This study is to explore the influence of maximum aggregate size(MAS)on the failure and corresponding size effect of concrete materials under low strain rates.The failure process of concrete was simulated by the mesos...This study is to explore the influence of maximum aggregate size(MAS)on the failure and corresponding size effect of concrete materials under low strain rates.The failure process of concrete was simulated by the mesoscale numerical method considering the internal heterogeneity of concrete and strain rate effect.Based on the mesoscale method,the failure behavior of concrete specimens with different structural sizes and MAS was investigated.Also,the influence of MAS on the failure modes,nominal strength and corresponding size effect of concrete were studied at the meso-scale.The simulation results indicated that MAS has an obvious influence on the failure modes of concrete subjected to axial compressive and tensile loads.The nominal tensile strength increased as the MAS increased,while the nominal compressive strength increased first and then decreased as the MAS increases under quasi-static load.In addition,it was found that the size effect on nominal strength of concrete would be weakened with the increase of strain rate.When the applied strain rate reached 1 s^-1,the size effect on nominal strength of concrete disappeard.Moreover,the MAS has an ignorable influence on the dynamic size effect of concrete under uniaxial compression and tension.展开更多
The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated...The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated. Results indicate that the porous concrete with a cement dosage only 150 kg/m^3 has high strength and satisfying permeability when the aggregate has a passing percentage of 4.75 mm around 10% to 15%, with the increase of the maximum size of the aggregate, the strength of the porous concrete decreases and the permeability increases. When the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate is about 20%, there are no interference among the particles by Weymouth theory, the strength of the pervious porous concrete reaches the peak value. The optimum continues gradation limit of the aggregate for porous concrete pervious road base material is recommended according to the theoretical calculation and experimental results.展开更多
基金supported by the National Key Basic Research and Development Program of China(No. 2018YFC1504302)the National Natural Science Foundation of China(Nos. 51822801,51421005).
文摘This study is to explore the influence of maximum aggregate size(MAS)on the failure and corresponding size effect of concrete materials under low strain rates.The failure process of concrete was simulated by the mesoscale numerical method considering the internal heterogeneity of concrete and strain rate effect.Based on the mesoscale method,the failure behavior of concrete specimens with different structural sizes and MAS was investigated.Also,the influence of MAS on the failure modes,nominal strength and corresponding size effect of concrete were studied at the meso-scale.The simulation results indicated that MAS has an obvious influence on the failure modes of concrete subjected to axial compressive and tensile loads.The nominal tensile strength increased as the MAS increased,while the nominal compressive strength increased first and then decreased as the MAS increases under quasi-static load.In addition,it was found that the size effect on nominal strength of concrete would be weakened with the increase of strain rate.When the applied strain rate reached 1 s^-1,the size effect on nominal strength of concrete disappeard.Moreover,the MAS has an ignorable influence on the dynamic size effect of concrete under uniaxial compression and tension.
基金Funded by the Opening Fund of the Key Laboratory of Silicate Material Science and Engineering,Ministry of Education(No.YSJJ2004-13)
文摘The effects of the proportion of fine aggregate, the maximum size of the aggregate and the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate on the properties of the porous concrete are investigated. Results indicate that the porous concrete with a cement dosage only 150 kg/m^3 has high strength and satisfying permeability when the aggregate has a passing percentage of 4.75 mm around 10% to 15%, with the increase of the maximum size of the aggregate, the strength of the porous concrete decreases and the permeability increases. When the proportion of the 9.5 mm to 4.75 mm particle in the coarse aggregate is about 20%, there are no interference among the particles by Weymouth theory, the strength of the pervious porous concrete reaches the peak value. The optimum continues gradation limit of the aggregate for porous concrete pervious road base material is recommended according to the theoretical calculation and experimental results.
