Research On Fluidized Bed Ash Roller Compacted Concrete For Rural Highway Pavement

With the rapid development of the construction of new socialist countryside in China,the construction of rural low-grade road has become an important task of transportation departments at all levels.In our country,especially in the western mountainous areas,the main problems confronted by the construction of the rural rural highway include: the length of the rural way is considerable,the traffic flow is small,the construction funds are in shortage,technical strength is weak,the construction is difficult.Therefore,it is of great social demand and broad prospect to develop the construction material and construction technology which are suitable for the rural highway construction in mountainous areas.This paper is based on the projects of "the application of RCC in mountainous rural areas","the application demonstration of FBC ashes roller compacted concrete on rural highway pavement".In view of the characteristics of the fluidized bed ash and combining with the requirements of the rural highway,the fluidized bed ash roller compacted concrete applied on rural highway pavement is analyzed by elaborating the two aspects of the material properties and its structure.According to the characteristics of construction techniques of vibrating compaction of roller compacted concrete,firstly,by combining with the vibration forming theory of roller compacted concrete and the mathematical model of vibration molding machine,the paper processes and improves the reforming plate vibration instrument through the comparative study with the actual construction equipment.It also uses the contrast method to compare the improved reforming plate vibration instrument with the traditional one so as to verify its rationality.According to the characteristics of fluidized bed ash,the basic characteristics of fluidized bed ash including chemical composition,physical properties and morphology are researched.The effect of fluidized bed ash on the performance of mortar is studied by means of the testing the mortar so as to analyze the effect of fluidized bed ash content for mortar fluidity,compressive strength and flexural strength.By summarizing and analyzing,it is concluded that the fluidized bed ash content is not more than 30%and the content of 20% is the most effective one.By consulting the relevant literature,the paper confirms the method of orthogonalexperiment design;it uses the volume method to carry out ratio calculation;based on the relevant principles of materials science,it analyzes the law of the various influence factors for the ash roller compacted concrete in terms of improvement of the value,strength and wear rate of VC so as to optimize the proportion design of roller compacted concrete of fluidized bed ash.The result that the effect is best when the ash content for the fluidized bed is 20% is demonstrated.Then,according to the optimal design,the influence of the fluidized bed ash content and the deposited time of the concrete on the workability of the roller compacted concrete is studied;the influence of fluidized bed ash content,water binder ratio and different cement types on mechanical properties and wear resistance of compacted concrete is also studied so as to provide a reference for the design and structure analysis of the compacted concrete pavement of the ash roller fluidized bed.In combination with the characteristics of rural highway pavement,the pavement thickness design is carried out according to the characteristics of roller compacted concrete of the fluidized bed ash and determine that the road of "the application demonstration of FBC ashes roller compacted concrete on rural highway pavement" is constructed with filling macadam as the base layer.The thickness of the base layer is100 mm and surface layer is the roller compacted concrete of fluidized bed ash with its thickness being 200mm;what is more,the stress analysis of pavement structure was carried out by FE EVER software.According to the performance of raw materials for construction engineering,the design of proportion of each material is made so as to obtain the most reasonable scheme;through the preparation phase,trial stage and construction stage,the construction technology which is feasible and economical of the roller compacted concrete pavement of rural road is put forward;the benefit analysis of the project is carried out from three aspects of economy,society and environment.This project has realized the design from the experiment in the test room to the design of the roller compacted concrete and than to the whole process of practical construction.The results of the study provide a new method to solve the problem of fluidized bed ash disposal.It also provides a new idea for the resource utilization of industrial wastes,such as fluidized bed ash and so on.