Numerical Simulation Study Of Bond-slip Between Bamboo Bars And Concrete

Steel reinforced concrete has been widely used since it was invented because its superior mechanical properties.However,they need consuming large amounts of resources non-renewable resource and the waste causes great damage on ecological environment when the steel bar was been made.With the sustainable architecture and the green building was put forward,scholars pay great attention to bamboo because it is renewable and environmental.But it develops slowly because of bonding strength between bamboo and concrete low material strength.In order to understand the problems of bonding performance between bamboo and concrete,in this paper,some researches is made:(1)In order to solve the problem of bonding performance between bamboo and concrete,the methods that bamboo surface is coated with epoxy and attached with sands and bamboo piece are proposed.And then,the drawing test of Bamboo reinforced concrete is studied.Results show that the bamboo reinforced concrete destruction forms are mainly the slip appear between bamboo and concrete so that bamboo pulled out;When bamboo surface is coated with epoxy and attached with sands or bamboo piece,the bamboo reinforced concrete exhibits better bonding performance,and the former is better.(2)In order to understand the effects on the bonding performance,different strength grade of concrete and different bamboo length are studied.After the bamboo reinforced concrete bond-slip test which the bamboo surface is coated with epoxy and attached with sands,a constitutive relation model of bond-slip between bamboo and reinforced concrete and bond strength calculation formula and the calculating formula of anchorage length was presented,the formula is scientific and reasonable.(3)Nonlinear finite element analysis of bamboo reinforced concrete beams with ABAQUS program was conducted in two cases considering and not considering the bond-slip performance between bamboo and concrete.Te failure process,bearing capacity of bamboo reinforced concrete beam,and the development of the cracks are studied.The different reinforcement ratio and different ways to deal with bamboo bar surface effect on bamboo bars and concrete strain coordination are analyzed by establishing a finite element model.The results show that:the ratio of the concrete strain and the bamboo reinforcement strain basically stable around 2.00 in cross section under different bamboo ratio when the beam damage.The treatment methods on bamboo surface affect on the ratio of the concrete strain and the bamboo reinforcement strain seriously.When bamboo bar surface without treatment,the strain ratio is 3.16,and the surface of bamboo attached with sands,the strain ratio is 2.03,and the surface of bamboo attached with bamboo piece,the strain ratio is 2.69.(4)Researches on bearing capacity calculation is carried out based on considering the slip between bamboo bars and concrete.(5)Bond-slip models are simulated using Spring2 element in the case of considering slip.In order to understand the effects on the properties of bamboo reinforced concrete beam,concrete strength grade of concrete,concrete cover degree,beam section height and different ways to deal with bamboo bar surface are studied.