纳米SiO_(2)-CaCO_(3)混凝土损伤本构模型及能量演化特征

Damage constitutive model and energy evolution characteristics of nano-SiO_(2)-CaCO_(3) sconcrete

采用纳米SiO_(2)-CaCO_(3)混合掺入混凝土中,对混掺纳米SiO_(2)-CaCO_(3)混凝土进行了受压性能试验,基于损伤力学理论和能量耗散原理分析了纳米SiO_(2)-CaCO_(3)增强混凝土的本构关系,建立了普通混凝土和纳米SiO_(2)-CaCO_(3)混凝土损伤本构模型。结果表明:混掺纳米材料比单掺纳米材料对提升混凝土强度效果更佳,强度最大增幅为31.46%;混掺纳米材料显著降低了混凝土的弹性应变能释放速率,增大了混凝土的总应变能和耗散能,从而提高了混凝土的延性和韧性。基于SEM微观测试结果揭示了纳米材料对混凝土增强效应的作用机理。

Nano-SiO_(2)-CaCO_(3) was mixed into concrete,the compressive performance test of nano-SiO_(2)-CaCO_(3) concrete was carried out,and the constitutive structure of nano-SiO_(2)-CaCO_(3) reinforced concrete was analyzed based on the theory of damage mechanics and energy dissipation.The damage constitutive models of ordinary concrete and nano-SiO_(2)-CaCO_(3) concrete were established.The results show that the effect of mixing nano-materials is better than that of single mixing nano-materials in improving the strength of concrete,and the maximum increase in strength is 31.46%.Mixing nano-materials significantly reduces the release rate of elastic strain energy of concrete and increases the total strain energy of concrete and dissipated energy,thereby improving the ductility and toughness of concrete.Based on the SEM microscopic test results,the mechanism of nano-materials on the reinforcement effect of concrete was revealed.