再生大骨料-自密实砂浆堆石混凝土力学性能研究

为研究再生大骨料粒径、原始强度和自密实砂浆强度对再生大骨料-自密实砂浆堆石混凝土力学性能的影响,采用压力机对7组不同再生大骨料-自密实砂浆堆石混凝土试块进行了一系列试验研究。结果表明:自密实砂浆能够充分填充更小骨料粒径构成的堆石体,骨料粒径由100 mm降至60 mm时,自密实砂浆仍可充分地填充堆石体,其立方体抗压强度仅下降5.97%,而轴心抗压强度与劈裂抗拉强度的降幅均在可行范围内,侧面反映出自密实砂浆可填充再生大骨料堆石体且效果显著; 在再生大骨料-自密实砂浆混凝土棱柱体轴心受压的应力-应变关系中,再生大骨料-自密实砂浆堆石混凝土的强度、静态弹性模量和峰值压应变均与骨料粒径、自密实砂浆强度和再生骨料原始强度呈正相关,再生骨料粒径的影响小于再生骨料原始强度和自密实砂浆强度的影响; 通过拟合提出的再生大骨料-自密实砂浆堆石混凝土的强度计算公式和单轴受压多项式型本构模型、有理分式型本构模型计算结果与实测值吻合度良好。

Study on mechanical properties of recycled large aggregate-self-compacting mortar rock-filled concrete

In order to study the effects of the particle size of recycled large aggregate(RLA), the strength of RLA and the strength of self-compacting mortar(SCM)on the mechanical properties of recycled large aggregate-self-compacting mortar rock-filled concrete(RLA-SCMRFC), a series of experimental studies were carried out on 7 groups of different RLA-SCMRFC using a press. The results show that the SCM can fully fill the rockfill body composed of a smaller aggregate particle size. When the RLA particle size decreases from 100 mm to 60 mm, the SCM can still fill the rockfill fully, and its cube compressive strength only decreases by 5.97%, while the axial compressive strength and splitting tensile strength are both within a feasible range, which reflects that SCM can fill RLA and the effect is significant. In the stress-strain relationship of RLA-SCMRFC prism under axial compression, it is concluded that the strength, static elastic modulus and peak strain of RLA-SCMRFC are positively correlated with RLA particle size, strength of SCM and strength of RLA, and the influence of RLA particle size is less than that of the RLA strength and SCM strength. The calculated value of the strength calculation formula and the uniaxial compression polynomial constitutive model and rational fraction constitutive model of RLA-SCMRFC proposed through fitting is in good agreement with the measured value.