重复作用的交通荷载可以在路面沥青混合料细微缺陷或裂缝的尖端造成应力集中并以复杂的形式自上而下扩展，最终导致路面的疲劳开裂破坏。本文应用断裂力学的原理探讨沥青路面疲劳寿命的预测方法。计算与分析表明：广义Paris公式可以考虑沥青路面结构内材料复杂的裂缝扩展；沥青面层的疲劳寿命随着面层厚度的增加以近似线性的幂函数的形式增加；另一方面，沥青面层的疲劳寿命随着面层材料模量的降低以负指数的幂函数的形式增加。

现行规范水泥混凝土路面的温度应力系数需要人工查图读取，不可避免地存在主观性，也不利于计算机技术的应用。通过查图读取数据，应用双线性函数、一般化的二次方程、以及其他简单函数拟合，得到了含有13个常量的改进的温度应力系数Bx经验公式。分析表明，基于查图数据，对应99%的保证率，使用公式引起的温度疲劳应力的误差不超过水泥混凝土弯拉强度的1%。公式对温度应力系数的解析描述，不但克服了查图的缺点，也为进一步的研究工作准备了条件。

通过对典型结构的理论分析，探讨沥青混凝土面层与半刚性基层之间的接触条件对半刚性沥青混凝土路面极限轴载的影响。计算与分析显示：对于给定的路面结构，存在一个极限轴载；面—基层间接触条件对极限轴载有重要影响，层间条件从连续到滑动的变化可以导致极限轴载降低大约40%；路面极限轴载与现实超载车辆轴载处于同一量级，所讨论结构在不同的接触条件下的极限轴载在183～399kN之间变化；虽然在某种意义上有破坏，半刚性沥青混凝土路面在极限轴载作用后不一定丧失承载能力。

现行JTJ014规范与AASHTO指南两种沥青路面结构设计方法是不同的体系，对两者作一定量的比较。分析和讨论表明，虽然两种结构设计方法有重要区别，但结果高度相关，区别主要体现在可靠度上。在标准排水条件下，JTJ014规范定值设计大体与AASHTO指南标准差S0=0.50、可靠度水平R=90%的结果相当；对于高速、一级公路，这个水平偏低,而对于三、四级公路可能不必要。可靠度的要求可以近似地用BZZ100累计作用次数的倍数表达；如果需要，可以采用放大或缩小设计累计轴次的方式考虑可靠度作为过渡措施。可靠度可以在很大程度上影响路面的设计结果；研究开发反映实际情况的沥青路面可靠度标准，应当可以提到议事日程。

本文的研究通过对典型半刚性基层沥青路面结构在各种不同层闻接触条件的理论计算，探讨层简接触条件对沥青路面极限轴载的影响。计算结果的分析表明：沥青混合料面层与半刚性基屡之间层间接触条件对高等级公路半刚性基层、底基层沥青路面极限轴载有重要影响；层间接触条件从连续到滑动的变化，可以导致极限轴栽降低近40%。在不同的层间接触条件下，对于18cm沥青混合料面层、25cm水泥碎石基层的路面，石灰土底基层20～30em的结构，路面双轮组、单轴极限轴栽在183～366kN之间变化，超过常见超载载货汽车的轴重。在大多数情况下，极限轴栽由石友土底基层层底拉应力决定。在各种层间接触条件下，极限轴栽作为底基层厚度的函数接近直线，而设计年限内一个车道上的累计当量轴次随底基层厚度的变化为指数函数；因而随着底基层厚度的增加，累计当量轴次远比极限轴栽增加得快。

在范得普诺模图的基础上，以针入度指数PI和实际温度与软化点（环球法）的差△T为变量，通过回归分析，推演了基于常规试验数据的沥青劲度模量一般公式表达。比较显示，查图与公式预测的沥青劲度模量达到了相当高的一致性，在保证率为90%时，误差对应的温度差不超过2℃。公式表达完成了从诺模图模拟性到数学确定性的转换，方便了使用，保证了精度，并为常规试验表示的沥青劲度融入现代计算技术提供了条件。此外，本文的成果，也为研究开发利用常规试验数据理性地描述沥青性质的方法准备了前提。

路面沥青材料包括沥青结合料和沥青混合料，是粘弹性材料，其动力性质，即复模量和相位角，是理解路面在交通荷载作用下反应的基础。本文通过探讨沥青结合料与混合料动力性质的关系，发现沥青混合料的复模量和相位角可以分别表示为沥青结合料复模量和相位角的函数，复模量的关系可用一般化的幂函数表示、相位角的关系可用改良的半正矢函数表示。与现有方法相比，这两个函数不仅反映了在剪切加荷条件下结合料作为粘弹性液体、混合料作为粘弹性固体的本质区别，而且完善了沥青结合料与混合料动力性质关系的整体。

Bottomash, as a byproduct of coal fired electric power plants, has recently been used in constructing transportation facilities. However, the use of bottom ash in asphalt mixture is still in early stages. The moisture resistance of asphalt mixtures containing bottom ash was not adequately researched. This study investigated the moisture susceptibility of asphalt mixtures containing bottom ash. Eight asphalt mixtures produced with one type of asphalt cement, two types of aggregate, three sources of bottom ash, and lime additive were evaluated using the principles in AASHTO T283. Analysis on test data indicated that granite mixtures had higher tensile strength (TS) values than limestone mixtures in dry condition. The lime or bottom addition did not substantially change TS values. All mixtures tested met the Superpave volumetric mix design requirement of tensile strength ratio (TSR) after one freeze-thaw cycle. The addition of lime significantly improved the moisture susceptibility of the asphalt mixtures as measured by TSR. With lime addition aggregate type, bottom ash addition, and bottom ash source were all insignificant with respect to TSR. Based on TSR rate (TSRR) values, the addition of lime also significantly improved the moisture susceptibility of the asphalt mixtures subjected to multiple freeze-thaw cycles, while lime addition aggregate type and bottom ash addition were insignificant. However, bottom ash source was a factor statistically significant in relating to TSRR, which was not found for TSR. Without lime addition, bottom ash played a role similar to lime in improving TSRR for the materials tested.

The air content of concrete plays an important role in the durability of concrete. Excess air may reduce the strength of the concrete, while inadequate air will result in premature deterioration of the concrete due to scaling caused by freeze-thaw cycles and deicing chemicals. Pumping of hydraulic concrete has been a common practice for placing concrete. Although the air content before pumping is relatively easy to control, the air change during pumping has not been well understood. The purpose of this study was to investigate the change in air content of hydraulic concrete due to pumping in several aspects. Air content, along with other properties, of concrete before and after the pump was measured in 36 construction projects in two phases. Analysis on data from 31 projects in Phase I indicated that most presented air loss during pumping. Many factors could affect the air change. nalysis on data from five projects in Phase II indicated that sampling methods had a moderate effect on the air change. Errors in measurement were minimal for certified testers and calibrated pots. The air change of concrete was significantly affected by the configuration of the boom, in addition to the air content before pumping. Attachments to the boom played key roles in reducing the air loss. Two mathematical models were developed for the prediction of air loss.

本文介绍准高速铁路路基的设计标准问题。对路肩宽度、基床填料、压实标准，基床厚度，以及路提地墓条件等问题提出建议。