Pavement Surface Research Articles

An exploratory framework for accelerated airport pavement testing using the geotechnical centrifuge

ABSTRACT Full-scale Accelerated Pavement testing (APT) has been regarded as an essential step to bridge the gap between research and practice for pavement design because it can fully mimic a large number of heavy wheel loading on pavements. Despite being able to test pavements in an accelerated manner compared to Long-term Performance Monitoring (LTPM), conducting one full-scale APT experiment is still demanding in terms of monetary cost, space, time, etc., and the accessibility to APT facilities is only available in a few countries nowadays. In this study, an exploratory APT study with a down-scaled pavement model in a high-g environment created by geotechnical centrifuge was performed with up to half a million simulated aircraft load repetitions. Through this test, it was proved that the centrifuge APT can reproduce the full-scale airfield pavement responses, including rutting, cracking, material fatigue, etc. The transient and permanent deflection of the pavement surface, variations in stress and strain states within the pavement structure over its lifespan can be well captured for analysis. This framework of centrifuge APT provides a new methodology for pavement testing and can significantly save the current cost and time of full-scale APT.

Nondestructive Detection and Early Warning of Pavement Surface Icing Based on Meteorological Information.

Monitoring and warning of ice on pavement surfaces are effective means to improve traffic safety in winter. In this study, a high-precision piezoelectric sensor was developed to monitor pavement surface conditions. The effects of the pavement surface temperature, water depth, and wind speed on pavement icing time were investigated. Then, on the basis of these effects, an early warning model of pavement icing was proposed using an artificial neural network. The results showed that the sensor could detect ice or water on the pavement surface. The measurement accuracy and reliability of the sensor were verified under long-term vehicle load, temperature load, and harsh natural environment using test data. Moreover, pavement temperature, water depth, and wind speed had a significant nonlinear effect on the pavement icing time. The effect of the pavement surface temperature on icing conditions was maximal, followed by the effect of the water depth. The effect of the wind speed was moderate. The model with a learning rate of 0.7 and five hidden units had the best prediction effect on pavement icing. The prediction accuracy of the early warning model exceeded 90%, permitting nondestructive and rapid detection of pavement icing based on meteorological information.

A lightweight encoder–decoder network for automatic pavement crack detection

AbstractCracks are the most common damage type on the pavement surface. Usually, pavement cracks, especially small cracks, are difficult to be accurately identified due to background interference. Accurate and fast automatic road crack detection play a vital role in assessing pavement conditions. Thus, this paper proposes an efficient lightweight encoder–decoder network for automatically detecting pavement cracks at the pixel level. Taking advantage of a novel encoder–decoder architecture integrating a new type of hybrid attention blocks and residual blocks (RBs), the proposed network can achieve an extremely lightweight model with more accurate detection of pavement crack pixels. An image dataset consisting of 789 images of pavement cracks acquired by a self‐designed mobile robot is built and utilized to train and evaluate the proposed network. Comprehensive experiments demonstrate that the proposed network performs better than the state‐of‐the‐art methods on the self‐built dataset as well as three other public datasets (CamCrack789, Crack500, CFD, and DeepCrack237), achieving F1 scores of 94.94%, 82.95%, 95.74%, and 92.51%, respectively. Additionally, ablation studies validate the effectiveness of integrating the RBs and the proposed hybrid attention mechanisms. By introducing depth‐wise separable convolutions, an even more lightweight version of the proposed network is created, which has a comparable performance and achieves the fastest inference speed with a model parameter size of only 0.57 M. The developed mobile robot system can effectively detect pavement cracks in real scenarios at a speed of 25 frames per second.

The preliminary study of the forecasting model between surface texture and various material parameters for the ISO 10844 test track

Pavement surface texture is an essential factor in influencing the sound emission of vehicles, and reducing noise pollution would be a big issue for all humans. According to the Economic Commission for Europe (ECE) R-117 requirement, all the vehicle tires vending in Europe should pass noise accreditation after September 2009, and the pavement surface of the test track should follow ISO 10844. The Mean Profile Depth (MPD) is adopted to be the texture parameter of the test track surface in ISO 10844. the MPD of the Test track should be controlled at specific intervals, and the material design should be a big challenge of pavement Engineering. This study aims to establish an MPD prediction function with material properties for pavement Engineers. In material, there were two fine aggregates, three gradation curves, three air voids of the specimen, and 18 mixture designs adopted in this study. There were three specimens in each mixture design; the total specimen number was 54 for MPD measurement. Fifty-four laboratory test specimens were compacted using a Superpave gyratory compactor (SGC). A High-Definition Pavement Texture Machine (HDPTM) measured the specimen surface MPD. The parameters in this study included fineness module (FM), fine aggregate angularity (FAA), air void (AV) of the specimen, and Gyration number (G) of SGC. Gene Expression Programming (GEP) was adopted to build a prediction model between MPD and various parameters. Based on the results of this study, the best MPD forecasting model using FAA, FM, and AV, the R2 of is 0.74, meaning the best MPD forecasting model could be a very nice tool to help pavement engineers to do MPD quality control on the test track for ISO 10844. In addition, GEP was an excellent method to discover the nonlinear relationship between MPD and various parameters of asphalt concrete, and it was worthy of further study.

Infiltration Analysis of Paving Block Cover on the Basis of Embankment Soil Variations

The large amount of infrastructure used causes less green land for rainwater absorption, so that rain that falls on the ground is not absorbed optimally. The resulting surface runoff is more than the amount of water absorbed. To overcome this, the method is to reduce the use of impermeable land cover (concrete pavement) and replace it with appropriate surface land cover. One of the efforts made is the use of pervious paving to reduce surface runoff and increase infiltration. This test aims to determine how much infiltration rate and capacity occurs when using paving block cover with variations in embankment soil. This research uses quantitative methods with an experimental approach using an artificial rain simulator. The soil used in this research is soil sourced from Lubuk Alung, Sarik River and Mount Sarik. The paving blocks used are in the form of hexagons which are usually used as ground surface pavement. Infiltration testing carried out several analyzes namely infiltration rate, infiltration capacity and cumulative infiltration. The results of this research show that good infiltration is the Sarik River landfill with the use of paving block cover, the infiltration rate value is 0.619-0.112 cm/minute, the infiltration capacity is 6.18 cm/hour, the cumulative infiltration is 8.97 and runoff occurs in the second minute. 09 and the chart intersects at the 30th minute. The results of infiltration testing using an artificial rain simulator showed that the use of paving block cover can increase infiltration thereby reducing the occurrence of run off.

Asphalt pavement surface repair area detection based on smartphone sensors

Asphalt pavement repair areas affect pavement performance and service levels. It is necessary to distinguish the repair areas from normal sections. Based on vehicle vibration signals, this study identified ten pavement repair areas and divided them into four cases by factors including length and form in conjunction with the driving approach. Additionally, time domain analysis, frequency analysis, and probability distribution analysis were used to form the characteristics of the repair cases as well as the normal sections. It was found that the maximum value, extreme deviation, standard deviation in the time domain, maximum amplitude in the frequency domain, and peak of the probability density curve would serve as judgment indexes. A framework for identifying the repair areas was also established based on the five indexes. By validation, the overall accuracy can reach 95.0%, demonstrating a strong generalization capability.

Optimization of crack healing in steel bridge deck asphalt pavement based on the microwave heating technology

Microwave technology can heal cracks in asphalt pavements by heating the pavement. When it is used to repair cracks in steel deck asphalt pavement (SBDAP), the temperature of the SBDAP is greatly increased because the steel deck reflects the microwaves, allowing the microwaves to reheat the SBDAP. This study established a numerical model for microwave-heated SBDAP, and analyzed the effects of the waveguide height above the pavement surface, the thickness of the SBDAP, microwave power and heating time on the average of the temperature gradient (Tavg) and the standard deviation of the temperature gradient (Tstd) of the SBDAP. The feasibility of the numerical model was validated through the laboratory microwave heating tests. The prediction models of Tstd and Tavg under the effect of four influencing factors were developed by response surface methodology, and the validity of the prediction models was verified based on the analysis of R2 values and analysis of variance. With the prediction models of Tavg and Tstd as optimization functions, the optimal combination of the aforementioned influencing factors was determined using the genetic algorithm. In summary, the results of this study can effectively guide the field construction of microwave heating technology to repair SBDAP cracks.

Use of geothermal energy to prevent road pavement icing and damage in cold climate areas

In cold climate or alpine regions, freezing temperatures and snow can result into road icing, with consequent threat of the circulation security (Figure 1(a)). When the road surface temperature goes below zero, not only the road surface ices, but also the soil below the pavement can undergo freezing. The phenomenon of soil freezing is complex due to the multi-phase and porous nature of the soil itself. Generally speaking, as ice expands in the soil pores, the soil volume increases (of about 9%, depending on the soil porosity and water saturation). This can induce frost heaving, with consequent damage of the road pavement. In this framework, the possibility to use geothermal energy systems embedded in tunnel linings for road pavement de-icing has rarely been investigated. In such systems, the concrete tunnel lining is equipped with a circuit of pipes, in which a heat carrier fluid circulates and exchanges heat with the ground. As the rock or soil around the tunnel is generally hotter than the external air temperature, heat is extracted from the rock or soil to the fluid, transported through the pipes circuit outside the tunnel, and used to de-ice the pavement road.
 The objective of this study is to go a step forward in the investigation of this innovative application, for both road de-icing and prevention of frost heave. A portion of a geothermally activated tunnel and its connection to a road pipe circuit was simulated numerically (Figure 1 (b)). Appropriate climatic conditions were considered as boundary conditions at the surface level and inside the tunnel, according to available data. The efficiency of the technology was investigated under different climatic and exploitation scenarios. Figure 1 (c) shows as an example the thermal field obtained after the activation of the geothermal plant. The evolution of temperature on the road pavement surface and at the road pipes depth (30 cm from the road pavement surface) are presented on Figure 2 (a), together with the evolution of the external air and tunnel temperature, imposed as boundary conditions according to the monitored climatic conditions in the city of Oslo [1].
 The geothermal system was activated after two years of simulation, by changing the fluid pipes velocity from 0 (non active system) to 0.9 m/s (purple curve on the right axis on Figure 2 (a)). The results show that the road temperature increases thanks to the activation of the system (i.e. when the fluid pipes velocity is imposed to 0.9 m/s).
 Furthermore, a recently developed thermo-hydro-mechanical constitutive model for frozen soils [2] was used to quantify the soil heave due to freezing, with and without the activation of the geothermal system. For this purpose, a similar numerical model has been developped where a column of saturated soil below the road and the tunnel were modelled. The phreatic water table is at the ground surface level and gravity as well as the geostatic stress conditions are considered. The soil is a clay with a low hydraulic conductivity of Kw=4.1×10-10 m/s and a thermal conductivity of Γ=2.35 W/m/K. The other soil properties are: soil stiffness E=100 MPa, Poisson’s ratio ν=0.3, porosity n=0.25, solid grain thermal volumetric expansion coefficient αs=3.4×10-4 K-1. The same soil surface climatic conditions used in the first part were applied. The temperature evolution obtained in the road from the previously mentioned analyses (Figure 2 (a)) was imposed to reproduce the effect of the geothermal activation on the road behaviour. Furthermore, the soil surface is free of stress to study the soil swelling and settlement. The bottom limit of the soil column is hydraulically drained and allows heat flux (at constant liquid pressure and temperature). The lateral far field boundaries are thermally adiabatic, hydraulically impervious, and with oedometric conditions. The results were firstly compared with the case without geothermal activation to quantify the effects in terms of road heave and settlement (Figure 2 (b)). Swelling and settlement are due to thermal expansion and compression of the soil under positive temperature (T>0°C) and to frost heave and thaw settlement under negative temperature (T<0°C). The liquid pressure at the road surface is also depicted (Figure 2 (b)). These results and comparisions allowed understanding the performance of the technology in reducing road mechanical damage induced by freezing.

PROPERTIES OF EKRANOSEMS OF THE CITY OF LVIV

Ekranozems are urban soils that occupy a significant area of cities and play an important role in urban ecosystems, because they have a wide range of properties. One of the main features of ekranozems is the presence of a closed impermeable layer - a screen, that is, an artificial surface, which includes asphalt concrete, paving stones, sidewalks, etc. At the same time, thanks to the processing of scientific and literary sources, it should be noted that ekranozems are still little-studied and under-researched due to their inaccessibility. They are the result of a variegated relief, the influence of zonal and climatic conditions of soil formation and anthropogenic factors. It is clear that these interactions varied depending on the location and age characteristics of the city. The structure, composition and properties of ekranozems, as well as their functioning, are determined by the structural features of roads, driveways, footpaths, etc., as well as the features of anthropogenic impact (before sealing) on the soil, taking into account its natural features in certain conditions of soil formation. Ekranozems occupy a significant part of the territory of the city of Lviv and are characterized by a great variety of properties. As a result of their stay under asphalt concrete and pavement surfaces, such negative processes as a decrease in water permeability, a decrease in the concentration of oxygen in the soil, and a change in the water regime occur. There is also soil compaction and a decrease in general sparability during the improvement of the territory. These soils are united by their lack of humus throughout the profile. The studied ekranozems are characterized by the presence of calcium carbonates throughout the profile, which are brought, for the most part, during the construction and laying of networks, as well as various repair works on the road. The acid-base properties of ekranozems are represented by the alkaline reaction of the soil environment, which is caused by the presence of carbonate salts (pH ranges from 7.7 to 8.1), which causes a slowdown in soil-forming processes and, as a result, a change in soil quality. Keywords: ekranozem; urban soil; sealed soil; urban ecosystem; anthropogenic soil; Lviv plateau; cultural layer.

Analysis of Aggregate Types with Micro-texture and Macro-texture Characteristics of Asphalt Mixture in Indonesia

Background: Micro-texture and macro-texture are two essential parameters that functionally evaluate friction on asphalt pavement surface. While micro-texture indicates the irregularity of aggregate using British Pendulum Tester (BPN), macro-texture shows the larger irregularity of asphalt mix surface using Mean Texture Depth (MTD). Both micro-texture and macro-texture contribute to increased skid resistance value, which is needed for road to meet the safety qualification. Aim: This study aims to investigate the effect of local aggregate types and aggregate proportion (%) on asphalt mix on pavement textures (micro and macro-texture). Methods: Laboratory experiments were conducted on four types of local aggregates (A, B, C, and D), which were carried from West Java, Indonesia, and aggregate has a different characteristic to each other. In addition, three asphalt mix types (SMA-fine, AC-WC, and HRS-WC), each containing varying proportion (%) of aggregates, were investigated to analyze change in texture on asphalt mix surface. Statistical analysis with two-way ANOVA was carried out to investigate the significance of aggregate type and asphalt mix type on pavement surface. Results: The results showed that each aggregate exhibited different characteristics chemically and mechanically. Four types of local aggregate possessed distinctive characteristics for the asphalt mix performance (i.e., OAC and density) and pavement textures. Statistically, it was clearly found that both aggregate type and asphalt mix type were strongly related to pavement texture. Conclusion: Therefore, the aggregate type and asphalt mix type with varying aggregate proportions (%), such as coarse aggregate (CA), aggregate-fine (FA), and filler (FF), affect the micro-texture and macro-texture.

A Study on the Contact Characteristics of Tires-Roads Based on Pressure-Sensitive Film Technology.

Tire-road characteristics are a critical focus of research in the automotive and transportation industries. On the one hand, the research can help optimize tires' structural design; on the other hand, it can analyze the mechanical response of the pavement structure under the vehicle load. In addition, the non-uniformity distribution of the tire ground stress will also have a direct impact on the skid resistance, which determines the driving safety. Due to the limitation of testing technology, the measurement of tire ground pressure was mainly carried out on a flat test platform, ignoring the roughness of the actual pavement surface texture. The tire-road contact characteristics research on the macro-texture and micro-texture of asphalt pavement needs to be broken through. A high-precision pressure-sensitive film measurement system is utilized to examine the actual contact characteristics between two types of automobile tires and three types of asphalt pavement in this paper. The influence law of pavement texture and patterned tires on the contact area and stress was explored, and the concentration effect of tire-road contact stress was evaluated. The results indicate that the contact area of grounding tires exhibits a nearly linear relationship with tire inflation pressure and load. Notably, the change in load has a more significant influence on the contact area than tire inflation pressure. On asphalt pavement, the contact reduction rate decreases by approximately 5-10% for block pattern tires and 10-15% for longitudinal pattern tires. Furthermore, as the texture depth of the pavement increases, the contact area between tires and the pavement texture decreases. The actual tire-road interface experiences significant stress concentration due to the embedding and meshing effects between the tire and road surface. Even on a flat steel surface, the peak stress at the edge of the tread block exceeds the 0.7 MPa design load, which is about 2.5-3 times higher than the design uniform load. The peak stress between the tire and asphalt pavement reaches 4-10 times the design uniform load, with a rising trend as the pavement texture depth increases. This study can provide relevant experimental technical support for tire design and functional design of asphalt pavement.

Study on properties and application of chloroprene rubber/polyurethane modified asphalt sealant

Under the long-term effect of loads and climate conditions, various diseases can appear on the surface of asphalt pavement, causing deterioration in its performance. To address the pavement surface cracks during service, the present study developed a crumb rubber/polyurethane (CR/PU) compound as the modified asphalt sealant with excellent properties. The optimal material proportion, ensuring the best asphalt compatibility was selected to meet the requirements of standard hot-poured sealants for pavement. Additionally, the fineness and content of CR were determined. The research investigated rheological properties, aging performance, microstructure, and modification mechanism of the CR/PU sealant was then applied in an engineering project to evaluate its effectiveness in treating pavement cracks, and suitable construction techniques were summarized. The results revealed that the in-situ polymerization method is an appropriate approach for preparing the CR/PU sealant, demonstrating good high-temperature deformation resistance and low-temperature crack resistance, indicating synergistic interactions between CR and PU. Among various compositions, the sealant with 30 %PU and 15 %CR content exhibited the best thermal oxygen and UV aging properties. Microscopic tests indicated that CR was physically blended with asphalt, while PU underwent chemical modification and formed a cross-linked network structure with asphalt, resulting in CR dispersion around it, enhancing the thermal stability of the system. Furthermore, the test section displayed an ideal crack treatment effect, demonstrating the sealant’s excellent sealing, durability, and watertight capacity.

Research on distresses detection, evaluation and maintenance decision-making for highway pavement in reconstruction and expansion project

Artificial walking survey, ground penetrating radar (GPR) and falling weight deflectometer (FWD) were used to test the actual condition of the highway pavement in reconstruction and expansion project for better maintenance decision-making. Therefore, a decision-making system with the application of four evaluation indexes including deflection value (DV), pavement surface condition within 20 m(PCI20), maintenance effect (ME) and internal crack rate (ICR) was constructed. Through the pavement empirical-mechanical calculation and the Delphi method analysis, the corresponding threshold for the DV, PCI20 and ICR were 27 (0.01 mm), 80, and 20 m/100 m2 respectively. Then, the decision-making system was applied for the 5.5 km section with the detection and evaluation results, and the advised maintenance plans of different lanes were determined. Lastly, the effect of the decision-making system was analyzed. Results show that the decision-making system can scientifically decide the treatment plans and save the maintenance cost by about 30.1 %. The deflection near the grouting holes significantly decreases resulting from the high-density cement slurry distribution. The milling and repaving have a high structural reinforcement ability of reducing deflection up to more than 66 %, which is positively related to the milling depth.

Prediction of Pavement Overall Condition Index Based on Wrapper Feature-Selection Techniques Using Municipal Pavement Data

Municipalities make significant efforts with limited resources to collect pavement condition data. Overall Condition Index (OCI), which uses the pavement surface evaluation and rating manual to identify roadways needing repair, is a convenient and common way of pavement condition assessment. Many data used in assessing the OCI are collected from fieldwork. Some data features give little insight into road conditions, and one feature may provide similar information to another; thus, effective data-collection resources can be optimized by selecting which data feature to keep and which to discard. In addition, the OCI reflects how local agencies highlight the important variables driving their pavement-management investments. It is also a reflection of the triggers that they use to propose various treatment strategies. This research aimed to evaluate pavement distresses in West Des Moines, Iowa, using machine-learning methods, and determine which combination of distresses and their distress proportions can accurately predict the OCI class of a particular pavement type. The wrapper feature-selection methods were used, fitting their results to classification-tree models. Automatic feature selection, using Featurewiz, was also considered to select the desired number of variables. Feature parameters were screened for OCI prediction using the mean decrease impurity, and the results could be used to model classification that may be used for year-long predictions. Results showed that an effective OCI estimate methodology could be determined with significant accuracy with fewer features.

Measuring Surface Deformation of Asphalt Pavement via Airborne LiDAR: A Pilot Study

Measuring the surface deformation of asphalt pavement and acquiring the rutting condition is of great importance to transportation agencies. This paper proposes a rutting measuring method based on an unmanned aerial vehicle (UAV) mounted with Light Detection and Ranging (LiDAR). Firstly, an airborne LiDAR system is assembled and the data acquisition method is presented. Then, the method for point cloud processing and rut depth computation is presented and the results of field testing are discussed. Thirdly, to investigate error factors, the laser footprint positioning model is established and sensitivity analysis is conducted. Factors including flight height, LiDAR instantaneous angel, and ground inclination angle are discussed. The model was then implemented to obtain the virtual rut depth and to verify the accuracy of the field test results. The main conclusions include that the measurement error increases with the flight height, instantaneous angle, and angular resolution of the LiDAR. The inclination angle of the pavement surface has adverse impact on the measuring accuracy. The field test results show that the assembled airborne LiDAR system is more accurate when the rut depth is significant. The findings of this study pave the way for future exploration of rutting measurement with airborne LiDAR.

Evaluation of the Pavement Distress and its Impact on the Sustainability of the Traffic Operation for Selected Roads in Al-Diwaniyah City

Roads and transportation infrastructure are critical assets for supporting political stability as well as economic and sustainable expansion in developing countries. Yet, pavement maintenance backlogs and the high capital expenditures of road rehabilitation need the adoption of pavement evaluation methods to ensure the best value for the investment. road maintenance is considered one of the main factors for preserving the road structurally and functionally, and before carrying out maintenance, pavement defects must be identified by evaluating the condition of the pavement to perform the appropriate maintenance. In this study, the Pavement Condition Index (PCI) method was relied upon to evaluate roads in Al-Diwaniyah City. Where several data were collected for the study, including the number of crashes for each region, the number of lanes, street width, the presence of a median, and the pavement condition evaluated for the regions with the highest crash rate, which are Al-Askari District with 707 crashes, Al-Urouba District with 379 crashes, Al-Wahda District with 271 crashes, Al-Jamhouri District with 235 crashes, and Al-Jazaer District with 212 crashes. This study is considered the first study to evaluate roads in Al-Diwaniyah city. The results of the study showed that the condition of the roads ranged from poor to satisfactory and there is no road reach to serious and failed. The results showed that the worst road is Al-Askari District, which lacks a lot of maintenance, at a rate of PCI 52.1. It is followed by Al-Wahda District with a PCI rate of 57.6, Al-Jamhouri District with a PCI rate of 67.2, Al-Urouba District with a PCI rate of 70.7, and Al-Jazaer District with a PCI rate of 73.7. The deterioration of the pavement surface condition affects the rash rate, and it is more dangerous when it is correlated to other road factors. Additionally, it was noted that the most prominent defects in the pavement surface of the five evaluated roads are: potholes, rutting, longitudinal and transverse cracks, corrugation, patching, raveling, depressions, and alligator cracks. The study recommended conducting more research on evaluating more roads in Al-Diwaniyah City on an annual basis and conducting periodic maintenance in order to improve the status of this city, which suffers from neglect in all respects, measures must be taken to enhance the environment and economy, sustain the streets, reduce maintenance costs, ensure traffic safety, and protect the lives of citizens.

Identifying Texture and Friction of Asphalt Pavement Surface with Optimized Close-Range Photogrammetry Method

Abstract An adequate pavement texture that provides sufficient brake friction is critical for drive safety. Thus, it is essential to quantify the pavement texture and friction efficiently and accurately. So far, the close-range photogrammetry (CRP) method has been manifested as a promising one. Nonetheless, related measurement parameters have not been well optimized toward its extensive promotion. For this reason, varying measurement parameters of CRP method were thoroughly discussed and optimized in this study. Additionally, the optimized CRP method was further validated using the sand patch test and X-ray computed tomography scan method. Based on this, the estimation of friction coefficients for asphalt concrete (AC-13), stone mastic asphalt (SMA-13), and open graded friction course (OGFC-13) were carried out. The results indicate the following: (1) the optimized CRP method was able to adequately feature the pavement macrotexture; (2) the mean texture depth derived from the CRP method was equivalent to the texture depth measured from sand patch method; in addition, (3) the OGFC asphalt mixture was superior to the SMA and AC asphalt mixtures in terms of the friction coefficients. The optimized CRP method could bring bright prospects for future measurements of pavement texture.

Efficient use of ceramic waste powder in Cementitious Grout for the Development of Sustainable Semi-Flexible Pavement Surfaces

Cement-based grouts are described as a liquid mixture with higher flowability that contains cement, additives, water, and a superplasticizer. Cement-based grouts can be utilized to fill minor voids and gaps in addition to repairing cracks in earthen structures to restore structural continuity. In most cases, structural grouting is used in conjunction with other strengthening methods like adding tie-rods or reinforcing meshes. Grout is usually used with semi-flexible pavement (SFP). SFP is a new pavement technology comprised of open-graded asphalt concrete with a high air void content that is filled by injecting special grouting materials. The goal of this research is to figure out what happens to the mechanical properties of grout when a proposed by-product is used as a supplement to cementitious materials. The specified grouts were made from cement, water, ceramic waste powder (CWP), and superplasticizer (SP). Scanning electron microscopy (SEM) and energy-dispersive x-ray (EDX) analysis were used to characterize the physical and chemical properties of the waste material after it had been crushed and finely ground. The pozzolanic behaviour of the material was evaluated by substituting ceramic waste for Portland cement at varying percentages (from 15% to 50%), and the modified grout was characterized through a variety of tests that included flow cone testing, as well as compression and flexural strength tests Based on the results of these tests, the best amount of CWP to use as a replacement for cement in terms of its mechanical properties is 20%.

Impact of Pedestrian Pavement Design on the Users’ Comfort Level in an Intermodal Passenger Terminal

AbstractThe design of intermodal passenger terminals (IPTs) facilities requires a careful study of different aspects, including the walkability of their pedestrian paths. As for paved surfaces intended for pedestrians, these infrastructures must perform several tasks: greater attention is paid to functional requirements, considering different physical and perceptive people abilities. The regularity, grip and comfort are the prevailing aspects that need more attention from the designer. IPTs’ users are generally passengers performing long trips, who are more likely to carry a luggage: for this reason, the comfort and the effort to which the traveller is subjected when pulling or pushing a suitcase are significant features to analyse. Thus, an integrated approach of experimental measurements was introduced to characterise the comfort level of paved surfaces of the Mediopadana high-speed rail station (Italy), using a smart and original procedure, named stone pavement suitcase trolley test. Through these measurements the hand-arm vibrations perceived by the user, the horizontal forces required to pull or push the suitcase and the work done by the users along a real path were determined. These parameters make it possible to evaluate, from an objective point of view, the comfort of travellers on different pedestrian routes, providing useful tools for their design.

Performance evaluation of low temperature cracking resistance on asphalt material by means of 3D pavement surface profiler and info-graphic approach

Performance evaluation of low temperature cracking resistance on asphalt material by means of 3D pavement surface profiler and info-graphic approach