玄武岩纤维沥青混合料长度级配设计

Length Gradation Design of Basalt Fiber Asphalt Mixture

为提出一种准确、高效的设计沥青混合料纤维掺量的方法,运用电子计算机断层扫描(CT)图像技术,提取不掺玄武岩纤维的沥青混合料的结构特征参数,确定3 mm、6 mm和9 mm这3种长度的AC-13级配玄武岩纤维的最佳掺配比例。按照不同比例设计5种组合的玄武岩纤维掺量,分别将其掺入此级配的沥青混合料中,进行相关的沥青混合料性能试验验证。研究结果表明:3 mm、6 mm和9 mm这3种长度的AC-13级配玄武岩纤维最佳掺配比例为2∶5∶2。与不掺玄武岩纤维相比,此比例搭配下的玄武岩纤维沥青混合料高温稳定性能、低温性能和抗开裂性能提高显著。动稳定度和贯入强度分别提高了21.1%和28.9%,低温性能提高了39.3%,CT_(index)指标和断裂能分别提高了147.56%和21.9%。

In order to propose an accurate and efficient method to design the fiber content in the asphalt mixture,the computed tomography(CT)image technology was used to extract the structural characteristic parameters of asphalt mixture without basalt fiber.The best fiber blending ratio of 3 mm,6 mm and 9 mm basalt fibers in the AC-13 asphalt mixture was then determined.Five types of fiber blending ratios were designed.The fibers were added in the asphalt mixtures to examine the best fiber blending ratio obtained from the CT image technology.Test results showed that the best fiber blending ratio of 3 mm,6 mm and 9 mm basalt fibers in the AC-13 asphalt mixture is 2∶5∶2.Compared with the mixture without basalt fiber,the high temperature stability performance,low temperature performance and crack resistance are improved significantly in the basalt fiber asphalt mixture with the best fiber blending ratio.The dynamic stability and penetration strength are increased by 21.1%and 28.9%respectively,and the low temperature performance are increased by 39.3%.CT index and fracture energy are increased by 147.56%and 21.9%,respectively.