Pullout Experiment Study Between Plastic Connector And Concrete In The Plastic-concrete Underground Granaries

Owing to the underground granary's natural low temperature,good sealability,perfect conceslment,and ability to inhibit the occurrence of pests and save the national land resources,the underground granaries are more valuable than the traditional granaries on the ground.Using the lining plastic to solve the underground granaries' waterproof and moisture problems,not only can overcome the inadequacies of the membrane,coating,steel board and other traditional ways of waterproof,but also can achieve the integration of the warehouse wall and foundation support and contribute to the promotion and application of the underground granaries.In this paper,a lot of data collection and field research are done to comprehend the physical,chemical and mechanical properties of commonly used plastics,selecting out the polypropylene as a experimental material.This kind of plastic is provided with advantages like corrosion resistance,high strength,good toughness and safety.In order to study the waterproof problems of the underground granary of plastic-concrete combined structure,this paper researches the pullout performance between the plastic bars and concrete warehouse wall when they combines underground,and experiments are done to analyse if this way of combination is able to resist the water pressure.After summary from much experimental studies on concrete and other materials under pullout conditions both at home and abroad,the pullout performance is researched by the stretching and pullout resistance experiments with polypropylene bars.In the pullout resistance experiment,the destructive forms,the pull force and slip value were analyzed.The sensitivity of each influencing factor of the pullout resistance was studied by using the control variable method.The distribution and trend of the stress and strain on PP bars surface were studied.Through the results of expereiments,the width of the slot has a great influence on the puloutl performance between the PP bars and the concrete.The current slotted form has met the underground 20 metres' deep water pressure environment,but it needs further experiments to explore the most appropriate surface form that meets requirements and is easy to facilitate the mass production.Additionally,the mathematical relationship between the influencing factors and the pullout resistance should be analyzed.