The profile of twenty four types of asphalt concrete pavement was measured by Circular Track Meter. It was shown that the ratio of Mean Profile Depth and Root Mean Square of the profile indicated the type of macrotexture, that is, positive or negative texture. Eighteen types of hot-mix asphalt concrete with various gradations were compacted in the laboratory using a newly developed compaction method that simulates the rolling that occurs in the field during construction. It was found that the ratio of the weight of aggregate retained 4.75mm sieve and passing 0.15mm sieve (R4.75/P0.15) has a large effect on the macrotexture. Secondary rolling with a rubber-tired roller tends to change the texture to a positive value when R4. 75/P0. 15 is small.

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The roughness of the road surface affects not only riding comfort but also handle operating. Authors have fixed their eyes upon the road surface conditions reflecting the relative position of vehicle wheels, and have developed a new index named “WONDERING INDEX (WI) ” which represent road surface conditions.
This paper describes relations between WI and handle operating works, and investigates how to measure road surface conditions reflecting the relative position of vehicle wheels. The results show that WI and handle operating works have a high mutual relation. Consequently, it is concluded that WI can be a useful index to evaluate the road surface that affect handle operating.

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Monitoring surface conditions and prediction of the damage of road surface have been carried out periodically from point of view of the traffic safety and the pavement management system (PMS). Nowadays, the true profile for a specified spatial frequency range can be easily obtained by a profiler although it has inherent detective properties. In this paper, we studied an estimation of the true profile using the measurement data of the PIARC EVEN experiment acquired by a conventional 3m profilometer. The results show that the profilometer enables to estimate the true profile accurately for practical use on general highways.

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This study proposes a method for detecting road roughness using the second-generation wavelet transform (SWT). New wavelet filters by the SWT are biorthogonal wavelet filters containing free parameters. This method is adopted to learn free parameters based on some training signals, which contain the localized road distress. Learning wavelet filters have the special feature of the training signals and an application of the filters for the test signals leads to detection of a characteristic waveform of the road roughness effectively.

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The difference of pavement texture gives effects on forming conditions of pavement freezing, denatured process and consumption conditions of road snow/ice due to traffic loads and chemical application. Since these effects are closely related with improvement of pavement skid resistance, it's important to investigate the properties of pavements with different textures for an optimization of chemical application, cost saving of snow/ice control, and compacted snow pavement control. Antifreezing effects of porous asphalt, stone mastic asphalt and dense grade asphalt were evaluated in remaining density of chemicals and coefficient of pavement friction on ice crust pavement lanes using full-scale wheel tracking test equipment in temperature controlled chamber.

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This report discuss about the basic study how to measure the road user cost regarding ride comfort of passengers as one of the sub systems of pavement management systems. Surface profiles have been measured and then IRI has been calculated on the actual road. Also ride comfort of passengers and the equivalent user cost to rehabilitation have been evaluated via panel rating. It is just on the earlier stage of study, however, it is found that the subjective information such as ride comfort is able to estimate as the user cost.

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We conducted horizontal repeated shear test in order to appreciate the resistance to aggregate fretting of porous asphalt pavement. Test results showed that the mixture which used the binder with higher bending work (the binder with lower stiffness) had good effect on the resistance to aggregate fretting. However, according to compare the test result with the calculation value of the shear stress acting on the surface layer, we recognized that using high quality binder was not always sufficient to control aggregate fretting. In addition, it suggested that the method to combine the technology to lower the surface temperature of porous asphalt layer with the high quality binder was better for aggregate fretting.

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The low noise pavements have been put in to practice in Tokyo metropolitan since 1994 in order to reduce the noise along roads, and the projects are increasing. The surveying results of the low noise pavements failures, the mechanism of the scattering, and the development a new apparatus to evaluate scattering have been reported last year. Based on the findings of last research, investigation on the actual processing state of the aggregate is carried out. In addition, measures to reduce the occurrence of scattering are examined in. It is concluded that controlling of the temperature in construction of the pavements is important. It is effective to use modified high viscosity asphalt, resin coat as a surface treatment to reduce the scattering of the aggregates.

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Pot hole came to occur in low noise pavement frequently. Pot hole it did though a point smelled bad as for the oil. Binder became soft, and cut-back was being done. I paid attention to the pot hole damage, and did the progress actual condition, cause study and the examination of the repression countermeasure. Bleeding occurred more than oil, and cut-back was done, and the cause of the damage reached pot hole. It could get to be effective to use adhesion prevention medicine instead of the light oil by this research to control pot hole. And, it could get to be effective that a top coat had it, too.

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We have studied the relationship between characteristics of pavement surface texture and generation of tyre/road noise on porous asphalt pavements. On the other hand, as the factor which gives influence on noise generation, void characteristic and thickness of layer greatly influence on other than pavement surface texture. This study analyzed percentage of void and thickness of surface layer including three types of mixture, which are dense graded, SMA and porous asphalt in addition to surface texture. We examined the relationship between tyre/road noise and these factors. As a result, the tyre/road noise of asphalt pavements could be evaluated more effectualy from void characteristics which considered thickness of layer and surface texture.

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In order to estimate life-cycle costs properly, pavement performance curve suitable to analysis period is indispensable. This study mentions performance prediction model created from Pavement Data Base. To establish the model, the method was proposed how to presume the relative frequency and mode of road surface condtions at the time of assuming that repair was not conducted. . Appropriate standard performance prediction model about cracking, rutting, and evenness was attained in this procedure. And estimating life cycle cost was available for network level using this model.

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The aim of this research was to develop an improved recycled asphalt pavement by using reinforcement sheeting to decrease the shortcomings of reclaimed asphalt pavement (RAP), and take advantage of its merits. Evaluation tests showed that the use of reinforcement sheeting in combination with recycled asphalt mixture resulted in a paving material that significantly outperforms virgin asphalt mixture in rutting resistance, crack resistance and serviceability. Concern for the state of the environment has grown considerably in recent years throughout the world. Road construction is no exception to this. This report was submitted in the hope that the proposals it contains would contribute to further promotion and expansion of effective use of recycled asphalt mixture.

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A new type of asphalt mixture, which is composed of very rough texture for road surface similar to that of porous pavement, as well as the same functions as stone mastic asphalt for inside was developed. For evaluation of surface texture and waterproof, laboratory specimen was fabricated using roller compactor, which is expected to give similar compaction in field. Then those key properties from the evaluation were successfully reflected into conventional items of Marshall Stability Test for standardization of this mixture. Since it is important to fabricate laboratory specimen with properties similar to those in field, volumetric design method needs to be studied for such a new conceptual asphalt pavement in the future.

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This study examines the prediction technique of a convenient traffic vibration of new pavement structure, when developing pavement which has the reduction effect in traffic vibration. The analysis model to four kinds of pavement was made, and the time history response which took input load into consideration about vibration by blow was analyzed. Moreover, the simple traffic vibration prediction formula in consideration of the road surface performance was also examined.
As the result, the tendency of an experiment value and an analysis value was in agreement in general in the vibration acceleration level. Moreover, the vibration from a vehicles run was able to be predicted in simple from the vibration from a blow, and road surface evenness.

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In recent years, the need for environmental conservation has been publicized around the world. Even in Japan, efforts toward energy conservation and reduction of carbon dioxide emissions have been strongly called for. And the reduction in the road construction cost is strongly requested on the age of real maintenance and mending as for the road maintenance. Therefore, we are currently conducting development of a semi-hot asphalt mixture suitable for the climatic conditions of Japan by employing semi-hot asphalt pavement technology from Finland. This paper will present an outline of this semi-hot asphalt mixture and report on the results of its use in construction in Hokkaido.

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Whitetopping is a thin concrete overlay on asphalt pavements. In case of road pavement, design thickness of whitetopping would be decided based on critical stress that develops at longitudinal free slab edge. However, in case of airport pavements, design thickness would be decided based on stress at joints of whitetopping. In this study, we constructed the field trial of whitetopping, conducted loading tests and measured strains in the concrete and asphalt layers. By comparing measured and analyzed strains using three dimensional FEM, we obtained bonding parameters and spring moduli of joints. Furthermore, we measured temperature gradient of concrete for a year and calculated temperature stress of concrete. Results showed that structural design of whitetopping could be applied for airport pavements.

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Objective of this study is to propose the structural evaluation method of concrete pavement based on back-calculation of FWD measurement data. Back-calculation has been carried out under the two conditions. One was under the condition that the elastic modulus of concrete slab was fixed and the other was varied. . As the result, it was confirmed that the back-calculation method under fixed condition was effective. And, velocity effects of the back calculated elastic moduli were examined using static loading result of the concrete slab and cyclic tri-axial testing results of mechanical stabilized base course material. Consequently, it was found that the velocity effects could be neglected by multiplying the reduction coefficient to the elastic moduli of subgrade and base course. And a reproducibility of load transfer ratio at the transverse joint was examined using this evaluation method. As the results, validity of the evaluation method proposed in this study was confirmed.

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The PC precast slab (PPC) used for airport pavement has a problem in respect of joint system and construction cost. In order to solve these, we has been developed about high strength RC precast slab (HRC) as durable as PPC, and joint system by the cotter joint. By this report, we considered about the design of HRC and the cotter joint used for airport pavement by Westergaard's formula, FEM analysis, and the examination by the specimen. As a result, we obtained the check of appropriation design of slab by allowable stress design of reinforced concrete's theory method and design principle of cotter joint.

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Recently, concrete pavements are often adopted due to both introduction of larger aircraft and increase of aircraft operations. To deal with these situations, RC precast slab pavement using high strength concrete with cotter joint system is studied. Through the repeated loading of 10, 000 times with B747 landing gear on the experimental pavement, the durability of both cotter joint and RC precast slab was found fully sufficient. Based on a series of studies, the applicability of high strength RC precast slab pavement in airports was verified.

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This paper describes the possibility of elongation of joint spacings in airport concrete pavements. First, experimental pavements of which joint spacings were 7.5 m and 8.5 m (conventional and longer) were constructed, and strain and temperature in concrete pavements were measured to study the influence of joint spacings on shrinkage stress and thermal stress. Then, the influence of joint spacings on stress due to both load and temperature change were analyzed by using finite element method. As a result, it was found that the differences of stresses due to both load and temperature change were negligible between two joint spacings, and the current design method of the slab thickness was also applicable in the case of longer joint spacings.

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This paper proposed an efficient method to conduct 3D-FEM in time domain on dynamic visco-elastic issues. Equations for both stress and strain increments were derived. By introducing Burger model to simulate the visco-elastic properties of asphalt mixture, a series of numerical simulations were carried out. Through the simulation, influences of model components on the behavior of pavement structures are explained.

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In pavements on steel bridge decks, large tensile strains occur at pavement surface above webs of the steel bridge decks that flexibly deform when subjected to traffic loads. These strains might cause the longitudinal surface cracks (LSC), which appear in wheel paths relatively early from the construction. In this study, the effects of axle load position, span length, stiffness of pavement on the strains were investigated utilizing the Strip-Link-Prism Element model. A fatigue curve was applied to the calculated strains to estimate the fatigue damage and the occurrence time and positions of the LSC were examined.

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The structural design of asphalt pavements in Hokkaido calls for a wearing layer and frost blanket, and takes into account the reduction in subgrade CBR during use. We reviewed such design methods, which are unique to cold regions, toward establishing pavements that would afford a design life cycle of 20 years. Also, we estimated the life-cycle cost of the pavements, toward evaluating the cost reduction that would result from extending the life cycle.

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Various measuring devices and methods based on the stress release method (SRM) have been developed to find the in-situ stress. In this paper, two methods were investigated in order to introduce SRM into the asphalt concrete evaluation. These two devices were developed originally; one is the surface unit cell (SU-cell) for surface strain of pavement layer, and the other is the solid inclusion cell (SI-cell) for inner strain of pavement. As the results, SRM can estimate properly in-situ strain and stress. Therefore, it will be possible to find the relationship between a few physical and mechanical properties of the asphalt concrete pavement.

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A series of laboratory tests was conducted to study the asphalt concrete with better performance for airport pavements, with the following results: (1) Asphalt concrete with modified asphalt has higher dynamic stability and lower cracking susceptibility than that with conventional straight asphalt. (2) The gradation of aggregates highly influences the performance of asphalt concrete. Both stone asphalt concrete and Superpave asphalt concrete show better performance for airport pavements. (3) As compaction effort increases, the air void ratio of asphalt concrete decreases and the stability increases. Increasing the compaction effort gives the asphalt concretes better resistance to both rutting and stripping.

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Using an aging test method, “UV Aging test by pressed thin film samples”, a straight asphalt and a modified asphalt type-II binder were examined for their aging behavior. The results confirmed that this method is effective to simulate the outdoor exposure test, and ultraviolet-rays radiation is a severe factor to the surface compared with the conditions of the Pressure Aging Vessel test.
Furthermore, addition of carbon black showed the tendency to prevent from changing in the chemical fraction by aging, and to restrain the producing of carbonyl group by ultraviolet-rays radiation. Therefore, carbon black will improve the durability of asphalt materials.

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Blistering of the runway surface course was found during a runway inspection at New Chitose Airport in June 2001. A more detailed survey revealed that water penetration has reduced the bearing capacity of both the surface course and the binder course below the joint, as well as the asphalt stabilization layer. Because of a working time restriction on the runway, the thick lift method, whereby asphalt is placed in a short time, was applied in combination with a large-grain asphalt mixture that can be placed at lower temperatures than usual. The study reports the causes of pavement failure and the results of measures against such failure.

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