Tire/road noise, texture, and vertical accelerations: Surface assessment of an urban road

Pavements are made up of several layers with different mechanical and functional characteristics. The correct design of the surface layerof a roadmay leadto pavements with bettercharacteristics regarding ride qualityand safety, but also pavements that may be used as a measure against noise.The use oflow-noise pavements maybe aneffective measure to reduce the generation of acoustic pollutionby roadtraffic.This work aims to assesssome functionalcharacteristicsof a rehabilitated urban street,after two months in service conditions.The pavement was fabricated with a gap-graded bituminous mixture type Stone Mastic Asphalt(SMA) with crumb rubber(CR)from end-of-life (EOL) tires.This work studies the acoustic performance of the pavement, as well as other surface characteristics such as the macrotexturedepth(MPD)and the unevenness(IRI), establishing the relationship between them and the tire/road noise at different frequencies.Finally, the mainvertical acceleration frequencies of the pavement/vehiclesystemat 50 km/h were also assessedand related to the pavement unevennessand conservation.According to the results, this mixture might be used as a noise mitigation measure within the Action Plans of some urban areas with problems related to noise. The macrotexturedepthofthe mixture contributes to its acoustic performance at low frequencies;however, its acoustic performance cannot be totally explained from a macrotexture point of vie

Impact of the Use of Crumb Rubber Modified Binder on Tire/Road Noise Generation

The recycling of waste material produced by human activity is one of the challenges of our generation. One of the most serious environmental problems of the recent years is mass production of tire and the diculty of disposing of them. The material and energetic valorization of the wasted tires is possible through the extension of green roads. The incorporation of crumb rubber from wasted tires in bi- tuminous binders allows the design of new asphalt pavements with a higher viscosity. A preliminary study to determine the impact of the use of crumb rubber modied bituminous binder in the sound generation level for a thin layer type BBTM11A, has been carried out by the LA2IC. These results are compared with sound level from a BBTM11A with a conventional binder. This work presents the acoustical characterization performed on the regional road CM-3102 in Ciudad Real (Castilla- La Mancha), based on the close proximity methodology (Tiresonic Mk4-LA2IC ). In addition, mea- surements of supercial macrotexture prole have been realized with the LaserDynamicPG-LA2IC to study the relationship with close proximity road noise. Furthermore, sound absorption measurements of BBTM11A compacted samples have been analyzed to understand the mechanisms involved in the sound generation. The results show that addition of crumb rubber by the wet process leads, in this case (20% crumb rubber content), to a decrease in the sound level emitted by the interaction between tire and road surface, at low frequency by muing the vibrations and by sounf absorption at high frequency

Pavement temperature influence on close proximity tire/road noise

The aim of this work is to analyze the influence of the surface temperature on the acoustical behaviour of a semidense asphalt pavement located in an urban area. The sound levels emitted by the interaction between a reference tire and the asphalt pavement at different surface temperatures were measured with the trailer Tiresonic Mk4 LA2IC-UCLM rolling at a speed of 50 km/h. The analysis of the results shows that increasing pavement temperature leads to a reduction in the close proximity sound levels assessed at a rate of 0.06 dB(A)/°C. Moreover, spectral analysis confirms that both the mechanisms associated with vibration and impacts and those related to the friction and adhesion between tire and pavement in the contact patch could be affected by the variation of the surface temperature

INFLUENCIA DE LA MACROTEXTURA DE UNA CAPA DE RODADURA DELGADA EN LA EMISIÓN SONORA

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capitulo 7: Elaboracion de un mapa de ruido

For the production of strategic noise maps and noise actions plans, as required by the European Noise Directive 49 CE/2002 and the Spanish Ley del Ruido (2003), improved assessment methods for environmental noise will be 2 required. LA IC (Laboratorio de Acústica Aplicada a la Ingeniería Civil), Dpto. Física Aplicada, E.T.S.I. Caminos, Canales y Puertos has trained hundreds of public and private sector employers on evaluation and control of environmental noise, and on preparation of strategic noise maps. On the other hands, the introduction of environmental noise control course in the Castilla-La Mancha University (E.T.S.I. Caminos) with a postgraduate character will provide improved knowledge for the assessment of noise impacts from roads, railways and industry to the civil engineers