Constitutive Relationship Of Reactive Powder Concrete Under Uni-axial Compression And Research On Paramenter Of Structural Design

As a new kind of cement-based composite material, Reactive Powder Concrete(RPC), owing to its high mechanical properties such as high strength, high tenacity,high durability, heat-resistance, anti-corrosion, impact-resistance, volume stability andso on, has attracted widely attention and also found an increasingly wide utilization inall production fields. As the our country developed, the further developmentof the RPCmaterial is essential to the structure research on the complex environment like thehigh-rise building, long span bridges, offshore drilling platform and so on, which isalso a research hotspot recent years.The weak link at the adhesive layer of ordinary aggregate concrete andcementingmaterial can easily lead to stress concentration when it forms fine cracks during theengineering process, which can finally bring out crack propagation. Aimed to thisproblems, this paper presents a new schemeof the RPC material to improve theconsistency between aggregate concrete and cementing material, decrease fine cracksand the internal air voids of the structure by removing the coarse aggregates, retainingfine aggregate and at the same time adding high activated admixture in the blendingprocess.And super-plasticize and chopped fiber reinforced composite are used toimprove the properties of the RPC material.Modeling the constitutive relationship of RPC is a choke point when using theRPC in structure. It is difficult to give an accurate constitutive relationship of concretewith some minus factors such as enormous complexity, uncertainty of internal damageandheterogeneity. With the high-dispersion results of the experiment and the immatureconstitutive relationship of concrete, there is nocode for designor the constitutional lawmodels under uniaxial tension or uniaxial compressionfor RPC structure. Based on thiscircumstance, this paper presents a method to get and fit the stress-strain relationscurve of RPC, and give some different curves under different mixture ratio at the sametime.To improve the overall stiffness level of test device, we put additional rigidelement on the test vehicle. Meanwhile, to guarantee the strength of RPC, control thepress load by Electrohydraulic Servo System and appropriate load by displacement control, can complete stress-strain curve be got in this way,.Different factors like water binder ratio, sand cement ratio, fiber content, curingsystem will all impact the performance of all aspects of RPC. This paper discusses theformation mechanism of these affecting factors of RPC and the influence tocompressive strength, mobility, and we get the optimum mix ratio of RPC100withoutfiber and basalt fiber by orthogonal design.In this paper, we get the complete RPC uni-axial compressive stress-strain curveequation through two ways: experiment and theory. We convert the test curve to thechart whose value of horizontal and vertical coordinates are both1, then compare itwith the simulation curve to get the values of undetermined parameter.The RPCstress-strain curves with different ratios can be given through experiments.With the experimental method presented in this paper, several importantparameters of architectural design such as the elastic modulus, proportional limit, peakstrain, Poisson Ratio can be determined. This paper also solves the problem abouttherate of standard compressive strength of RPC100, and gets the values ofcompressive strength, the tensile strength of the RPC100. We also get the design valueand the trial strength, which lays foundations on design and application in engineering.