对轴向拉力状态下混凝土的抗冻融耐久性进行了研究,通过自制的拉力加载装置,对12个两端插入螺纹钢筋的100 mm×100 mm×400 mm的混凝土试件施加0.1倍的设计强度的轴向拉力,使试件在持荷状态下经历不同冻融循环后,得到试件质量、动弹性模量和抗折强度的变化规律,得到拉应力对混凝土抗冻性的影响。结果表明:拉应力状态下混凝土各项性能衰减速度较快未达到设计的抗冻强度等级F200,质量和动弹模量下降较少时就已破坏,抗折强度损失较大。拉应力的作用明显削弱了混凝土的抗冻性。
The frost-resistant property of hydraulic concrete at axial tensile force state is analyzed.By homemade tensile loading device,twelve 100 mm×100 mm×400 mm concrete specimens inserted thread steel on both ends was applied 0.1 times design tensile stress.After different freezing-thawing cycle,the holding load specimen quality,dynamic elastic modulus and flexural strength was measured.The influence of tensile stress on the frost resistance of concrete was found.It is concluded that the concrete at tensile stress is broken fast and do not reach the frost resistance grade F200.The quality and dynamic modulus decrease less when they have been destroyed.The flexural strength loss is much.Tensile stress significantly reduced the frost resistance of concrete.