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沥青路面低温开裂破损现象非常普遍,目前国际上广泛采用SHRP提出的沥青弯曲梁流变试验(BBR)进行预防,但低温开裂现象仍然普遍存在。该文介绍加拿大安大略省基于BBR试验而成功研究和推广应用的改进弯曲梁流变试验(EBBR)方法,该方法致力于完全避免或减少沥青路面早期开裂或过量开裂问题。EBBR将BBR中的1个低温养护温度、1h养护时间及1个低温测试温度的试验方法进行了拓展,提出了2个低温养护温度、3个养护时间、2个低温测试温度的试验方案,除常规蠕变劲度及其变化率指标外,增加了低温等级损失指标来评价路面沥青的低温性能。该文重点介绍了EBBR与BBR方法的差异、试验方案、数据采集方法、数据计算分析方法、研究推广应用情况等。
Asphalt pavement cracking and damage at low temperature is very common. At present, the SHRP is widely used to prevent bitumen bending deformation test (BBR), but the phenomenon of low temperature cracking is still widespread. This paper presents an improved bending beam test (EBBR) method based on the BBR test in Ontario, Canada, that is successfully developed and applied to completely avoid or reduce the problem of early cracking or excessive cracking of asphalt pavement. EBBR extends BBR’s test methods for a low temperature curing temperature, a 1h curing time and a low temperature testing temperature, and proposes two test schemes of low temperature curing temperature, three curing time and two low temperature test temperatures, except for Conventional creep stiffness and its rate of change indicators, an increase of low temperature grade loss indicators to evaluate the low temperature performance of pavement asphalt. The paper mainly introduces the differences between EBBR and BBR methods, the experimental scheme, the data collection method, the data calculation and analysis method, and the research popularization and application.