Use of bio-based products towards more sustainable road paving binders: A state-of-the-art review

Many industrial sectors exploit fossil sources to develop useful and necessary materials for our needs,such as bituminous paving materials.Bitumen,a key component of asphalt mixtures,is derived from oil refining and its properties are influenced by the crude oil source and refining process,resulting in a significant carbon footprint.With growing awareness of resource depletion and environmental concerns,pavement researchers are exploring sustainable alternatives to reduce dependence on fossil sources.This includes a rising trend in using renewable materials like biomasses to produce bio-based binders as substitutes for bitumen,aiming for a more sustainable approach.Biomasses,including vegetal and animal wastes,and waste cooking oils,as substitutes for crude oil in the production of bio-binders.Through thermochemical conversion(TCC),such as pyrolysis,biomasses can be converted into bio-char and bio-oils,which can replace fossil-based components in binders.Researchers have utilized these bio-products to reduce the dependency on fossil fuels in binders.However,there are no set minimum requirements for bio-components in bio-based binders.As the percentage of replaced bitumen increases,various types of binders are produced,including modified bitumen,extended bitumen,and alternative binders,where the fossil replacement is gradual.Overall rheological tests on bio-binders,reveal that those containing biochar exhibit increased viscosity,stiffness,rutting resistance,and sometimes antioxidant properties.Conversely,bio-binders with bio-oils as bitumen substitutes show poorer performance at high temperatures but improved behavior at low temperatures.These results suggest that bio-binders could provide versatile solutions for various climatic and loading conditions in road construction.However,the development of pavement mixtures based on bio-binders has not been studied in depth and requires further attention to unlock its full potential.As sustainability considerations,including life cycle assessments(LCA)and life cycle cost analyses(LCC),are crucial aspects for future studies.It is essential not only to collect data on the performance characteristics of bio-binders but also to understand their environmental impact and recyclability.In-depth evaluations using methods such as LCA and LCC will provide valuable insights into the overall sustainability and long-term viability of these products.

Tactile Paving Recognition Method Based on Improved YOLOv7

Tactile paving is a professional road facility to ensure the safe travel of people with visual impairment.However,there are many problems with tactile paving travel in practice.For one,some tactile paving is seriously damaged,and the other is the accumulation of obstacles.How to help visually impaired people recognize and locate obstacles in tactile paving is a problem worth studying.In this paper,image recognition technology is used to recognize the tactile paving pictures with obstacles,and an attention mechanism is used to optimize samples to improve recognition accuracy.

Effects of parameters of asphalt concrete surfacing on mechanical property of paving layer

The important parameters that influence the mechanical property of the pavinglayer on an orthotropic steel bridge deck are the paving layer thickness and modulus of the asphaltconcrete surfacing. Three important indices that control the typical failures of the paving layerare the maximum tensile stress of paving layer, the maximum shear stress between the steel deck andthe paving layer, and the maximum deflection on the paving surface. In this paper, the analyticalmodel of paving systems on orthotropic steel bridge deck is established, and the finite elementmethod is adopted to study the stress and strain of paving system. With the variation of asphaltconcrete modulus in high or low temperature season, the influences of paving layer thickness onthree control indices are researched. The results provide a theoretical basis for the determinationof thickness of the paving layer on the steel bridge deck.

Formulating Highway Paving Asphalts from the Vacuum Residue of a Paraffinic Crude

Many specifications of paving asphalts are closely related to their colloidal stability, which is, however, determined by their exact chemical compositions. The Yumen vacuum residue (YVR), the bottoms of a paraffinic crude oil is unfit for the production of highway paving asphalts directly, Neither are the de-oiled asphalts of the YVR. In this research a blending method and an optimal process of solvent de-asphalts are adopted to investigate the feasibility of formulating highway-paving asphalts from YVR. Results show that highway paving asphalts are formulated by blending solvent de-oiled asphalts with one or more of the materials including YVR, decanted oil from FCC process, and furfural extracts from lubricating base stocks. Further investigations indicate that adding oil decanted from FCC process to the solvent de-asphalting process can increase the de-asphalted oil production, improve the de-oiled asphalts quality, and thus optimize the refinery processes. The methodology of this research can be extended even to refineries processing non-paraffinic crude oils.

Influences of Used Parameters of Screw Distributor upon Mixture Paving Segregation

The paving segregation of asphalt mixture was closely related to the structure size and using parameters for the screw distributor of paver,and the paving uniformity of the mixture was determined by the screw blade diameter,pitch,and the position of the mixture in the screw distributor.Through researching the kinematics of the mixture in the screw distributor,the mathematical model was established,and the mathematical model was related with structural parameters,used parameters and material parameters.Through the mathematical model,the various parameters on the screw distributor job performance were analyzed,and the unstable area,meta-stable area and stable area were determined.In the project,the full-scale test in actual project was conducted by using the AC25 mixture.By changing the using parameters compare the paving operations,the results show that,the reasonable parameter will greatly improve the uniformity of paving,and the surface proportion of structural depth of mixture decrease from the 2.13 to 1.60.

Modification of FCC slurry oil and deoiled asphalt for making high-grade paving asphalt

With the rapid development of modern industry,high-grade paving asphalt is massively required to meet the demands for modern transportation.As one of additives,natural asphalt is indispensable since it can improve the performance of paving asphalt in all aspects.However,the application of non-renewable natural asphalt is increasingly restricted by its limited reserves.It is imperative to find alternative approaches to produce high-grade paving asphalt.Fluid catalytic cracking(FCC)slurry oil is an ideal soft component for producing paving asphalt due to its high content of aromatics and resins.However,its bad ageing resistance limits its application to only low-grade paving asphalt.In the present work,a novel approach for producing high-grade paving asphalt was investigated using chemically modified FCC slurry oil and deoiled asphalt(DOA).The FT-IR and NMR results showed that dehydrogenation and condensation reaction occurred during the ageing process.From a series of aliphatic alcohols and aldehydes,propanal was selected as a proper modifier to improve the ageing resistance of FCC slurry oil.The propanalmodified slurry oil possessed more substituted aromatic units and less aromatic hydrogen atoms than other modified slurry oils,thus showing better ageing resistance.With the increase of length of aliphatic chains in modifier,the modified slurry oil contained more and longer alkyl substituent group on aromatics.Compared with the cross-linked oil(slurry oil modified by cross-linking agent),modified slurry oil possessed similar ageing resistance but higher flowing ability.Also,the effect of operation conditions on the kinematic viscosity of modified slurry oil were investigated.Blended with modified slurry oil,the penetration ratio of asphalt product increased from 53.7 to 66.2,which met the standard of 70#paving asphalt.Both the microscopic observations and FT-IR results indicated that modification process effectively reduced the oxidation degree of asphalt product,thus increasing the ageing resistance.Consequently,with aid of this process,high-grade paving asphalt was readily produced from low value oil from downstream products of refinery,instead of the depleting natural asphalt.

Characterization of Coal Tar Pitch and Paving Pitch by UV,EA and NMR

In order to enlarge the use of coal tar pitch(CTP) in paving road,CTP and 60th paving pitch (PP) were extracted by n-heptane,toluene and ethanol step by step in a Soxhlet apparatus.The three fractions of CTP and PP were detected using UV-absorption(UV-A),elemental analyses(EA) and nuclear magnetic resonance(NMR) firstly as a whole unit after quality characterization of physical nature of CTP and PP were finished.The CTP had more saturate aliphatic and residue compounds dissolved in ethanol.On the other hand there were more continental type structures of aromatic ring than that of PP.There was almost no residue in PP after extracted by ethanol.The results explained why CTP was crisp in cold winter and was soften in summer.The following research will focus on how to change the chemical construction of CTP into the relative similar structures with those of PP through adding polymer.

Paving the Way for Sino-Foreign Economic and Trade Ties——Notes on Second Session of CCPIT Second Council

The China Council for the Promotion of International Trade (CCPIT) held the Second Session of the Second Council of its National Congress in the latter half of July. Attending the session were officials in charge of foreign economic relations and trade from related Chinese ministries, provinces, municipalities and autonomous regions, chairmen of 46 local and 14 industrial sub-councils throughout

Paving the way toward retinal regeneration with mesencephalic astrocyte-derived neurotrophic factor

Neurodegenerative diseases are a leading cause of disability worldwide,and despite significant resources put toward the discovery of potential therapeutic targets,there are currently no effective treatments.The rise of methods to derive and propagate stem cells in vitro offered

Construction Technology and Quality Control of Double Layer Continuous Paving of Cement Stabilized Macadam Base

The construction method of continuous paving of the upper and lower base of the water stable macadam base can improve the construction efficiency,overcome the quality problems of the traditional layered paving of the upper and lower base,such as untimely curing,slow construction,poor interlayer bonding,contraction joint and interlayer,so as to ensure the construction quality of the water stable macadam.It is also the promotion and application of new technology.

Paving the Way for Friendship in the 21st Century—In commemoration of the 25th anniversary of normalization of Sino-Japanese relations

This year is the 25th anniversary of the normalization of Sino-Japanese Rela-tions. In the past 25 years, relations between the two countries were by and largegood, but problems never ceased to occur. Some problems were considered pre-dictable but others were quite weird, to the Chinese part at least. To improve thebilateral relationship in the 21st Century, both Beijing and Tokyo need to

Application of Millimeter 3D Automatic Paving System in Highway Engineering Construction

In the construction of asphalt mixture pavement,there are many paving construction procedures,high requirements for machinery and personnel,unreasonable technology and so on.In this paper,the millimeter-scale 3D automatic paving control technology of asphalt mixture pavement is studied with an engineering example.From the analysis of the test results in the later stage of construction,it can be seen that the technology has achieved the goal of high precision paving,and the successful application of the technology provides valuable reference experience for similar asphalt concrete pavement construction in the future.

Paving Materials and Engineering Applications of Permeable Pavement

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

Paving the Way

China’s largest private equity fund focusing on African investments boosts its footprint on the continent THE China-Africa Development Fund (CADFund),which has traditionally kept a low profile,has often been seen in the public spotlight over the past year. The fund and cement producer,Jidong Development Group,decided to invest approximately $220 million to set up a cement plant

Paving A Way Home --Aid to Homeless Children in Zheng zhou

No stranger could detect anything unnatural to see the 14-year-old Zhang Lizheng burst into the house with the greeting remark, "Mom, I’m back!" He’s just returned from school. "You’re the last to come back today," says the "Mom" indulgently, taking off the boy’s jacket and hanging it on the clothes rack next to the door. "Wash your hands and dinner is ready." On the round dinner table lie several dishes and six sets of bowls and chopsticks. "You’ll also have your favorite scrambled eggs and tomatoes tonight," smiles the lady in her late 20s, who looks too young to be a mother of four boys.

BRICS Paving the Way for African Development

THE Ninth BRICS Summit will be held in China＇s Xiamen City in early September. The last time China hosted the BRICS Summit was in 2011, when South Africa was accepted as a full member. South Africa＇s accession not only strengthens the BRICS countries＇ direct links with the Afri- can continent, but also broadens BRICS in terms of economic aggregates, population and area. More importantly, the move has greatly enhanced the representative- ness of the mechanisms as its coverage expanded from Asia, Europe and America to Africa, making it an economic coopera- tion mechanism for emerging economies covering the whole world,

A Modified Paving Approach and Automatic Mesh Grading Method to Quadrilateral Mesh Generation

A modified paving technique for automatic generation of all-quadrilateral mesh fromarbitrary 2-D geometry is presented. The generated mesh elementS are nearly square andperpendicular to boundaries. Aner the nodes and elementS formation is completed. a fully automaticgrading method is applied to increase the accuracy and reliability of engineering analysis. In thispaper, we mainly describe the theory of mathematical algorithm and present some examples ofautomatically generated mesh.

In-situ experiment tests and particulate simulations on powder paving process of additive manufacturing

In this work,in-situ experimental tests are first performed to investigate the powder spreading process of additive manufacturing,where different kinds of scrapers and spreading speeds are employed.Detailed kinetic behaviours of individual powder particles are discussed by discrete element method simulations.It is found that the decrease of inclination angle of the scraper improves the powder pressure and compaction in the spreading process,leading to a denser powder flow and thus a denser powder bed.The increase of spreading speed also improves the powder pressure and compaction in the spreading process.However,the powder flow becomes looser due to the volume dilation,and thus the quality of the paved powder bed decreases.In industrial applications,if the higher powder spreading speed is employed to improve the processing efficiency,the scraper with a smaller inclination angle can be used to ensure the powder bed quality.

A new energy landscape paving heuristic for satellite module layouts

This article describes a study of the satellite module layout problem （SMLP）, which is a three-dimensional （3D） layout optimization problem with performance constraints that has proved to be non-deterministic polynomial-time hard （NP-hard）. To deal with this problem, we convert it into an unconstrained optimization problem using a quasi-physical strategy and the penalty function method. The energy landscape paving （ELP） method is a class of Monte-Carlo-based global optimization algorithm that has been successfully applied to solve many optimization problems. ELP can search for low-energy layouts via a random walk in complex energy landscapes. However, when ELP falls into the narrow and deep valleys of an energy landscape, it is difficult to escape. By putting forward a new update mechanism of the histogram function in ELP, we obtain an improved ELP method which can overcome this drawback. By incorporating the gradient method with local search into the improved ELP method, a new global search optimization method, hELP, is proposed for SMLP. Two representative instances from the literature are tested. Computational results show that the proposed hELP algorithm is an effective method for solving SMLP with performance constraints.