Study On Manufacturing Processes Design And Quality Control Of PC Track Beams

Developing rapid rail transit has become a strategy and a general trend in China's large cities and mega-cities in the present and the future. Developing rapid rail transit (including new passenger transport system), which is considered in the long run to slow down traffic congestion in major cities and regional roads, provides one of the effective ways to improve travel safety, efficiency, environmental protection. The development of urban rail traffic should be achieved at a multi-level, diversified, three-dimensional coordinate development in terms of the socio-economic level, the town geographical conditions and urban layouts.In straddled-type monorail traffic system, the PC track beam is not only a load-bearing structure, but also vehicles running track, accordingly it is necessary to ensure its strength requirements while ensuring the efficient use and comfort for passengers. Therefore the track beam is required to be characterized with high-precision, high-strength and durability which others structures or other ordinary beams do not have.This paper summarizes main track beam characteristics in the current application of all types of PC, including structure, load and stress method, based on this, the general requirement for the PC track beam quality is proposed.Manufacturing process of PC track beams are designed in strict compliance with the corresponding technical standards. Specific requests for the raw materials of PC track beam is put forward by comparing a large number of test results, and taking engineering application characteristics as a standard. Concrete bridges are not only required, but also other five specific kinds of components, including non-prestressed reinforced, pre-stressed Strand, embedded parts, anchorage and bearings, are required. The entire manufacturing process of PC track beam plays a crucial impact to its quality during use. The entire manufacturing process will be broken down into 22 major steps, including steel production, internal model production, car caving line, the installation of bearings, steel group, embedded parts installation, the installation of corrugated pipe, end module assembly, installation- formworks, erecting formworks, concrete mixing concrete reperfusion, clean concrete surface, conservation, tension, grouting, anchor closed, blocking, PC track beam surface, hoisting and storage, and the key parts in each step is proposed for specific requirements. In order to satisfy the requirements of high strength and durability for PC track beam, we achieve more reliable concrete determining method by summing up large test study. Reliability and economy are considered in the choice of Concrete raw materials. By analyzing contrast experimental results, and summing up specific targets to control the quality of cement, fine aggregate, coarse aggregate, active mineral admixture, additives, water and others, purposes of controlling PC track beams quality is achieved. Then by comparison, it is indicated that admixture and additive have important influence on mechanical properties of high-performance concrete. Basing on satisfying basic requirements of concrete mix proportion, we could determine the optimal sand ratio and sand varieties through a large amount of tests, and scientifically adjust the mixture ratio in accordance with the specific situation on the construction site.The manufacturing process of PC track beams is not only requested, but construction quality is required to strictly control, for guaranteeing performance requirements for straddled-type monorail traffic system. The first PC track beam construction quality control is the control of raw materials. Then we could gain quality control standards for raw materials through a large number of test results. Finally, by summing up practice, considering transportation, pumping, pouring, destroyed the vibration, form removal and maintenance as the main construction technology processes, and we put forward specific requirements for all quality controlling procedures above.