The purpose of this study is to develop roughness criteria of airport pavements based on aircraft response to ensure the safety in operation and the ride comfortability of aircraft. As the results, relationship between aircraft vertical acceleration and roughness of pavement was clarified using simulation program of aircraft response, APRas, and the roughness criteria in order to keep aircraft vertical acceleration under 0.4g for both runway and taxiway were obtained. To verify these roughness criteria, longitudinal profile was measured on runway of major domestic airport for three years, and roughness evaluation of the airport pavements was carried out using these criteria.

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A difference in level, incline and closs slope on sidewalks are serious barriers for aged and physically handicapped persons. However, even if they are small, roughness of sidewalk would increase wheelchair traveling load in case of rough sidewalk.
In this study, measurements of longitudinal profile and torque of wheelchair traveling at a constant speed were conducted at 5m length test sections on steep and rough sidewalks. The relationship between the longitudinal profile and the wheelchair traveling load was also analyzed. It was found that the wheelchair traveling load cased by roughness could be estimated from the longitudinal profile.

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Unevenness of sidewalk pavement was evaluated by using of the acceleration of front and rear wheel of a wheelchair. At first, vibration accelerations of running wheelchair were measured according to the orthogonal axis x, y, z, and basic characteristics of the wheelchair and effects of wheelchair speed and weight of seated persons were revealed. Secondly, vibration level of the wheelchair was calculated by considering the frequency-weighted acceleration values. The wheelchair vibration and the comfort of seated persons were evaluated according to ISO2631 (1978) . As a result, it became clear that unevenness of the sidewalk affects seated person's health.

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Maintenance strategy might be changed in future due to uncertainty included in cost of maintenance and operation, degradation of infrastructure, budget, change of social system, technology innovation and so forth. The present value (PV) method commonly used for alternative evaluation cannot consider uncertainty that is expected to occur in future. On the other hand, real options (RO) method is new technique that can consider the value of flexibility of alternative. In this study, optimization system of maintenance strategies for road pavement by using real options has been developed. Through the numerical simulations on road pavement, it was confirmed that the alternatives which have flexibility more abundantly were drawn as optimum solution by considering of option values.

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Distress other than cracking or rutting has been often seen recently at airport asphalt pavement such as Nagoya Airport. In such major local airports, both operating condition and working hours are severely restricted. This report introduces the distress and repair method of airport asphalt pavement, by taking Nagoya Airport and New Chitose Airport for example. At both airports, blistering, segregation etc. were found a few years after the overlay construction, and thick lift construction, increase of durability and improvement of workability have been adopted as the countermeasures.

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In this paper, we studied the estimating range when estimating a true profile using measurement data from a profilometer. Especially, the experiment using the KIT Driving Simulator (KITDS) was described. The purpose of the experiment was to confirm the peak of the frequency component of the acceleration of a vehicle contained in the estimating range. Consequently, it was shown from the filter performance and the acceleration of sprung-mass of the KITDS that the standard of the estimating range in the case of a general road is Wave Number=0.04-0.33m^-1.

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This study examines how pavement roughness affects the subjective riding comfort of drivers running on a road section in service versus on a road section in a driving simulator. Subjects were also asked weather pavement repair was necessary, and their willingness to pay for pavement repair. In this way, monetary conversion of subjective riding comfort was attempted. It was shown that when the IRI increases, the subjective riding comfort and sense of safety decrease and the subjective evaluation of the need for repair increases. Each subject's WTP increased with increases in IRI. However, the WTP differed greatly among subjects. Also, the subjective riding comfort and sense of safety of an actual road in service and a driving simulator were found to be shown in similar tendencies.

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In this research, a design procedure of large stone asphalt mixture, which is superior in plastic flow resistance, was discussed. The feature points of the design procedure are as follows. 1) Large stone aggregate, top size of 30 mm, was mainly mixed. 2) The mix proportion was decided in focusing matrix structure of the top size coarse aggregate. 3) A gyratory compactor was used for specimen compaction. From the results, it was found that the mix proportion with No. 4-sized and No. 7-sized crushed stone has a good matrix structure of the coarse aggregate. And it was also confirmed that this mixture has high efficiency in flow resistance and abrasion resistance as compared with past large stone mixtures.

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SBS-modified asphalt is finding widespread application as a binder for rutting-resistant mixtures, mixtures for porous pavement, etc. The performance is greatly affected by the morphology of the SBS. In this study, we made trial SBS-modified asphalt products of varying morphologies and clarified the relation of the dispersed conditions of SBS-modified asphalt products to its performance and storage stability as the binder and various performances of paving mixtures. As a result, we could show the morphology of SBS-modified asphalt required to ensure its proper performance.

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Recently distress types of porous asphalt pavement including partial plastic flow and others have been observed in the Japanese expressways, resulting from stripping of aggregates of its underlying binder course mixture. As a first countermeasure against the problems, evaluation method of durability for existing binder course mixture for every rehabilitation project is to be developed. This paper presents development process of the evaluation method of stripping resistance which is applied to existing binder course mixture.

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In this research, the evaluation method of the road surface temperature is studied for development of heat reflection pavement. Some kinds of heat reflection pavement, which used drainage pavement as the base mixture, were used for research. First, the prediction method of the outdoor road surface temperature of a summer was considered from the result of an indoor examination. Next, the prediction method of the outdoor road surface temperature of a summer was considered from outdoor road surface temperature other than summer.
Consequently, the practical prediction formula could be drawn from the result of a laboratory test. Moreover, the prediction formula that is practical also from the result of road surface temperature other than summer could be drawn.

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In recently, high viscous modified asphalts have been formulated that is various polymers and additives in rich contents compared with normal high viscous modified asphalt. They have been used for porous asphalt applied in severe condition areas such as heavy duty intersection, cold regions and steel plate deck bridges and also they have been used for porous asphalt with small top sized aggregates and/or high voids which are often adopted in road constructions with performance-relating specifications. This research work studied for quality guarantee periods for high viscous modified asphalt using the indoor manufacturing/storage pilot equipments which had better correlation with those of the factory. And more practical evaluation method for bitumen polymer dispersion morphology was proposed.

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The noise-reduction performance of drainage pavement in Hokkaido deteriorates early. In the cold, snowy climate, voids in the pavement which are scattered by tire chain and snow ploughing. As an alternative, low-noise pavement made using more durable materials is being developed. The open-graded joint pavement is a low-noise pavement in which voids are filled with protective materials in the upper part of the pavement. It mitigates the crushing closed and clogging of the voids. The noise-reduction performance is extended by the synergic effect between the voids and elastic materials. Also, ice prevention can be expected.
This report discusses the benefits and usability of open-graded joint pavement as determined in an indoor experiment and an experiment to verify its performance.

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The test pavements using recycled porous asphalt are performed in each research institute, but drainage asphalt pavements are manufactured only with new material now, because the technology of recycling is not established. However, drainage asphalt pavements also need to consider to use of recycling aggregate from now on. Then, we examined the reproduction of porous asphalt mixtures with two kinds of aggregate, the recycling aggregate of drainage pavements, and conventional reproducted aggregate. Consequently, we showed clearly that each of two methods can put in practical use.

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At present, use as the aggregates of molten slag made by the ash of domestic wastes is examined, and that utility is confirmed. However, the conditions which molten slag is used for are not organized because quality as the aggregates is not examined in detail, This paper showed the experimental study, which could specially become materials for the quality standard of molten slag as fine aggregate for paving.
As the results of using five types molten slag, relationship between a difference in the quality of molten slag and the performance of the asphalt mixture became definite.

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As the abolished materials, which were produced with construction or rehabilitation works at airport pavements, are assumed to have high quality, they should be reused there. As the current specifications might not treat these issues, some new procedures have been studied here. This paper shows the reutilizing procedures of abolished asphalt concretes in airport pavements; especially, the applicability to the stabilized bases. Through a series of laboratory tests, it was found that the abolished asphalt concretes could be effectively utilized as the cement treated base.

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In current plant recycling for porous asphalt mixture, existing porous materials with undersize of 5mm are difficult to reuse in practice. This paper presents how to deal with the problem in mix design and manufacture at plant for sustaining quality of the recycled mixture in case much use of them are used. It was found that more contents of recycled aggregates can be used by sizing them in 13-5mm and 5-0mm rather than only crushing them in 13-0mm. Moreover prevention of adhesive materials in heating dryer and adjustment of recycled mix at plant are also presented for practice.

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This study aims to examine hot asphalt mixtures in terms of 1) differences in fatigue failure characteristics with different mixing proportions of components, and 2) the distribution of the numbers of stress applications to reach of fatigue failure for hot asphalt mixtures.
Field surveys on fatigue cracking of roads in service and laboratory tests on stress fatigue confirmed that hot asphalt mixtures with different mix proportions differ to a statistically significant degree in the number of stress applications to reach fatigue failure. The life of the asphalt concrete layer is depends greatly on the mixing proportions of components of the bottom layer.

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The purposes of this study are to evaluate the applicability of design fatigue curve which takes the probability of failure into account, and to inspect the validity of application of Miner's rule for concrete pavement design. As the result of simulation for fatigue failure of concrete slab, it was found that the failure probability of concrete slab agree with the failure probability of design fatigue curve. From the results of fatigue test for specimens which cut off from in-service slabs, it was verified that the Miner's rule can explain the process of fatigue failure of concrete.

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It has been indicated, during FWD test, that variations of loading time and time integration of load have influences on the estimated elastic modulus and K-value of subgrade even if the peak load is same. The above indication could not be found from the impact numerical FE analysis of elastic model for the portable FWD. In this study, analytical study has been carried out to investigate the influences of various parameters, such as the rigidity of subgrade, the mass and drop height of falling weight, on the loading time and time integration of load from the numerical analysis of viscoelastic subgrade model.

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Generally, backcalculation analysis based on FWD test data is an unstable procedure greatly influenced by several types of errors. These errors may be categorized by accuracy of forward analysis, measurement error, instability of backcalculation analysis, etc. Due to instability of the backcalculation algorithm, seed values of layer moduli highly influence backcalculation results, especially in case of thin asphalt concrete layer. In this paper, following verification of the accuracy of forward analysis, importance of dynamic backcalculation analysis will be explained and the use of Monte Carlo simulation for seed values of layer moduli to accurately backcalculate layer moduli will be presented.

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Partial plastic flow of porous asphalt surface course and particles of binder course mixture blowing up from its porous, due to stripping of the underlying mixture have been observed in the Japanese expressways. Judging from structural surveys of porous asphalt and neighboring dense graded asphalt pavements, it was found that deterioration of underlying layers of porous asphalt is difficult to outlook, and that deflection curve of the pavement is shown unnatural in case where stripping of the underlying mixture takes place. Therefore monitoring using FWD measurement is to be conducted, mainly in the sections where drainage of road surface takes time, such as sags and inflections.

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Some of the sections in service over 10 years in Japanese expressways have been structurally damaged and have to be repaired by replacing with thick asphalt materials. This requires unacceptable repair costs and traffic regulation with social nuisance during the repair work. Like in the structures of bridge and tunnel, that of pavement should be almost permanently durable with no needs to be repaired for structural damages. In this study structural conditions for pavements to be stable in long-term years are specified, based on the relationship between equivalent single axle loads and structural damages of the pavements in the expressways.

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In the theoretical design of pavement, strains that occur in pavement layers are obtained by a mechanical analysis and the number of years to fatigue failure is estimated based on the fatigue characteristics of materials. It is very important to accurately estimate the strain induced by traveling vehicles. We installed test pavement sections designed for different design periods which were calculated by TA method and multilayer elasticity theory. We evaluated the bearing capacity of test pavements by FWD, measured strains by vehicle-traveling test. To establish a theoretical design, we compared measured strain to theoretically evaluated strain to determine whether the theoretical method gives valid results.

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In this study, Handy-FWD tests and plate. bearing tests were carried out on the test base to discuss an appropriate data analysis. To know elastic modulus of base, we carried out static and dynamic analysis by using load and displacement historical data from handy-FWD. From these results, dynamic analysis has advantages and problem.
In addition, a new indicator of strength of base by using the historical time data was introduced. We also justify validity of proposed procedure by comparing the result of the new procedure with one of the plate-bearing test.

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It is well known that the function of base layer is to disperse the load acting on the pavement surface and this highly influences durability of the pavement. In pavement analysis, linear multi-layer elastic system is used and it is hereby proposed that k-q nonlinear model be used to represent material properties for base and subgrade layers instead of a linear model. In this research, comparison between linear and nonlinear models for multi-layer elastic subgrade and unconfined base materials is made from the point of view of expected pavement life. Effects of percolation of water into base layer and degree of saturation on the load dispersion capacity and expected life, respectively, were evaluated. Results confirmed the importance of developing a model that properly represents behavior of unconfined materials.

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Many pavements in Hokkaido, a cold, snowy region, experience thermal stress cracking (hereafter low-temperature cracking) due to low temperature. The causal mechanisms of such cracking are not understood. We used the stress release method to clarify those mechanisms. Our study aimed to examine measures against low-temperature cracking. To this end, we summarized the results of thermal stress measurements in asphalt pavement body during the cold season taken by stress release method, and examination results of causal mechanisms of low-temperature cracking.

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Since there are few tire/road noise measurement cars used for completion inspection of performance regulation formula construction, comprehensive evaluation formula construction, etc., the owner is anxious by adjustment of measurement time. Since the number of times which evaluates the tire/road noise in a construction stage and a management stage will increase further from now on, the request of development of the examination equipment which can measure tire/road noise is high. For this reason, in the Public Works Research Institute, joint research “development of tire/road noise measurement equipment” was performed in three years [2001-2003] with 17 companies (7 groups) . This paper reports the factor which influences the tire/road noise measurement considered in this development.

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Test surface for road vehicle noise has been standardized as ISO 10844. The surface course has to be paved with dense graded asphalt concrete using straight asphalt. There exists a need to obtain the effect on noise measured value due to change of the surface texture depth during usage of the surface. This paper presents evaluated characteristics of the surface texture, comparing change of the surface texture depth with evaluated value of power spectral density of surface texture. This study also discusses the relation between surface texture depth and tire/road noise, and same knowledge as porous asphalt is obtained.

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It is known that the noise reduction effect of low noise pavement is affected by both of its surface texture and the state of air voids. At the present, surface texture is evaluated by a few profile data on the single measuring line on the pavement surface. Therefore, it follows that the evaluation of the texture of the whole pavement surface is difficult by the use of the present procedure due to the variation of the surface conditions.
In this paper, a fundamental study on a sampling of precision data and an analysISOf them were carried out for evaluating the texture of the whole pavement surface, based on the way of plane measurement of the pavement profile. As a result, it is shown the variation tendency of the texture for the whole pavement surface and a minimum number of the profile data for analyzing the whole surface texture. Furthermore, a probability of the evaluation of the whole surface texture with accuracy is also shown in consideration of the selection of the present analysis procedures.

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Stress distributions in ground are quite important for the development of analytical pavement designs to introduce new pavement materials. Therefore a roller loading apparatus was newly developed to measure stress distributions in model ground subjected to roller loads. Vertical and shear stresses at the bottom of the ground are able to be monitored. Using the apparatus, a series of laboratory model test was conducted. The test results showed that the thickness of the model ground significantly affected the stress distributions, while the density of the ground had little effect. It was also found that the ratio of shear to vertical load acting to the roller had relatively large effect on the location of the peak stress.

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This report discuss about early age strength of ultra high early strength steel fiber reinforced roller compacted concrete which were combined ultra high early strength concrete and steel fiber reinforced roller compacted concrete. The consistency of ultra high early strength steel fiber reinforced roller compacted concrete and standard roller compacted concrete are equivalent. As for the curing time which reaches mix strength is shortened by 1/6-1/9 as compared with standard RCCP. We clarified early age strength for ultra high early strength steel fiber reinforced roller compacted concrete as compared with ultra high early strength steel fiber reinforced concrete with slump.

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