排水降噪沥青路面配合比确定方法浅析

透水降噪沥青路面能有效的排除路表雨水,降低路面噪声,与普通密级配沥青路面相比,噪声可降低3分贝以上,与水泥混凝土路面相比,能降低7分贝以上;可提高潮湿路面的抗滑性故。本文研究的目的是提供一种排水降噪路面结构的配合方法及路面材料级配,以指导排水降噪路面的拌制与施工,解决改善道路路面的排水降噪问题。     

Effect of Traffic Speed on Stresses and Strains in Asphalt Perpetual Pavement

Increasing traffic volumes and loads as well as public expectation for a long-lasting transportation infrastructure have necessitated designing perpetual pavements. The KDOT （Kansas Department of Transportation） conducted a field trial to investigate the suitability of perpetual pavement concept for Kansas highway pavements. The experiment involved construction of four thick pavement structures. To verify the approach of designing perpetual pavements on the basis of an endurance strain limit, the pavements were instrumented with gauges for measuring tensile strains at the bottom of asphalt base layers at various speeds. Pavements were also instrumented with pressure cells to measure stress on the top of subgrade. Pavement response measurements under known vehicle load were performed in August 2006. FWD （Falling-weight deflectometer） was also used to collect deflection data at 15 m intervals on the same date. FWD first-sensor （center） deflections were normalized and corrected to 20 ℃ temperature based on measured mid-depth pavement temperature. The result shows that strain and stress measurements show significant amount of variations. Measurements in the thickest section are the most consistent. The higher the traffic speed, the lower the strains and stresses. The difference between strains and stresses at 30 kmhar and 65 km/hr is higher than the difference between 65 km/hr and 95 kin/hr. This shows the effect of speed on stresses and strains decreases as the speed increases. Softer binder in the asphalt base layer results in lower strains, which confirms that softer binder results in higher fatigue life.     

A Comparison of Different Approaches in Numerical Modeling of Pavement Granular Material

Modeling pavement granular materials have played through an experimental or numerical approach to predict the a significant role in pavement design procedure. Modeling can be granular behavior during cyclic loading. Current design process in western Australia is based on linear elastic analysis of layers. The analysis is largely performed through a well-known program CIRCLY which is applied to model bound pavement material behavior. The KENLAYER is one of the common pavement software models used for pavement design in the United State which performs non-linear analysis for granular materials. Alternatively, a general finite element program such as ABAQUS can be used to model the complicated behavior ofmultilayer granular materials. This study is to compare results of numerical modeling with these three programs on a sample constructed pavement model. Moreover, a parametric study on the effects of Poisson ratio over the surface deflection of the flexible pavement has been conducted. It is found that increase in Poisson ratio of asphalt layer will increase the surface deflection while the increase in Poisson ratio of granular layers decreases the surface deflection.     

Concrete Containing Marginal Aggregates for Use in Concrete Pavement

The study presented an analysis accessing the feasibility of using concrete containing marginal aggregates in concrete pavement slabs. The physical properties of aggregates were first determined and concrete was produced from them. Marginal aggregates were found to have higher fines, absorption, soundness loss, micro-Deval abrasion loss, LA （Los Angeles） abrasion loss and lower specific gravity and unit weight when compared with standard aggregates. Workability of concrete containing marginal aggregate was found to be similar to concrete containing normal aggregates when Shilstone mix design method was used to optimize the concrete mixes. The compressive strength, splitting tensile, flexural strength and modulus of elasticity of concrete containing marginal aggregates were determined and found to be generally lower than concrete containing standard aggregates. A typical concrete pavement in Florida was modeled in FEACONSIV （finite element analysis of concrete slab） software developed at the University of Florida. Laboratory determined mechanical and thermal properties of concrete were inputted in FEACONS IV and analyzed for maximum induced stresses. Critical stress to strength ratios, i.e., ratio between maximum computed stresses obtained from FEACONS IV to modulus of rupture （strength） of concrete, was used as evaluation criterion for different concrete pavement mixes. It was found that, in general, concrete containing marginal aggregates have higher stress to strength ratios as compared with concrete containing standard aggregates.     

浅谈沥青路面就地热再生施工质量控制

结合卡罗泰康列车,通过热再生施工实践,对沥青路面就地热再生施工的质量控制进行了探讨,重点从室内试验和热再生的现场质量控制方面进行了论述,以积累沥青路面就地热再生施工经验,确保沥青路面热再生的工程质量。     

就地热再生技术对改性沥青路面的成功应用

指出沥青路面就地热再生技术可节约大量的沥青、砂石等原材料,同时有利于环保,开放交通快,沥青路面就地热再生技术应用具有重要的意义,通过实例对沥青路面就地热再生技术在改性沥青路面上应用的可行性得到充分论证。     

临长高速公路沥青路面就地热再生应用研究

以临长高速公路就地热再生工程为依托,简述了就地热再生技术的施工流程,阐述了原沥青路面混合料试验、沥青掺加再生剂试验要点,并通过再生混合料施工配合比设计,总结了施工过程中的质量控制措施。     

沥青路面就地热再生技术特点及施工工艺浅析

归纳了沥青路面就地热再生技术的优点,介绍了沥青路面就地热再生技术的使用条件和施工工艺,指出沥青混凝土路面就地热再生技术具有节约材料、降低沥青路面造价,节省工程费用和保护环境的作用,具有巨大的社会效益和经济效益。     

浅谈沥青路面就地冷再生技术的施工工艺控制

结合省道239路面维修工程,着重对沥青路面就地冷再生的施工工艺进行了研究,探讨了沥青路面就地冷再生技术在旧沥青路面改造施工中的应用实践,以进一步推广该技术的发展和应用。     

沥青路面就地热再生影响分析与热平衡计算

对沥青路面就地热再生工艺进行了介绍,对沥青路面就地热再生加热影响因素进行了分析,推导出了路面加热机在加热一遍时工作速度的计算公式,为就地热再生工程中,加热机运行速度的选择与控制提供了理论依据.     

泡沫沥青技术在沥青路面现场冷再生中的应用

泡沫沥青具有节省能源及减少污染的环保优势,采用泡沫沥青对沥青路面进行现场冷再生是最近几年欧美国家积极采用的路面再生技术之一。该文介绍了泡沫沥青的产生机理及其特点,探讨了泡沫沥青混合料的技术性能和设计方法,说明了泡沫沥青混合料在沥青路面现场冷再生中的应用。     

纳米复合改性沥青混合料路用性能研究

为评价纳米复合改性沥青混合料的路用性能,对纳米ZnO改性沥青混合料、纳米ZnO/TiO_2改性沥青混合料以及纳米ZnO/TiO_2/SBS复合改性沥青混合料进行了高温性能试验、小梁弯曲试验、劈裂试验及相关耐久性试验,并与基质沥青混合料和SBS改性沥青混合料进行对比分析.结果表明:上述3种纳米改性沥青混合料的高温稳定性、低温抗裂性、间接抗拉性和耐久性均优于基质沥青混合料,其中纳米ZnO/TiO_2/SBS复合改性沥青混合料的上述性能优于SBS改性沥青混合料.由此可见,纳米材料可显著改善沥青混合料的性能,纳米复合改性沥青的性能优于聚合物改性沥青,将其应用于道路是可行的.     

沥青混合料动态压-拉双模量及其在路面响应分析中的应用

沥青混合料层模量是沥青路面响应分析的必备参数,其数值的准确性关乎路面设计结果的可靠性。受骨料嵌挤作用的影响,沥青混合料在承受压应力与拉应力时模量表现不同。文章旨在从双模量的角度分析沥青混合料的动态压-拉模量特征,并将压-拉双模量用于路面响应预测,探讨双模量体系下的路面响应特点。首先,基于双模量框架下的有限元模型,建立间接拉伸试验中沥青混合料压 拉双模量、泊松比的计算方法;其次,以一种密级配混合料(AC-13)为例,分析沥青混合料在不同温度与加载频率下动态压-拉双模量、压-拉泊松比与单模量、单泊松之间的差异性;最后,将所确定的压 拉模量及泊松比用于路面沥青层力学响应预测,并与现有的单模量体系下的预测结果进行对比,分析单、双模量两类体系下路面力学响应的特点及其联系。研究表明,AC-13混合料压模量主曲线在全频域内均明显高于拉模量主曲线;单模量体系计算的模量主曲线更接近于压模量主曲线,且所计算的泊松比在中高温时失效;混合料压 拉模量比值分布在1.6～4.0,随温度升高而升高。与双模量体系下路面响应计算结果相比,现有单模量体系模型低估了柔性路面沥青层应变响应及柔性/半刚性路面沥青层的最大剪应力响应,而弯沉响应计算结果具有较好的一致性。研究成果可为考虑材料压、拉模量差异性的路面设计提供参考。     

浅谈纤维在桥面铺装中的应用

桥面铺装沥青混凝土层直接承受行车荷载、梁体变形和环境因素的作用,受力情况复杂,因此对桥面铺装沥青混凝土的性能提出更高的要求。该文通过水稳定性、高温车辙、低温弯曲和单轴静态蠕变试验系统研究了纤维改性沥青混凝土的性能。研究结果表明,掺加纤维后能够有效提高沥青混合料的残留稳定度和冻融劈裂强度比,同时能够改善低温抗拉性能和抗高温变形能力,纤维增强沥青混合料适宜用作桥面铺装层。     

旧沥青路面再生技术的研究现状

就目前我国沥青再生技术的研究现状做了概述,分析了旧沥青路面再生机理,并对沥青路面再生技术的方法,现场冷、热再生技术的施工工艺进行了阐述,以推动我国在再生技术上的发展。     

浅谈沥青路面就地热再生养护技术

对沥青路面就地热再生养护技术的含义、类型、适用条件及实施步骤进行了论述,从技术、环保、经济等方面着手,将就地热再生与传统工艺进行了比较分析,展现出就地热再生技术的优势,为进一步推广应用奠定了基础。     

应用英达就地热再生技术进行SMA路面处治

介绍了传统就地热再生技术在SMA路面应用的难点,研究了英达就地热技术进行SMA路面再生所具有的技术优势,指出其具有节约、环保、高效的特点,充分利用了旧沥青混合料的稳定性,是公路养护的发展趋势。     

高寒地区水泥混凝土桥面沥青铺装层抗疲劳开裂性能分析

混凝土桥面沥青铺装层在使用期间产生的疲劳开裂是世界各地桥面铺装常见的问题,该文依托内蒙古教来河大桥采用有限元分析软件ANSYS对于高寒地区混凝土桥面沥青铺装层的疲劳开裂性能进行分析研究。分析提出高寒地区混凝土桥面沥青铺装层深度0~2 cm区域可作为铺装层内部常温拉应力的峰值分布区域;铺装层内的常温拉应力均随着上面层/下面层厚度的增加而减小;通过增加高寒地区混凝土桥面沥青铺装层的厚度来改善桥面铺装层的抗疲劳性能。     

半刚性基层沥青路面耐久性对设计影响分析

利用JTG D50—2006《公路沥青路面设计规范》中路面各结构层层底拉应力验算公式和BISAR3.0设计分析软件,对半刚性基层沥青路面疲劳寿命及影响因素进行了分析。分析结果表明,延长路面使用寿命的关键是增加半刚性基层和底基层的疲劳寿命,减小在行车荷载作用下的半刚性基层和底基层层底的拉应力。这可通过增加路面各结构层厚度和土基模量等措施获得,而其中增加底基层厚度和土基模量是既经济又有效的措施。     

浅析沥青路面就地冷再生底基层混合料配制

以平青乐线K297＋752-K301＋102段冷再生底基层工程为例,介绍了沥青路面全深式就地冷再生底基层混合料配制要点,对冷再生旧料特征,新添骨料性质及相关试验分析步骤作了具体阐述,以期指导实践。