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Research Concerning The Distribution of Temperature in Asphalt Mixtures with The Help of Thermo-Physical Characteristics for Laboratory Tests

asphalt concrete. J Mater Civ Eng 2005;17:72-9. [5]. Spalding DB. Pun WM.- A review of methods for predicting heat transfer coefficients for laminar uniform property boundary layer flow. Int J Heat Mass Transfer 1999;5:239-49 [6]. Zhao J. Ai X. Li YZ. - Transient temperature fields in functionally graded materials with different shapes under convective boundary conditions. Heat Mass Transfer 2007;43:1227-32. [7]. Xu Q. Solaimanian M. - Measurement and evaluation of asphalt concrete thermal expansion and contraction. J Test

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Influence of high temperatures on technical state of streets and roads structures with asphalt surfacing

Abstract

In this paper will be presented the influence of high temperatures on asphalt street pavement in terms of the influence of temperature on permanent deformations and thus the technical condition of the streets, comparable to the effects induced on extra-urban roads.

Environmental factors are one of the mayn factors being assaulted in operation and road structures are very important in terms of the influence they can have on the state road transport technical infrastructure.

Will be presented differences between urban road structures (streets) and extra-urban (road) both in terms of construction, the demands of traffic and environmental conditions to which they are subject.

Road structures extra-urban and urban areas are required differently in terms of the environmental conditions of the location ambient different thereof, that is, when the streets they are inside localities and the built environment significantly affect road infrastructure, unlike in the case of roads where they are located just outside the settlements, reducing the effect of air currents accumulation pavement surface temperature.

To demonstrate the influence of high temperatures on the pavement were conducted laboratory tests on asphalt mixtures in order to demonstrate the occurrence of reduction of physical characteristics, with adverse implications on the performance of applications similar to traffic.

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Comparative Study Between Experimental Results and the Numerical One of the Lateral Buckling Resistence for the Two Curved I Girders of a Curved Bridge Model

Rezumat

Articolul prezintă un studiul al rezistenţei la flambaj lateral pentru grinzile curbe utilizate la poduri.

Rezistenţa la flambaj lateral va fi evaluată printr-o analiză geometric şi fizic neliniară utilizând programul de calcul Lusas®, fară a considera imperfecţiunile de execuţie. Pentru a da veridicitate rezultatelor analitice, studiul numeric se va realiza pe unul din modelele fizice prezentate în lucrarea [1] care pune la dispoziţie valori ale încercărilor experimentale.

Geometria modelului fizic din lucrarea [1] se bazează pe o analiză dimensională a grinzilor curbe „I” utilizate în mod frecvent la poduri. Modelul fizic este alcătuit din două grinzi I curbe, dublu simetrice, prevăzute cu antretoaze şi contravântuiri la nivelul tălpilor. De antretoazele de capăt sunt sudate pe direcţia axei curbe două console scurte de lungime e .

Schema statică a structurii este grinda simplu rezemată cu console, ale cărei aparate de reazem sunt dispuse pe direcţia coardei. Consolele scurte vor fi încărcate cu prese hidraulice la o forţă P care are ca efect în grinda principală un moment încovoietor uniform având valoarea P *e şi forţă tăietoare zero.

Pentru analiza neliniară s-a folosit formularea Total Lagrange, împreună cu utilizarea metodei lungimii arcului modificat formulată de Crisfield. De asemenea s-a considerat comportarea neliniară a materialului.

Evaluarea rezistenţei la flambaj lateral constă în determinarea momentului încovoietor critic pentru care grinda îşi pierde stabilitatea. Comparaţia rezultatelor numerice cu cele experimentale preluate, confirmă posibilitatea evaluării numerice a rezistenţei la flambaj lateral pentru grinzile curbe.

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Ecological Solutions Applied to Hot Mix Asphalt

, preparation and implementation work. (Revised AND 605-2013); [9]. SR EN 13108-1 Bituminous mixtures. Material specifications. Part 1: Asphalt Concrete; [10]. SR EN 933-1 Tests for geometrical proprieties of aggregates. Part 1: Determination of particle size distribution - sieving method; [11]. SR EN 12697-12 Bituminous mixtures. Test methods for hot mix asphalt. Part 12: Determination of the water sensitivity of specimen; [12]. SR EN 12697-23 Bituminous mixtures. Test methods for hot mix asphalt. Part 23

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Influence of Hydrated Lime on the Properties and Permanent Deformation of the Asphalt Concrete Layers in Pavement

Mixes”, in SPT 1147 Effects of Aggregates and Mineral Fillers on Asphalt Mixtures Performance, ed. By R. C. Meininger, ASTM, Philadelphia PA, 107-130. 1992. [7]. ASTM, “Road and Paving Materials, Annual Book of ASTM Standards, Volume 04.03”, American Society for Testing and Materials, West Conshohocken, USA. 2004. [8]. BAIG, M. G., “Laboratory Evaluation of Hedmanite and Lime Modified Asphalt Concrete Mixes”, M.Sc. Thesis, Civil Engineering, King Fahd University of Petroleum & Minerals, Dhahran, Saudi Arabia. 1995. [9

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