Flexural Behavior Of Reinforced Concrete Beams Reinforced By Steel Fiber Ferrocement Mortar

Reinforced concrete structures are the widely used structures. In China,there are lots of reinforced concrete structures that need to be rehabilitated due to bad construction,long-term use,improper maintenance or alteration of function. The commonly used reinforcement methods are FRP,steel plate and the traditional section increment method etc.Steel fiber cement mortar reinforce technology is a new method to reinforce the concrete structure. Steel fiber cement mortar is a new composite material which is made by the motor with addition of steel fiber. It overcomes shortcomings of ordinary mortar, including the low tensile strength, small ultimate elongation and poor crack resistance, instead it has advantages with better bending strength and impulse strength, abrasion resistance, high fatigue strength.The characteristics of working materials endow them with a prosperous prospect.However there is no relative research reports on this technic in China. Investigation and analysis must be made to test the rehabilitation effect of this technic,proper calculating method should be established so as to accelerate the application of this kind of rehabilitation technic.In this dissertation, firstly, some basic materials mechanics performance tests have been tested to the steel fiber ement mortar,then,the author conducted a flexural behavior study of reinforced concrete beams reinforced by steel fiber cement mortar reinforce technology.A contrastable beam and six test beams reinforced with steel fiber ferrocement mortar technology are introduced. By changing the reinforcement ratio and the force pattern of reinforced steel bar, the influence of ultimate load, mode of failure, section stiffness and fissure's distributing with this strengthening method is investigated. On the basis of the trial,through the theoretical analysis, formulas are proposed for the interval and width of cracks and stiffness of section. Then used the ANSYS software carry on the non-linear finite element analysis on three beams, in order to testify the effectivity of strengthening method ,and the test values are compared with the results of model. Finally, introduced the strengthening method construction technics and the performance test method with a project example.In this thesis, through research the flexural behavior of reinforced concrete beams which reinforced by steel fiber cement mortar,we provide the part basis to authorize the regulation of the fiber mortar to reinforce the RC structure technology, and has impotant theory value and the practical significance to accelerate this reinforcement technology.