THE EFFECT OF CONCRETE STRENGTH, PRESTRESSING SYSTEM, T-HEADED BARS AND STEEL LINER SYSTEM ON THE PUNCHING PERFORMANCE OF CONCRETE PANEL SPECIMENS SUBJECTED TO IMPACT LOADS

摘要

The protection of Nuclear Power Plants (NPP) against aircraft crash impact is a safety requirement and is considered in nuclear regulators and organizations. Candu Energy participated in the internationally organized IMPACT program at VTT's testing facilities in Finland since 2006. After successfully completion of IMPACT Phase I & II testing program, Candu Energy has developed a total of four punching test specimens labelling P7, P8, P9 and P10 as a part of IMPACT Phase III testing program to study a number of parameters affecting local impact behaviour and in particular high-strength concrete which has not been accounted as a significant effective parameter during Phase I and II. All of these specimens including high-strength concrete specimens are reinforced with bending reinforcing bars, T-headed bars and prestressing dywidag rod system. In addition these four specimens have steel liner plate combined with anchorage system. The test specimen is a prestressed concrete panel subjected to a projected hard missile mass with relatively high impact velocity. The purpose of the above testing program is to demonstrate that a single containment structure will be capable of resisting large commercial aircraft crash impact and meeting both Canadian and international regulatory design requirements. In addition, the result of this testing program can be used in numerical simulations. This paper presents the experimental results of three specimens, P7, P8 and P9 performed (the specimen P10 in progress) from IMPACT Phase III testing program. In addition, the results of these tests are compared with C2 and C21 specimens from previous IMPACT II testing program in order to evaluate the effects of T-headed bars and concrete strength on the performance of concrete panel specimens subjected to missile impact loads. Successful completion of this program provides technical information to account for the effect of high-strength concrete, prestressing, T-headed bars and liner anchorage system and will be also presented.