Assessment of the in situ compressive and tensile strength of existing massive hydraulic structures

Federal Waterways Engineering and Research Institute, Karlsruhe, Germany

^* Corresponding author: frank.spoerel@baw.de

Abstract

In Germany hydraulic structures like weirs or locks under the responsibility of the Federal Min-istry of Transport and Digital Infrastructure have an average age of about 80 years. They often show static characteristics, such as construction methods or very large cross sections that are no longer common practice today. When retrofittings are planned new calculations to verify its conformity with stability requirements become necessary. As no adapted regulations have been released for re-assessing the statics of existing solid hydraulic structures a Code of practice has been developed. Compressive and tensile strength derived from concrete cores are decisive input parameters for the calculations. During the last decades concrete cores of more than hundred existing hydraulic structures have been examined by the Federal Waterways Engineering and Research Institute (BAW). These investigations were analysed comprehensively concerning the variation of strength properties and the correlation between compressive and tensile strength in massive hydraulic structures. Furthermore given correlations and factors in technical guidelines which were usually derived by investigations on lab specimen at an age of 28 days were verified concerning their applicability on in situ concrete of old, massive structures. The findings are presented in the paper.