Study On Uniaxial Compressive Properties Of Waste Glass Powder Concrete Under Different Strain Rates

There is a rate effect of concrete under dynamic loading.With the increase of strain rate,the mechanical properties and failure modes of concrete will change compared with the mechanical properties and failure modes of concrete under static loading.Nowadays,the wide application of concrete in various projects has made the raw materials of concrete increasingly scarce.It is urgent to find materials for replacing concrete raw materials.At present,pulverizing waste glass into powder instead of part of cement to make concrete helps reduce the pressure on the reduction of concrete raw materials.Therefore,in this paper,waste glass powder concrete as the research object,in order to explore the change of mechanical properties and damage morphology of waste glass powder concrete under dynamic load,the uniaxial compression test of waste glass powder concrete is carried out with a certain range of strain rate.A dynamic constitutive model consistent with the test was constructed.A uniaxial compression test of concrete was conducted for four different strain rates and three different waste glass powder contents.The data collected from the test are analyzed from the stress-strain curve,compressive strength,peak strain,elastic modulus and Poisson’s ratio and other mechanical properties.And from the perspective of the mesoscopic structure,force characteristics,and test process of the waste glass powder concrete,reasonable explanations are given for the mechanical properties and failure modes of the waste glass powder concrete.At the same time,in order to improve the constitutive model analysis of waste glass powder concrete under dynamic loading,this paper considers the strain rate enhancement effect under dynamic loading and the damage weakening effect of waste glass powder concrete itself,a damage-based constitutive model for dynamic compression of waste glass powder concrete was constructed.The results of fitting the constitutive model with the experimental data are compared with the experimental results to determine if the constitutive model is reasonable.After the analysis of the test results,the following conclusions were obtained:(1)There is bound to be an optimal amount of waste glass powder incorporated into the concrete so that the performance of the waste glass powder concrete is optimal.(2)The dynamic load compression test of waste glass powder concrete still meets the description of the concrete compression test under static loading.(3)Strain rate has a significant effect on the mechanical properties of waste glass powder concrete.In addition to the Poisson’s ratio remained basically unchanged,with the increase of strain rate,the compressive strength of waste glass powder concrete increases,the peak strain decreases,the elastic modulus increases,and a specific relationship is obtained.(4)There is a certain degree of discrepancies in the test data.Systematic analysis and interpretation are performed in terms of test piece materials,curing conditions,test equipment,test methods,and loading methods.(5)Based on the nonlinear elastic constitutive model-Ottosen model,considering the strain rate enhancement effect and the damage weakening effect,the Ottosen model was modified by introducing the strength improvement factor and the damage attenuation factor,and a damage-based dynamic constitutive model for waste glass powder concrete was established,and proved the rationality of this model.