Assessment of the Mechanical Properties of Carbon-Fiber Heating Cables in Snow and Ice Melting Applications

The use of carbon-fiber heating cables(CFHC)to achieve effective melting of snow and ice deposited on roads is a method used worldwide.In this study,tensile and compressive tests have been conducted to analyze the mechan-ical properties of the CFHC and assess whether the maximum tensile and compressive strengths can meet the pavement design specifications.In order to study the aging produced by multiple cycles of heating and cooling,in particular,the CFHC was repeatedly heated in a cold chamber with an ambient temperature ranging between-20℃ and+40℃.Moreover,to evaluate how the strength of the pavement is affected by its presence,the CFHC was embedded at different depths and concrete blocks with different curing ages were subjected to relevant com-pression and splitting tensile tests.Numerical simulations based on the ANSYS software have also been performed and compared with the outcomes of the static loading tests.The results show that the CFHC embedded in the concrete does not affect the compressive splitting tensile strengths of the pavement.Overall,the CFHC meets the conditions required for continued use in road ice melting applications.

Observation and modelling of snow and sea ice mass balance and its sensitivity to atmospheric forcing during spring and summer 2007 in the Central Arctic

Snow depth and sea ice thickness were observed applying an ice mass balance buoy(IMB)in the drifting ice station Tara during the International Polar Year in 2007.Detailed in situ observations on meteorological variables and surface fluxes were taken during May to August.For this study,the operational analyses and short-term forecasts from two numerical weather prediction(NWP)models(ECMWF and HIRLAM)were extracted for the Tara drift trajectory.We compared the IMB,meteorological and surface flux observations against the NWP products,also applying a one-dimensional thermodynamic sea ice model(HIGHTSI)to calculate the snow and ice mass balance and its sensitivity to atmospheric forcing.The modelled snow depth time series,controlled by NWP-based precipitation,was in line with the observed one.HIGHTSI reproduced well the snowmelt onset,the progress of the melt,and the first date of snow-free conditions.HIGHTSI performed well also in the late August freezing season.Challenges remain to model the“false bottom”observed during the melting season.The evolution of the vertical temperature profiles in snow and ice was better simulated when the model was forced by in situ observations instead of NWP results.During the melting period,the nonlinear ice temperature profile was successfully modelled with both forcing options.During spring and the melting season,total sea ice mass balance was most sensitive to uncertainties in NWP results for the downward longwave radiation,followed by the downward shortwave radiation,air temperature,and wind speed.

Characterization of sea ice and its snow cover in the Arctic Pacific sector during the summer of 2016

A comprehensive analysis of sea ice and its snow cover during the summer in the Arctic Pacific sector was conducted using the observations recorded during the 7th Chinese National Arctic Research Expedition(CHIANRE-2016)and the satellite-derived parameters of the melt pond fraction(MPF)and snow grain size(SGS)from MODIS data.The results show that there were many low-concentration ice areas in the south of 78°N,while the ice concentration and thickness increased significantly with the latitude above the north of 78°N during CHIANRE-2016.The average MPF presented a trend of increasing in June and then decreasing in early September for 2016.The average snow depth on sea ice increased with latitude in the Arctic Pacific sector.We found a widely developed depth hoar layer in the snow stratigraphic profiles.The average SGS generally increased from June to early August and then decreased from August to September in 2016,and two valley values appeared during this period due to snowfall incidents.

Physical and optical characteristics of sea ice in the Pacific Arctic Sector during the summer of 2018

The reduction in Arctic sea ice in summer has been reported to have a significant impact on the global climate.In this study,Arctic sea ice/snow at the end of the melting season in 2018 was investigated during CHINARE-2018,in terms of its temperature,salinity,density and textural structure,the snow density,water content and albedo,as well as morphology and albedo of the refreezing melt pond.The interior melting of sea ice caused a strong stratification of temperature,salinity and density.The temperature of sea ice ranged from–0.8℃ to 0℃,and exhibited linear cooling with depth.The average salinity and density of sea ice were approximately 1.3 psu and 825 kg/m3,respectively,and increased slightly with depth.The first-year sea ice was dominated by columnar grained ice.Snow cover over all the investigated floes was in the melt phase,and the average water content and density were 0.74%and 241 kg/m3,respectively.The thickness of the thin ice lid ranged from 2.2 cm to 7.0 cm,and the depth of the pond ranged from 1.8 cm to 26.8 cm.The integrated albedo of the refreezing melt pond was in the range of 0.28–0.57.Because of the thin ice lid,the albedo of the melt pond improved to twice as high as that of the mature melt pond.These results provide a reference for the current state of Arctic sea ice and the mechanism of its reduction.

Large spread across AeroCom Phase II models in simulating black carbon in melting snow over Arctic sea ice

Over two dozen global atmospheric chemistry models contributing to the Aerosol Comparisons between Observations and Models(AeroCom)project were used in this study to drive the Los Alamos sea ice model to simulate the black carbon(BC)concentration in melting snow on Arctic sea ice.Measurements of BC during the melting season show concentrations in the range 2.8–41.6 ng·g−1(average:15.3 ng·g−1)in the central Arctic Ocean and Canada Basin.Most results from models contributing to the Phase I project were within the 25th and 75th percentiles of the observations,and the multimodel mean was slightly lower than that of the observations.In contrast,there was larger divergence among the Phase II model simulations and the mean value of BC was overestimated.The multimodel mean bias was−3.1(−11.2 to+6.7)ng·g−1 for Phase I models and+3.9(−9.5 to+21.3)ng·g−1 for Phase II models.The differences between the models of the two phases were probably attributable to the updated aerosol scheme in the new contributions,in which removal processes are parameterized by considering the actual dimensions and chemical compositions of the particles.This means the removal mechanism acts in a way that is more selective and leads to more BC particles being transported to the Arctic.In addition,higher spatial resolution could be another important reason for overestimation of BC concentration in snow in Phase II models.

相变材料在冬季沥青路面中的应用分析

沥青路面在冬季低温雨雪气候下易发生结霜、结冰现象,致使路面抗滑性能降低,从而导致事故发生率上升,给行车安全及路面使用性能带来严重影响。传统的被动式除雪法效率低,且须占用行车道影响道路正常运行,化学融雪剂还会造成土壤和水污染。本文通过文献调研,总结常见的主动融雪化冰路面类型,分析相变材料在沥青路面中的应用研究重点,提出将相变材料掺入沥青路面中,以预防或减少冬季沥青路面冰冻病害。

The responses of hydro-environment system in the Second Songhua River Basin to melt water

Based on the continuous monitoring data of hydrology and water quality in the period from 1972 to 1997, the responses of hydro-environment system to melt water in the Second Songhua River basin were derived. Because of melt water, the water quality in the Second Songhua River is good and changes very except that the contents of Hg and Mn in the water are higher. The contribution of melt water to the water fluxes in the Second Songhua River basin is distinct: the water flow in April increases remarkably, reaches the peak in the upper reaches. The pollutant contributions and water pollution indices (WPIs) of the Second Songhua River in April are high in the upper reaches while that in the lower reaches are low. The responses of hydro-environment system to melt water of that basin are affected by content of packed snow and the underlining surface systems.

道路融冰雪技术应用现状及进展

在我国北方地区,冬季道路积雪结冰会导致路面抗滑性能急速下降,引发汽车在部分路段制动失效,进而发生交通事故。从保障道路畅通、行车安全的角度出发,对道路积雪结冰进行及时清除是道路养管部门关注的重要问题。首先结合目前国内外常用的融冰雪技术,概述了传统融雪化冰技术的应用现状及发展趋势;然后分析了目前主要的道路融冰雪技术研究成果和进展;最后总结对比。

橡胶颗粒/融雪剂复合改性沥青混合料主动除冰试验研究

为解决冬季道路沥青路面易结冰和难除冰的问题,结合橡胶颗粒物理作用和盐化物融雪剂化学作用,制备了橡胶颗粒/融雪剂复合改性沥青混合料,并通过水滴结冰延迟试验、覆冰破损试验和融冰速率试验测试了融雪剂改性沥青混合料以及橡胶颗粒/融雪剂复合改性沥青混合料的抗凝冰能力。结果表明:1)温度介于-2℃~-5℃时,橡胶颗粒/融雪剂复合改性沥青混合料具有良好的抗凝冰能力;2)在-5℃时,掺入5%的融雪剂,试件表面结冰延迟约8 min,其结冰质量损失率是未掺融雪剂试件的13.62倍,其平均融冰速率较未掺融雪剂试件提升了约26%;3)在温度降至-10℃时,融雪剂改性沥青混合料抑冰效果不再明显,但在荷载作用下,橡胶颗粒/融雪剂复合改性沥青混合料仍具有一定的除冰能力。

道路积雪后非预热式主动过程融雪特性实验研究

针对新型道路热融雪过程,开展三种不同埋管节距道路实验。研究主动融雪过程中道路热融雪特性和路面融雪形态和传热规律,分析道路路面温度、单位面积耗热量和单位流程温差的变化规律,探索融雪过程因素影响特征,认知道路埋设盘管热流体循环融雪过程。实验研究表明:积雪和降雪的融化过程分为四个阶段,由于埋管节距的不同,密距型道路在四个阶段所需时间最少;同时,埋管节距越小,其表面无雪率越大,融雪能力越强,单位面积耗热量也越大,但单位流程温差存在一定的增长限度。

路面主动融冰(雪)技术的发展与展望

针对目前路面融冰(雪)技术存在滞后性、效果差、能耗大等问题,分别从刚性路面、柔性路面两个角度,深入研究了6种路面主动融冰(雪)技术的现状、应用效果及发展前景.对其优、缺点以及适用地区进行了全面的分析,为解决冬季道路冰雪问题提供了系统的思路和途径.

主动融冰雪沥青路面技术在冬奥保障道路中的应用

北京市延庆区松闫路作为2022年冬奥会保障道路,举办期间正值寒冬,要求能够快速,高效地清除冰雪,保证道路交通畅通。因此,在大修中需要在沥青表面层掺加道路用相变材料,从本质上改变沥青路面性能。道路用相变材料利用存储的太阳能和机械能,在低温时释放相变潜热,使道路表面温度升高,主动融化冰雪。因此阐述了相变材料的作用机理和在道路工程建设中的应用意义,并进行了经济、社会和环境效益的分析。

道路融雪方法综述

对目前的融雪方法进行总结,分别介绍了传统除雪融雪方法和主动融雪铺装技术,提出了未来开发主动融雪技术的趋势,较为详细地介绍了抑制冻结铺装类和利用能量转化装置融雪的方法,为今后研究奠定了基础。

碳纤维电热丝主动融雪系统路面铺装设计与研究

传统的除雪方法主要是机械除雪或者融雪剂融雪,都是雪后除雪,通过碳纤维电热丝主动融雪系统铺装间距设计计算、碳纤维电热丝电热转换性能试验以及室外融雪试验,确定碳纤维电热丝铺装间距,实现沥青混凝土路面主动实时融雪。

低碳智慧技术在济潍高速公路施工中的运用

随着《交通强国建设纲要》和“双碳”国家重大战略的实施,建设行业必然发生一场广泛深刻的经济社会变革。修建智慧道路、低碳道路是道路行业的必然选择,是实现绿色低碳高质量发展的必经之路。本文依托济潍高速公路项目施工所采取的智慧技术、低碳技术进行研究,分析总结实现主动融雪、隧道不降速通行技术原理;通过试验数据自动化采集、质量追溯体系数字化和施工过程智能化,加强了质量控制,实现了智能化减人;植物毯边坡、光伏边坡一体化应用均为减碳提供了相应思路。济潍高速公路低碳智慧技术的成功实施可为类似项目提供有益借鉴。

主动除冰雪路面融雪化冰特性及路用性能研究综述

为了进一步推进路面主动除冰雪技术的发展,综述了国内外路面主动融雪化冰方法的研究进展。首先,介绍了不同类型路面主动除冰雪技术的融雪化冰机理,并基于此将主动除冰雪路面划分为自应力弹性铺装路面、低冰点路面和能量转化型路面3类;然后,分别对3类主动除冰雪路面的路用性能及融雪化冰特性进行了梳理,在路用性能方面主要包括沥青混凝土路面高温性能、低温性能、水稳定性、黏附性能和耐久性等,以及水泥混凝土路面抗拉、压性能等,而在融雪化冰特性方面主要包括路面抗摩擦性能、冰-路界面黏结性能、破冰性能、融雪速率、适用温度范围及长期稳定性等;进而归纳了材料组成、结构类型、外界环境及系统运行条件等对主动除冰雪路面工作性能的影响规律;此外,为了便于主动融雪化冰路面技术选型,从融雪化冰效果、经济成本及节能环保等方面对比分析了不同路面主动除冰雪技术的优缺点;最后建议路面主动除冰雪系统应与冰雪灾害评估系统及冰雪预警系统相结合。

环保型长效自融冰雪路面涂层试验

分析了环保型长效自融冰雪路面涂层的除冰融雪原理,采用多种融冰雪材料对比试验的方法,进行了人工环境下融雪、冻雨和二次结冰试验,通过碳钢条腐蚀试验和三叶草浇灌试验进行了环保性能分析,并在某试验段进行了道路融雪能力验证。分析结果表明:自融冰雪路面涂层大于0.6kg·m-2时融雪效果较佳,一次涂刷能多次融雪;涂层对冻雨和二次结冰具有良好的抑制作用,对结构物和植被基本无影响,环保性能较佳;涂层一次施工能多次除冰融雪,可满足一个冬春季长效要求。

降水模拟下主动融冰雪沥青混合料性能衰减研究

为研究降水对主动融冰雪沥青混合料路用性能及融冰雪性能的影响,准确得到降水影响下沥青混合料中盐化物融冰剂的流失,从而对其性能的衰减程度提出了降水模拟试验。根据降水模拟不同周期后的各项路用性能以及规范值预估路用性能的有效期限,同时通过冰层掉落试验、落球冲击试验预估融冰雪性能的有效期限。结果表明:降水模拟试验极大地缩短了试验时间,通过不同周期的降雨模拟试验,得到主动融冰雪沥青混合料的高温稳定性、低温抗裂性有效期限分别为9和8个周期,但低温抗裂性仅为4个周期,表明缓释融冰剂对沥青混合料的路用性能的影响主要表现在水稳定性方面;通过冰层掉落试验、落球冲击试验可预估主动融冰雪沥青混合料的融冰雪性能分别可持续约10和9个周期。以上结果为主动融冰雪沥青混合料的在降雨情况下的性能衰减研究奠定了试验基础,为提高主动融冰雪沥青混合料使用寿命提供参考价值。