透光混凝土基LED主动发光交通标线的光纤设置

为提高交通标线的可视化、智能化与信息化水平,将透光混凝土引入公路领域,构建一种透光混凝土基发光二极管(LED)主动发光交通标线.采用方差分析与多重比较法分析了4类通用光纤的物理性能、导光性能与经济性,选定PMMA(聚甲基丙烯酸甲酯)光纤作为导光材料.通过LED光强分布曲线与光波在光纤中的传播机理,确定了光纤直径的理论计算值;基于直径1～8 mm的PMMA光纤导光率的实测数据,采用S型曲线拟合PMMA光纤导光率与直径之间的函数关系,符合0.05的卡方拟合优度检验,且实测值与理论分析结果一致,选定直径6 mm的PMMA光纤.基于LED主动发光交通标线在不同环境照度、光源颜色、光纤掺量条件下的实测静态视认距离,采用对数回归模型,计算确定设计速度为60～120 km·h~(-1)时光纤掺量的合理范围是2～6 pcs.

Fiber-Optic Parameters of Light Emitting Diode Active-Luminous Traffic Markings Based on Light-Transmitting Concrete

To improve the visualization, intelligence and informatization level of traffic markings, light-transmitting concrete is introduced to highway field, and the light emitting diode (LED) active-luminous traffic marking based on light-transmitting concrete is constructed. The analysis of variance and multiple comparison methods are used to analyze the physical property, light transmitting rate and economy of the four types of general-purpose fiber-optic. As a result, Polymethyl Methacrylate (PMMA) fiber-optic is selected as the light-transmitting material. After that, theoretical diameter is determined according to the light-intensity distribution curve and the light-propagation path in fiber-optic. Based on the measured data of 1~8 mm PMMA fiber-optic, the S-shaped curve can effectively fit the change trend of light-transmitting rate with fiber-optic diameter, and it is consistent with the theoretical analysis results. Therefore the PMMA fiber-optic diameter is determined to be 6 mm. Based on the measured visible distance of the LED active-luminous traffic marking under different brightness, color and dosage, using logarithmic regression model, the reasonable fiber-optic dosage is determined to be 2~6 pcs when the design speed is 60~120 km?h-1.