It becomes effective for analysis such as with evaluation of ride comfortable of road user and noise vibration problems that grasping rougghness of road surface when evaluates service ability of pavement. By the development of measurement device that road surface property was automatic, collection of vertical section unevenness data became possible in 0.25 m interval in extension direction by usual vehicles traveling speed. We carried out analysis about data interval for the evaluation that was reasonable rougghness and carried out analysis about the unit section that evaluated rougghness length. Furthermore, we carried out comparison examination about IRI and rougghness suggested in world bank as an index of ride comfortable.

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In case of a short curing time for subgrade stabilization, its undesirable influence upon the performance of asphalt pavement is concerned about. In this paper, deformation characteristics of the stabilized subgrade with a short curing time are investigated by repeated loading triaxial compression tests and also from FWD measurements. As an exemplification, using these deformation characteristics, the rut depth and fatigue life of an asphalt pavement are predicted based on multi-layered elasticity theory. The results showed that the short curing time exhibited in a sudden increase in rut depth but that such large rutting was resolved by constructing a surface layer 7 days after opening for traffic, the performance being almost equivalent to that with a sufficient curing time.

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Pavement performance is evaluated based on “New Investigation on national highways” carried out by Japanese Ministry of Construction since 1989 related to pavement structures and surface conditions. Combining the performance curves and the measured FWD deflections, a new performance model is proposed taking pavement structural adequacy into consideration. The proposed model is applied on Japanese National Highway No.12, and an attempt is made to optimize pavement rehabilitation strategy using Genetic Algorithm (GA) through FWD deflection measurements and performance prediction in terms of Maintenance Control Index (MCI).

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We introduced wavelet analysis as a useful and powerful data processing method to detect specified information for road roughness especially for defects on road profile. It is clarified that space-frequency analysis is a very potent method to find the location of defects such as pothole, fault and rutting with a space frequency domain.
Furthermore, Multi-resolution analysis is applied for denoising from acceleration data at a vehicle body induced from road irregularity and a continuous wavelet transform is used to detect a self-similarity of road profile. By use of wavelet analysis, several new findings on road surface evaluation are reported in this paper.

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This paper presented fatigue strength of plain pavement concrete and roller compacted concrete with recycled aggregate. Comparative studies on the bending fatigue strength conducted with other researchers are also included. Bending fatigue strength characteristics of recycled aggregate concrete are emphasized. In the study the modified Goodman diagram is fairly well applicable for the determination of fatigue strength of recycled aggregate concrete. Weibull and the normal probability distribution functions agree well with the experimental results.

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As one of surface finishing methods of concrete pavement, exposed aggregate method with small coarse aggregate has been studied to improve surface texture and noise problem. Compared with traditional maximum size of coarse aggregate (40mm), concrete mixture with maximum size of 13mm needs more amount of cement to keep durability. Therefore, it is desirable that the concrete slab consists of two layers of different concrete mixture (upper layer (1/3): 13mm, lower layer (2/3): 40mm) for economical reason. To study effect of drying shrinkage strain caused by two layers of different concrete mixture, many type of dummy slabs were made and the strain was recorded. As a result of analysis, the drying shrinkage strain between two layers is not so large and dose not give any major damage like cracking on concrete slab.

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This paper covers the basic study on ultra-thin white topping that is also been developed in European countries and U. S. A. The aims are to find out its applicability through making mini model experiments, research on the interface shear stress under various temperature and traffic loads by FEM program. As the results, the characteristics of slab temperature and underlying existing asphalt pavement, the effects of the pavement temperature on the interface shear stress and bending stress, and fatigue damage are revealed.

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This paper describes a structral design method developed for composite pavement which consists of a continuously reinforced concrete slab (CRCS) and a asphalt surface layer. The design method is based on the fatigue analysis of CRCS. In the analysis, loading and thermal stresses in CRCS are calculated by plate FEM model. Two effects of asphalt layer are considered in the design. One is a mechanical effect which reduces the load stress in CRCS. The other is a thermal effect which reduce the temperature differential in CRCS. The former is taken into account by using the concept of equivalent thickness besed on the composite plate theory. The latter is incorporeted by intorducing a reduction factor for temperature differential in CRCS. Values of paramters required in the method were obtained from field measurements. Based on the model, the effects of design parameters on the fatigue damage were also investigated.

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Mechanical behavior of precast concrete pavement with dowel bars at joint was examined. The effects of subbase and dowel bars at joint were discussed. The theraml stresses were also calculated and discussed. Based on the results, fatigue and faulting analysis were conducted to compare the fatigue behavior and amount of faulting of precast concrete pavement slab with the normal concrete pavement slab. As the results, increasing the flexural strength of concrete and the K-value of subbase for PCCP was found to be required.

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FWD testing and backcaluculation (BC) have been proved to be useful in pavement structural evaluation. However, the greatest amounts of calculating time and engineering judgments are needed in using current BC programs. By applying regression analysis to FEM calculation results, a simple in-situ evaluation approach has been developed in this paper, which can be conveniently used to estimate the modulus of subgrade reaction and slab elastic modulus under slab interior, joint and corner FWD loading cases. Furthermore the evaluation results from several pavements are presented to investigate the validity and accuracy of the proposed procedures.

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Two aspects were included in this paper:(1) evaluating the seriousness of earthquake induced cracks;(2) identifying the effectiveness of maintenance and rehabilitation (M&R). Firstly, through a theoretical analysis of elastic three-layer pavement model, pavement deflections D45 as well as D₂₅₀ under FWD loading conditions at cracked and uncracked sections were recommended as indices to evaluate the seriousness of cracks. By means of statistical test, the structural evaluation procedure was proposed. Its validity was verified by coring tests. Then, by comparing the FWD deflections before and after M&R, the effectiveness of sealing, patching and overlay was identified.

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Backcalculation method based on the least square mean concept is widely used to identify pavement structural adequacy from FWD deflection basin. However, it is often pointed out that this kind of calculation yields unsuitable layer moduli, when a) the surface layer is extremely thin, b) modulus of surface layer is significantly larger than that of base course, or c) modulus of surface layer is almost identical to that of base course.
This study proposes a new backcalculation method based on Genetic Algorithm (GA) that determines the most suitable offset position of each sensor on such pavements. The deflection data given at the proposed positions reveals more stable solutions in calculation of layer moduli.

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Elastic modulus of asphalt mixture depends on temperature. Even though FWD test is carried out at the same point, deflection varies with temperature. Therefore, the temperature correction of deflection and elastic modulus by backcalculation is necessary to get the pavement behavior under the same temperature condition. In this study, temperature correction system with both prediction of temperature and correction of deflection in asphalt layers is developed based on the data in the test yard for FWD. After all, this system is found to be also sufficiently applicable to FWD data in site.

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Temperature profile in asphalt pavement manifests nonlinear distribution which varies with time. In the past researches, there exist two major approaches; one uses a correlation between air temperature and temperature measured in pavement, and the other considers the effect of solar radiation. However, asphalt which has a strong characteristics of absorbing and storing heat, also emit the heat to the atmosphere. Dust and waterdrop in the atmosphere also radiate heat to pavement This paper presents a general thermal flow model between pavement and its surroundings and the effect of factors involved in the model on the temperature distribution in pavement using meteorological data

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In this paper, the compression test and fabric anisotropy measurement of crushed stone for mechanical stabilization (M-25) was carried out, to estimate the influence of anisotropy on mechanical property of granular base course material. The mechanical property was evaluated from stress ratio - strain relationship from the compression test. And the fabric anisotropy was analyzed by fabric tensor from orientation fabric and twodimensional distribution of normals as factor of fabric anisotropy. As a result, the ratio of fabric tensor components by distribution of normals presented anisotropy strength of assembly, and orientation fabric of granular base course material was superior in horizontal direction.

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When evaluating rut depth of on-service asphalt pavement with surface cracks, it appears important to take into account the deterioration of base-course material due to repeated loading under water penetration through the surface cracks. This paper presents the results of the model test of repeated loading on crushed stone base-course under water penetration, and discusses the development of settlement and excess pore water pressure and also the formation of softened and deteriorated zone due to finer particles migration during repeated loading.

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The main object of this study is to establish the estimation methods of subgrade strength affected by the train loads. The displacements of the surface of sleeper and subgrade are measured by HFWD (Handy type of FWD) on the opening traffic tracks.
The spring coefficients of rail support and elastic coefficient of subgrade are estimated by the displacement measured by HFWD and calculated by limited beam model analysis or multi-layered analysis. As the spring coefficient of subgrade be calculated by the original method using these coefficients, the data of the subgrade strength can be stored up.

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The peak data on load and deflection as well as career data of time are obtained from the FWD device. In order to examine the applicability of FWD device for the base and subgrade, we have conducted the plate loading test and investigated physical properties of the soil material using RI density meter under three different kinds of soil conditions.
We have conducted the static flat plate loading test and the dynamic FWD loading test on the base course surface where the earth pressure and acceleration gauge are buried under the soil, and have realized the differences between effects on dynamic and static loading test as well as the influence of loading energy.

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To increase the service life of existing asphalt pavement, we considered the new method by compaction grouting as the construction method which the existing subgrade can be improved without replacing the pavement structure. We investigated the various influence factors on subgrade improvement effect and reinforcement effect on bearing capacity of existing asphalt pavement by FEM analysis. The following result were obtained. Placement style of the improvement column and its depth in subgarade largely affect on subgrade improvement and the service life of existing asphalt pavement can be increased longer than design life in new constructin by compaction gruoting.

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In general, pavement with many pores has better drainage. Large pores are preferable for reasons of permeability and function restorability, while numerous small pores are effective in absorbing noise. One of the best ways to satisfy both requirements at the same time would be to provide a layer with large pores that allow good drainage beneath conventional water-draining pavement. The authors propose a dual water-draining pavement which consists of a top layer of conventional water-draining pavement and a bottom layer of a specially-designed bed. The bottom bed is a plate with miniature railroad-like rails attached to it at intervals.The results of laboratory experiments show that the dual structure is superior to conventional water-draining pavement in all aspects of water permeability, noise absorption, pore clogging and restorability. The dual structure is promising for increasing the life of such functional pavement, though materials, expansion/contraction effects and durability of the bottom bed are to be studied further.

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This paper focuses on the road performance of porous asphalt pavements for noise prevention. The method to evaluate the noise reduction effect of porous asphalt is also developed by this research. From these investigations it is found that the low noise porous asphalt pavements are durable as well as the usual pavements using modified asphalt. The noise measurement using a running car which is called an RAC car reveals that it is useful to estimate the noise reduction effect of low noise porous asphalt pavements.

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This report is concerned with the mix design method for porous cement concrete which can be used for drainage surface layers compacted with rollers.
Firstly, we state the usefulness of newly developed consistency and workability evaluation tests, then proposed the rational design method for mix proportion by applying the evolution tests and devised mix model.

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When a highly aged society is expected, sidewalk pavements should be more human friendly than ever. This paper presents results of a study on relationship between physical properties and feeling of human being. A proposed formula enabled quantitative evaluation of walking comfortability of sidewalk pavements, based on hardness, skid resistance and roughness, measured by objective methods.

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Blocks have largely taken the place of asphalt as a material of pavement. With various types of its shape and surface finish, blocks have an advantage over asphalt in the improvement of road's appearance. On the other hand, blocks do not always present an advantage in walkability since pedestrians sometimes stumble or twist on joints of blocks. In this study, we interviewed pedestrians on walking condition and their feelings about different materials and types of joint. As a result, the relation between pedestrian's walkability and joints of block pavement was clarified and we would suggest that the joint should be designed and maintained more carefully than ever.

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Recently the sidewalk space is regard as comfortable area for city life, and it is required to establish the test method for the evaluation of safety and amenity. For keeping the safety of walk, the slip of pavement materials is the important factor There were some machines for measurement of slip-resistance, but they were not enough for the evaluation of sidewalk pavement.
In this paper, the development of new machine for sidewalk pavement materials which was based on the DF-Tester, and the evaluation test results were reported. The new machine was able to measure the coefficient of static and dynamic friction of side walk pavement. From these two parameters, it is able to evaluate the slip-resistance and the surface texture of pavement. From the test results, the coefficient of friction was not affected by the surface temperature of the pavement materials.
Finally, it was found that the value of coefficient of static friction for keeping the safety of sidewalk pavement is greater than 0.5.

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Low temperature cracking is a significant failure of asphalt pavements in cold regions, which is mainly depended on asphalt characteristics. Using the sandwich sliding plate viscometer developed in this study, the low temperature viscosity of seven kinds of currently used asphalt is evaluated. By comparison with he conventional evaluation method, for example, Fraass breaking point test and low temperature ductility test, the more distinct mechanistic model and precise measurements of the sliding plate viscometer have been demonstrated. Meanwhile, the influence of bitumen viscosity on asphalt mixture viscosity is also investigated.

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As for this study, when using ethylen ethyl acrylate as improvement material, it is plemented one how composition of ethylen ethyl acrylate and property influence the property of asphalt and hot asphalt mixtures.
In case of examinaition, as composition and property of ethylen ethyl acrylate, it took up ethyl acrylate containing quality, melt index and dgrees of that the graft polymerizing was done.
As a result, the compotision of ethylen ethyl acrylate which suited of hot asphslt mixtures and asphalt and property became clear, and it confirmed apply ability to asphalt pavement.

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In this paper, it was experimented on the wheel tracking test and triaxial test in order to make new basic theory of rutting. Wheel tracking test was achieved by changing thickness of pavement. It was found to be maximum thickness of pavement to bring the minimum deformation. It was found to the range of similarities to wheel tracking test in Triaxial test. It was determined by the intercept f0 and increment mo making the relationship between maximum deviator stress and confining pressure.

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In case of analyzing mechanical behavior of asphalt mixture by means of distinct element method (DEM), element assembly should be regarded as an equivalent mixture model. It means that individual element does not express each aggregate particle. At the point of view, element packing, which decides initial location and radius of each particle element, is puzzling procedure as an necessary preparation for calculation. In this paper, numerical simulations of triaxial compression test were carried out using various typical packing ways, and characteristics of element packing were proved. Applicability of these packing ways was discussed by comparing with results of asphalt mixture testing. From the comparison, it was shown that appropriate packing way should be selected according to the analyzed problem, since calculation result is deeply depend on initial packing model.

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With the 21th century coming soon, the environmental conservation in global size becomes increasingly important, therefore it is required to promote saving-energy, saving-resources and repression of global warming. Considering this situation, we have developed a new technology by introducing the concept which is the mitigation of temperature conditions for hot asphalt mixture generally used, in both of production and execution. This technology is effective to reduce the amount of carbon dioxide made in process of asphalt paving, and to improve recycle technique in field of pavement engineering. As the results, it is confirmed that the new technology is applicable to various purposes in environmental conservation.

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The depression of the freezing point is achieved when powder-type chloride compounds contained in asphalt pavements dissolve on ice-covered pavements. Since the use of studded tire was prohibited in Japan in 1985, countless experiments were undertaken to test deicing pavements in winter to ensure traffic safety below the freezing point. The rapid decrease of the deicing capacity of a certain number of deicing pavements, as well as the short lasting deicing properties were met with skepticism.
In the present study, the improvement of long lasting deicing properties are discussed in detail. Furthermore, means of evaluation of deicing pavements are also part of the discussion.

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It is strongly required to establish an urgent repair system for earthquake induced damages such as cracks, faults and potholes in airport asphalt pavements. This paper discusses both the buildup of the system framework and the selection of materials as its first part. First, the framework was developed. Then, based on this, the possible materials were preliminary selected, and finally the materials suitable for the system were decided. As a result, the following conclusions were obtained:(1) As a material for repairing faults and potholes, hot mixed asphalt material with pulverized asphalt, cold mixed polymer material is applicable to major airports, local airports, respectively.(2) Cold asphalt material is appropriate for sealing cracks.

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