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

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 &phgr;s*, illustrated in Fig. 7.103N in EN 1992-3, was proved. Coefficients k&phgr;1 and k&phgr;2 are defined, which enable the calculation of the acceptable reinforcing bar diameter &phgr;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&phgr;1 and k&phgr;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 &phgr;s* depending on the concrete mechanical properties and geometrical properties of an RC tank wall.