The Performances Of Energy-absorption And Dynamic Damage For Eps Concrete Subjected To Impact Loading

EPS concrete,a composite material containing waste foams and cement matrix,alleviates the pollution leaded by industrial wastes as well as enriches the variety of building materials.Due to the excellent deformation capability,the light-weighting aggregates improve greatly its dynamic bearing performances,including buffering performance and dynamic damage during impact.Based on existing experiments on SHPB tests,the finite element method(FEM)models are established to study the influence of material coefficients and loading regimes on its mechanical performances.The main conclusions in this study can be described as:1)With the increase of aggregates,the damage type of EPS concrete turns from quasibrittle destruction to plastic destruction and extruded-flow destruction,and the cracking process transform gradually from dominated cracks to minute fissures in the same loading conditions.2)A variable describing buffering property of materials was described,which is named after buffering acceleration.And employing this coefficient,the buffering performances of materials are assessed comprehensively.The aggregate size effect and buffering property are affected by its grading type as well as grain size range.When aggregates have the same size,the size effect in EPS concrete enhances obviously with the increase of aggregates,while when its aggregates have multiple sizes,there are little influences of average grain size on the size effect of EPS concrete.The results show that there is a nonlinear positive correlation between buffering acceleration and aggregate content,namely the derivative of buffering acceleration and aggregate content increases as its aggregate content increases.And taken the interface summation of aggregates into consideration,the impact of its summation on buffering acceleration was analyzed.The study results indicate that the larger the interface summation is,the better the buffering performance of materials is.3)In the premise of a constant value on impact potential energy,the peak value and its occurrence moment of impact loading have a close correlation to its damage status of EPS concrete.Overall,there are three practical measures to improve buffering performances of EPS concrete that enhancing impact speed,shortening impact loading period and advancing the occurrence moment of peak loading,which lead to a worse destruction on bearing capability for buffering materials.4)In the foundation of fractal theory,the fractal influence coefficient was introduced to address the complex problem under multifactor coupling loading condition.The analysis results show that the aggregate content is the dominated factor on material buffering performance,and the peak value of impact loading is the overriding factor on damage and bearing capability of EPS concrete,while the loading duration and peak occurrence moment are the secondary factors compared with the former one.