The Influence of Mesoscopic Characteristics of Mineral Powders Fillers on the Rutting Factor(G^(*)/sinδ)of Asphalt Mortar

This study aims to investigate the efiect of the mesoscopic characteristics of mineral powder fillers on the rutting resistance of asphalt mortar.Extraction and sieving tests were used to obtain the buton rock asphalt(BRA)ash with particle size smaller than 0.075 mm,which is consistent with that of the conventional mineral powder.The mesoscopic characteristics of BRA ash and conventional mineral powder were measured by SEM image analysis and the osmotic free pressure water method.Mesoscopic structure models of structural and free asphalts in mortar were obtained.The 70#matrix asphalt was used to prepare two kinds of asphalt mortar with BRA ash and conventional mineral powders fillers.The rutting factor of the two asphalt mortars was tested by dynamic shear test(DSR).Test results show that the ash extracted from BRA has a similar mesoscopic classification with the conventional mineral powder.Still,its fractal dimensions are larger,indicating the particles in BRA ash have more complex shapes and rougher surfaces,which is beneficial for forming structural asphalt and subsequently increasing the rutting factor(G*/sinδ),i e,improving the rutting resistance of the asphalt mortar.

A Data-Driven Rutting Depth Short-Time Prediction Model With Metaheuristic Optimization for Asphalt Pavements Based on RIOHTrack

Rutting of asphalt pavements is a crucial design criterion in various pavement design guides. A good road transportation base can provide security for the transportation of oil and gas in road transportation. This study attempts to develop a robust artificial intelligence model to estimate different asphalt pavements’ rutting depth clips, temperature, and load axes as primary characteristics. The experiment data were obtained from19 asphalt pavements with different crude oil sources on a 2.038km long full-scale field accelerated pavement test track(Road Track Institute, RIOHTrack) in Tongzhou, Beijing. In addition,this paper also proposes to build complex networks with different pavement rutting depths through complex network methods and the Louvain algorithm for community detection. The most critical structural elements can be selected from different asphalt pavement rutting data, and similar structural elements can be found. An extreme learning machine algorithm with residual correction(RELM) is designed and optimized using an independent adaptive particle swarm algorithm. The experimental results of the proposed method are compared with several classical machine learning algorithms, with predictions of average root mean squared error(MSE), average mean absolute error(MAE), and a verage mean absolute percentage error(MAPE) for 19 asphalt pavements reaching 1.742, 1.363, and 1.94% respectively. The experiments demonstrate that the RELM algorithm has an advantage over classical machine learning methods in dealing with non-linear problems in road engineering. Notably, the method ensures the adaptation of the simulated environment to different levels of abstraction through the cognitive analysis of the production environment parameters. It is a promising alternative method that facilitates the rapid assessment of pavement conditions and could be applied in the future to production processes in the oil and gas industry.

Analytical Study on the Effect of Electric Arc Furnace Dust(EAFD)on the Rutting of Asphalt Concrete Mixtures

As a byproduct of the steelmaking process,significant amounts of hazardous electric arc furnace dust(EAFD)are produced.Utilizing the solidification/stabilization technology with asphalt mix is one way to safeguard the environment from its negative effects.Rutting was used as an indicator to assess the asphalt mixture with EAFD since it is an important factor in pavement design.This study’s major goal is to ascertain how EAFD affects the rutting of asphalt-concrete mixtures.To evaluate the ideal asphalt content,the Marshall test method was applied to asphalt-concrete mixtures.EAFD was added to the asphalt cement in four different volume percentages as a binder addition.Then,using the Universal Testing Machine,participants were exposed to a replica of the rutting test(UTM).Experiments were conducted at 25℃,40℃ and 55℃,and at frequencies of 1 Hz,4 Hz and 8 Hz.Rutting was measured for each specimen.Test results showed that rut depth has a negative correlation with EAFD%and a positive correlation with temperature.The use of EAFD has dual advantages,protecting the environment from the adverse impact of EAFD and reducing the cost of asphalt mix without jeopardizing pavement performance.

Genetic Optimization Method of Asphalt Pavement Based on Rutting and Cracking Control

Nowadays asphalt pavement structure bearing is not the main subject for pursuers to study.Comparatively,the pavement performance is more important and emphasized.Based on this,rutting and cracking analysis is introduced into pavement optimization.A optimization model based on these two considerations is also established.The genetic algorithms (GAs) is adopted to solve the model.It is an intellective method.This research provides a new idea and technique for asphalt pavement structure optimization.

Rutting Resistance of HMA Rehabilitated with Micro-Surfacing

The work presented here is a study on the measurement and prediction of the rutting resistance of previously rutted asphalt mixes rehabilitated with a layer of micro-surfacing manufactured with virgin and recycled aggregates at different stages of aging. The experimental procedure consisted of rutting tests on hot mix asphalt slabs already degraded and repaired with virgin and recycled micro-surfacing. Then, the evolution of the behavior of micro-surfacing cast on the hot mix asphalt slabs is observed according to loading cycles of the pavement rutting tester MLPC. Before rutting tests, slabs are subjected to 24 hours at 50&degC and aged for 2 days and 5 days at 85&degC in the oven. The results showed rutting percentages of 6.3% for hot mix asphalt slabs aged for 2 days and 7.2% for 5 days. These hot mix slabs repaired with virgin micro-surfacing have rutting percentage of about 9.2 % for 2 days of aging and 6.5% for 5 days of aging. While, the HMA slabs repaired with recycled micro-surfacing have rutting percentage of about 8.1% for 2 days of aging and 5.9% for 5 days of aging. These results allowed the development of a prediction model based essentially on three predictor variables including cycle number, rutting state and percentage of water in the micro-surfacing material. The developed model shows a strong correlation between the predicted rutting values and the rutting values measured with the MLPC rut tester. Thermal aging in oven has a positive impact on the resistance to permanent deformation of new asphalt mixes and those rehabilitated with micro-surfacing. The parameters of rutting state and contribution water are significant in the rutting prediction model, while the cycle number remains a non-significant parameter in the model but determinant.

Experimental Characterization of Rutting Performance of HMA Designed with Aggregate Gradations According to Superpave and Marshall Methods

The permanent deformation (rutting) of pavement is a major distress in flexible pavement. It is related to vehicles properties and/or pavement materials and conditions. This article presents an extensive experimental investigation in order to compare between the aggregate gradation according to Superpave and Marshall methods of asphalt concrete mix design on pavement rutting and to examine the sensitivity of rutting resistance to aggregate gradation. A wheel truck machine has been used for measurement of pavement rutting (permanent deformation). The tests were carried out at two controlled different air temperature 55℃ and 25℃. The results obtained showed that the adopting of aggregate gradation procedure of Superpave method of pavement mix design for Marshall method of asphalt concrete mix design can reduce the pavement rutting by about 50%. This achievement may be related to missing of three sieves in aggregate gradation procedure of Marshall method which controls rounded and finer aggregate particles. These sieves provide more continuity for aggregate gradation to ensure filling unnecessary gaps and produce more contact points between the aggregates in Hot Mix Asphalt (HMA). The outputs of the research support modifying Marshall method of asphalt concrete mix design by adopting aggregate gradation proposed in Superpave method. The results of study also showed that the coarser aggregate provided more resistance to pavement rutting.

Relating Cone Penetration and Rutting Resistance to Variations in Forest Soil Properties and Daily Moisture Fluctuations

Soil resistance to penetration and rutting depends on variations in soil texture, density and weather-affected changes in moisture content. It is therefore difficult to know when and where off-road traffic could lead to rutting-induced soil disturbances. To establish some of the empirical means needed to enable the “when” and “where” determinations, an effort was made to model the soil resistance to penetration over time for three contrasting forest locations in Fredericton, New Brunswick: a loam and a clay loam on ablation/ basal till, and a sandy loam on alluvium. Measurements were taken manually with a soil moisture probe and a cone penetrometer from spring to fall at weekly intervals. Soil moisture was measured at 7.5 cm soil depth, and modelled at 15, 30, 45 and 60 cm depth using the Forest Hydrology Model (ForHyM). Cone penetration in the form of the cone index (CI) was determined at the same depths. These determinations were not only correlated with measured soil moisture but were also affected by soil density (or pore space), texture, and coarse fragment and organic matter content (R2 = 0.54;all locations and soil depths). The resulting regression-derived CI model was used to emulate how CI would generally change at each of the three locations based on daily weather records for rain, snow, and air temperature. This was done through location-initialized and calibrated hydrological and geospatial modelling. For practical interpretation purposes, the resulting CI projections were transformed into rut-depth estimates regarding multi-pass off-road all-terrain vehicle traffic.

Impact of Intrinsic Properties of Aggregate and Volumetric Properties of Hot Mixture Asphalt (HMA) in the Influence of the Resistance to Rutting

Several studies show that properties of Hot Mixture Asphalt (HMA) mix design materials, aggregate gradation and volumetric properties had an influence on their resistance to rutting. However, these properties do not impact in the same way this performance. For a given aggregate type, an infinity aggregate gradation type can be observed, and for each type of HMA several types of bituminous binder can be used. This article aims to measure the evolution of resistance to rutting according to the three main classes of National Cooperative Highway Research Program (NCHRP) aggregate gradation (dense-graded, fine-graded and coarse-graded). To this end, a study was conducted on the measurement of rutting resistance for eight bituminous mixtures manufactured with two bitumen types and two types of manufacturing aggregates. The results showed that there is a priority order of these different parameters on the influence of the resistance to rutting. This highlights a competition between the properties of aggregate and type of granular skeleton. Indeed, for the same type of aggregate, asphalt binder type first impacts resistance to rutting of the HMA followed by aggregate gradation, volumetric properties of the mix and finally by the angularity of the aggregates. However, this order cannot be fixed and can depend of the intensity of each parameter.

Rutting Resistance of Asphalt Pavement Mixes by Finite Element Modelling and Optimisation

Asphalt pavement rtting is a major safety concem and is one of the main distress modes of asphalt pavement.Research into asphalt pavement mixes that provide strong resistance for nutting is considered of great significance as it can help provide extended pavement life and significant cost savings in pavement maintenance and rehabilitation.The objectives of this study are to develop numernical models to investigate the ntting of asphalt concrete pavements and to find optimal design of asphalt pave-ment mix for nutting resistance.Three-dimensional Finite Element mod-els were first developed to simulate both the axial compression and wheel track testing in which a visco elastic-plastic material model was used to predict the ntting of the asphalt concrete pavements.A strain hardening creep model with the material parameters developed from experimental testing was employed to model the time-dependent characteristics of the asphalt concrete pavements.The results were validated against the pre-vious experimental wheel track test results of different pavement mixes.Finally,optimisation techniques using the Design Of Experiments method were applied to the simulation rutting results by varying creep parameters to identify their effects on rutting resistance in order to obtain an optimal asphalt pavements mixes.The results of this paper clearly demonstrate an efficient and effective experimental-numerical method and tool set towards optimal design for asphalt concrete pavements for rutting resis-tance.

Review:Asphalt Pavement Rutting Distress and Affects on Traffics Safety

Highway is an essential facility that led to both economic success and quality of life.Maintenance is necessary to ensure that highway will able to continue to carry out its functions.The rutting of asphalt pavement structures during their exploitation is considered to be one of the main problems in the entire world.This kind of pavement distress makes a negative impact to the exploitation characteristics of the asphalt pavement to the residual life of pavement structure,also to the safety and quality of the traffic.The main purpose of this review is to define the effects of rutting on roads safety.

Rutting Resistance of Asphalt Overlay with Multilayer Wheel Tracking Test

The rutting resistance of maltilayer asphalt overlay was researched by using laboratoty wheel tracking test. The effects of loading level and test temperature on rutting resistance of asphalt overlay structure were evahuaed by means of multilayer specimens . In comparison with multilayer tests, standard specimens of various layers were also conducted to evaluate the rutting resistance. Experimental results indicated that the test tempercature and applied load have a significant effect on rutting resistance of asphalt concrete. Higher test tempercature and heavier applied load resulted in higher rut depths. In addition, the mutilayer wheel tracking test has been demonstrated to be a more reasonable solution in evaluation on rutting resistance of asphatt pavement structure beasuse it reflects the cumulative permanent deformation in all of asphalt layers.

High Temperature Rheological Performance of Graphene Modified Rubber Asphalt

To elucidate the high temperature rheological capability of graphene modified rubber asphalt,three contents of graphene and crumb rubber were prepared by a combination of mechanical agitation and high speed shearing machine,then used dynamic shear rheological test(DSR)and multiple stress creep recovery(MSCR)tests to evaluate.The hardness and softening point with rotational viscosity of samples raised with the addition of graphene,especially the addition of 0.04%.Dynamic shear rheological test revealedthat the dynamic shear modulus G*,rutting factor G*/Sin δ,and zero shear viscosity(ZSV)of graphene-modified rubber asphalt were greatly influenced along with graphene-increased,on the contrary,phase angle δ which characterize the viscoelastic ratio of asphalt decreased.Multiple stress creep recovery(MSCR)tests showed that the graphene-enhanced rubber asphalt had high-temperature stability through non-recoverable creep compliance(Jnr).Based on these findings,graphene-modified rubber asphalt binders with the addition of 0.04% graphene had good viscoelastic properties as well as high temperature rutting resistance performance.In the meantime,G*/Sin δ,ZSV,and Jnr100,Jnr3200 have good correlation,which can reveal the excellent high-temperature stability performance of asphalt.

Anti-rutting performance evaluation of modified asphalt binders: A review

Asphalt pavement inevitably suffers rutting distress induced by repeated loads under high temperatures, which can be effectively alleviated by the modification of asphalt binders.This paper summarized the asphalt modifiers for enhancing the performance of asphalt pavement at high temperatures in terms of the modifier type, additive amount and improving effect. Then, the anti-rutting performance evaluation methods of asphalt binder were introduced with details, including the ring and ball(R&B) test, the dynamic viscosity test, the zero/low shear viscosity(ZSV/LSV) test, the dynamic shear rheometer(DSR) test,the repeated creep and recovery(RCR) test, and the multiple stress creep and recovery(MSCR) test. Furthermore, the sensitivity of the evaluation method to asphalt modifier was analyzed using the normalization method. It was found that the indicators from the MSCR test could clearly reveal the influence of asphalt modifiers on high temperature performance of asphalt binder. But it still had some limitations affecting the accuracy of evaluation results, such as the number of creep-recovery cycles, the stress level and the recovery time. In addition, according to the rutting resistance improvement ratio(RRIR),the styrene-butadiene-styrene(SBS) modifier performed better in improving the rutting resistance of asphalt binder, compared with other modifiers when added within the usual dosage range.

Evaluation of fatigue and rutting properties of asphalt binderand mastic modified by synthesized polyurethane

Fatigue and rutting phenomena are major distresses in asphalt pavements.Asphalt mixture properties are highly dependent upon the asphalt binder and the mastic behavior.The purpose of this study was to investigate the behavior of the asphalt binder and the mastic,modified by the synthesized polyurethane,at high and intermediate temperatures.The filler/asphalt binder ratio(by weight)was 1.0.The dynamic shear rheometer(DSR)was used to measure fatigue(G^(*)sinδ)and rutting(G^(*)/sinδ)parameters.In this study,the multiple stress creepandrecovery(MSCR)testwasalso utilizedto calculate the ruttingpotential of theasphalt binder and themastic.Parameters of the non-recoverable compliance(Jnr)and the percentage recovery(%)were evaluated at high temperatures.The obtained results indicated that the synthesizedpolyurethaneimproved the ruttingandfatigue properties.Therewasa significant correlation between the asphalt binder and the mastic in terms of the complex modulus(R^(2)=0.9958),rutting(R^(2)=0.9944),and the non-recoverable compliance(R^(2)=0.9707).For the fatigue parameter(R^(2)=0.9852),the complex modulus(R^(2)=0.9855),and the phase angle(R^(2)=0.8262),significant relationships were observed between the asphalt binder and mastic samples at intermediate temperatures.Overall,the chemical reaction between the filler and the asphalt binder could be effective in different behaviors of the mastic and asphalt binder.Therewasa 112%-164%increase in the G^(*)sinδparameter formastics,compared to that of the asphalt binder.The complex modulus was 6 times higher by adding the filler content.

Rutting prediction models for flexible pavement structures: A review of historical and recent developments

Rutting is the major distress mode in flexible pavements occurring due to the repeated movement of traffic loading. Deformation in the pavements comprise of both recoverable(elastic) and irrecoverable(plastic) part. Overall deformation occurring in the flexible pavement system due to continuous vehicular movement is contributed from all the components of pavement. A number of empirical models have been proposed by several researchers for analysis and prediction of accumulated rutting in different components of pavement. The accumulated permanent strain has been expressed as the function of the number of load applications and deviator stress applications in most of the models proposed;however, factors such as stress state, moisture content, material type and environmental conditions also impose a significant influence on the permanent deformation characteristics of pavement materials under cyclic loading. In this article, a comprehensive review has been carried out covering every aspect of deformation related to distress occurring in pavements. Important rut models, modeling approaches and modern concepts in the rutting analysis of pavement structures have been presented. In addition to review, fallacy existing in the current design practices related to adaptation of stiffness parameters and negligence of shear strength aspect of subgrade soil has been also presented with the support of literatures.

Effects of accelerated loading on the stress response and rutting of pavements

In order to assess the difference in performance of pavements under conventional loading and accelerated loading,in this paper,based on the characteristics of pavement strain recovery in accelerated pavement tests(APTs),we define accelerated loading and conventional loading in pavement permanent deformation research.The finite element method is then used to establish a flexible contact model between tire and asphalt pavement.By using simulation,the difference in dynamic stress and rutting of a pavement under the two different loadings is studied.It is discovered that if the APT forms an accelerated loading effect,the pavement will produce deeper rutting under the same axle loading cycle.

Effect of Active Mineral Filler on Rutting Performance and Fatigue Properties of Granite Asphalt Concrete

Granite is well known as an acid aggregate. An active mineral filler produced in the laboratory is first used as an anti-stripping filler in the granite asphalt concrete. Four aggregate gradations were chosen in this study,and the effects of the active mineral filler and aggregates on the rutting resistance performance and fatigue properties of granite asphalt concrete were investigated by means of rutting test and four-point bending fatigue test. The results indicate that the dynamic stability of granite asphalt concrete increase significantly with the addition of active mineral filler and the fatigue properties can also be improved especially at lower strain level. Meanwhile,the results demonstrate that granite asphalt concrete has better rutting resistance performance and fatigue properties than limestone asphalt concrete.

微织构铣刀干铣削RuT500切削性能研究

为探究微织构对刀具加工蠕墨铸铁RuT500切削性能的影响,改善RuT500的可加工性,利用激光技术在刀具前刀面制备了3种形式的微织构并通过单因素试验方法,在不同切削速度下将微织构刀具和无织构刀具对RuT500进行铣削加工,对比分析了微织构的方向和类型在加工中切削性能的差异。结果表明,表面微织构可以有效降低切削力,改善切屑形态和工件表面质量,在一定程度上降低了前刀面磨损;3种微织构在部分相同切削速度下对切削性能的影响有较大差别;切削速度较大时,微织构更有利于RuT500的切削加工。在3种微织构中,以平行于主切削刃的沟槽织构刀具切削性能最优。

复合涂层刀具加工RuT500的铣削力研究及参数优化

为探究和改善蠕墨铸铁RuT500的铣削力,基于单因素试验,选用TiAlN/AlCrN、TiCN/Al_(2)O_(3)复合涂层硬质合金刀具对RuT500进行铣削加工,结合响应面探究涂层和铣削参数对RuT500铣削力的影响规律,并进行了铣削参数优化。结果表明:相比于TiAlN/AlCrN复合涂层硬质合金刀具,TiCN/Al_(2)O_(3)复合涂层硬质合金刀具铣削RuT500时会产生更大的铣削力;对蠕墨铸铁铣削力影响最显著的因素是背吃刀量,其次是进给量,铣削速度对蠕墨铸铁铣削力的影响程度相对较少;铣削参数交互作用对铣削力的影响具有一定的显著性;取较大的背吃刀量a_(p)、适当的进给量f和较大的铣削速度v_(c)时,可以获得较低的铣削力F和良好的加工效率。

提升柴油机气缸盖内腔质量的工艺措施

针对柴油机气缸盖铸件内腔的披缝和烧结缺陷问题,分析认为气缸盖内腔的水套砂芯形状复杂、砂芯的配合面多且壁厚偏薄是产生缺陷的主要原因。通过在模具上提升模拟射砂仿真技术、优化射砂嘴结构、引进电火花技术;并调整制芯工艺解决了缺陷问题,批量生产出合格铸件。