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采用以卵石为粗骨料的原生混凝土作为再生混凝土来源,通过破碎、筛分获取再生卵石粗骨料,配制再生卵石骨料混凝土.以取代率为变化参数,设计99个试件.通过试验,获取其立方体抗压强度、棱柱体抗压强度、抗折强度、弹性模量、泊松比等力学性能指标及应力-应变全过程曲线.分析了再生卵石骨料混凝土损伤演化、变形和能量耗散等力学性能.采用分段式本构关系模型和损伤本构关系模型对再生混凝土的应力-应变本构关系进行研究,并提出相应的本构方程.结果表明,与天然混凝土相比,再生卵石骨料混凝土的抗压、抗折强度略为增大,而弹性模量、变形系数与耗能系数则有不同程度的降低;不同取代率下,再生混凝土应力-应变曲线与天然混凝土相似,但下降段变得陡峭;再生混凝土损伤发展较为迅速,尤其在ε=(3~5)×10-3之间;分段式本构方程和损伤本构方程的计算结果均与实测值吻合较好.
Cobbled coarse aggregate as raw concrete was used as the source of recycled concrete, coarse aggregate was obtained by crushing and sieving to prepare recycled pebble aggregate concrete.With the substitution rate as a parameter, 99 samples were designed.Through the experiment, Obtained the cubical compressive strength, prismatic compressive strength, flexural strength, elastic modulus, Poisson's ratio and other mechanical properties and stress-strain curves of the whole process.The damage evolution, deformation and energy consumption of recycled pebble aggregate concrete Bulk mechanical properties, etc. The stress-strain constitutive relations of recycled concrete are studied by using the segmented constitutive model and the damage constitutive model, and the corresponding constitutive equations are proposed. The results show that compared with natural concrete, The compressive strength and the flexural strength of the pebble aggregate concrete slightly increase, while the elastic modulus, the deformation coefficient and the energy dissipation coefficient decrease to some extent. The stress-strain curves of the recycled aggregate concrete are similar to the natural concrete under different replacement rates The descending section becomes steep; the damage of recycled concrete develops rapidly, especially in the range of ε = (3 ~ 5) × 10-3; the staged constitutive equation and the damage constitutive equation The results were in good agreement with the measured values.