The blocks, after being cleaned from adhering dirt, should be set with reasonable care, well bedded in the sand cushion, and laid at such an elevation below the completed pavement surface, that after being well rammed, the surface will be at the proper elevation below the pavement datum.
The grouting of the joints is the most important part of the work. See that the mortar is made and used in accordance with the specifications, and that the joints are completely filled.
27. Broken Stone Foundations.—The specifications for broken stone foundations are sufficiently explicit, and compliance should be insisted upon. Thorough rolling is especially important.
SHEET ASPHALT PAVEMENTS
28. The manufacture of the mixture for sheet asphalt pavement, and the laying of it on the street, involve a number of separate elements or operations. The quality and durability of the pavement will depend largely upon the skill, intelligence and accuracy with which each and all parts of the work are carried out. The inspector, both at the mixing plant and on the street, must give constant and intelligent attention to the work.
29. Inspecting at Paving Plant.—Inspectors at the plant where the asphalt paving mixture is made will be provided with the following apparatus:
1 nest of standard sieves, Nos. 10, 30, 50, 80, 100 and 200 2 thermometers for sand 1 tank thermometer 2 standard flow-plates and one dozen cartridges for same 1 balance for weighing sand 6 dishes, glass or porcelain, 4 inches in diameter.
30. The more important things for the Plant Inspector to watch during the manufacture of asphalt paving mixture are:
a. Quality and grading of the sand. b. Temperature of heated sand. c. Uniform quality of the refined asphalt and flux. d. Temperature of melted bitumens. e. Uniform consistency of asphaltic cement. f. Correct ratios of sand and asphaltic cement. g. Thorough mixing of materials.
31. Sand.—The general quality and grain-size of the sand, required by the specifications, must be closely watched and adhered to.