沥青路面早期破损的预防措施

沥青路面早期破坏的成因比较复杂,涉及设计、施工、养护、管理等方面。本文从工程施工的角度,主要讨论施工及原材料方面的原因,以及根据成因应采取的预防及改善措施。     

对大中桥沥青路面早期破损的分析

目前来讲,我国大部分的高速公路以及路桥的修建都采用了沥青路面,但是由于沥青本身的材质有所不同,其质量差异也是很大的,同时还受到施工时候的设计及施工水平的影响,从而往往会导致沥青路面在施工不久就出现的早期破损现象,如裂缝、沉陷等,这些现象都十分严重的影响着行车的安全,本文就是对于大中桥梁沥青路面的早期破损问题的形成进行了分析,并提出了相应的解决办法和预防措施。     

公路沥青路面破损的原因及防治措施

现代公路建设中,由于沥青路面的诸多优点而获得了越来越广泛的应用。沥青路面的质量的好坏,可以提高行车的舒适性,增加行车安全,提高路面的通行能力,减轻行车的颠簸和噪音,减少汽车机件和轮胎破坏、降低油耗。由于施工水平及交通荷载,还有自然因素地理位置的影响,公路破损现象经常发生,给社会人们的生活带来诸多不利影响。在当前公路建、养资金严重不足的情况下,研究沥青路面的早期破损原因及防护具有特别重要的现实意义。     

公路沥青路面破损的原因与防治措施

现代公路建设中,由于沥青路面的诸多优点而获得了越来越广泛的应用。在当前公路建、养资金严重不足的情况下,研究沥青路面的早期破损原因及防护具有特别重要的现实意义。     

高速公路沥青路面的养护对策

分析高速公路沥青路面的特点.介绍沥青路面破损状况,提出养护与维修的对策及建议.     

浅谈提高沥青路面耐久性的措施

本文分析了沥青混合料（包括沥青混凝土）路面强度形成机理,提出了提高沥青路面的使用品质和耐久性的措施。     

关于道路沥青路面破损的预防

本文对沥青公路路面破损产生的原因和现象进行了分析与论述,探讨了处理此类现象的措施与方法。     

公路沥青路面的早期破坏及防治措施

本文作者对沥青路面早期的破坏这一质量通病做出深入的探讨,并分析了产生的原因,产生的影响,从设计、施工、养护等几方面提出了沥青路面早期破坏和防治措施。     

高速公路施工中沥青路面早期破坏分析

我网高速公路沥青路而早期破坏主要有裂缝、水破坏、松散、泛油等,这些破坏也是公路质量的通病,严重影响高速公路的正常使用。文章结合自己的经验阐述了以上几种病害的成因并提出了相应的预防措施。     

沥青路面早期损坏探讨

近年来,随着交通量的增加,一些国省道主干线的交通组成中重载车辆的比例增大且超载现象严重,同时受季节性冰冻地区的地质、水文、气象等自然及人为因素的影响,造成部分沥青路面出现不同程度网裂、坑槽、拥包、车辙、泛油等早期损害现象,导致路面服务功能下降,影响正常运营,增加了养护费用的投入。因此,如何路面早期损坏,延长路面的使用寿命,防止病害的发生已成为公路建设急待解决的问题。     

沥青路面早期破坏研究

沥青路面的破坏形式是多种多样的,而沥青路面的早期破坏是指路面在尚未达到使用年限之前发生的破坏,这种现象越来越具有普遍性。本文归纳了沥青路面早期破坏的类型、分析其破坏原因并探讨了防治措施。     

自密实钢纤维轻骨料混凝土的早期性能与损伤分析

在自密实轻骨料混凝土基础之上掺入钢纤维配制出自密实钢纤维轻骨料混凝土,分析了自密实钢纤维轻骨料混凝土的抗压强度、抗拉强度等主要力学性能以及收缩、抗碳化等耐久性能,并与普通骨料自密实混凝土进行对比分析。探讨了钢纤维对于改善自密实轻骨料混凝土损伤所起的作用及其机理。结果表明:掺入钢纤维后自密实轻骨料混凝土的抗压强度增大,劈拉强度明显提高,收缩及抗碳化能力也有明显改善。与普通骨料混凝土相比,自密实钢纤维轻骨料混凝土初始裂缝的产生与发展得到有效抑制。     

包装破损的环境因素及对策

商品在流通过程中因包装不善造成损失的原因可分为两种,一种是因包装材料使用不当或包装结构设计不合理造成商品在储运、销售过程中的破损.另一种是因所使用的包装材料、包装结构、包装装潢等因不符合所销售地区的法规、标准、习俗等原因造成破损。本文将引起第二种损失的原因进行了分析,并提出了防止损失的对策。     

Damage model for environmental conditioned fatigue test with CAST

The aim of this paper is to suggest a unified test method that allows investigation into the different effects and contribution of water damage and temperature cycles on fatigue performance of asphalt mixtures by means of a CoAxial Shear Test (CAST). A continuum damage approach, based on the elasticity theory, is chosen to determine the damage level of each tested specimen. The proposed mathematical model allows the simulation of the modulus evolution in the fatigue test and takes into account the temperature cycles. In this way, a unique scalar damage factor determines the damage process severity in each specimen and allows a rational comparison between each different condition.     

粘层材料剪切疲劳特性及层间设计方法研究

沥青路面的性能及使用年限很大程度上取决于其结构层间粘结状态的好坏。在进行沥青路面设计时,路表弯沉及沥青面层层底拉应力通常被视为重要的设计指标,而沥青路面层间剪切疲劳破坏却被忽视,为沥青路面病害的产生埋下隐患。通过系统的沥青路面层间剪切疲劳试验建立了沥青路面层间剪切疲劳方程及疲劳寿命预估模型,并根据沥青路面的实际工作状态,对该模型进行了修正。提出了基于剪切疲劳破坏的沥青路面层间设计方法,结合工程实例,对沥青路面剪切疲劳破坏进行了验算及寿命预估。结果表明:在以传统的路表弯沉及沥青面层层底拉应力为设计指标时,其层间接触不能满足路面剪切疲劳的要求,因此,建议在沥青路面设计中增加沥青层间剪切疲劳设计指标。     

Light-coloured grey asphalt pavements: from theory to practice

This paper presents the technological development and application of hydrated lime in treating the surface of asphalt concrete to develop light-coloured, grey asphalt pavements. When appropriately applied on the surface of fresh asphalt concrete, hydrated lime makes the surface grey, significantly increases its albedo and effectively reduces the pavement's temperature caused by hot weather. Two application case studies are presented, focusing on how to ensure hydrated lime's long-term effectiveness on the surface of asphalt pavements and take into account the effect of the subsequent reduced temperature on the resilient modulus of asphalt concrete in the design of long-life flexible pavements. The increased asphalt concrete modulus, owing to lowered temperature, can reduce the design thickness of the asphalt concrete without sacrificing pavement performance. This also has a positive influence on reduced pavement heat island effects. It is concluded that the appropriate use of hydrated lime on asphalt pavement surfaces is an effective and economical method to produce light-coloured, grey asphalt pavements.     

Effect of Reinforcement Corrosion Sediment Distribution Characteristics on Concrete Damage Behavior

Reinforcement corrosion directly affects the mechanical behavior of reinforced concrete structures. An electric corrosion test was conducted on a reinforced concrete test specimen, and a finite element model of the reinforcement corrosion damage was established. In addition, the damage behavior of reinforced concrete under different corrosion sediment distribution characteristics and different corrosion rates was studied. It was noted that when corrosion sediments are in a “semiellipse+semicircle” distribution, the results of numerical calculation are consistent with those obtained experimentally, reflecting the damage characteristics of reinforced concrete test specimens. Further, the results showed that the distribution characteristics of corrosion sediments greatly influence the damage behavior of reinforced concrete. In particular, when the corrosion sediments demonstrate a “semiellipse” distribution, reinforced concrete members may easily suffer from reinforcement damages. In the case of “semiellipse+semicircle” and “circle” distributions, the cohesive force between the reinforcements and concrete decreases: With the same corrosion rate, the damaged area expands with the increase in the number of reinforcements, which indicates a reduction in the cohesive force and thus, a reduction in the damage in the reinforcement area. This paper analyzes in-depth the effects of reinforcement corrosion expansion on the concrete damage behavior, provides references for practical engineering.     

Comparing rutting of airfield pavements to simulations using Pavement Analysis Using Nonlinear Damage Approach (PANDA)

This study presents the rutting performance results of full-scale pavement test sections subjected to F-15E and C-17 aircraft wheels at two different temperatures. Pavement structures for the tests were constructed under shelter in the U.S. Army Engineer Research and Development Center's (ERDC) pavement test facility. The full-scale test results are used to validate viscoelastic, viscoplastic and hardening-relaxation constitutive relationships implemented in the Pavement Analysis Using Nonlinear Damage Approach (PANDA) model. PANDA is a mechanistic-based model which incorporates nonlinear viscoelastic, viscoplastic, hardening-relaxation, viscodamage, moisture-induced damage and ageing constitutive relationships. Results of dynamic modulus and different repeated creep-recovery laboratory tests are analysed to extract the parameters associated with viscoelastic, viscoplastic and hardening-relaxation constitutive relationships implemented in PANDA. Once calibrated, PANDA is used to predict the rutting performance observed in full-scale pavement test sections. The simulation results illustrate that PANDA is capable of predicting the rutting of airfield pavements subjected to heavy aircraft wheel loads at intermediate and high temperatures. It is shown that PANDA successfully predicts the effect of shear flow and upheaval at the edges of the wheel. The data from simulation suggested that PANDA, once calibrated, can provide insight into the critical locations of tensile and compressive stresses within the pavement structure. PANDA simulations not only provide a tool for evaluating existing structures, but also can be used in designing more sustainable pavement structures and materials.     

绿色道路胶凝材料的研究现状及发展趋势

主要介绍了国内外公路的发展现状,通过对水泥路面和沥青路面的比较,以及对水泥工业发展、沥青资源利用和碱胶凝材料研究进展的分析,浅谈了绿色道路胶凝材料的发展趋势.充分利用工业废渣制备性能优良的道路胶凝材料,符合科学发展观的原则,符合推动资源节约型和环境友好型行业建设,实现交通可持续发展的战略.