The tests of the permeability of cement mortars and concretes, and of
water-proofing and damp-proofing materials, have numbered 3,470.
The results of the work of the Structural Materials Division have
already appeared in preliminary bulletins, as follows: No. 324, “San
Francisco Earthquake and Fire of April 18, 1906, and Their Effects on
Structures and Structural Materials”; No. 329, “Organization, Equipment,
and Operation of the Structural-Materials Testing Laboratories at St.
Louis, Mo.”; No. 331, “Portland Cement Mortars and Their Constituent
Materials” (based on nearly 25,000 tests); No. 344, “Strength of
Concrete Beams” (based on tests of 108 beams); No. 370, “Fire-Resistive
Properties of Various Building Materials”; No. 387, “The Colloid Matter
of Clay and its Measurements.” A bulletin on the results of tests of
reinforced concrete beams, one on the manufacture and chemistry of lime,
and one on drying tests of brick, are in course of publication.