Experiment And Research Of Reactive Powder Concrete’s Shrinkage And Creep Behavior

Reactive powder concrete is a new material which was invented in last ten years of 20th century. In comparison of high-intensity and high-performance concrete, RPC has great advance in many aspects of material properties. Until recently, researchers have known some about the mechanism, manufacturing technology, and mechanic properties of RPC. However, because of the short history of RPC, nowadays, the researches and application of RPC are still expected to improve. As is known to all, concrete shrinkage and creep is two kinds of time-dependent properties of concrete which have significant influence on usage and safety of structures at service stage. In addition, up to now, there are not enough researches of RPC shrinkage and creep effects, which may lead to the diseconomy and danger for design analysis of RPC structures.For these cases, this article reviews the researches of RPC and NC shrinkage and creep. As the result, an experiment research of RPC shrinkage and creep is carried out. Prediction models of RPC shrinkage and creep are proposed based on the analysis of experiment data and classical B3 prediction model. Finally, these shrinkage and creep prediction models are used in a finite element analysis of a 20-meter RPC T-beam, the results of which are compared to that of a normal concrete T-beam with the same dimension as RPC beam. All the conclusions of this research are+ listed below:(1) Based on the codes of normal concrete shrinkage and creep experiment and the special performance of RPC, a unique experiment scheme of RPC shrinkage and creep is designed. In detail, the size of specimens, the creep machines and the strain gages are different from the old ones.(2) Prediction models for calculating shrinkage and creep effects of RPC is proposed. These two models are proposed based on the classical B3 model and regressing analysis of experimental data. In addition, the ultimate values of RPC shrinkage and creep are given out based on the modified B3 prediction models.(3) Finite element models of a 20m RPC T-beam and a NC T-beam with the identical dimension are established on the platform of ABAQUS. Two load cases, including dead load and prestressing load with a period of 7300d, are considered in FE models.(4) Deflection calculated from RPC and NC beams are compared. It shows that deflection of RPC beam is smaller than that of normal concrete beam, and deflection development speed of RPC beam is slower than that of normal concrete model. Additionally, the method which can be used to estimate the final deflection was proposed.(5) Comparison of prestressing loss caused by shrinkage and creep effects from RPC and beams is given. The result shows that prestressing loss of RPC beam is much smaller that of normal concrete beam. The formula for calculating the prestressing loss due to shrinkage and creep effects of RPC beam are further suggested.