220 ANNUAL REPORT 
‘The specifications in use in Peoria, Illinois, are as follows: 
CONCRETE FOUNDATION. 
28, Thickness, —Upon the sub-grade prepared in accordance with the 
specifications for grading, will be laid a concrete foundation six (6) inches 
thick after being compacted. 
29. Proportions, —-The concrete shall be composed of one (1) part by bulk 
of American Natural Hydraulic Cement, one and one-half (1%) parts by 
bulk of clean, sharp sand, and four (4) parts by bulk of broken stone. 
30. Intention of Proportions, —The proportions herein specified are in- 
tended to produce a concrete in which the mortar will fill all the voids, and 
the proportions will be so adjusted that when rammed in place free mortar 
will flush to the surface. 
MIXING AND SPREADING CONCRETE. 
33, Mixing Sand and Cement.—The sand and cement shall be thoroughly 
mixed dry in a tight mortar box and then made into a mortar of the proper 
consistency and thoroughly worked over with hoes. Broken stone thoroughly 
cleaned of dirt, drenched with water, but containing no loose water in the 
heap, shall then be added to the mortar in the proper proportion. The con- 
crete will then be turned and mixed until mortar adheres to each fragment. 
32, Consistency of Concrete, —The concrete thus mixed shall have such 
a consistency that when rammed the mass will not shake like jelly; but will 
when struck, compact within the area of the face of the rammer without 
displacing the material laterally. 
33. Immediate Use of.—The concrete thus prepared shall be immediately 
placed in the work. It shall be spread and thoroughly compacted by ramming 
until free mortar appears on the surface. 
34, Mixing and Laying,—The whole operation of mixing and laying each 
batch of concrete shall be performed in an expeditious and workmanlike 
manner, and be entirely completed before the cement has begun to set. 
35, No Re-tempering,—No re-tempering of concrete will be permitted, and 
concrete in which mortar has begun to set will be rejected. 
36. Conform to Grade. —The upper surface of the concrete shall be made 
to conform exactly to the form of the pavement to be laid, and shall be made 
perfectly smooth by thoroughly brooming with wire brooms. 
37. Protection, —AS soon as laid, and before the top becomes dry, the 
entire surface of the concrete foundation shall be covered with one (1) inch 
in depth of clean sand to protect it from the sun and wind. The sand so 
spread shall be kept moist until the pavement is laid. 
38. Time for Setting, —-No driving over the concrete foundation will be 
permitted, and it shall be allowed to set for four days before any further 
work shall progress on the same, and any damage done by passing over 
it shall be repaired by the Contractor without extra pay. 
39, Minimum Temperature When Laid,—No concrete shall be laid when the 
temperature at any time during the day or night falls below thirty-five (35) 
degrees Fahrenheit. 
