If asphalt is to be applied to a concrete surface, the concrete should be dry; and it will be found generally more satisfactory to coat the dry surface first with asphalt cut with naphtha. Unless the concrete is heated, it is generally very hard to make the asphalt adhere to the concrete. Hot asphalt applied to ordinary concrete surfaces will generally roll up like a blanket when it cools. The concrete should be heated by hot sand, or the asphalt should be cut with naphtha. When the coat containing the naphtha has been applied - like a coat of paint - and is dry, then the asphalt mastic is applied. The asphalt mastic is composed of 1 part asphalt to 4 parts of sand. This is smoothed off with hot irons, and thoroughly tamped into place. If stone or earth is to be placed next to the asphaltic surface, it is best to cover the surface with roofing gravel to protect the asphalt.

Asphalt paint has been used for a protective coat for all kinds of masonry where earth is to be placed against it.

A coat of asphalt 1/4 inch thick applied with mops to a grout surface, has been used satisfactorily for coating the interiors of tanks, for heads greater than 19 feet, by Mr. J. W. Schaub ("Transactions" of the American Society of Civil Engineers, Vol. LI). Mr. Schaub states that he believes the 1/4-inch coat, in addition to the grout, is sufficient for a water pressure of GO feet.

Fig. 10. Floor of Pure Water Basin.

Fig. 10. Floor of Pure-Water Basin.

TYPICAL FLOOR SLAB CONSTRUCTION ON STEEL FRAME FOR A REINFORCED CONCRETE FLOOR.

TYPICAL FLOOR-SLAB CONSTRUCTION ON STEEL FRAME FOR A REINFORCED CONCRETE FLOOR.

Reproduced by Courtesy of Expanded Metal &Corrugated Bar Company.