高温后路缘石再生骨料混凝土的力学性能

Mechanical Properties of Curb Recycled Aggregate Concrete after High Temperature

为探究高温对路缘石再生骨料混凝土力学性能的影响,结合热重-差示扫描量热分析,进行了路缘石再生骨料混凝土高温后的力学性能测试,以研究取代骨料粗细类别及温度对路缘石再生骨料混凝土力学性能的影响规律.结果表明:升温时路缘石粗骨料在573℃时出现明显的吸热峰,路缘石细骨料砂浆在430℃左右及750~850℃之间出现明显的吸热峰;路缘石粗、细骨料混凝土的抗压强度、抗拉强度和弹性模量均随着温度的升高逐渐降低,抗压强度在400℃内降低幅度不明显,在800℃时分别较常温下降低了60.1%和55.1%;劈裂抗拉强度在600℃时分别较常温下降低了74.6%和70.4%;弹性模量在600℃内明显降低,在600℃时分别较常温下降低了89.8%和90.9%.

To investigate the effect of high temperature on the mechanical properties of concrete with curbs recycled aggregate,the mechanical properties of concrete were tested after high temperature. Combined thermogravimetric analysis and differential scanning calorimetry,the effect of replacing aggregate coarse and fine categories and temperatures on the mechanical properties of concrete was studied. The results show that the curb coarse aggregate at 573 ℃ shows a prominent heat absorption peak,while the curb fine aggregate mortar at 430 ℃ and 750-850 ℃shows a pronounced heat absorption peak. The compressive strength,splitting tensile strength,and modulus of elasticity of curb coarse and fine aggregate concrete all decrease gradually with the increase of temperature.Compared with the room temperature,the compressive strength decreases slowly at 400 ℃ and decreases by 60.1%and 55.1% at 800 ℃;the splitting tensile strength decreases significantly at 600 ℃ and decreases by 74.6% and70.4% at 600 ℃;the modulus of elasticity decreases significantly at 600 ℃ and decreases by 89.8% and 90.9%at 600 ℃,respectively.