Recently, even in asphaltpavement, itisanxiousabout securingofthequality in executionunder the specialcondition because of labor aging, decrease of skilled labors, etc. This study, based on sucha background, proposes the asphalt concrete plate for the roadway that aimed at saving labor and standardization, in addition to making up for the decline of technical skills in the execution site. As a concreteobject, self-propelledparkinglotisselected, the various investigations, an experiment from the decision ofthe specification to manufacturing method are attempted, and effective compaction method, a means of in stallation, etc. areexamined.

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Civil materials are expected to be one of major application targets for coal ash recycling. Previous attempts to use coal ash for such as road base materials and soil improvement materials, where coal ashis solidified with lime or cement in an ambient temperature, are not fully satisfactory. In this study, a novel process, where powdery coal ash is solidified with lime and gypsum in a hot saturated steamatmosphere, and the solidified coal ash is crushed to macadam, is proposed. The evaluation by a testing reveals the satisfactory usability of the solidified macadam.

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In this study, measuring method for the surface displacement of the rubber-chip board due to vehicle loads throgh vehicle tires is discussed in order to examine the relative protrusion height of the spikes. The measureing results by the method of pin-displacement showed good reappear-ability ones. In addition, numerical simulation are carried out using FEM code MARC and some reasonable results were found.

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When a recycling additive is used in large-scale construction, characteristics of the additive have to be cleared. In this paper, the influences of additive on mix design and mixture characteristics of the recycled asphalt mixture are investigated from the view point of the ingredients. Through the procedure of mix design and bending test for aged and new mixture, following results are obtained ; a required quantity of recycling additive greatly depends on ingredients of the additive, and the ingredients of an additive affect the mixture characteristics of recycled asphalt, when the binder penetration of recycled asphalt is adjusted as the same value as that of plain mixture binder recovered from the mixture of production right after.

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The studies made so far on the top-coat system with MMA type resin for porous asphalt have proven the effect of the system on improvement of permeability of porous asphalt and its capability for reducing deposition blocking up the voids. This effectiveness simply attributed to the difference of tackiness between asphalt binder and MMA type resin. However it was hypothesized that this effect would be developed by the difference in surface free energy (γs) between top-coat materials and asphalt binders. Therefore some porous mixes were prepared using different binders having differentγs values, then the changes in permeability were measured by repeatedly filling the voids with slurry, and the effects ofγs of the binder were examined.

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Based on the use of a bandonedtires, construction material designed for implementation in upper layers of pedestrian oriented pavements as well as of pavements found in athleticfacilities, is currently being used in a limited range. Recycling of such material is therefore is strongly justified in the future. The authors have considered properties such as elasticity, shock absorption and weather resistivity, and have considered examining an elastic rubber chip mixture composed of polyurethane resin, rubber chips and silica sand for use in vehicle pavements. As a result, findings show that travel safety, as well as durability of these pavements do not significantly differ compared with traditional pavements. Moreover, it has been determined that rubber chip pavements effectively reducevehicl enoise.

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Permeable asphalt pavements, which infiltrates rain water to the subgrade is expected to insure preservation of water circulation as well as safety and comfortability of vehicle operation and pedestrian. Until now, application of permeableasphaltpavements has been limitedtoplaceslikesidewalksand parking areas, where traffic conditions are less severe compared to the roadway, which is generally not yet covered. This study performed and examined tests on the application ofpermeableasphaltpavements to heavy traffic road. Results from FWD deflection tests and dynamic plate bearing tests on subgrade sand base showed that the pavement system could assureits structural durability after repetitive dumpt ruck loading.

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The Marshall stability test has been used in Japan as the mix design method for hot mix asphalt since 1961 when this method was adopted in the ‘Manual for Asphalt Pavement’ . Recently, this method has been considered to be an emprical one that can especially design a durable mixture which is rut resistant. We, therefore, propose a rational mix design method whose procedure is to calculate the voids in mineral aggregate from the aggregate gradation then add the necessary asphalt content to get an appropriate air voids ratio of the mixture. The required material properties are checked in both this calculation and in the actual compacted specimens.

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Through a series of experiment in laboratory, this paper mainly clarifies the effects of the factors such as maximum stress level, minimum stress level, loading frequency and rest period on the fatigue life of concrete for airport pavement, and analyzes the failure probability due to flexural fatigue under different stress level. As a result, it is found that under high stress level, namely the maximum stress level is equal to or greater than 80%, the minimum stress level has no clear influence on the fatigue life of concrete, but when the maximum stress level is 70% its effect can not be ignored. Accordingly, the flexural fatigue equation of concrete for airport pavement, considering the minimum stress level, is derived.

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Mechanical properties of cement treated asphalt mixtures (CTAM), which are applicable to rehabilitating airport asphalt pavements, are investigated in laboratory tests. As a result, the following items are found: 200mm thick construction of CTAM with curing period of two hours is possible when asphalt mixture with modified asphalt, of which air void is 25%, is used. The coefficient of elasticity of CTAM in repeated loading tests decreases with an increase of strain amplitude and with a decrease of loadingfrequency.

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To evaluate the behavior of asphalt pavement in high temperature based on deflection just like FWD a repeated plateloading test was carried out on relatively-large scaled model asphalt pavements with 4 different sections under three different temperatures conditions, as immediately after construction, normal temperature and 60°C. As a result, a large deflection near the loading plate took place for the temperature condition of immediately after construction. But as temperature goes down, the deflection decreases near the loading plate and a bit increases away from the loading plate due to rejuvenation of the stiffness, as load transmissibility of asphalt mix layer accompanied with temperature decrease. From the back-analysis of measured deflection, a tendency was observed that the elastic modulus asphalt mix layer decreased with its average temperature and that the estimated values of elastic modulus werea bit larger than those of past studies at a relatively high temperature. It was also indicated that there was a room for research and investigation on the back-analysis method and interpretation of the test results on ground that the modified asphalt mix layer was a bit more sensitive to temperature thanthe straight one exhibiting a bit lower elastic modulus at a relatively high temperature, which seem to contradict the reality.

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[in Japanese]

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There is a need for further porous asphalt concrete advancement following its wide development. In the application to the snow cold district, its wearing resistance characteristic has become an important subject. At present, after the usualmix designtests, ravelling test byusing chains is performedinorder to confirm durability of porous asphalt concrete when applied to areas that may be worn by tire chains. This report presents all the ravelling test results and mix designs that have sofarbeendonea swellas the irrelationship. Furthermore, since the desirableaggregatest obeused and the trend of them ixdesign were established, they are al so reported.

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The purpose of this study is to contribute making a technical guideline for road administrators who are responsible for user's needs. This study consists of two parts. In the first part, calculation of IRI from longitudinal profile measurement on the four site of expressways and the driving comfort evaluated by users were carried out, then an equation of relationships between the IRI and user evaluation were obtained. In the second part, we developed a three-degree-of-freedom mathematical model of a vehicle. It is shown that the simulation method of the vehicle enable us to find an influence of the vehicle speed, lane change distance and rut depth on the parameter regarding the control and stability such as lateral acceleration of the vehicle synthetically.

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A program package for analysis of concrete pavement based on 3 dimensional finite element method (pave3d) was developed. In the structural model of pave3d, concrete slab, base course and subgrade are divided into solid elements with 8 nodes and interface between the concrete slab and the base course or joint is modeled by a interface element which has originally been developed in this study. The validity of this model was verified by comparing the computed results with the results by a multi elastic layer program and the experimental data. Furthermore, the stress states in the base courese due to curling of the concrete slab were also analysed.

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Development of AAMES (Axi-symmetric Analysis of Multi-layered Elastic System) is presented, which can evaluate displacements, stresses and strains in pavement structures caused by surface loading from a closed form solution based on Hankel transformation along with Michell displacement function. A shear spring is utilized to model an interface slip between two adjacent layers. AAMES can handle up to ten layers with varying interface conditions and a maximum of 30 loads. Semi-infinite integration involved in the inverse Hankel transformation, which is found a major cause of error near surface, is carefullyexamined to improve accuracy of results. The accuracy is confirmed through identical response data using BISAR.

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In block pavement for roadways, only a block type with a size of 10×20cm is usually used. However, block dimension and shape should be determined in terms of structural integrity and improvement of environmental scenery of road. The aim of this study is to examine the applicability of relatively large size blocks to roadway pavements based on the experimental results obtained by using a traffic load simulator which simulates moving wheel on pavement. In this study, the effects of size and thickness of block and type of base course on deflection and stress of pavement were investigated. Furthermore, the experimental results were confirmed by simulations using a finite element model.

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Mechanical behaviors of bonding between concrete and asphalt layers and the mechanical parameters of the asphalt are important for the analysis of whitetopping. In this study, we constructed the whitetopping, conducted loading test and measured the strains in the concrete and asphalt layers. Through comparing the measured and analyzed strains, we obtained the spring coefficient of the element between the concrete and asphalt layers and the elastic moduli of the asphalt layers. The results show that the spring coefficient is different for each position of the slab and the elastic moduli of asphalt layers are almost the same as those computed by McLeod's nomograph. As the results, the mechanical parametersin the analytical model have been proposed.

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Since 1987, theLTPP (Long Term PavementPerformance ) program had been implemented in theUSaspartofthe SHRP (Strategic Highway Research Program ). After the termination of the SHRP in 1992, the FHWA (Federal Highway Administration) continued the research and collection of data on the LTPP program, as this program isa 20-year-term plan. This report focuses on the rutting of asphalt pavement, as recorded on the DATA PAVE97compiling achievements obtained by the FHWA during this program - and presents results of study regarding the real status of rutting and relevant factors.

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