相同条件下大样本沥青混合料的疲劳性能

采用一个沥青混合料小梁试件大样本,在相同条件下进行了应变控制疲劳试验研究,分析了沥青混合料试件疲劳寿命、初始模量和累计耗散能的分布规律,探讨了疲劳寿命与初始模量和累计耗散能的关系,以及疲劳寿命、初始模量和累计耗散能与试件空隙率之间的关系.试验结果表明:应变控制疲劳寿命数据的离散性大;沥青混合料的疲劳寿命、累计耗散能和初始模量呈三参数W eibull分布和对数三参数W eibull分布,三参数W eibull分布可以用于分析沥青混合料的疲劳数据;相同条件下,试件的疲劳寿命与初始模量数据线性和对数线性负相关,与累积耗散能数据呈现非常良好的线性正相关,疲劳寿命对数和累积耗散能对数与空隙率负相关性较好;初始模量与空隙率的相关性不明显.文中的研究结果验证和揭示了沥青混合料的应变控制疲劳破坏规律.

Fatigue Properties of Large-Sample Asphalt Mixture Under the Same Conditions

Experimental investigation into the strain-controlled fatigue properties of large-sample asphalt mixture under the same conditions was carried out,and the distributions as well as the correlativity of three parameters including the fatigue life,the initial modulus and the cumulative dissipated energy were analyzed.Moreover,the relationships between the air void ratio in asphalt mixture and the three above-mentioned parameters were analyzed.The results indicate that the strain-controlled fatigue life is greatly discrete,that the fatigue life,the cumulative dissipated energy and the initial modulus all follow the simple and the logarithmic three-parameter Weibull distributions,revealing the feasibility of applying the simple three-parameter Weibull distribution to the analysis of the fatigue test data,and that,under the same conditions,there are negative and logarithmic negative linear relationships between the fatigue life and the initial modulus,a strong positive linear relationship between the cumulative dissipated energy and the fatigue life,a negative linear relationship between the air void ratio and the logarithmic cumulative dissipated energy as well as the logarithmic fatigue life,and a weak correlativity between the initial modulus and the air void ratio.All these above-mentioned statements demonstrate the laws of strain-controlled fatigue of asphalt mixture.