Road Materials Research Articles

A Comprehensive Implementation of Road Surface Classification for Vehicle Driving Assistance: Dataset, Models, and Deployment

The prior monitoring of the road surface conditions provides valuable information to vehicle trajectory planning and active control systems. Road surface perception with vision sensors is an emerging technology that has recently gained much attention. However, there are few reports on an exhaustive technical scheme and application practice for driving assistance. This study first creates a large-scale road surface image dataset containing one million samples with detailed road friction level, material, and unevenness level annotations. A convolutional neural network (CNN) classification model constrained by a combined loss function and adapted optimization strategies is trained on the dataset. Then we propose a decision-level fusion method based on the improved Dempster-Shafer evidence theory to enhance the robustness of the classification algorithm. Finally, the developed models are deployed on the embedded hardware platform. The top-1 accuracy for classifying road surface images reaches 92.05% by the CNN model and 97.50% after fusion. Onboard experiments illustrate the advantage and superiority of the developed technical framework, which has excellent potential in real-vehicle applications for driving assistance.

Surface modification of recycled tire rubber powders with Tannic acid and Nano-TiO2 for enhanced performance and photocatalytic properties of Rubberized Cement-Based materials

The utilization of recycled rubber powder in civil engineering is currently insufficient, leading a significant hurdle to the environmentally friendly disposal of waste tires. To mitigate the adverse effects of rubber powder (R) in cement-based materials and enhance their application in road materials, this study aims to explore a novel modification approach. Tannic acid (TA) and TiO2 (<100 nm, SBET = 43.22 m2/g) were used to modify the surface of R through a simple adhesion self-assembly reaction, resulting in the formation of R-TA-TiO2 composites. A series of characterization tests, such as WCA, AI, FTIR, XRD, SEM, EDS, BET, XPS and UV–Vis-DRS, indicated that the hydrophilicity and chemical activity of the modified R-TA-TiO2 were significantly improved, and its surface possessed numerous cross-linking and stable sites for photocatalytic activity. Leaching and photocatalytic experiments confirmed the excellent heavy metal ion immobilization ability and photocatalytic performance of R-TA-TiO2. The results of basic mechanical tests and microscopic characterization of cement mortar revealed that the modified rubber enhanced the bonding ability between modified rubber and cement mortar, mitigated the negative effects in cement mortar, and exhibited pro-cement hydration ability. The flexural and compressive strengths of the modified rubber-cement mortar were considerably increased compared to those of the untreated rubber-cement mortar. Moreover, the modified rubber-cement mortar demonstrated excellent photocatalytic properties, and cyclic adsorption experiments verified its photodegradation stability and repeated properties. Microscopic characterization further showed that the modified rubber-cement mortar maintained its internal stable structure during photodegradation, indicating its potential for use in green road materials.

Pemanfaatan Recycling Asphalt untuk Lapisan AC-WC dengan Penambahan Material Bottom Ash pada Perkerasan Lentur

Increasing road construction by adding a thick layer of asphalt on flexible pavement can cause problems, where the more viscous the asphalt layer, the higher the road will be than the houses. In addition, limited natural resources and large-scale use can damage the environmental system and make raw materials increasingly scarce, and their prices continue to increase. This research aims to show that recycled asphalt and bottom ash materials can be reused for flexible pavements. Researchers used experimental methods in the laboratory by testing using the Marshall Test. The results of this study indicate that the asphalt resistance based on the compressive strength of the asphalt mixture of recycled materials and the combination of recycled materials and bottom ash of 10% and 15% so that the values of VMA, VFA, Stability, Meltability, and MQ values ​​obtained from the Marshall Test according to with the General Specifications of Highways of the Ministry of Public Works. It was obtained from the provisions of the physical and mechanical test results of Bottom Ash sourced from the Petra UK Road Materials Laboratory Research with the bottom ash parameter passing the sieve of 18.2%. From the results of all asphalt tests, it is known that the addition of bottom ash to asphalt recycling where the extracted material from recycled asphalt (recycled) both asphalt and the aggregate material itself cannot be reused for flexible pavement layers. This is because the condition of asphalt recycling is old, and the strength of the material itself is weak, so it cannot last long if it is reused.&#x0D; &#x0D; &#x0D;

ASSESSMENTS OF THE GRAVEL ROAD DETERIORATION HAVING LACK OF MAINTENANCE: CASE STUDY IN JIMMA ZONE

Gravel roads deterioration with absence of maintenance is one of the serious issue and common problem in the world. It’s majorly affected by deterioration which manifests as removing from gravel road materials with the major factors such as traffic volume and environmental conditions. Jimma zone might have been a standout amongst those ranges influenced toward the issue for gravel road having lack of maintenances. In order to achieve the objective of this study, the researchers were used questionnaire survey method. The existing road sections having lack of maintenance on a given time have been identified. Then the representative road (Sarbo-Busa, Saka-Ushane and Buxure-Sanxama) and questionnaire surveys samples have been selected by non-probabilistic purposive and systematic sampling respectively. The questionnaire’s survey was focused on identifying the causes of absence of maintenance and pre-conditions considered. questionnaire survey was analyzed by RII. The absence of maintenance was occurred due to lack of budget fund, poor management, lack of skilled manpower, lack of good material quality, lack of regular inspections, poor working environments. The pre-conditions considered while maintaining the gravel roads are: Cost of maintenance, class as the road, maintenance schedule, skilled manpower, topography, number of road users, traffic volume, and economic standards of the society and location of the road from the center. In Jimma zone the deterioration of gravel roads have been increasing with the absence of maintenance time.

Effect of using recycled aggregates as road subbase materials: A case study from Kuwait City

In the State of Kuwait, the rise of the construction industry increases the construction and demolition activities and generates large amounts of aggregates. This study focuses on the use of recycled aggregates as road sub-base materials. Two different types of recycled aggregates have been used; namely, recycled concrete aggregates (RCA) and reclaimed asphalt pavement (RAP). Three mixtures are formed: control mix, RCA mix, and RAP mix. California Bearing Ratio (CBR) value was used as an acceptance criterion to evaluate the performance of the mixes. Results of CBR test were compared with the minimum limit of CBR value of road sub-base set by the Ministry of Public Work (MPW) specifications (MPW, 2012; section 3), (minimum 30%). The soaked CBR values of the control mix and RCA mix were equal to 73% and 80%, respectively, and they satisfy MPW specification (2012). While the soaked CBR value of RAP mix was equal to 29%, and it did not conform with MPW CBR limit for road sub-base (minimum 30%). The performance of RAP mix was enhanced by following two different scenarios. In the first scenario, the amount of RAP aggregates was decreased by mixing RAP with fresh aggregates. In the second scenario, cement was added to the RAP mix with two dosages, 2% and 4%. Both scenarios gave CBR values that meets the MPW requirement. It was concluded that RCA can be used as sub-base material, while RAP aggregates can be used as sub-base material when mixed with fresh aggregates or by adding cement as a modifier.

Environmental investigation on the use of a phosphogypsum-based road material: Radiological and leaching assessment

The transformation of phosphate ore into phosphoric acid results in the generation of high volumes of phosphogypsum (PG), an industrial by-product largely stockpiled worldwide. This solution, considered as the least damaging to the environment, constitutes a risk for the receiving environment due to the presence of harmful impurities such as heavy metals and radionuclides which hinder its large-scale valorization. This paper presents an environmental characterization of Moroccan phosphogypsum and an investigation on the environmental performance of a new lime (L) - fly ash (FA) treated phosphogypsum based road material. The concentration of metallic trace elements (Cr, Pb, Ni, Zn, Cu) in raw phosphogypsum ranged between 0.2 and 243 ppm, while its radioactivity reached 970 Bq/kg for Ra-226. The environmental performance of the proposed new road material (40% PG, 42% FA, 18% L) was evaluated using radiological risk indices besides static and dynamic leaching tests. The results showed a radioactivity reduction up to 82%, and an immobilization of metallic trace elements ranging from 25 to 100%. The stabilization/solidification mechanisms involved in the lime - fly ash treatment would be responsible for the fixation of these contaminants within the newly formed matrix.

EnRDeA U-Net Deep Learning of Semantic Segmentation on Intricate Noise Roads.

Road segmentation is beneficial to build a vision-controllable mission-oriented self-driving bot, e.g., the Self-Driving Sweeping Bot, or SDSB, for working in restricted areas. Using road segmentation, the bot itself and physical facilities may be protected and the sweeping efficiency of the SDSB promoted. However, roads in the real world are generally exposed to intricate noise conditions as a result of changing weather and climate effects; these include sunshine spots, shadowing caused by trees or physical facilities, traffic obstacles and signs, and cracks or sealing signs resulting from long-term road usage, as well as different types of road materials, such as cement or asphalt; all of these factors greatly influence the effectiveness of road segmentation. In this work, we investigate the extension of Primordial U-Net by the proposed EnRDeA U-Net, which uses an input channel applying a Residual U-Net block as an encoder and an attention gate in the output channel as a decoder, to validate a dataset of intricate road noises. In addition, we carry out a detailed analysis of the nets' features and segmentation performance to validate the intricate noises dataset on three U-Net extensions, i.e., the Primordial U-Net, Residual U-Net, and EnRDeA U-Net. Finally, the nets' structures, parameters, training losses, performance indexes, etc., are presented and discussed in the experimental results.

Evaluation of the Structural Performance of Lime-Stabilized cubitermes sp Termite Mound Soil as a Sub-Base Layer for Sustainable Pavements

The scarcity of road materials that can be used directly in the sub-base layer of a road without preparation has led to the use of non-conventional materials. This study describes the feasibility of using hydrated lime-treated cubitermes sp termite mound soils for road construction, based on laboratory tests. Tests of Atterberg limits, dry density, CBR, compressive strength, static modulus and measurement of sinking of the material under traffic were carried out with different proportions of lime (0%, 3%, 5%, 6%, 7%, 9%). The results obtained show that the mechanical properties of soil-lime mixtures improve up to the point of lime fixation at 6% and that above 6% lime, the mechanical properties decrease. The traffic simulation at the rut shows that for the 6% lime mix, microcracks appear from 20.000 cycles and that the average settlement is 2 mm. The friction of the grains under the stresses developed by the passage of the wheel reduces the mechanical bonds of the soil-lime mixture. The rigidity of the material leads to the induced slab effect, which gives the material good behavior in hot weather, without strain or rutting. The mechanical connections during the setting of the soil-lime mixture reduce the friction of the grains under the stresses developed by the wheel. Lime welds the fines into much larger, more or less impermeable particles on the surface, which reduces the crumbling of the material by attrition, a major cause of pavement deterioration. The optimal mix can be used as a sub-base layer or wearing course for low-traffic earth roads (T1 &amp;lt; 300) and for the treatment of the upper parts of embankments. All these results are consolidated by X-ray diffraction (XRD) and scanning electron microscopy (SEM) analyses.

Experimental study on the interface bonding characteristic of polyurethane and pavement materials

As a new grouting material, polyurethane has been used in the repair engineering of longitudinal joint distress of semi-rigid base asphalt pavement. It is necessary to study the bonding characteristics of the interface between polyurethane and road materials. In this paper, the interface characteristics of composite materials were considered from the two materials about pavement material and base material. Shear test and split tensile test were carried out on the specimens with different interface roughness and polyurethane density. Based on the test data, the strength models of shear strength and splitting tensile strength with roughness and density were established. The micro-characteristics of the composite interface were analyzed. Polyurethane formed a dense film at the interface, and the film thickness increases with the increase of density. The failure mode of the specimen was affected by the polyurethane film. In addition, the influence of normal stress is considered in the shear test, and the friction angle of the interface was analyzed. The stress-strain curve characteristics of shear test and split tensile test of two kinds of composite materials were summarized. The failure modes were generally three types: failure along the boundary of polyurethane material, failure along the boundary of base material, and joint failure of polyurethane material and base material along the interface. The research results provide a basis for better understanding the influencing factors and failure modes of the bonding characteristic between asphalt mixture, cement stabilized macadam and polyurethane materials.

Utilization of coal-based synthetic natural gas slag as road base construction material through geopolymerization

The development of the Coal-based synthetic natural gas industry inevitably produced lots of slags. The application of coal-based synthetic natural gas slag (CSNGS) to road base not only effectively alleviated the accumulation and pollution of CSNGS, but also reduced the consumption of resources, which had significant economic and social benefits. However, CSNGS has a higher crushing value and water absorption, thus its mix design, mechanical properties and pavement performance must be further investigated when applied as the raw material of novel cementing material and aggregate. The purpose of this study is to investigate and comparatively analyze the optimal mixing ratio and mechanism of the strength of CSNGS applied in road base. For this, this study prepared the precursor of geopolymer by milling CSNGS into powder and mixing it with 20% cement. Then sodium hydroxide and sodium silicate were used as alkali activators to activate CSNGS, and the 7d unconfined compressive strength was used as the evaluation index to develop the optimal mix ratio of coal-based synthetic natural gas slag geopolymer (CSG). CSNGS with particle sizes ranging from 0 to 4.75 mm and 0 to 9.5 mm were used as aggregates to replace natural stones, then the cement and CSG were selected respectively to stabilize the slags-aggregates, and the relevant tests were carried out to investigate the mechanical and road properties. The results showed that the performance of CSG stabilized aggregates was lower than cement stabilized aggregates in the tests of unconfined compressive strength, splitting strength, unconfined compressive modulus of resilience, dry-wet cycles, and freeze–thaw cycles. The performance of the mixture deteriorated with the incorporation of CSNGS when the cementitious material was cement. The temperature shrinkage test found that the shrinkage of CSG stabilized specimens was less than cement stabilized specimens, which indicated that CSG had excellent anti-cracking potential. In addition, the temperature shrinkage coefficients of mixtures with different CSNGS dosages varied with temperature when the cementitious material was cement. Finally, to further verify the macroscopic test results, this study combined with scanning electron microscope (SEM) test to deeply analyze the strength formation mechanism of several mixtures.

Study on the high-temperature and aging properties of agricultural waste-modified asphalt based on rheology.

The modifier of road materials from agricultural waste (AW) as raw material has been widely noticed. Considering the environmental impact of AW treatment and the National policy on the promotion of resource reuse, the feasibility of four AW (namely, bamboo powder, rape straw, corn cob, and wheat straw) for styrene butadiene styrene (SBS) asphalt modification is studied from the properties and mechanism perspectives. Through properties evaluation tests (such as the dynamic shear rheometer, multiple stress creep recovery, and rotating thin film oven test), the influence of four AW and different mixing amounts on the properties of SBS modified asphalt pavement is analyzed from the aspects of high-temperature deformation resistance and anti-aging properties. The results reveal that the four AW can improve the SBS asphalt's high-temperature deformation resistance and anti-aging properties, among which rape straw has the most significant improvement effect. In addition, through the fourier transform infrared spectroscopy test, the microscopic mechanism of the AW/SBS composite modified asphalt binder is revealed from the functional groups. The analysis shows that the AW is physically mixed with the SBS asphalt binder, which inhibits the growth of sulfoxide groups and the cracking of the SBS modifier during aging.

Design of Asphalt Mixing Plant Industry Information System

Asphalt mixing plant is a production equipment that produces hot mix in the form of a mixture of asphalt with some aggregate materials used as road pavement materials. The asphalt mixing plant produces hot mix which must be at a certain temperature so that it does not harden and cannot be used for road pavement. The accuracy in the delivery time of the product to the location where it will be held determines the quality of the production after it is held on the road media. The existence of an information system is a tool for controlling production costs, in this case hotmix products produced from asphalt mixing plant machines are needed to monitor every production process from several departments that have been worked on so that data management can be done quickly and accurately. Seeing the existing problems, this research aims to design and build an industrial information system for the asphalt mixing plant at PT. Wasis by Nugraha. Tools used in making this system is Visual Basic. The application design method uses the ProtoTyping method. The results of this study are that with the design and construction of an industrial information system for the asphalt mixing plant at PT. Wasis Karya Nugraha received a very good category in the functional suitability aspect and a very appropriate predicate in the usability aspect in helping to overcome conventional system problems in the administration of raw material procurement to the production process, sending finished products to consumers and financial reporting which can be caused by human error.

Research Progress of Epoxy Asphalt Material for Roads

Asphalt is a semi-solid or solid mixture formed by hydrocarbons and non-metallic elements. It is widely applied in the fields of building waterproofing and road paving. Asphalt is a low noise, durable, and renewable pavement material. However, asphalt materials have some shortcomings such as liquefying at high temperatures and brittleness at low temperatures, which are less adaptable to different environments. Therefore, people have gradually shifted their focus to asphalt modification. This paper presents an in-depth analysis and research on the composition, structure, and performance of epoxy asphalt materials for roads, so that this material can be widely used.

Application of neuro-fuzzy systems technology for control the density of asphalt concrete mixtures in the paving process

The increase in the number of cars and trucks, and the intensity of their use, directly affects the asphalt-concrete road surfaces of roads. This is manifested in the reduction of overhaul terms of operation and large financial costs. Improving the quality and increasing the service life of asphalt concrete pavements of roads is a national economic problem. This problem is solved by improving the regulatory framework, improving the properties of road materials, optimizing and automating technological processes in road construction. Road roller density monitoring and control systems are based on Intelligent Compaction and Continuous Compaction Control technologies. In the Russian Federation, the quality of road surface construction largely depends on the results of the work of pavers, who ensure the acceptance, laying and compaction of mixtures. Many defects in the operation of road surfaces are eliminated by high-quality compaction. Automatic control and control of the sealing process for asphalt pavers have not been developed.The aim of the study is to build a density management system for asphalt pavers based on an intelligent automatic control system with feedback. Real-time prediction of the volume density of the layer, effective manual (operator) and automatic density control is organized to achieve the required quality indicators.The results of the development of a new system for intelligent control of the density asphalt concrete mixtures by pavers is considered. The automatic control system with feedback includes a continuous density control system designed to calculate the seal quality index based on the implementation of the neural network structure algorithm in real time, as well as a neuro-fuzzy PID regulator. The study considers a system with models of control objects of high order – the fourth and sixth orders. The structure of a neuro-fuzzy network of the ANFIS type is proposed. The generation of a fuzzy output system is performed on the basis of the lattice partition method. ANFIS training is performed by a hybrid method on an array of variables obtained as a result of modeling an automatic control system with an analog PID controller. Possible modes of use an intelligent compaction control system: continuous automatic control with manual control of the operating modes of compaction; automatic density control. Automatic measure of density and control compaction modes is aimed at improving the quality of asphalt concrete pavements of roads and improving the quality of asphalt pavements efficiency of technological processes road construction.

Flexural performance and microstructural characterization of cement-treated sand reinforced with palm fiber

Sands are mixed with cement to create cement-treated sands (CTSs) for embankment and road materials in civil engineering works. However, CTS exhibits undesirable brittle behavior because the CTS can break suddenly after the applied stresses reach their peak strength. CTS reinforced by natural fibers is called CTSF. This paper aims to study the influence of palm fiber on the flexural performance and microscopic characterization of CTSF specimens. Palm fiber contents of 0.5, 1, and 2% by volume and fiber lengths of 10,20, and 40 mm were utilized. The four performances of CTSF are peak strength, residual strength, toughness, and equivalent flexural strength. The interaction mechanism of the CTSF fiber was examined using scanning electron microscopy. The results show that the palm fibers change the behavior of CTS from brittle to semi-ductile or ductile. The 1% fiber content and 40-mm-long fiber improve the flexural of unreinforced samples by a factor of 2.7. The best residual strength at a deflection of 2 mm is obtained from the specimen with a 2.0% fiber content and a 40 mm fiber length exhibiting the residual-peak flexural strength ratio of 1.0. All palm fiber-reinforced samples show softening behavior because an equivalent strength ratio is less than 100%. The 2% fiber content and 40 mm fiber length provide the best equivalent strength ratio since the equivalent strength ratios are enhanced by a factor of 20. The fiber content and length mainly affect the equivalent strength ratios. A single failure plane is seen for CTS and CTSF samples with low fiber content, whereas numerous cracks are observed for CTSF samples. Regarding failure mode and flexural performances, palm fiber inclusion is suitable as the base and subbase for the bound pavement structure in civil and pavement engineering works.

BOQ and BOM in the road management of Ukraine

The article highlights theoretical and practical approaches to the use of BOQ and BOM forms in the road industry of Ukraine. Both BOQ and BOM are used to determine the quantity and specification of materials. A BOQ is specific to construction projects and focuses on estimating costs, while a BOM specification is also used in manufacturing and focuses on specifying the materials and components required for construction. Understanding the road industry's pricing system and transitioning to the use of a Bill of Quantities (BOQ) and Bill of Materials (BOM) is vital to effective project management in both the construction and manufacturing sectors. While the BOQ mainly focuses on the quantification and costing of materials and labor, the BOM emphasizes the components required to produce the building materials as a product. BOQs focus on items, measurements, quantities, pricing, and cost breakdowns specific to construction projects, while BOMs emphasize components, specifications, descriptions, and hierarchical organization related to the production of road materials and the manufacturing environment. By using these two vital documents, you can streamline the business processes of project planning, procurement, and execution, leading to increased efficiency and successful project outcomes.&#x0D; By integrating BOM and BOQ into a single digital environment with financial ERP tools, businesses can gain real-time insight into project costs. It helps in budgeting, forecasting and ensuring the financial viability of the project and making operational changes to the 4d-5d BIM model. BIM can improve the accuracy and efficiency of both Bill of Quantities (BOQ) and Bill of Materials (BOM) by providing a more detailed and comprehensive set of data, providing a detailed and accurate representation of the project. BIM can also help identify potential clashes or conflicts between different components that can be resolved before construction begins. In addition, BIM can facilitate collaboration between the various stakeholders involved in a project.

Research on fracture damage characteristics of loess solidified with steel slag, calcium carbide slag and metakaolin

This paper examines the fracture damage characteristics of loess cured by solid wastes. The results demonstrate that the production of substantial amounts of gelling substances, such as calcium-silicate-hydrate (C-S-H) and hydrated-calcium-aluminosilicate (C-A-S-H) in the specimens, enhances the fracture toughness of the loess. Furthermore, it is confirmed that the fracture angle is the primary factor that controls the fracture damage pattern of the specimens. This study reveals the fracture damage characteristics of solidified loess from multiple perspectives, which provides a fundamental theoretical reference for preventing, controlling, and resolving hazards associated with using solid waste materials as road base materials.

Investigation of road performances of rejuvenated styrene-butadiene-styrene modified asphalt mixture

Exploring the effective recycling of waste styrene-butadiene-styrene block copolymer (SBS) modified asphalt mixture is the difficulty and hotspot in the field of road materials research. Common rejuvenation method and reactive rejuvenation method were used to recover the road performances of aged SBS modified asphalt mixture (ASMBM) in this paper. The recovery effect of high- and low-temperature performance, fatigue resistance and water stability for ASMBM after rejuvenation was studied, and the road performance development of ASMBM after reactive rejuvenation in the early stage was also investigated. The results show that reactive rejuvenation method could significantly enhance the Marshall stability and rutting resistance of rejuvenated ASMBM, and further improve its low-temperature cracking resistance as compared with common rejuvenation method, which attributes to the reconstruction of aged SBS cross-linking structure and its improvement on the interface stability of rejuvenated mixture. Meanwhile, the fatigue life of reactive rejuvenated ASMBM under strain level of 400 με is 26.6 % higher than that of common rejuvenated mixture. Water stability test results show that reactive rejuvenation is more beneficial to restore the water-immersed Marshall stability and Hamburger rutting resistance of ASMBM. Furthermore, the road performances of reactive rejuvenated ASMBM have a further improvement with the extension of time in the early stage after rejuvenation, its Marshall stability, the freeze-thaw splitting strength ratio and water-immersed Marshall stability could restore to the initial level of fresh mixture. Thus, reactive rejuvenation method is more conducive to realizing the high-performance recycling of waste SBS modified asphalt mixture and enhance its recycling value.

Research of a Fiber Sensor Based on Fiber Bragg Grating for Road Surface Monitoring

Road infrastructure is a key public asset because it benefits the social and economic development of any country. It plays an important role in the development of the industrial complex and the production sector, and the surfaces of transport roads should be of high quality and have a long service life. Road infrastructure, like all infrastructure, requires preservation, maintenance and repair. There are special requirements for roadways that must be observed during construction or repair. The uncertainty of the composition, temperature sensitivity and viscoelastic characteristics of road materials make the structural analysis of pavement very difficult compared to other civil structures, such as bridges, tunnels and buildings. For this reason, the question of how to improve fiber sensors based on fiber Bragg grating (FBG) arose. The novelty of this study is to modernize fiber sensors based on FBG so that they display deformation, stress and displacement, temperature and other parameters with much greater accuracy, which would provide a reliable scientific basis for modifying the theory, as well as the use of a fiber sensor based on FBG for simultaneous measurement of deformation and temperature when monitoring the road surface. This article is devoted to a detailed study of the use of fiber-optic sensors (FOS) based on fiber Bragg grating for road surface monitoring. Such a fiber sensor, consisting of a fiber Bragg grating and a pair of grids, can offer the possibility of simultaneous measurement of deformation and temperature for monitoring the pavement. Temperature and deformation measurements were carried out by installing a sensor on the surface of a made asphalt sample. The built-in fiber sensor based on FBG provides important information about how the pavement structure can withstand the load and subsidence of soil and implement road safety and stability measures in a timely manner to evaluate and predict the service life of the pavement. The results of the study showed that the synchronicity, repeatability and linearity of the characteristics of the fiber sensor are excellent. The difference between the experimental and theoretical results was about 7%. Thus, based on the results of the obtained data, the fiber sensor on the FBG can be used for monitoring and designing road surfaces and in general transport infrastructure.

Effects of Drying–Wetting Cycle and Fines Content on Hysteresis and Dynamic Properties of Granite Residual Soil under Cyclic Loading

In southern China, granite residual soil (GRS) is widely used as road base material. Thus, it is important to study the effects of hot and rainy climates and cyclic loads generated by trains on the dynamic properties of GRS. In this work, by means of dynamic triaxial tests, the effects of the number of drying and wetting (D–W) cycles, fines content and number of load cycles on the hysteresis curve, dynamic shear modulus Gd and damping ratio λ of GRS are systematically investigated. The experimental results illustrate the changes in the morphology of the hysteresis curve and dynamic parameters with the numbers of load and D–W cycles, as well as the fines content. Namely, the area S, center offset d, and residual strain εsp of the hysteresis curve decrease with the increase of load cycle number, increase with the growth of fines content, and first decrease with the increase of D–W cycle number, then slowly increase to stabilized values. However, the major axis gradient k exhibits exactly the opposite relationships. Meanwhile, the dynamic shear modulus Gd increases with the growing load cycles and decreases with the addition of fines content, and the damping ratio λ shows the opposite behavior. It is also shown that Gd and λ vary linearly with respect to logN, where N is the number of D–W cycles. The dynamic properties of GRS are mostly affected by the number of load cycles, which is followed by the fines content and then the number of D–W cycles. The influence of the latter two factors on the dynamic properties of GRS may be primarily due to contact form changes between soil particles.