多孔水泥混凝土防滑磨耗层应用

技术的研究

Research  on Application Technology of Anti - skid Wear Layer of Porous Cement Concrete

研究生：杨学良

指导教师：郭忠印

二○○四年三月

摘要

本文在总结国内外研究成果的基础上，从材料的组成、配合比设计、混凝土的性能、有限元模型的计算和施工工艺五个方面，对多孔水泥混凝土作路面防滑磨耗层的应用技术进行了系统的研究和探讨。

在材料方面，根据防滑磨耗层在路面结构中的功能，提出多孔混凝土组成材料的技术要求。通过分析普通混凝土的设计方法，提出以目标孔隙率为基础的多孔混凝土配合比设计方法。在多孔混凝土性能方面，首先分析了孔隙构造和破坏机理，即大孔隙结构下的应力集中现象是多孔混凝土破坏的主要原因。研究了集料级配、水泥用量、水灰比、外加剂等因素对多孔混凝土力学性能的影响，结果表明集料集配和水灰比对多孔混凝土力学性能的影响要比普通混凝土敏感，水泥用量和水灰比对和易性影响较大，从而通过影响混合料成型的密实度来影响强度。这些因素相互作用，共同确定了多孔混凝土最终的强度。通过对多孔混凝土透水系数和抗磨耗性能的测最，说明多孔混凝土作为防滑磨耗层在排水、抗磨耗方面有良好的使用性能。

为了对多孔混凝土防滑磨耗层的应用提供理论基础，本文通过建立有限元模型来分析实际路面结构内的应力水平。计算多孔层厚度、弹性模量以及多孔层与普通层层间接触条件对结构应力的影响。

在施工工艺方面，结合室内足尺板和试验段的铺筑，研究两种施工工艺对多孔混凝土防滑磨耗层力学性能和使用性能的影响。提出施工过程中应注意的问题，并在施工现场配比、施工机具、施T条件、施工工序的组织等方面对施工经验进行了总结。

关键词：多孔混凝土；配合比设计；强度；透水系数；足尺板；有限元模型；施工工艺

ABSTRACT

On the base of research conclusions of porous concrete both  home and abroad, this paper presents a study on the application of porous  concrete used as skid-resistance top layer on highway roads，which includes  investigation of aggregates，design method of mixture composition, evaluation of  propenies，stress  analysis of finite element model and construction techniques．

Considering the requirements of mechanical performance，aggregates used in  porous concrete should have higher quality than those in conventional  concrete．And  this paper suggests some factors，which should be considered when decide which kind of  aggregate to select．After analyzing the mechanism of pores forming and wrecking，a new design method of  mixture composition is introduced, which involves the important  factor-anticipant porosity．Based on the experiments，the effects of gradation of coarse aggregate, water  cement ratio(W/C)，content of cement, and admixture to the properties of porous concrete  are analyzed．The  results show that the mixture of porous concrete is more sensitive to W/C and  workability has a huge influence on the compaction of mix．All these factors  combined contribute to porous concrete properties．To show application  properties of porous concrete used in skid-resistance and permeable layer,  pervious index and friction index are measured through specimen and  full-scale experiments．

In order to promise that skid-resistance top layer of  porous concrete can be properly applied on highway roads，a finite element model  is set up to analyze the stress level in the pavement structure．During the process of  analysis，several  design factors about thickness of top layer, modulus of elasticity and  adhesion condition between porous layer and bottom layer are considered．

This paper also studies some construction techniques by  full-scale experiments and test lane．Two construction methods are introduced and evaluated  according to mechanic effects and application effects．In addition，some experience is  summarized, which involves construction condition，machines and tools used  in construction, and construction plan and management．

Key words：porous concrete；mixture composition design；mechanical properties；pervious index；full-scale experiments；finite element model；construction techniques