140 



3. Slructiiral Steel. Embedded structural steel shall be coated with at least 2^2 

 inches of concrete. The protective coating shall be reinforced with gah'anized wire 

 mesh of at least No. 13 wire on 4-inch centers embedded 1 inch from the surface. Before 

 structural steel is coated with concrete it shall be given two coats of red lead, one shop 

 coat and one field coat, and a final coat of graphite paint. 



4. Timber. Kmbedded timber, such as encased piles, shall be coated with at least 

 21^ inches of concrete placed in the dry and thoroughly tamped. The protective 

 coating shall be reinforced with galvanized wire mesh of at least No. 13 wire on 4-inch 

 centers embedded 1 inch from the surface. Concrete protections of embedded timber 

 members shall extend from above high tide to at least 3 feet below the mud line. 



SECTION E 

 Constructing and Driving Concrete Piles 



1 . Reinforced Concrete Piles shall be composed of one-to-five concrete of the quality 

 hereinbefore specified and shall be constructed to the dimensions and of the shape 

 shown on the plans. Reinforcing steel of the size and quantity shown on the plans 

 shall be placed in the manner hereinbefore specified. Each pile as it is cast shall be 

 dated and no piles shall be handled until at least forty (40) days after being cast. 

 In handling, piles shall be uniformly supported with slings or skids to prevent cracking 

 or other damage. The method of handling shall be satisfactory to the Engineer and 

 any pile cracked or damaged in handling or driving which is rejected by the Engineer 

 shall be removed by the Contractor and replaced without extra cost to the Owner. 



Piles shall be accurately spaced and driven to the depths shown on the plans, 

 or to refusal, as the Engineer may direct. Unless otherwise authorized the driving shall 

 be done with a steam hammer having a striking part weighing 5,000 lbs. and a normal 

 stroke of 36 inches. If required by the Engineer, a water jet shall be used simul- 

 taneously with the driving. Where piles are driven into loose rock or rip rap, a steel 

 point bull-dozer shall be driven at the location of each pile immediately preceding 

 the driving of the pile. Pile heads shall be stripped of concrete to a neatly cut square 

 face at the cut-off' line shown on the plans. In case cracking due either to stripping or 

 to driving extends below the cut-off line indicated, the stripping shall be extended 

 until a square face of uncracked concrete is obtained. If by order of the Engineer 

 piles are not driven to the elevations shown on the plans, the Contractor shall cut 

 them off and strip the tops without additional cost. 



2. Concrete Jacketed Piles shall be made up of a timber pile encased in a concrete 

 coating from below the mud line to above the high tide line. Unless otherwise specified 

 concrete coatings shall be precast as hollow casings which are placed in position and 

 grouted after the pile has been driven. Pre-cast concrete coatings shall be constructed 

 of the materials and in the manner specified above for reinforced concrete piles. The 

 depth of penetration below the mud line shall be determined by the Engineer. The 

 space between pile and casing shall be sealed at the bottom and pumped out before 

 filling with grout. 



APPLICATION OF SPECIFICATIONS TO CONSTRUCTION CONDITIONS 

 The problem of durability in marine concrete construction has become confused 

 through the general grouping of all sea water exposed structures without regard to 

 many factors which affect durability, irrespective of the quality of concrete. The 

 influences affecting durability may be combined for study and discussion as those 

 relating to the type of structure exposed and those relating to the nature and intensity 

 of exposure. Effects of type include such considerations as size and mass of structure; 



