Modification of the simplified method of crack control included in EN 1992-3

摘要

The methods of crack control for liquid-retaining RC tank walls are analysed taking into account external load (EN 1992-1-1) and imposed strain occurring at the construction stage (EN 1992-3), i.e. during the concrete-hardening period. The convergence ranges of the simplified method of crack control included in EN 1992-3 and the detailed calculation methods included in EN 1992-1-1 and EN 1992-3 are defined. Apart from the compatibility areas, overestimation of the acceptable reinforcing bar diameter phi(s)*, illustrated in Fig. 7.103N in EN 1992-3, was proved. Coefficients k(phi 1) and k(phi 2) are defined, which enable the calculation of the acceptable reinforcing bar diameter phi(s)* in order to obtain the values complying with the direct calculations. For practical purposes, graphs have been plotted to facilitate the definition of coefficients k(phi 1) and k(phi 2) without performing direct calculations. On the basis of the analyses performed and the relations proposed, it can be concluded that there is a possibility or a necessity to increase or decrease the acceptable reinforcing bar diameter phi(s)* depending on the concrete mechanical properties and geometrical properties of an RC tank wall.