The Influence Of Sleeve Type And Inner Surface Shape On Reinforcement Connection-characteristic

With the development of technology and continuous innovation,which greatly promoted the rapid development of the construction industry.Building parts were assembled at the construction site,the traditional concept and practices of the housing construction has been completely changed.Reducing energy consumption and pollution,protecting ecology and environment;using new materials,applicating new technology;improving project quality,improving work efficiency;reducing field operations;strengthening key technical innovation and system integration were contributed to the housing construction diversification and industrialization,which would be the trends of construction industry.In prefabricated buildings,prefabricated unit were connected by the grouting sleeve for rebar's splicing to form a whole,to resist a variety of adverse external loads.Because prefabricated beams and columns were manufactured in a factory,and its quality was good,however,the joint of each component was weak,which would form an unfavorable structure of strong beam and column-weak nodes.The node destruction was the main way in prefabricated buildings in the earthquake damaged.Thus,in prefabricated buildings,the grouting sleeve for rebar's splicing played a decisive role!With the funds support of National Natural Science Foundation of China(Grant No.51278312),according to rebar connection with grouting sleeve,there have tested the diameter of 25mm rebar couplers for III class reinforcing bar on testing machines.Single direction tension and the repeating of tension and compression in elastic range tests have been done.The results show that experimental Study on grouting sleeve for rebar's splicing was established at static response along the axial direction.The results showed there are three kinds of interaction that exist in the reinforced grouting sleeve connection,respectively is chemical adsorption force,friction force and mechanical bite,including minimum chemical adsorption force,planes,grouting materials and grouting steel sleeve between forces mainly by mechanical bite each other to convey.We researched that static response of grouting sleeve for rebar's splicing was studied by ABAQUS finite element software.The main research contents include:According to the actual structure of grouting sleeve for rebar's splicing,the numerical model of grouting sleeve for rebar's splicing was established at static response along the axial direction.The results showed that umbrella—shaped annular compressed grouting material columns were formed to transfer load between rebar and sleeve.By changing the distribution of sleeve rib,influencing factors of grouting coupler for rebar's splicing were studied.The results indicated that sleeve rib spacing was ranged between 28mm and 14mm,the grouting material could effectively transfer load between the rebar and the sleeve.When the sleeve rib spacing was too large,the grouting material stress was uniform,some parts grouting material Min.principal stress was far beyond grouting material compressive strength;when the sleeve rib spacing was too small,grouting material was sheared,through the shearing stress mainly,grouting material transfer the load between the rebar and load.Grouting material was easy to shear failure;even rebar was pulled out from the sleeve.