Pavement Area Research Articles

ANALYSIS OF GLOBAL URBAN TEMPERATURE TRENDS AND URBANIZATION IMPACTS

Abstract. Due to urbanization, urban areas are shrinking green spaces and increasing concrete, asphalt pavement. So urban climates are different from non-urban areas. In addition, long-term macroscopic studies of urban climate change are becoming more important as global urbanization affects global warming. To do this, it is necessary to analyze the effect of urbanization on the temporal change in urban temperature with the same temperature data and standards for urban areas around the world. In this study, time series analysis was performed with the maximum, minimum, mean and standard values of surface temperature during the from 1980 to 2010 and analyzed the effect of urbanization through linear regression analysis with variables (population, night light, NDVI, urban area). As a result, the minimum value of the surface temperature of the urban area reflects an increase by a rate of 0.28K decade-1 over the past 31 years, the maximum value reflects an increase by a rate of 0.372K decade-1, the mean value reflects an increase by a rate of 0.208 decade-1, and the standard deviation reflects a decrease by rate of 0.023K decade-1. And the change of surface temperature in urban areas is affected by urbanization related to land cover such as decrease of greenery and increase of pavement area, but socioeconomic variables are less influential than NDVI in this study. This study are expected to provide an approach to future research and policy-planning for urban temperature change and urbanization impacts.

Compaction Process Control of Asphalt Pavement

Abstract The quality of compaction is important to the performance of hot mixed asphalt (HMA) pavement. Most premature failures of asphalt pavement are the consequence of poor compaction. The process control method of compaction was studied here. The allowable compaction time of HMA pavement was estimated through field measurement and computer simulation. An instantaneous compaction procedure was recommended according the environment conditions and behaviors of compaction machines. The passing route of each roller was obtained using the global positioning system real-time kinematic technique. High quality compaction was achieved by controlling the operation of rollers. A pavement compaction process monitoring system was introduced to collect all the compaction information, such as the passing numbers of rollers, paving speed of pavers, and area of pavement not be compacted in time and so on. Alarm messages would be sent to roller operators, contractors, and managers when any improper operations occurred during compaction.

Design and experiment of thermoelectric asphalt pavements with power-generation and temperature-reduction functions

Asphalt pavements tend to absorb solar energy and accumulate heat, which results in several negative effects. They contribute to the urban heat-island effect, plastic deformation of pavements, and aging of asphalt materials. One solution is to convert or transfer the pavement heat. A brand new road thermoelectric generator system (RTEGS) is designed for this purpose. The system added three modules to the traditional asphalt pavement structure: heat-conduction, thermoelectric-conversion, and cold-end cooling. The modules convert heat absorbed in asphalt pavements to electrical energy and reduce the pavement surface temperature. Field testing of the new system subject to a full seasonal change (half a year) was conducted. The data of temperature reduction and voltage output in a field environment were obtained. The results showed that the system reduced the pavement surface temperature by 8–9 °C in hot seasons, and the electrical output from an asphalt pavement of size 300 mm × 300 mm × 100 mm reached 0.564 V. At this output, a 10,000 m2 (1 km long and 10 m wide) pavement area would generate about 33 kWh of electrical energy in a single day in the summer, not considering the scale effects of the RTEGS. The system provides a new approach to alleviate the urban heat-island effect, and to convert and utilize solar heat absorbed in asphalt pavement.

Hydrologic and Water Quality Evaluation of a Permeable Pavement and Biofiltration Device in Series

Two stormwater control measures (SCMs) installed in series were monitored for their individual impact on the hydrology and water quality of stormwater runoff from a 0.08-hectare watershed in Fayetteville, North Carolina, for 22 months. Runoff was first treated by permeable interlocking concrete pavement (PICP), the underdrain of which discharged into a proprietary box filter (Filterra® biofiltration) which combined high-flow-engineered media with modest biological treatment from a planted tree. Due to a deteriorating contributing drainage area and high ratio of impervious area to permeable pavement area (2.6:1), clogging of the permeable pavement surface caused an estimated 38% of stormwater to bypass as surface runoff. Fifty-six percent of runoff volume infiltrated underlying soils, and the remaining 6% exited the Filterra® as treated effluent; the hydrologic benefit of the Filterra® was minimal, as expected. Primary treatment through the PICP significantly reduced event mean concentrations (EMCs) of total suspended solids (TSS), total phosphorus (TP), total nitrogen (TN), and total Kjeldahl nitrogen (TKN) but contributed to a significant increase in nitrate/nitrite (NO2,3–N) concentrations. Secondary treatment by the Filterra® further reduced TSS and TP concentrations and supplemented nitrogen removal such that treatment provided by the overall system was as follows: TSS (removal efficiency (RE): 96%), TP (RE: 75%), TN (RE: 42%), and TKN (RE: 51%). EMCs remained unchanged for NO2,3–N. Despite EMC reductions, additional load reduction due to the Filterra® was modest (less than 2%). This was because (1) a majority of pollutant load was removed via PICP exfiltration losses, and (2) nearly all of the export load was from untreated surface runoff, which bypassed the Filterra®, and therefore the manufactured device never had the opportunity to treat it. Cumulative load reductions (based only upon events with samples collected at each sampling location) were 69%, 60%, and 41% for TSS, TP, and TN, respectively. When surface runoff was excluded, load reductions increased to over 96%; lower run-on ratios (which would reduce clogging rate) and/or increased maintenance frequency might have improved pollutant load removal.

Study on correlation between air temperature and urban morphology parameters in built environment in northern China

Air temperature in built environment is a critical indicator of both outdoor thermal comfort and space cooling or heating loads in buildings. The objective of this work is to investigate the correlation between air temperature variations in built environment and urban morphology in northern China.Field measurement was firstly carried out to record the air temperature at 46 points within an 8-km2 urban area continuously in Tianjin city, China, from January 2015 to July 2016. Weather conditions at a nearby meteorological station were also measured. A GIS model was built up to extract the urban morphology parameters at 46 measurement points, such as the Green Plot Ratio (GnPR), Sky View Factor (SVF), pavement area percentage (PAVE), building area percentage (BDG), etc. Using multilinear regression analysis, models were proposed to correlate air temperatures with urban morphology parameters and weather parameters in both summer and winter seasons. The analyzed air temperatures included daily maximum (Tmax), minimum (Tmin), average (Tavg), daytime average (Tavg-day) and nighttime average (Tavg-night) temperatures. Models were validated by comparing the air temperatures estimated by proposed models with the results measured on the days different from those selected for model development. Parametric study was conducted to investigate the impact of urban morphology parameters on air temperatures. In summer, it was found that increasing GnPR by 0.5 could reduce Tmin and Tavg-night by 0.7 °C and 0.5 °C respectively. In winter, only Tavg, Tmin and Tavg-night were affected by urban morphology, and they increased with taller building height and narrower street width.

Assessing the effects of landscape characteristics on the thermal environment of open spaces in residential areas of Beijing, China

For high-density urban environments, improving local landscapes can effectively ameliorate the thermal environment. With the aim of assessing the effect of landscape characteristics on thermal performance in open spaces of residential areas, we took field measurements using mobile traverses in 18 residential areas of Beijing, China during the daytime in summer (June–August 2014) and winter (December 2014–February 2015). The net differences (d) of air (dATs) and radiation temperature (dRTs) between residential and nearby corresponding urban open environments, regarded as indicators of the thermoregulation of the 18 residential areas, were calculated. The effects and relative contributions of different landscape characteristics to the indicators were further investigated. Within residential areas, there were overall lower ATs and RTs compared with the control sites in open urban environments. The maximum and minimum dAT and dRT ranged from 0.53 to 6.14 °C and 3.16 to 8.65 °C in summer, and from −0.50 to 1.25 °C and −0.84 to 4.01 °C in winter, respectively. The net dATs and dRTs were significantly different among the 18 residential areas. An increasing percentage of vegetation cover and arbor-shrub planting density and decreasing percentage of pavement area, percentage of building cover and distance to downtown had varying degrees of favorable effects on dAT and dRT. In contrast, average building height had a slight seasonally opposite regulating impact. Compared with dAT, the net dRT is more sensitive to changes in landscape characteristics. The relative contribution of different landscape parameters to explaining the differences in the two types of temperature differed and varied by season. The percentages of pavement area and vegetation cover played the most important roles in summer and winter. If appropriately combined, local landscape characteristics could effectively ameliorate local thermal environments.

Impact of urban morphology on microclimate and thermal comfort in northern China

Abstract This work is an experimental study focusing on the impact of urban morphology on the urban heat island (UHI) intensity, microclimate conditions and thermal comfort in a newly-developed urban area in Tianjin city, China. According to the Koppen–Geiger climate classification system, the studied area is classified as hot summer continental climate, characterized by hot and humid summers as well as cold and dry winters. Air temperature, relative humidity (RH) and wind speed at 46 points within an 8-km2 area are measured during both winter and summer seasons. Based on measured results and climatic mapping, the impacts of urban constituents such as building, pavement, greenery and water area on UHI intensity and microclimate conditions are analyzed. Results show that UHI intensity reaches up to 4.5 °C during daytime and 5.3 °C at night in summer, and 2.6 °C during daytime and 5.0 °C at night in winter. Thermal comfort level at the measurement points is predicted using the Thermal Sensation Vote (TSV) model developed for the local climate. The cooling effect of trees is evident during both daytime and nighttime in summer, but negligible in winter due to the reduction of leaf area and evaporation. The presence of both greenery and water body result in an increase in RH in air. Trees tend to reduce wind speed and improve thermal comfort in winter. Radiant heat dissipated from buildings and roads is the main contributor to nighttime UHI in both summer and winter seasons. Based on research results, urban design recommendations are proposed so as to improve outdoor thermal comfort in urban areas located in temperate climate zone during summer and winter.

STUDI PERSEPSI DAN PREFERENSI PENGHUNI TERHADAP RUANG HIJAU DI RUMAH SUSUN SEDERHANA SEWA PROVINSI DKI JAKARTA SERTA STRATEGI PERBAIKANNYA

The development of Simple flats (Rusunawa) is one of Jakarta municipality’s program in overcoming both high level of urbanization and land limitation issues. Simple flats that dominated by massive multi-storey buildings and pavement areas needs to be balanced by the development of green spaces. The purposes of this study were to analyze resident’s perceptions and preferences of green space and to develop improvement strategies and design concept to increase resident’s comfort. This study assessed in four Simple flats: Jatirawasari, Tambora, Pulogebang, and Marunda Cluster A. The methods of this study were studied responden’s perception and preference by questionaire and SWOT analysis. The results showed total score perception analysis of green space in four Simple flats in good category. Matrix mapping based on IFE and EFE SWOT method showed that all four simple flats green space improvement strategy are in the hold and maintain position. Suggested recommendation in this study were preservation of existing trees, adding new trees and facilities on available spaces on sites.

STUDI PERSEPSI DAN PREFERENSI PENGHUNI TERHADAP RUANG HIJAU DI RUMAH SUSUN SEDERHANA SEWA PROVINSI DKI JAKARTA SERTA STRATEGI PERBAIKANNYA

The development of Simple flats (Rusunawa) is one of Jakarta municipality’s program in overcoming both high level of urbanization and land limitation issues. Simple flats that dominated by massive multi-storey buildings and pavement areas needs to be balanced by the development of green spaces. The purposes of this study were to analyze resident’s perceptions and preferences of green space and to develop improvement strategies and design concept to increase resident’s comfort. This study assessed in four Simple flats: Jatirawasari, Tambora, Pulogebang, and Marunda Cluster A. The methods of this study were studied responden’s perception and preference by questionaire and SWOT analysis. The results showed total score perception analysis of green space in four Simple flats in good category. Matrix mapping based on IFE and EFE SWOT method showed that all four simple flats green space improvement strategy are in the hold and maintain position. Suggested recommendation in this study were preservation of existing trees, adding new trees and facilities on available spaces on sites.

Bundling or Grouping Pavement and Bridge Projects: Analysis and Strategies

Project grouping is a concept that aims to reduce the overall costs of projects by combining smaller-scale pavement, bridge, and other projects under a single contract. To investigate the potential for state agencies to realize the benefits of project grouping, this study looked at economies of scale and economies of competition. The study documented the decline in unit cost as the size of the project increased for numerous bridge and pavement work types. Scale economies are true for single- and multiple-project contracts. Larger contracts lend themselves to economies of scale but can discourage all but the largest firms from bidding on the work. As a result, there is a range of contract sizes (measured in this study in terms of bridge deck area or lane mile of pavement) within which the contract is neither too small nor too big. From an examination of the work types for which adequate data were available, the size of combined projects that led to the best balance between economies of scale and economies of competition were ( a) about 20,000 ft2 of deck area for bridge projects and ( b) 10 to 20 lane miles for pavement projects. The single-project and multiple-project unit cost models developed in this project can be used to screen projects for which engineers’ estimates are available and identify single projects that should be considered for grouping into a multiple-project contract.

A mechanistic empirical approach for the evaluation of the structural capacity and remaining service life of flexible pavements at the network level

Road asset managers need to utilize reliable indicators for the structural condition and remaining service life at the network level to make rational decisions of the required funding and the optimum strategies for maintenance and rehabilitation. The surface deflection bowls and pavement critical responses were generated by computer simulations for a total of 2880 flexible pavement sections. The normalized area was computed from the deflection bowl data and it was found to be very well correlated with the compressive strain at the top of the subgrade. While the pavement surface curvature and area under pavement profile were highly correlated with the tensile strain at the bottom of the asphalt concrete layer. Thus, these parameters were used to evaluate the remaining service life in rutting and fatigue. Field data showed an excellent match between the trends obtained from the field and computer simulated data.

LIDAR-INCORPORATED TRAFFIC SIGN DETECTION FROM VIDEO LOG IMAGES OF MOBILE MAPPING SYSTEM

Mobile Mapping System (MMS) simultaneously collects the Lidar points and video log images in a scenario with the laser profiler and digital camera. Besides the textural details of video log images, it also captures the 3D geometric shape of point cloud. It is widely used to survey the street view and roadside transportation infrastructure, such as traffic sign, guardrail, etc., in many transportation agencies. Although many literature on traffic sign detection are available, they only focus on either Lidar or imagery data of traffic sign. Based on the well-calibrated extrinsic parameters of MMS, 3D Lidar points are, the first time, incorporated into 2D video log images to enhance the detection of traffic sign both physically and visually. Based on the local elevation, the 3D pavement area is first located. Within a certain distance and height of the pavement, points of the overhead and roadside traffic signs can be obtained according to the setup specification of traffic signs in different transportation agencies. The 3D candidate planes of traffic signs are then fitted using the RANSAC plane-fitting of those points. By projecting the candidate planes onto the image, Regions of Interest (ROIs) of traffic signs are found physically with the geometric constraints between laser profiling and camera imaging. The Random forest learning of the visual color and shape features of traffic signs is adopted to validate the sign ROIs from the video log images. The sequential occurrence of a traffic sign among consecutive video log images are defined by the geometric constraint of the imaging geometry and GPS movement. Candidate ROIs are predicted in this temporal context to double-check the salient traffic sign among video log images. The proposed algorithm is tested on a diverse set of scenarios on the interstate highway G-4 near Beijing, China under varying lighting conditions and occlusions. Experimental results show the proposed algorithm enhances the rate of detecting traffic signs with the incorporation of the 3D planar constraint of their Lidar points. It is promising for the robust and large-scale survey of most transportation infrastructure with the application of MMS.

LIDAR-INCORPORATED TRAFFIC SIGN DETECTION FROM VIDEO LOG IMAGES OF MOBILE MAPPING SYSTEM

Abstract. Mobile Mapping System (MMS) simultaneously collects the Lidar points and video log images in a scenario with the laser profiler and digital camera. Besides the textural details of video log images, it also captures the 3D geometric shape of point cloud. It is widely used to survey the street view and roadside transportation infrastructure, such as traffic sign, guardrail, etc., in many transportation agencies. Although many literature on traffic sign detection are available, they only focus on either Lidar or imagery data of traffic sign. Based on the well-calibrated extrinsic parameters of MMS, 3D Lidar points are, the first time, incorporated into 2D video log images to enhance the detection of traffic sign both physically and visually. Based on the local elevation, the 3D pavement area is first located. Within a certain distance and height of the pavement, points of the overhead and roadside traffic signs can be obtained according to the setup specification of traffic signs in different transportation agencies. The 3D candidate planes of traffic signs are then fitted using the RANSAC plane-fitting of those points. By projecting the candidate planes onto the image, Regions of Interest (ROIs) of traffic signs are found physically with the geometric constraints between laser profiling and camera imaging. The Random forest learning of the visual color and shape features of traffic signs is adopted to validate the sign ROIs from the video log images. The sequential occurrence of a traffic sign among consecutive video log images are defined by the geometric constraint of the imaging geometry and GPS movement. Candidate ROIs are predicted in this temporal context to double-check the salient traffic sign among video log images. The proposed algorithm is tested on a diverse set of scenarios on the interstate highway G-4 near Beijing, China under varying lighting conditions and occlusions. Experimental results show the proposed algorithm enhances the rate of detecting traffic signs with the incorporation of the 3D planar constraint of their Lidar points. It is promising for the robust and large-scale survey of most transportation infrastructure with the application of MMS.

Limestone Pavements in Great Britain and the Role of Soil Cover in Their Evolution

Clanek obravnava povezavo med korozivno mocjo prsti in skalnimi oblikami v apnencu. V ta namen so vzorcem iz razlicnih skrapljiπc, drugih oblik kraskega povrsja in vrtac v Severni Angliji, dolocili pH in delež karbonatov. Rezultati meritev so potrdili, da so oblike pod kislo prstjo globlje in da prisotnost apnenca mocno zvisuje pH prsti. The goal of the research was to verify the connection between the solutional power of soil and the shape of rocky features in limestone. Soil samples from runnels, grikes, foot of pavements, top of limestone, grass patches and dolines were collected on limestone pavement areas of North England and examined for the pH and carbonate content. The results of the measurements proved that the soils with lower pH are related to deeper solution features and that proximity to limestone causes a higher soil-pH.

Experimental study on the hydrological performance of a permeable pavement

Permeable pavements play an essential role in urban drainage systems, making them the subject of great interest to both researchers and practitioners. However, previous studies have demonstrated a significant degree of uncertainty regarding both the hydrological performance and the maintenance requirements of this type of pavement. Within this context, the presented research involved the construction of a one metre square surface area of permeable pavement and a laboratory rainfall simulator to investigate the influence of rainfall intensity on the hydrologic response of permeable pavements. The design of the permeable pavement complied with the SuDS Manual guidance and British Standards (BS 7533-13:2009). The laboratory test programme was designed to investigate the influence of rainfall intensity on the hydrologic response of permeable pavements. The results demonstrate that the hydrologic performance varied according to rainfall intensity. The total volume of discharge from the permeable pavement ranged between 8% to 60% of the inflow. More than 40% of the total rainfall from all rain events was temporarily detained within the structure. Permeable pavement design optimisation has therefore been tested in the study. The SuDS Manual guidance has been found to meet current optimisation requirements.

도로복구를 위한 레고식 차도블록 시스템의 동적 해석

Lego block system forms a temporary pavement area using the assembled structure block in the road excavation work for the maintenance and installation of facilities. This system was developed for a safe passage of vehicles and pedestrians. The concept and function of lego block system developed for the road recovery of an advanced country type were established by this study. The dynamic behavior was investigated by dynamic finite element analysis subjected to moving load considering real vehicle loads. Also, both the compaction effect of the ground caused the maximum vertical displacement and dynamic structural safety caused the upward displacement were evaluated by dynamic analysis results. As a result, lego block system showed the excellent compaction effect of the ground. Although the maximum upward displacement in lego block system was occurred by vehicle loads, safety of this system is fully satisfied.

Study of Deterioration Phenomenon and Causes in Pavement of Ramp Area

PURPOSES : The objective of this paper is to understand the deterioration phenomenon and causes in the pavement of a ramp area. METHODS : Ramp areas need to be sloped because of the centrifugal force, which depends on the vehicle speed and grade of the ramp area. As a result, vertical and horizontal forces are applied on the pavement surface of the ramp area. Furthermore, the horizontal force depends on the vehicle speed and grade of the ramp area. In order to analyze the pavement structure of a ramp area, a multi-layered elastic analysis program was used to evaluate the weakest link of fatigue cracking deterioration, according to the simultaneously applied vertical and horizontal forces. RESULTS : From case studies related to the bonding conditions between the surface and base layer in a ramp area, it was found that the partially bonded cases resulted in a critical potential of fatigue cracking deterioration, in a comparison of 50%, 70%, and fully bonded cases. CONCLUSIONS : According to the results of the case studies, the pavement structure system should be reinforced by upgrading the material or increasing the thickness compared to the general pavement areas, in order to provide a performance life similar to the mainline pavements in the ramp areas.

Aging albedo model for asphalt pavement surfaces

One of the most significant factors affecting pavement-induced Urban Heat Islands is the albedo. Several studies have shown albedo's effect on air temperature and building energy usage. Albedo depends on the optical properties of the material constituents of the surface layer of the pavement, which can change over time or with additives. The albedo of a series of full-scale asphalt and concrete pavement test sections of varying ages in Rantoul, Illinois (USA) was measured and a non-linear aging albedo model for asphalt pavements was developed. For a hypothetical pavement section, the current practice of assuming a constant albedo over time was found to overestimate the Global Warming Potential of the asphalt pavement by about 25%. In addition, the albedo of translucent polymer fibers was determined to be 0.07 using a spectrophotometer. This does not have a thermal impact on the pavement as long as the fibers remain coated with cement paste. However, if the fibers become exposed because of abrasion, they will have an impact on albedo depending on the pavement area containing exposed fibers.

The foot-in-the-door technique, crime, and the responsive bystander: A field experiment

A bystander’s reaction to a theft following a foot-in-the door (FITD) technique was observed in a field setting. An experiment was conducted in the pavement area of a bar where a first male confederate was seated alone with his suitcase on the ground. In the FITD condition, the confederate asked a participant for the time, thanked him/her, and left to go into the bar. In the control condition, no initial verbal contact was displayed, and the confederate just left to go into the bar. About 20 seconds after the first confederate had left to go into the bar, a second male confederate arrived, looked carefully around him, took the first confederate’s suitcase, and then left the place. More participants intervened in the FITD condition to stop the theft (84 per cent) than in the control condition (47 per cent). Social responsibility activation was used to explain these results, which has significant implications for encouraging public involvement in crime prevention.

Urban Micro-climate Research in High Density Cities: Case Study in Nanjing

What kind of high density urban form presents a better micro-climate environment in summer days is the main question of this study. The micro-climate of three different urban form were simulated using the software ENVI-met. Parameters including building density, floor area ratio, green plot ratio, pavement area, building height are concerned in the simulation. By comparing and analyzing the air temperature (Ta), solar radiation, mean radiation temperature (Tmrt) and wind speed, the micro-climate performance in three cases are presented. The alternative thermal index physiological equivalent temperature (PET) is also used to evaluate the outdoor thermal comfort in the three cases.