Study On Uniaxial Tensile Principal Structure Relationship Of Bamboo Fibre Concrete

Bamboo fibres are inherently easy to obtain,low cost and abundant,and they also have good tensile properties.The addition of bamboo fibres to concrete not only brings good economic benefits but also improves the tensile properties of concrete.Most of the current research on bamboo fibre concrete is focused on mechanical experimental studies,and further research is needed on the intrinsic relationship of bamboo fibre concrete.This paper combines the existing bamboo fibre concrete research results,the uniaxial tensile principal structure relationship of bamboo fibre concrete studied,and its tensile damage mechanism and strengthening mechanism is analysed.The main contents are as follows:(1)In this paper,slump tests were conducted on bamboo fibre concrete and the effect of bamboo fibre admixture on the slump of concrete was investigated.The test results show that the slump of concrete decreases with the increase of bamboo fibre admixture,and the higher the admixture,the faster the trend of slump decrease.(2)In this paper,17 sets of bamboo fibre specimens were designed at 0.0%,0.5%,0.6%,0.7%,0.8%,0.9%,1.0%,1.1%,1.2%,1.3%,1.4%,1.5%,1.6%,1.7%,1.8%,1.9%and 2.0%by volume,and the direct tensile test method was used to study the uniaxial tensile properties of bamboo fibre concrete.The uniaxial tensile properties of bamboo fibre concrete were investigated by direct tensile testing.The test results showed that the addition of bamboo fibres significantly improved the tensile properties of concrete,the ductility and crack resistance of bamboo fibre concrete were stronger compared with ordinary concrete,and the tensile properties of concrete became better with the increase of bamboo fibre admixture,but after reaching a certain admixture,the tensile strength of concrete began to show a decreasing trend.(3)This paper explores the uniaxial tensile damage mechanism and strengthening mechanism of bamboo fibre concrete.Through the experimental phenomenon and combined with the theoretical analysis,the tensile damage process of bamboo fibre concrete is divided into six stages,and bamboo fibre improves the crack resistance of concrete and makes concrete present certain plastic characteristics.Bamboo fibres mainly bear local stresses during the tensile damage of concrete and prevent cracks from arising.Combined with the theory of fibre reinforcement of concrete,the higher the amount of bamboo fibre,the stronger the reinforcing effect on concrete.(4)In this paper,according to the stress-strain curve of bamboo fibre concrete,the full stress-strain equation of bamboo fibre concrete for each fibre admixture is analysed and the parameters of the equation are calculated and analysed,and the results show that this stress-strain equation curve agrees well with the test stress-strain curve.