"STEELCRETE" JV1ESH AND THE PROBLEM OF BOND. 



None the least of the lessons to -be-iearned fronv the -tests -of flat arches is the tremendous 

 importance of securing a reinfoffiemerit in -which the bond attained between the steel and the 

 coricre'te is "a" "maximum. 'This is doubly so; jfiasmuch as the -anchorage cannot be ma.de in the 

 adjoining span but in the. short space available in the haunches of the arch only. This brings us 

 to the bond question. 



When "Steelcrete" Expanded Metal is chosen the question of bond is one about which the 

 "Steelcrete" engineer need have no concern whatsoever. The bond attained between the diamond meshes, 



Bond all under tension, is the most perfect that ingenuity could devise. No possibility of slipping is 



encountered. The connecting ties are stronger than the strands themselves. They do not depend 

 on- the care of a common laborer in their manufacture, as, it is mechanically impossible to vary 

 this tie a measurable -amount. The possibility of slipping is eliminated from, reinforced concrete 

 work. -When -the steel has slippecl.it can. take no stresses from the concrete. 



Steel and concrete, by a fortunate combination of desirable properties, unite to form a build- 

 ing material surpassed by none. In order for them to work together it is evident that the bond 

 between them, should be as nearly perfect as possible, as the stresses must be continually trans- 

 mitted from tjie steel into .the concrete and from the concrete into the steel. It is evident from 

 the inspection of a sheet of ^Steelcrete" mesh that the bond attained by the enmeshing in the con- 

 crete is perfect. There is seen to be no possibility of slippage. In addition to this, the indi- 

 vidual strands have 'the rough surface of a sheared, bar, which makes an ideal grip for the 

 cement. . . .. 



^*"W*i ' 



As a medium 'for mechanical .bond, the surface offered by a wire, galvanized or plain, is 

 obviously inferior. -A slight jnill will destroy the bond, there being no pits or small indentations to 

 mechanically aid the concrete. . This fact having been recognized, cr6ss-wires are either welded 

 to or wrapped around the main longitudinal wires in 6rdef to increase the mechanical bond. 

 These mechanically attached cross-wires do not offer a proper guarantee against slipping. When 

 the main longitudinal wires are subjected to great strain their cross-section is reduced. This 

 reduction of the 'cross-section immediately destroy* the tight hold of the cross-wires, and the 

 mechanical bond offered by them is destroyed. 



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