Fig. (8) Illustrating the common method of placing the reinforcement in the construction 

 shown in Fig. (4). The location being at, if not below, the neutral axis at this point, and the 

 absence of cracks in the slabs demonstrate the fact that there is little, if any, tension over 

 the support in this form of construction. See the discussion of this construction on page 11. 



We submit that the enormous loads carried by these slabs, far exceeding all calculations of 

 continuous beam construction, the absence of tension over the support, the tension noted on the 

 rods connecting adjoining beams; all of these points can only be explained by an arch action. 



If no tension exists over the support, it follows that no tensile stresses can be transmitted 

 between adjoining spans. To anchor the reinforcement in the adjoining slabs would imply that 

 the tension would be transmitted over the support. We have seen that the arch construction 

 will not transfer any tension over the support. Hence it must be admitted that there can be no 

 advantage in continuing the reinforcement other than for the practical reasons encountered in some 

 styles of construction. These will be shown subsequently. 



It will be argued that this arch action takes effect only in small span construction. It has 

 been noted in spans up to 15 feet, and this covers all practical cases encountered in flat slabs. 



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