Crack Distribution and Control Analyses of the Vessel

In the uncracked part of the vessel concrete, tie strain assumed is 100 microstrain. Therefore, the average strain in the bonded steel is 

Various theories gave different values of and L and they are tabulated in Seetion 8.2.1.2. 

As the pressure increases more and more cracks are formed and the value of L will be reduced. It is necessary therefore to limit the size of the craeks by providing sufficient bonded reinforcement. The size of the crack is limited to 0.3 mm (0.0118 ) and the number of G.K -I- 60 bars of 1 dia. required to do so 

It is assumed that smaller crack developed in major crack zones is progressively increased to 2 inch (50 mm) width at ultimate load and it is necessary to check the bursting stress in the bar and the bond length required at that stage, in Section 8.2.1.5, analysis is carried out to check the minimum GK-60 inch bond length of steel provided in the vessel. Previous research indicates that at ultimate load 15 (40 mm) dia. GK + 60 bar can span over 2 (50 mm) crack for a stress differential of 40,000 psi. Thus, at ultimate load conditions 2 no. 11 (30 mm) dia bars will still be a reasonable number to control the crack. The number of bars from Brice theory in this area comes out to be 3. Thus, in major crack zones, this number is maintained in either direction as shown in Fig. 8.1 and Table 8.1. 

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