大粒径透水性沥青混合料组成

设计与应用研究

Study on the composing  designe and use of large stone porous asphalt mixes

研究生：房建果

指导教师：郭忠印教授

二〇〇六年九月

摘要

我国高速公路经过十多年的高速建设，到2005年底通车里程已达41000km，总里程位居世界第2位，仅次于美国。半刚性基层沥青路面是我国高等级公路的主要结构形式，在高速公路和更多的一级公路中95％的里程采用了半刚性基层沥青路面。半刚性基层沥青路面的主要优点是路面结构性能好，承载力高：但同时最大的缺点是半刚性基层导致沥青路面出现反射裂缝及结构排水问题造成的早损坏等。本文进行了适合我国国情的大粒径透水性沥青混合料（LSPM）应用研究，系统研究了该材料的级配组成与设计方法、抗变形能力、抗疲劳能力、防反射裂缝能力以及其施工工艺和质量控制标准，并在烟青204国道进行试验路验证。主要研究结论如下：

（1）在沥青混合料集料多级嵌挤级配理论的基础上，提出了具有较好高温稳定性和排水性能的大粒径透水性沥青混合料级配参考范围；建立LSPM以沥青膜厚度、设计空隙率、析漏与飞散为控制指标、采用8cm～12cm的车辙板进行稳定性验证的混合料设计方法；比较完整了解决了该类沥青混合料设计问题。

（2）本文以大量沥青混合料小梁弯曲疲劳试验结果为依据，对13个沥青混合料疲劳影响因素进行了严密的灰关联系统分析，并进一步对沥青混合料空隙率、混合料沥青饱和度、集料4.75mm筛孔通过率、2.36mm筛孔通过率和0.075mm筛孔通过率五个关键影响因素进行相关性分析。严格论证了沥青饱和度VFA和沥青混合料劲度模量E是影响LSPM料疲劳性能的关键独立变量。

（3）通过应变控制的沥青混合料小梁弯曲疲劳试验，获得了大粒径透水性沥青混合料疲劳方程模型，根据我国沥青路面容许弯沉调查结果，对疲劳模型进行现场修正，提出了该类沥青混合料在柔性沥青路面应用中的疲劳设计标准。

（4）通过对大粒径透水性沥青混合料路用性能的初步研究，主要包括高温稳定性试验、水稳定性试验、力学性能与渗透性能试验，探讨了大粒径透水性沥青混合料的性能技术要求。

可以看出，级配良好的大粒径透水性沥青混合料（LSPM）可以抵抗较大的塑性和剪切变形，具有较好的抗车辙能力，提高了沥青路面的高温稳定性；同时有着良好的排水功能，可以兼有路面排水层的作用；由于大粒径透水性沥青混合料有着较大的粒径和较大的空隙，可以有效地减少反射裂缝。大粒径透水性沥青混合料的应用不仅可以改善半刚性基层沥青路面早期损坏的问题，而且可以直接用于沥青路面柔性基层或作为柔性加铺层用于老路补强。

最后通过试验路铺筑系统研究大粒径透水性沥青混合料施工工艺。经过4～5年行车荷载作用后，实测数据表明大粒径透水性沥青混合料加铺旧沥青路面具有良好的抗高温永久变形能力和防止反射裂缝的能力。在以上研究的基础上比较系统地建立了大粒径透水性沥青混合料成套应用技术。

关键词：大粒径透水性沥青混合料，贝雷法，抗变形性能，灰关联分析，疲劳方程，反射裂缝，柔性基层

ABSTRACT

After more  than 10 years rapid construction，the length of expressway in China opened to traffic nationwide has  reached 41000 km at the end of 2005 and the total length just less to that of  American taking the second place in the world．The semi-rigid base asphalt pavement is the main  construction style of the national high-grade highway，which was adopted by  expressway and more frequently used in the first class highway．95 percent of lengths of  highway are asphalt pavement of semi-rigid base layer-The main advantages of  the semi-rigid base asphalt pavement are good performance of pavement  structure and high load bearing，but the biggest disadvantages ale reflection crack caused by  semi-rigid base layer and premature destroy due to drainage problem．The paper conducts an  extensive research on the application of large stone permeable asphalt  mixture (LSPM) according to the national situation．The aggradations，design method，the abilities of resisting deformation，fatigue and reflection crack，construction craftwork and  quality control criteria are studied systematically．Moreover，the conclusions have been  validated in Yan-Qing 204 national highway．The main conclusions Call be drawn as following：

(1)  Based on the aggregate  inter-lock mechanism，a preferred gradation of large stone permeable asphalt mixture  that has 900d deformation performance at high temperature and drainage  ability is recommended．Design method of LSPM is established，which include some control indexes such as  asphalt film thickness，air voids，binder leakage and Cantabro reveling，and the 8cm-12cm rutting plate is used to verify  the high temperature performance of LSPM．By this way，the design problem of this kind of asphalt mixture was solved  successfully．

(2) According to the results of bending  beam fatigue test of LSPM，13 factors influencing the fatigue of asphalt mixture are analyzed  by grey relation degree method．Key factors including air voids，voids filled with asphalt(VFA)，aggregate percentage passing  of 4.75mm，2.36ram  and 0.075mm sieve are analyzed，and it indicated that VFA and stiffness are independent variables，which affect the fatigue  performance of LSPM．

(3) By means of bending beam fatigue test  of control strain mode，fatigue function of LSPM is obtained．According to the result of allowable deflection  of asphalt pavement，the fatigue model is revised，and fatigue design standard of LSPM applied in flexible base  asphalt pavement is put forward．

(4) According to the preliminary study of  the performance of LSPM including high temperature stability performance，water stability，mechanical stability and permeability  property，the  technical requirement of LSPM is researched．

The  well-aggradations large stone permeable asphalt mixture not only has the ability  of resisting bigger plastic and sheafing deformation and resisting rutting，which increases high  temperature stability performance of asphalt pavement，but also has the drainage  function as pavement drainage layer．What is more，LSPM could decrease the reflection effectively because of its  large-size grain and biggish voids．The application of LSPM not only could improve the situation of  premature destroy of semi-rigid base asphalt pavement，but also could directly be  used in asphalt pavement flexible base layer or flexible additional layer in  old highway repair．

Finally，the construction technology  of LSPM is researched systematically by through in-situ test road．After 4-5 years vehicles  loading，the test  section data shows LSPM overlay on existing asphalt pavement has good high temperature  stability and anti-reflection crack ability．On the basis of research，complete application  technology of LSPM is established．

Key Words：large stone permeable asphalt  mixture(LSPM)，Bailey  method，performance  of resisting deformation，grey relation analysis， fatigue function，reflection crack，flexible base