“Computational Civil Engineering - "Intersections" International Journal

176 E. Diaconu, C. RăcănelTo have the OSSR values for wearing course mixture it is necessary to make alaboratory analysis in the beginning and then a computational analysis.Table 1. Intrinsically characteristics of asphalt mixturesMixtureLoading rate,φ,c,mm/minoMPaBA16-A in wearing course 0.46 45 o 51’49” 0.061290.46 46 o 38’10” 0.07258BA16-B in wearing course12.5 47 o 33’3” 0.1949650.0 46 o 50’22” 1.76843MASF16-A in wearing course 0.46 47 o 31’53” 0.15389MASF16-B in wearing course0.46 48 o 57’4” 0.1885912.5 48 o 57’4” 0.29014The laboratory analysis consists in static triaxial tests performed on cylindricalsamples (Φ = 70 mm and h = 140 mm) made by the following asphalt mixtures:BA16 asphalt concrete and MASF16 asphalt mixture with fiber, with 16 mmmaximum size, both for wearing course, containing ESSO asphalt binder, D 50/70pen (noted by A) and Suplacu de Barcau asphalt binder, D 60/80 pen (noted by B).During the test, the loading rate was maintained constant, at a value equal to 0,46mm/min. to simulates a stationary load and 12.5 mm/min. and 50 mm/min. tosimulates a mobile loads on pavement structure.Table 2. The pavement structure without geocomposite (1), taking in accountsMixtureh layermPoissson ratio,µElasticmodulus,MPawearing course BA16-A 266or wearing course BA16-B 2780.04 0.35or wearing course MASF16-A 312or wearing course MASF16-B352existent asphalt layers 0.095 0.35 300macadam 0.08 0.27 400ballast 0.20 0.27 239soil ∞ 0.35 110From this test, result the shear strain of cylindrical samples and then we can havethe angle of internal friction and cohesion for the asphalt mixture tested. For eachrecipes of asphalt mixture it is necessary to make triaxial test at failure forminimum two samples with different lateral stress (σ 3 = 2 daN/cm 2 , σ 4 = 4daN/cm 2 ) (table 1).