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This paper examines the effect of tire footprint and contact stress distribution under various combinations of tire pressures and tire loads on the pavement response through 3-D finite element static analysis with linear elastic material model. Analyzed footprints include a field-measured footprint and two cases of simplified ones. Our results indicate that factors including tire load, the distribution of contact stress, and the shape of footprint will affect the tensile strains at the bottom of the asphalt concrete layer as well as the compressive strains on the top of the subgrade. However, the compressive strains on the top of the subgrade are more sensitive to tire load than the shape of footprint. The research demonstrated that pavement response analysis could be carried out using field-measured footprints instead of the simplified approximations. Reduced tire pressure was effective in reducing the tensile strains at the bottom of asphalt concrete layer, but did not decrease significantly the compressive strains at the top of the subgrade. Key words: tire-pavement contact stress, tire footprint, tire pressure, pavement response, asphalt concrete pavement, strain, finite element analysis. Le present article etudie l'effet de l'empreinte des pneus et de la distribution de la contrainte de contact selon diverses combinaisons de pressions et de charges de pneus sur la reponse de la chaussee au moyen d'une analyse statique tridimensionnelle par elements finis selon une modelisation elastique lineaire du materiau. Les empreintes analysees comprennent une empreinte mesuree sur le terrain et deux cas d'empreintes simplifiees. Nos resultats indiquent que les facteurs telles la charge du pneu, la distribution de la contrainte de contact et la forme de l'empreinte auront un effet sur la contrainte de tension au bas de la couche de beton bitumineux et sur les contraintes de deformation sur le dessus de la couche de fondation. Toutefois, les contraintes de deformation sur le dessus de la couche de fondation sont plus sensibles a la charge du pneu qu'a la forme de l'empreinte. La recherche a demontre que l'analyse de la reponse de la chaussee pourrait etre realisee en utilisant des empreintes mesurees sur le terrain plutot que des approximations simplifiees. Une pression de pneu reduite a permis de reduire les contraintes de tension au bas de la couche de beton bitumineux, mais n'a pas reduit de maniere significative les contraintes de deformation sur le dessus de la couche de fondation. [Traduit par la Redaction] Mots-cles : contrainte de contact pneu-chaussee, empreinte de pneus, pression de pneu, reponse de la chaussee, chaussee en beton bitumineux, contrainte, analyse par elements finis., 1. Introduction The critical pavement damage mechanisms in flexible pavements are fatigue cracking in the asphalt concrete (AC) layer and rutting in the subgrade (Huang 1993). Fatigue cracking develops in [...]

Pavement surface texture is critical to tire/pavement interaction. Texture characteristics of concrete containing nanosilica pavement surface has not yet been directly investigated, although researchers have found that nanosilica improved pavement friction values and durability. Specimens with various nanosilica content are tested for three-dimensional (3D) texture height maps which are decomposed using discrete wavelet transform for the calculation of 3D texture indices for macrotexture and microtexture. It is found that 3D texture indices increase correspondingly with the increment of nanosilica content. Significant relationship with R 2 values between 0.80 and 0.99 is found between various texture indices and nanosilica content. The increased texture amplitude indicates enhanced pavement friction and then safety. The increment of core material volume implies more texture in the core region, which indicates better longevity of texture. The findings of this research agree with the results of other studies that nanosilica increased the abrasion resistance and frictional property of concrete surface. [ABSTRACT FROM AUTHOR]

The objectives of this research were to characterise concrete pavement surface texture using three-dimensional (3D) surface texture indicators, to explore the relationship between pavement noise/friction and texture parameters. A newly constructed Portland cement concrete pavement with 13 types of textures was selected as test site. Pavement texture heights were recovered using photometric stereo technique. A comparative study was conducted between proposed 3D texture parameters and other established two-dimensional texture measurements, i.e. the circular track meter and the high-speed texture profiler. Correlation analysis between 3D texture parameters and noise/friction data were also carried out to explore relationship between pavement texture and noise/friction. In addition to texture amplitude, the direction and distribution of pavement texture have strong impacts on pavement noise and friction. It is possible to have a better understanding of surface texture and pavement noise/friction using combinations of the proposed 3D texture parameters. [ABSTRACT FROM PUBLISHER]