煤矸石混凝土冻融损伤本构关系试验研究

通过对冻融后煤矸石混凝土的单轴受压试验,研究了冻融循环次数和煤矸石取代率对煤矸石混凝土力学性能的影响,提出了冻融作用下煤矸石混凝土峰值应力、峰值应变的退化规律,并拟合应力-应变曲线,提出了煤矸石混凝土冻融损伤单轴受压本构关系。试验结果表明,随着冻融循环次数的增加,煤矸石混凝土峰值应力逐渐降低,峰值应变和极限应变逐渐增加,应力-应变曲线趋于扁平,受压早期压实效应尤为明显,弹性模量迅速降低,应力-应变曲线前端部分出现下凹。此本构关系精度较好,对煤矸石混凝土的推广应用和进一步改性研究有一定参考价值。

Experimental Study on Freezing-Thawing Damage Constitutive Relationship of Coal Gangue Concrete

In this paper, it was studied the effect of freezing-thawing cycle and replacement ratio of coal gangue on the mechanical properties of coal gangue concrete, and it was put forwarded the degradation rule of peak stress and peak strain of coal gangue concrete under the freezing-thawing action, and stress-strain curve was fitted, and it was put forwarded the freezing-thawing damage uniaxial compression constitutive relationship of coal gangue concrete, by uniaxial compression test of coal gangue concrete experienced freezing-thawing. The test results show that with the increase of the freezing-thawing cycles number, the peak stress decreased gradually, the peak strain and ultimate strain increased gradually, the stress-strain curve tends to be flat, the compaction effect was obvious of the early compaction, the elastic modulus decreases rapidly, the concave was appeared in the front of stress-strain curve. This constitutive relation has a good accuracy, and has some consultative value of application and further study on modification of coal gangue concrete.