混凝土冻融循环损伤后力学性能衰减规律研究

Law of Mechanical Properties Attenuation of Concrete After Freezing and Thawing Cycle

桥梁承台、墩柱混凝土经历冻融损伤后,影响整体受力性能。为研究混凝土冻融循环损伤后力学性能衰减规律,依托西藏拉林铁路连续刚构桥,采用快冻法对承台C30混凝土和墩柱C40混凝土试块开展冻融循环试验,利用动弹仪测量混凝土试块动弹性模量,并测量混凝土试块质量损失。试验结果表明,随着冻融循环次数的增加,混凝土试块动弹性模量与质量递减。根据试验数据拟合得到冻融循环损伤下混凝土试块冻融循环次数与动弹性模量及质量的关系,进一步揭示了混凝土静弹性模量、抗压强度和抗拉强度随冻融循环次数增加的衰减规律。

After the concrete of bridge cap and pier column undergoes freezing and thawing cycle damage,the overall mechanical performance is affected.In order to study the attenuation law of mechanical properties after concrete freezing and thawing cycle damage,the freezing and thawing cycle test was carried out on the C30 concrete of the cap and the C40 concrete of the pier column by using the quick freezing method based on the continuous rigid frame bridge of the Lalin Railway in Tibet.The dynamic elastic modulus of the concrete test block was measured by a kinematic tester,and the mass loss of the concrete test block was measured.The test results show that with the increase of the number of freezing and thawing cycles,the dynamic elastic modulus and mass of the concrete block decrease.The relationship between the number of freezing and thawing cycles and the dynamic elastic modulus and mass of the concrete block under freezing and thawing cycle damage was obtained by fitting the test data.It reveals the decay law of concrete static elastic modulus,compressive strength and tensile strength with the increase of freezing and thawing cycles.