Simulation Of Roller-compacted Concrete Compaction Process And Compaction Properties Analysis Based On Particle Flow Code

Compaction properties of roller-compacted concrete(RCC)are important factors affecting the RCC compaction quality.The conventional methods focus on the field or lab experiments and the long-term monitoring data of practical operations,which consume lots of materials and time.In addition,the finite element method(FEM)is based on the assumption that the RCC material is continuous and difficult to simulate the random distribution and motion of aggregates during compaction process.The above methods are difficult to quantitatively analyze the influence of rolling parameters on compaction quality in the macroscopic level.The motion and stress of aggregates under rolling load are important for analyzing the compaction mechanism and interlayer quality of RCC.According to the granular material property of RCC,this thesis is aiming at simulating the compaction process with the particle flow code(PFC)theory.It may provide a new way for analyzing RCC compaction process in the meso-level.The main contents and achievements of this thesis include as follows:(1)Based on the PFC theory,the PFC simulating method of RCC compaction process was presented,and the RCC PFC model was built,as well as the detailed simulation steps were described.(2)Combined with a case,the PFC simulation of compaction process was realized,and the influence of deferent modeling methods with adopting deferent model parameters was analyzed.The changes of contact stress field,velocity field and porosity rate during compaction process were illustrated in the meso-level,and the influence of rolling parameters(exciting force,rolling speed and frequency)on compaction quality were analyzed.(3)The method of building PFC model of RCC sublayer with different curing time was presented.The stress-displacement curves,which are used to build and verify the model,were obtained from uniaxial RCC compression tests.And the PFC model parameters of the sublayer RCC were determined.It will provide the prerequisite for analyzing the interlayer bonding quality control and the aggregates embedding mechanism between adjacent RCC layers.