No coin nor oath required. For personal study only.
547 25 to 30, 30 to 40, 40 to 50, 5 ° to 60, 60 to 7 o, 85 to IOO, IOO to I2O, I2O to 15o, 15o to 2oo; for joint filler for various types of construction : 3o to 5o, 5 ° to 6o, 6o to 7 o, 85 to IOO.
The first is used primarily for brick pavements and does not require the admixture of sand, whereas the latter three, which are identical with three of the grades adopted for asphalt pavement construction, are those which would ordinarily be used in admixture with sand to produce an asphalt grout.
In adopting these limits, it is understood that the producer will furnish asphalts with penetration equal to the midpoint in each range, a plus and minus tolerance from that midpoint being acceptable to all parties, but in n.o case shall the deviation exceed the limits of the grade specified.
This recommendation is to become effective oi1 all deliveries of material after January I, 1924.
📜 SIMILAR VOLUMES
IN conformity with the general policy of the Government in restricting expenditures wherever possible without serious detriment to the public service, the Bureau of Standards has, during the fiscal year ended June 3 ° , 192I, confined its activities to the more urgent research problems and testing.