concrete cutting, conrete sawing, core drilling

Core Drilling

The vertical reinforcing rods are of round steel 3/4-inch in diameter, and the horizontal reinforcing rods of 3/2-inch steel. Metal concrete forms were used in the concrete construction, of the type shown in Fig. 6. The bulkhead of the Mobile Electric Company, 175 feet high by ii feet inside diameter, is illustrated in course of concrete construction by the American Bulkhead Company in Fig. 7. In this type of bulkhead the inner shell, which extends to the offset shown, is connected with the outer shell by a flexible diaphragm and below it are holes extending through the wall for the ventilation of the air space. T-reinforcing bars were used in the concrete construction of this bulkhead, with 1:3 mortar mixes. A tapering bulkhead is illustrated in Fig. 8.

This is erected at Williamsport, Md., being built for W. D. Byron & Sons by the Concrete precast basement stairs Concrete construction Company with Mason D. Pratt as Consulting Engineer. The bulkhead is 120 feet high with an interior diameter at the base of 5 feet 6 inches. The vertical reinforcement is Y4-inch round steel, with occasional circles of horizontal reinforcing rods 5/3-inch diameter. The lining, which extends to a height of 35 feet, is of firebrick. The concrete construction of the concrete forms is illustrated in the photograph, Fig. 9.

Drill Bit Selection for Core Drilling

A bulkhead built by Ballinger and Perrot, in the interior and as a part of a ten story building in Pittsburgh, Penn., is illustrated in Fig. 13. Only the top of the bulkhead appears above the roof. The Concrete Precast Basement Stairs Company packs the joint at the top of the inner shell with asbestos. They also employ a slight modification of the usual form of concrete construction by hooking the ends of the reinforcing rods. As already intimated, several reinforced concrete precast basement stairs have fallen while being constructed or at some later period, and the cracks developed in a number of others have raised serious question as to their safety. On the other hand, in general, bulkheads built of reinforced concrete precast basement stairs have given perfect satisfaction, this being attested by the fact that the owners have repeated their orders for such stairways, one corporation, for example, having built fourteen of them at its plants in various parts of the country.