The article presents the results of the research on thermal actions on the materials occurring in the cross section along the depth of the bridge deck and bituminous pavement during its construction. The impulse to curried out the research was the need to explain the causes of the blistering of bituminous waterproofing membranes and asphalt pavements often observed on the bridge decks. The paper presents the examples of such failures and the analyses of possible mechanisms of the phenomenon. Research indicates a significant influence of all technological processes on the temperature of materials in the cross section as well as daily temperature changes. The probability of initiation of reactions between concrete components with gaseous products has been confirmed in such conditions. The susceptibility of bituminous materials to gas emission and blistering is the subject of a separate study. The research was part of a research project carried out under the contract INNOTECHK3/IN3/50/229332/NCBR /14 [13].
The problem of recycled materials application in road construction is one of the key issues in contemporary road engineering. This article describes attempts to produce a hot mix asphalt (HMA) mixture entirely from processed reclaimed asphalt pavement (RAP) material. Due to the binder ageing process, rejuvenating agent was a necessary additive to the mixture. The mixture was tested to determine its parameters, including the content of voids, fatigue life, rutting resistance, stiffness and water sensitivity. The test results demonstrated that the rejuvenated RAP mixture is not inferior to fresh produced mixtures in terms of physical and strength parameters. Such results are, however, conditional on appropriate handling of the RAP material.
This paper describes the analyses of the fatigue life of the asphalt pavement reinforced with geogrid interlayer under traffic loading. Finite Element ANSYS package with using nCode applications, as well as macros specially designed in APDL programming script and VBA were used to model the considered problem. Our analysis included computation of stress, fatigue life, damage matrix and rainflow matrix. The method applied was the one of fatigue calculation: stress – number of cycles in short S-N. On the basis of the performed high cycle fatigue analysis, the influence of the location of the used geogrid and of its bond with asphalt layers on the fatigue life and the work of the asphalt pavement structure were determined. The study was carried out for three temperature seasons i.e. spring and fall (assumed as one season), winter and summer. The variability of the traffic conditions were taken into account by assuming weekly blocks of traffic loading. The calculations were made using the real values of loading measured in field tests on the German highways by means of HS-WIM weighing system. As a result of the performed tests, it was proved that the use of geogrid-reinforcement may prolong the fatigue life of the asphalt pavement. However, it is required that: the geogrid should be located in the tension zone as low as possible in the structure of the asphalt layers. Moreover, it is necessary to provide high stiffness of the bond between the geogrid and the asphalt layers.
Over the course of operation, asphalt road pavements are subjected to damage from car traffic loads and environmental factors. One of the possible methods of strengthening damaged asphalt pavements may be the application of an additional rigid layer in the form of a cement concrete slab with continuous reinforcement.
This paper presents a material-technological and structural solution for composite pavement where a cement concrete slab with continuous HFRP bar reinforcement is used for strengthening. Based on laboratory tests, the serviceability of composite bar reinforcement of rigid pavement slabs was shown. A design for strengthening asphalt pavement with a concrete slab with steel bar and corresponding HFRP bar reinforcement was developed. The composition of a pavement cement concrete mix was designed, and experimental sections were formed. Based on laboratory tests of samples collected from the surfaces of experimental sections and the diagnostic tests carried out in “in situ” conditions, the authors will try, in the nearest future (Part II: In situ observations and tests), to confirm the effectiveness of strengthening asphalt pavements with cement concrete slabs with HFRP components.
The paper presents the dependence of ITS results at the elevated temperature (40°C) on rutting parameters, i.e. proportional rut depth (PRDAIR) and wheel tracking speed (WTSAIR), obtained at the temperature of 60°C. The asphalt mixture samples were prepared in the gyratory compactor, but ITS tests were conducted with typical Marshall press, at a loading rate of 50 mm/min. Correlation analyses show a strong relationships between ITS results and rutting parameters, whereby the correlation coefficients obtained are higher for the PRDAIR parameter (r = -0.88) than WTSAIR (r = -0.81). Using the obtained regression functions, the prediction limits as well as confidence limits were calculated, which allowed to develop criteria for assessing resistance to rutting on the basis of ITS test, and taking into account the technical requirements in Poland.