Large Reduction of Deflections Due to HPC
This chapter summarises the principal findings of a thesis work which has been done in continuation of various researches. The objective of the research was to show that it is possible to greatly reduce, almost by a factor of two, the long-term deflections of RC structures, in particular RC slabs, through the use of high performance concrete (HPC). The reductions curve is characterized by a "peak" whose magnitude and location depend upon the static system of the slab and the HPC used. The use of HPC provides an interesting solution to the problem of their excessive deformations. The CEB moment-curvature relationship which has been established for ordinary concretes is valid for HPC. The principal difficulty is to find moment-curvature laws which properly represent the behaviour of a concrete structure taking into account the cracking, the time-dependent effects and the reinforcement. The chapter presents a brief description of the test and the results concerning deflections.