New Formula to Calculate Minimum Flexure Reinforcement for Thick High-Strength Concrete Plates

Most concrete codes have empirical equations to estimate the minimum steel reinforcement requirements for flexural members. High-strength thick concrete plates are used for offshore and containment structures for nuclear power generation. An accurate estimate of the minimum steel flexure reinforcement ratio can result in saving millions of dollars for a single project. The recommended concept utilizes the fracture mechanics principles to modify the sandwich panel model and account for thick slabs. A comparison between the proposed equations with experimental tests carried by Battista is conducted; also, a comparison of the proposed equation with different code formulas is illustrated. The results obtained by the proposed equations are confirmed by the Norwegian code (NS 3474E) and suggestions by Bosco and Carpinteri. In summary, the two new main contributions in this research are as follows: the first contribution considers the size effect through fracture mechanics, and the second contribution considers the torsional moment for thick plates in calculating the minimum reinforcement of thick plates.