastic slump in production, however, the Portland Cement Association
continued with increased vigor promotion of cement for all classes of construction.
 Considerable publicity was given to experimental highways of cement-bound
macadam. Wide adoption of this type of highway would open a large market
for portland cement in secondary road construction. Concrete in residential
construction, especially concrete joists, a system of precast reinforced-concrete
mine timbering, wider use of concrete in large monolithic structures, and
concrete mats for levee and flood-control work also offer potential outlets
for large quantities of cement.

MARKETS

 The Portland Cement Association released the following estimate of cement
distribution by consuming markets for 1928, the peak year of cement shipments.

Distribution of portland cement by consuming markets, 19~8 1
.
Percent
Barrels

Concrete roads, streets, alleys, curbs and gutters, and pavement bases  
    
Structural concrete in commercial, industrial, public, and private buildings
of
ailtypes                                                    
Rural uses exclusively, including products and all farm structures of concrete
- -
Concrete products, including block tile and brick, cast stone, and stucco
but not
products used on farms                                         
Railways, all uses, including street railways                           
Sewerage, drainage, irrigation, culverts, concrete pipe, draintile, and specialties....
Sidewalks and private driveways, exclusive of rural                     
Bridges, river and harbor works, dams and water-power projects, storage tanks,
and reservoirs                                                
32. 5
25.0
15.5

7.5
6.5
5.0
4.0

4.0
57,000,000

43,900,000
27,200,000

13,200,000
11,500,000
8,900,000
7,000,000

7,000,000
.
Total                                                   
100.0
2 175,700,000