Study On Stress-strain Curves And Failure Criterion Of Reactive Powder Concrete In Triaxial Stress State

As a new type of concrete material, reactive powder concrete (RPC) which exhibits properties such as ultra-high strength,high toughness and high durability has applied to the fields of bridge、water project, etc. Triaxial stress-strain curve of RPC is an important mean to study bearing capacity and deformation of RPC, and analyze bearing capacity of the RPC elements and establish RPC constitutive models. Most RPC structures actually under multi-axial stress state. For the extension of reactive powder concrete, The stress-strain curves of RPC in triaxial stress state were studied in this paper, The main research contents are as followed:In order to measure the stress-strain curve of the RPC test for comparing two types of anti-friction more accurately, two reducing friction were compared, the results shows that when using the anti-friction method of three-layered teflon with yellow glycerin between each layer. the discrete degree of RPC strength is smaller.The failure characteristics of specimens and the crack directions were recorded and described respectively. The influence of confining pressure on the failure modes was also analyzed.The relationship between axial peak strain and confining pressure of RPC was studied. The variation law of elastic modulus and Poisson’s ratio of fiber content of 1% of the RPC and the plain RPC is analyzed.The axial and radial stress-strain curve of RPC was fitted, A relatively simple mathematical expressions were proposed. The fitted curve and the check curve were compared. the results showed that the mathematical expression satisfied the project precision’s request and had practical value.By studying the RPC triaxial test data, the RPC damage strength under different confining pressure were obtained, and the three failure criterions of Newman, Ansari, Richart were compared. the destruction envelope of RPC in principal stress space was established based Drucker-prager yield criterion, which provide experimental and theoretical foundation for strength analysis of RPC.