Study On Quality Problems And Control Technology Of Concrete Structure Housing In Rural Area

With the construction of the comprehensive well-off society, there has been sharp increase in the total rural house.In the city suburbs, urban-rural towns and villages, there is a large number of multi-layer and high-rise reinforced concrete structure housing. But the design and construction of rural concrete structure residential is very irregular and meet the quality requirements. Lots of quality problems exist in concrete structure housing in rural area, which seriously affects the daily lives and production activities of the majority of rural residents. The thesis is an important part of the project of Ministry of Housing and Urban-Rural Development—"Key technologies and equipment development of residential construction", it studys quality problems and control technology of concrete structure housing in rural area, the contents of which includes five chapters as follows:The first chapter is preface. The research background and significance of the subject is described. Meanwhile quality problems and treatment technology research about rural concrete housing are systematically reviewed. The main quality defect and causes of concrete housing are summarized. In conclusion, the most serious and widespread quality problems of present concrete structure housing are cracks in concrete structures, deviation of protective layer thickness, concrete visual quality defects after construction.the concrete quality problems of concrete structure housing should be controlled from design, construction techniques and quality control of raw materials and so on.The second chapter proposes concrete quality control of raw materials according to literature. The classification and causes of concrete visual quality defects are summarized and analyzed. Concrete defect control measures are put forward from the raw materials and construction.The third chapter analyzes the formation mechanism of concrete cracks based on the concrete tensile stress-strain curve, concrete tensile strength and ultimate tensile. The classification and causes of concrete cracks are summarized and analysed, control principles and requirements of concrete drying shrinkage crack and load crack are highlighted. Based on shrinkage strain formula and crack width calculation of China, the United States and the European norms, factors affecting drying shrinkage and crack width control measures are summarized and compared from the control target value of maximum crack width, the minimum reinforcement ratio, steel net spacing, bar diameter, reinforcement stress, etc. In the forth Chapter, The basic control methods of concrete cracks and basic requirements of structural component quality control are briefly introduced. Concrete parts of structural components easy to crack in housing projects are summarized. The cracks and quality issues in the housing concrete components, such as slabs, beams, columns and walls are analyzed and summarized. Crack control and quality requirements of concrete components are given from raw materials, construction, design and management.In the fifth chapter, the main achievements of this paper are summarized and the further research of this field is pointed out.