Research On Mechanical Performances Of Prestressed Hollow Slabs Strengthened With Carbon Fiber Reinforced Plastic And Polymer Mortar

In the 1960 s and 1970 s,prestressed concrete hollow slabs were widely used all over the country due to its lower price,ready fabrication in factory,easy on-site installation and other advantages.At present,a large number of buildings using prestressed concrete hollow slabs are still in service.However,according to the “GB50292-2015 Standard for appraisal of Reliability of Civil Building”,they could not satisfy the current “GB50010-2010 Code for design of concrete structures”,nor meet the “GB50011-2010 Code for seismic design of buildings” any more.In other cases,buildings taking prestressed concrete hollow slabs as floors from the perspective of the use of construction requirements,building renovation and alteration point of view,there are many problems,many of these buildings need to reinforce the floor reinforcement.Existing researches mostly study on the strengthening influence of carbon fiber reinforced plastic(CFRP)on the bearing capacity of prestressed hollow slabs.Whereas,the compositely reinforced concrete hollow slabs are rarely studied.What is more,whether the prestressed concrete hollow slabs using the composite reinforcement with concrete and carbon fiber reinforced polymer together have a influence on the actual use of existing buildings or not has not been considered.If the composite reinforcement with carbon fiber reinforced polymer and concrete is implied,the net clearance of a building will be affected.In the case of composite reinforcement with carbon fiber reinforced polymer and concrete,the polymer mortar could not only be used as a reinforcement layer,but also as a decoration layer(e.g.,the use of the mortars in floor layings),and thus there will be better comprehensive reinforcement effects.This research makes reinforement study on 9 prestressed concrete hollow slabs.Among them,2 contrastive slabs are unreinforcement,4 slabs are reinforced with carbon fiber reinforced polymer,1 is reinforced with polymer mortar,and 2 are compositely reinforced with carbon fiber reinforced polymer and polymer mortar.Through experiments,the mechanical properties and failure modes of prestressed concrete slabs under different reinforcement methods are studied.the finite element software ANSYS was used to analyze the test slab and compared with the experimental results.Finally,the calculation method and related formula of the flexural capacity of prestressed concrete hollow slabs with carbon fiber reinforced plastic and polymer mortar are given.Also,the restrictions of prestressed concrete hollow slabs reinforced with carbon fiber reinforced polymer are found.