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Calculating of cracking moment for T beam

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Determine the cracking moment for the beam shown in figure 1.
knowing that fc'=27.5 Mpa, and fr=0.7√fc'= 3.67 Mpa=3670kn/m2

Figure 1


  • first step is to calculate the neutral axis


    •                           
    neutral axis=20cm from the top (reference axis shown in figure 2
Figure 2                     






    I=500,000cm4=0.005m4


    cracking moment calculated at extreme tension fiber.
    tension fiber located at 40 cm from the neutral axis=0.4

     

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