Showing papers in "JOURNAL OF PAVEMENT ENGINEERING, JSCE in 1999"
TL;DR: In this paper, a structural evaluation method of airport concrete pavements using FWD with 200kN is described, which consists of two phases; one is to estimate both elastic coefficient of concrete and coefficient of subgrade reaction based on measured deflections at slab center, and the other is to evaluate structural integrity, load transfer effectiveness and voids underneath slab, based on the deflection at joints and cracks.
Abstract: Nondestructive structural evaluation method of airport concrete pavements using FWD with 200kN is described. The method consists of two phases; one is to estimate both elastic coefficient of concrete and coefficient of subgrade reaction based on measured deflections at slab center, and the other is to evaluate structural integrity, load transfer effectiveness and voids underneath slab, based on the deflections at joints and cracks. In the process of this development, deflections measured at various airport pavements in service and some experimental pavements have been analyzed, and then practical criteria are described after comparing with the current procedure.
2 citations
2 citations
TL;DR: In this paper, a condition survey was conducted to investigate surface condition of pavement on steel plate deck of bridge and the results of the survey showed that main distress mode of the pavement are longitudinal cracks which occur at web of longitudinal rib as well as at the position between the webs.
Abstract: A condition survey was conducted to investigate surface condition of pavement on steel plate deck of bridge. The results of the survey showed that main distress mode of the pavement are longitudinal cracks which occur at web of longitudinal rib as well as at the position between the webs. To make clear the causes of the crack, we performed strain analysis using overlaid FSM. The strain analysis indicated that, although large tensile strains appeared in the pavement at the web of rib, the strains between the webs were basically compressive. These results can not explain the cracks between the webs. Laboratory experiment modeling the pavement on plate deck was conducted and the results indicated the possibility of occurrence of the cracks by repetition of compressive strain.
2 citations
TL;DR: In this paper, the authors have analyzed the relationship between MPD by CTM and MTD by Sand Patch Test and measured the coefficient of friction with D. F. Tester at the same spots as that the texture was measured by the CTM.
Abstract: The Circular Texture Meter (CTM) recently developed is a device which has a CCD Laser Displacement Sensor mounted on an aim designed to rotate on a circumference of 142 mm radius. The CTM can measure the texture with about 0.9 mm pitch on the same circumference of that coefficient of friction is measured with a D. F. Tester.In this study, we have analyzed the relationship between MPD by CTM and MTD by Sand Patch Test. Also, we have measured the coefficient of friction with D. F. Tester at the same spots as that the texture was measured by the CTM.We have observed a good correlation between the MPD by CTM and the MTD by the Sand Patch Test. And it is found that International Friction Index can be computed from the CTM measurements and the D. F. Tester measurements.
1 citations
TL;DR: In this article, Zhao et al. showed that the bonding can be obtained through a suitable selection of bonding material and an adoption of appropriate surface treatments on the existing layer of a pavement.
Abstract: Pavement using porous concrete is expected to be a promising technique with high drainage capability and low-tire/road noise property, because of its high porosity. In case porous concrete is applied to a rehabilitation technique of an existing pavement, thin bonded overlay on both ordinary jointed concrete pavements and asphalt pavements is thought to be a practical method, because most of the rehabilitation job does not allow the high raise of formation. In this technique, the bonding is the important key to success; therefore fundamental experiments and the following fields test regarding bonding were executed. In conclusions, bonding can be got through a suitable selection of bonding material and an adoption of appropriate surface treatments on the existing layer. In addition, full-depth porous concrete construction method is applicable to the thin bonded rehabilitation only with applying the bonding material in advance.
TL;DR: In this paper, the measured deflection becomes smaller year by year, and the back-calculated modulus of the asphalt layer is larger as the years go by, the calculated cumulative traffic passes to the failure tend to be bigger and the fatigue crack is more critical, as the asphalt itself becomes harder due to ultra violet and other aging factors.
Abstract: FWD tests have been carried out for these four years at the testpit, whose bearing capacity was designed for D traffic. The measured deflection basins were statically back-calculated and failure analysis was performed by Asphalt Institute's formula. From the measured deflection and the back-calculated layer moduli, and furthermore, the calculated cumulative traffic passes to the failure by fatigue crack and rutting, the following results were obtained, 1) the measured deflection becomes smaller year by year, 2) the back-calculated modulus of the asphalt layer is larger as the years go by, 3) the calculated cumulative traffic passes to the failure tend to be bigger and the fatigue crack is more critical, as the asphalt itself becomes harder due to ultra-violet and other aging factors.
TL;DR: In this paper, the authors applied the theory of a beam on Winkler foundation to investigate the stress analysis procedure of pavement slabs and investigated the model of composite structure that consists of a thin cement concrete layer and an existing asphalt pavement layer, taking the degree of bond between these two layers into consideration.
Abstract: There is a method to place thin cement concrete overlay on an asphalt concrete pavement as one of the rehabilitation methods for improving an existing asphalt pavement. However this method doesn't become popular at present. In this research, to begin with, applying the theory of a beam on Winkler foundation, we will investigate the stress analysis procedure of pavement slabs. Next, we will investigate the model of composite structure that consists of a thin cement concrete layer and an existing asphalt pavement layer, taking the degree of bond between these two layers into consideration. As the result of measurement of strain at the bottom of a thin cement concrete overlay, we confirmed usefulness of this calculation method.
TL;DR: In this article, a field observation was continued to estimate the thermal radiation from asphalt pavement, the surface temperature, solar radiation, infrared radiation, temperature, humidity, wind velocity and precipitation were observed for a period of about 8 months including summer and winter.
Abstract: The field observation was continued to estimate the thermal radiation from asphalt pavement. The surface temperature, solar radiation, infrared radiation, temperature, humidity, wind velocity and precipitation were observed for a period of about 8 months including summer and winter. Surface temperature, solar radiation and infrared radiation measured were compared with that of calculated using multiple regression analysis equations, surface temperature and the radiations were estimated within 5°C and 50W/m2. The equations are able to estimate the total heat flux (=infrared radiation + reflected solar radiation + sensible heat transportation) from pavement surface and showed a good correlation with the measured.
TL;DR: In this paper, an element model of the Finite Element Method based on the structure and acoustical properties of porous pavement is proposed for calculating sound propagation on porous pavement, and it is shown that this model gives a good fitting to measured acoustic properties.
Abstract: The acoustical properties and model of porous pavement is discussed in this study. The acoustical properties of porous pavement are quite different from that of the sound absorbing material such as glass wool and urethane foam because of the structure. The acoustical model, acoustic impedance model, used for the sound absorbing material is not suitable for porous pavement. The acoustic model for calculation of sound propagation on porous pavement is newly developed in this study. This acoustic model is the element model of the Finite Element Method based on the structure and acoustical properties of porous pavement. It is shown that this model gives a good fitting to measured acoustical properties and applicable to calculate sound propagation on porous pavement.
TL;DR: In this article, road profiling by a high-speed profilometer is conducted over the expressways in Japan and the evaluation of road evenness is established using the roughness indicators such as IRI and RN.
Abstract: The purpose of this study is to contribute making a technical guideline for the road administrators who are responsible for user s needs. In this study, road profiling by a high-speed profilometer is conducted over the expressways in Japan and the evaluation of road evenness is established using the roughness indicators such as IRI and RN. Furthermore, we studied the subjective evaluation of ride quality by means of a rating panel for the expressways. Finally, the dynamic behavior of the vehicle on the rutted road is examined by the lane change test experimentally and by use of a dynamic simulation model of the vehicle theoretically.
TL;DR: Selecting three layer pavement as an example structure, artificial neural network is trained to acquire knowledge on relationship among layer modulus, layer thickness and surface deflections and the system constructed in this manner is verified.
Abstract: Structural evaluation of pavement has been conducted from a set of surface deflections measured by a fallingweight deflectometer (FWD). However, because a backcalculation requires repetitive computation, layer modulican not be estimated instantaneously after FWD tests. This study aims to overcome this shortcoming.Selecting three layer pavement as an example structure, artificial neural network is trained to acquireknowledge on relationship among layer modulus, layer thickness and surface deflections. The systemconstructed in this manner is verified by applying the system to FWD test data and by comparing the systemgenerated layer moduli with those obtained from backcalculation.
TL;DR: In this paper, a structural model for pavement on steel plate deck is presented to analyse the local deformation of pavement, particularly with low stiffness, and the validity of the model is verified with numerical examples and comparisons with the experimental results obtained on an actual pavement on a steel plate board.
Abstract: The structural model for pavements on steel plate deck should be able to deal with structure of the steel plate deck as well as pavement structure. This paper presents a structural model using the strip element and prism element. In this model, the steel plate deck is modeled by the strip element and the pavement is divided with the prism element. The strip element and the prism element are connected with a link element. This model is able to analyse the local deformation of pavement, particularly with low stiffness. The validity of the model was verified with numerical examples and comparisons with the experimental results obtained on an actual pavement on a steel plate deck.
TL;DR: In this article, the authors described properties of SHRP LTPP deflections using FWD and investigated the dispersion and variable of deflection data, and proposed a simplified deflection-based flexible pavement design procedure.
Abstract: This paper describes properties of SHRP LTPP deflections using FWD and investigates the dispersion and variable of deflection data. From the results of the analysis, it was found thatdeflections collected from test section showed normal distribution and sensor 1 deflection was increased with time gradually.Furthermore, a simplified deflection-based flexible pavement design procedure was proposed.
TL;DR: In this article, the sound propagation over the porous pavement surface is discussed and the sound reduction while propagating over the pavement surface, called excess attenuation, is evaluated and found out the effect of porosity, thickness and aggregate size.
Abstract: The sound propagation over the porous pavement surface is discussed in this study. The sound propagation over the porous pavement is calculated by the finite element method (FEM) using the acoustical model of the porous pavement. The sound reduction while propagating over the porous pavement surface, called excess attenuation, is evaluated and found out the effect of porosity, thickness and aggregate size. Since the measured sound reduction of the porous pavement commonly used in Japan is 3 to 5 dB and the calculated attenuation value is around 1dB, the sound reduction effect of the porous pavement is mostly depend on the sound gen rating mechanism between the tire and the porous pavement surface.