Cellular Porous Brick—A Novel Permeable Pavement Strategy

Permeable pavement is generally considered as one of the most effective prac-tices of rainwater management. This paper analyses the defects of current permeable pavement. Inspired by the honeycomb bionic structure which has superior mechanical properties and structural efficiency, an innovative “honeycomb-like” model of permeable brick measuring 190 × 100 × 60 mm in size was proposed and constructed. The mechanical strength and permeability performance of the honeycomb permeable brick were experimentally assessed by universal testing machine and artificial rainfall equipment, respectively. Ex-periment results demonstrated an excellent performance in compressive toler-ance and permeability. The critical damage load (Fc) and compressive strength (Ec) of honeycomb brick were 336.46 KN and 17.70 MPa, which were 18.06% and 11.04% higher than that of ordinary solid permeable bricks, respectively, compared with the conventional permeable bricks. The honeycomb brick is capable of increasing the permeability coefficient by 19.2% and 11.96% under rainfall repetition period of 20 and 30 years respectively. These results demon-strated that the permeable brick with honeycomb-like structure can provide a new paving strategy for the construction of sponge city.

Utilisation of Geothermal Heat Pumps within Permeable Pavements for Sustainable Energy and Water Practices

Geothermal heat pumps （GHPs） are an attractive proposition for renewable energy worldwide as it uses energy naturally stored in the earth. The Earth is a very resourceful form of energy, using the natural solar energy collection and heat storage capabilities as an infinite heat source/heat sink at the base of permeable pavements, which can provide excellent temperature gradients for GHP＇s. Experimental rigs were setup up at The University of Edinbttrgh for a combined permeable pavement and GHP system. At the base of a pavement structure （approximately 1 meter） below the ground＇s surface, temperatures are constant of 10℃ in the U.K all year round. The GHP performance efficiency was analysed by the coefficient of performance （COP） in a heating cycle and the energy efficiency ratio （EER） in a cooling cycle. The mean COP and EER for both systems averaged between 2-4.5 and 3-5 respectively. The combined GHP and pavement structure operated at an optimum efficiency for both heating and cooling cycles and has shown to be unaffected by higher summer or lower winter temperatures. This hybrid system is an attractive renewable energy technology and has additional environmental benefits such as urban runoff reuse and recycling.

Paving Materials and Engineering Applications of Permeable Pavement

The stability of roads in cities directly affects the safety of traffic and transportation.In the process of pavement laying,relevant personnel should use permeable paving materials in the process of construction.Based on the analysis of road drainage requirements,traditional paving materials have relatively poor water permeability,which leads to ponding problems during road use[1].Within this frame of reference,beginning with the characteristics of permeable paving materials,this paper makes an in-depth exploration on practical application measures.

Investigating the Relationship between Porosity and Permeability Coefficient for Pervious Concrete Pavement by Statistical Modelling

A study evaluating the relationship between porosity and permeability coefficient for pervious concrete (PC) is presented. In addition, the effect of mixture design parameters particularly, water-to-cement ratio (W/C) and size of aggregate on the permeability coefficient of PC was investigated. The PC mixtures were made with 4 range of W/C and 2 range size of aggregate. PC mixes were made from each aggregate and were tested. The results showed that the W/C and aggregate size are key parameters which significantly affect the characteristic performance of PC. Permeability coefficient of coarse pervious concrete (CPC) is bigger than fine pervious concrete (FPC) and the porosity of CPC are bigger than porosity of FPC. A regression model (RM) along with analysis of variance (ANOVA) was conducted to study the significance of porosity distribution on permeability coefficient of PC. The statistical model developed in this study can facilitate prediction permeability coefficient of CPC and FPC as the sustainable pavements.

Pore Characteristic Design Method of High-strength Pervious Concrete Based on the Mechanical Properties and Rainstorm Waterlogging Resistance

High-strength pervious concrete(HSPC) with porosity ranging from 0.08% to 2.011% was prepared. The mechanical properties and rainstorm waterlogging resistance of HSPC were evaluated,and a design method of HSPC pore characteristics(porosity and pore diameter) based on the mechanical properties and rainstorm waterlogging resistance was proposed. The results showed that the reduction of effective cross-sectional area caused by artificial channels was the main factor affecting flexural strength but had limited influence on compressive strength. Compared with the concrete matrix without artificial channels,the compressive strength of HSPC with porosity of 2.011% decreased by 7.4%, while the flexural strength decreased by 48.3%. The permeability coefficient of HSPC can reach 16.35 mm/s even at low porosity(2.011%).HSPC can meet the requirements of no rainstorm waterlogging, even if exposed to 100-year rainstorms. When the mechanical properties and rainstorm waterlogging resistance are compromised, the recommended porosity ranges from 1.1% to 3.5%, and the recommended pore diameter ranges from 0.8 to 2.7 mm.

Mechanical and Permeability Analysis and Optimization of Recycled Aggregate Pervious Concrete Based on Response Surface Method

In this paper,the effects of different influencing factors and factor interaction on the compressive strength and permeability of recycled aggregate pervious concrete(RAPC)were studied based on the response surface method(RSM).By selecting the maximum aggregate size,water cement ratio and target porosity as design variables,combined with laboratory tests and numerical analysis,the influences of three factors on the compressive strength and permeability coefficient of RAPC were revealed.The regression equation of compressive strength and permeability coefficient of recycled aggregate pervious concrete were established based on RSM,and the response surface model was optimized to determine the optimal ratio of RAPC under the conditions of meeting the mechanical and permeability properties.The results show that the mismatch item of the model is not significant,the model is credible,and the accuracy and reliability of the test are high,but the degree of uncorrelation between the test data and the model is not obvious.The sensitivity of the three factors to the compressive strength is water cement ratio>maximum coarse aggregate particle size>target porosity,and the sensitivity to the permeability coefficient is target porosity>maximum coarse aggregate particle size>water cement ratio.The absolute errors of the model prediction results and the model optimization results are 1.28 MPa and 0.19 mm/s,and the relative errors are 5.06%and 4.19%,respectively.With high accuracy,RSM can match the measured results of compressive strength and permeability coefficient of RAPC.

木质素纤维增强型透水性沥青稳定碎石疲劳研究

为提高增强型透水性沥青稳定碎石(asphalt treated permeable base,ATPB)的抗裂性能和耐久性,以SBS改性沥青为胶结材料配制掺入木质素纤维的ATPB混合料——纤维增强型透水性沥青稳定碎石(fiber asphalt treated permeable base,FATPB),并制作不同木质素纤维掺量的FATPB-25梁式试件进行不同应力比下的四点弯曲疲劳试验。将木质素纤维掺量为0.3%的FATPB-25与普通的AC-25、ATB-25的疲劳性能进行对比分析,探究考虑失效概率的应力比与纤维掺量对疲劳寿命的影响。研究结果表明:纤维掺量为0.3%的FATPB-25的抗疲劳性能明显比普通的AC-25和ATB-25的高,可用作耐久型的透水性下面层或柔性基层;通过包含失效概率的双对数方程可以对FATPB-25的疲劳寿命进行预测。

水凝胶包裹的透水材料在寒区河道工程中应用及性能分析

随着人们生活水平的提高,对河道工程的完善提出了更高要求,提升寒区透水混凝土铺装使用时间的重要举措就是在防冻胀设计上做到有效性。将实际工程作为对象,利用现场试验方法,分别设定3种找平层材料和基层材料,分析不同方案下寒区河道工程的抗冻胀性能。试验结果显示,河道工程基层与找平层材料可使用透水水稳与中粗砂材料。建议使用相应的工程技术机制,对滞留基层的径流进行及时排空,最大限度弱化冻胀的破坏问题。

基于物理实验的典型透水铺装水文效应研究

为了研究典型透水铺装水文效应,设计研制了一套人工模拟降雨实验系统,经过降雨特性检验,对透水混凝土铺装和植草砖铺装进行了定雨强下渗实验和设计暴雨情景下降雨径流实验。结果表明,本实验系统可实现雨强自动连续变化,人工降雨与设计暴雨在降雨峰值、降雨总量和降雨过程上接近,模拟降雨效果较好。透水混凝土铺装初始下渗率较大,相比于植草砖铺装更早进入稳定下渗阶段,稳定下渗率也更小;植草砖铺装在充分供水条件下也可一定程度控制径流;Horton模型对于透水铺装下渗特性有较好的描述能力。透水混凝土铺装产流过程与降雨过程呈现较高相关性,相同重现期下透水混凝土铺装产流时间均早于植草砖铺装,且产流量大;在削减径流总量和径流峰值、延后径流峰值方面,植草砖铺装都表现更好。

基于StormDesk的不同因素对透水铺装“净”效果的影响

为更有效地改善径流污染问题,以苏州市某校园为例,利用StormDesk构建研究区的水文水质模型,模拟分析了不同结构形式、不同土质类型的透水铺装对径流污染物的去除效果。研究表明,全透水型铺装“净”效果最好,但其效果随重现期的增大逐渐下降,下降幅度呈递增趋势;在较小的重现期下,不同土质类型的透水铺装“净”效果无明显的差距,而随重现期逐渐增大,土壤层为粘土的透水铺装“净”效果明显优于壤土和砂土;对改善径流污染需求较高的路面改造建议优先选择全透水型铺装+粘土。研究结果可为相似地区进行LID设施改造提供参考意见。

陶瓷透水路面砖渗透系数与孔隙特征的定量关系模型

利用X射线计算机断层成像及图像三维重构技术获取了陶瓷透水路面砖的孔隙特征参数与渗透系数.基于沿程水头损失及局部水头损失影响因素,选取合适孔隙特征参数,并利用量纲分析法建立了渗透系数与孔隙特征参数的定量关系模型.结果表明:通过统计学检验方法对建立的定量关系模型进行检验,发现所建立模型是合理可靠的;渗透系数受有效孔隙迂曲度、有效孔隙半径均值的影响最大,受有效孔隙比表面积、有效孔隙等效喉道半径及有效孔隙等效喉道长度的影响较小.

混掺纤维透水沥青混料的路用性能试验研究

外掺纤维材料可在一定程度上综合提升透水沥青混合料的服役性能,研究对不同组合方案下的透水沥青混合料与普通透水沥青混合料进行性能对比分析。纤维组合方案包括单掺BF、单掺PP、复掺BF+PP在内共计15种。分别对混合料的高温稳定性、水稳定性、低温抗裂性、疲劳性能及排水性能进行综合考察,认为玄武岩纤维可综合促进透水沥青混合料的高温稳定性、低温抗裂性及疲劳性能,但对水稳定性的提升不明显。而经过适宜比例复掺的混合料(0.4%BF+0.2%PP和0.4%BF+0.1%PP),能够对水稳性能在内的各项路用性能都进行显著提升,提升幅度可达到20%以上,这对于透水沥青路面的高品质发展及推广应用具有重要意义。

我国透水路面发展研究综述

从政策、标准、方法、技术、效益评估等方面综述了我国透水路面的技术方案和综合效益,并将我国透水路面的发展历程划分为学习阶段、启动阶段、发展阶段、快速建设阶段、规范化阶段5个阶段。讨论了现行透水路面的分类方式、评价指标和建设规划,分析了透水路面的效益及评价方法。针对我国透水路面铺设缺乏方向性、技术标准不全面等问题,提出了完善透水路面评价机制、制定适当的透水路面建设指导原则、科学定量分析透水路面建设的可行性、对各地透水路面建设的合理性进行评估、鼓励在适宜区域内建设透水路面、加强标准和技术规范的制定和修订等建议。

彩色透水混凝土路面铺装技术在公园工程中的应用

该文将率先介绍彩色透水混凝土路面铺装技术的运用优势,再通过专业的研究与调查,并以某公园工程为例,详细阐述该技术在工程项目中的应用过程,内容包括明确施工操作流程、铺设模板、浇筑混凝土、表面处理及路面养护等,然后借助对混凝土路面的合理规划,探索出改善该施工技术的有效措施,有效增强公园工程路面铺装质量,提升公园内部的美观性、生态性。

排水沥青路面超渗流行为时空分布规律的试验研究

为探究排水沥青路面在不同降雨环境下真实的超渗流行为,并弥补现有渗水试验表征排水能力的不足,以目标空隙率为20%和22%、公称最大粒径为13.2 mm的排水沥青混合料(PAC-13)为研究对象,基于自主研发的降雨排水试验装置,采用降雨峰值比例为0.4、降雨历时为30 min的广州地区芝加哥雨型进行室内降雨试验和数据分析;探明重现期分别为0.5,1,2,10,50,100 a的降雨强度下,合成坡度为2.5%的路面超渗流行为时空分布规律;提出以极限降雨强度、超渗流水位曲线和径流时间参数来综合评价排水路面的排水性能。结果表明:(1)自主研发的降雨排水装置能得到排水沥青路面超渗流行为的时空分布规律;(2)20%和22%空隙率试验组的极限降雨强度分别为1.6 mm/min和2.0 mm/min,试验最大径流均出现在峰值降雨阶段,出现的位置一般在距离道路中心线0.7~1.5 m之间;(3)提升空隙率可以在一定程度上减少径流量的大小;(4)超渗流水位曲线越平缓,其内部渗流越流畅,排水能力越好;(5)超渗流水位曲线越集中,其排水能力越接近极限;(6)增加空隙率对路面径流的水膜厚度影响有限,但对路面径流的持续时间有着良好的削减作用,重现期越长这种削减作用越强,同时还能降低径流量持续时间随着重现期的增大而增加的速率。

灌入式复合路面的经济和环境效益综合评价研究

灌入式复合路面作为一种新型路面养护技术,其经济与环境效益尚不明确。本研究基于实际工程,采用生命周期评价和生命周期成本分析,量化评估了灌入式复合路面的经济成本和环境影响,并与传统铣刨重铺进行了比较。采用热图可视化方法进一步探究了路面使用寿命对评价结果的影响,明确了其实现经济和环境优势所要达到的使用寿命要求。结果表明,灌入式复合路面相比铣刨重铺在材料生产和施工阶段的能耗、碳排放和综合造价分别高5.16%、58.10%和136%。考虑路面使用寿命后,灌入式复合路面只要能比铣刨重铺多服役一年以上,就具有能耗优势。若其使用寿命能进一步达到铣刨重铺的1.58倍以上,就能实现减碳作用。经济效益方面,由于灌入式复合路面的初期投入成本较高,仅当其使用寿命远高于铣刨重铺时,如灌入式复合路面服役14年,铣刨重铺仅服役5年,才能具有经济优势。

基于海绵城市建设的透水混凝土研究及应用

为降低城市洪涝风险、维护城市生态环境及提升城市生态系统功能,我国倡导并实施海绵城市建设,这一理念突破性地摒弃了传统的“以排为主”的城市雨水管理模式。随着全球变暖和空气污染日益严重,海绵城市的建设受到越来越高的重视,而透水混凝土这种具有良好渗漏率、抗压强度、弹性和持久性的新型建筑材料正是主要的贡献者。另外,通过采用具有良好渗漏、通风和减少噪音的透水、渗油和渗碳技术,可以更好地促进海绵城市的实施和发展。基于此,深入剖析了当前透水混凝土的研究和使用情况,指出在解决当前环境挑战方面存在的困难,并给出有效的解决方案,为推动海绵城市建设和实现可持续发展的愿景做出贡献。

透水混凝土路面堵塞与恢复研究进展

透水混凝土路面作为“海绵城市”建设中的重要组成部分,得到了广泛的推广与应用。良好的透水性能是其能够正常使用的前提。透水混凝土路面在正常使用条件下,会受到各种物质进入其内部结构造成透水孔隙堵塞,降低透水混凝土的透水性能,影响透水混凝土路面的正常使用。对透水混凝土路面的堵塞现象和恢复其透水性能的具体措施,以及利用数值模拟方法研究透水混凝土路面堵塞与恢复的现状进行了综述,有助于我们了解透水混凝土路面的堵塞机制并提出合理的维护建议。

透水沥青混合料PAC-16级配优化

为改善透水沥青混合料的高温抗剪切性能,对透水混合料PAC-16三轴剪切试验进行模拟,构建虚拟三轴剪切试验数值模型,并对其模拟准确性进行验证。基于此,结合数值仿真和室内试验对PAC-16级配进行优化。结果表明:虚拟试验方法所测的不同围压水平峰值应力、内摩擦角及黏聚力均与室内试验实测结果的误差不超过5%,且试验规律与实际相符;推荐粗集料最佳用量为4.75~9.5 mm:9.5~13.2 mm:13.2~16 mm:16~19 mm=10:15:12:3、细集料最佳级配取i=0.75对应的级配、粗细集料用量比为80:20,并确定0.075 mm,4.75 mm及16 mm关键筛孔通过率,提出PAC-16优化级配。优化级配的高温性能至少提升10%,整体路用性能更加出色。

复掺纤维对改性沥青混合料性能影响的研究

为研究透水沥青路面的性能,以含有质量分数为12%苯乙烯-丁二烯-苯乙烯三嵌段共聚物(SBS)改性剂的沥青混合料为基础材料,通过标准飞散试验、水稳定性试验、高温车辙试验、抗疲劳试验,在复掺不同含量聚酯纤维和玄武岩纤维的情况下,对改性沥青混合料的性能进行了研究,结果表明:复掺质量分数为0.2%的聚酯纤维和质量分数为0.1%的玄武岩纤维对沥青混合料透水性能的改善效果最好。