In the design of asphalt mixtures for paving, the choice of components has a remarkable importance,as requirements of quality and durability must be assured in use, guaranteeing adequate standardsof safety and comfort.

In this paper, an approach of analysis on the aggregate materials using fractal geometry is proposed. Following an analytical and an experimental approach, it was possible to find a correlation betweencharacteristics of the asphalt concrete (specific gravity and porosity) and the fractal dimension ofthe aggregate mixtures.

The studies revealed that this approach allows to draw the optimal fractal dimension and, conse-quently, it can be used to choose an appropriate aggregate gradation for the specific application;once the appropriate initial physical parameters are finalized.

This fractal approach could be employed for predicting the porosity of mixed asphalt concretes,given as input the fractal characteristics of the aggregate mixtures of the concrete materials.

The aim of the study is to compare flexible pavement design lifespans and the main factors which create their values for a standard structure and one with an anti-fatigue course AF at different parameter values of pavement and its load, relevant to their design processes. Depending on the mixture used for the anti-fatigue course or the course thickness, durability improvement of the pavement (compared to the durability of a standard structure) can be obtained by extending the design lifespan of the asphalt base course or by extending the design lifespan of the AF course. On sections with predominantly slow traffic, the lifespan decreases significantly compared to sections with typical vehicle speed – the relative decrease is greater if anti-fatigue course is applied.

Traffic related noise is currently considered as an environmental pollution. Paper presents results of multidirectional study attempting to serve urban traffic without the need to erect noise barriers interfering urban space. Initial concept of the road expansion included construction of 1000 m of noise barriers dividing city space. Improvement in the acoustic conditions after construction completion is possible due to the applied noise protection measures: vehicle speed limit, smooth of traffic flow, use of road pavement of reduced noise emission and the technical improvement of the tramway.

The paper presents a numerical study of an aircraft wheel impacting on a flexible landing surface. The proposed 3D model simulates the behaviour of flexible runway pavement during the landing phase. This model was implemented in a finite element code in order to investigate the impact of repeated cycles of loads on pavement response.

In the model, a multi-layer pavement structure was considered. In addition, the asphalt layer (HMA) was assumed to follow a viscoelastoplastic behaviour.

The results demonstrate the capability of the model in predicting the permanent deformation distribution in the asphalt layer.

Communication noise is classified as one of the pollutions for the current environment. Experimental techniques to measure tire-pavement noise generation from asphalt pavements in the laboratory have been limited. A series of experiments were conducted on six different asphalt mixtures to determine if Purdue University’s Tire-Pavement Test Apparatus (TPTA) could be used to overcome these limitations. The procedure produced samples with low tire-pavement noise; however, the air void contents of the samples were higher than designed. Despite these difficulties, the sample preparation technique and the TPTA testing protocol were shown to offer an effective approach for quick laboratory assessment of tire-pavement noise characteristics of hot mix asphalt pavements at a substantially reduced cost compared to field testing.

The article presents numerical analysis of the portion of concrete airport pavement that consists of two concrete panels connected with dowels, subjected to thermal and service loads, in terms of changes in base rigidity, plate thickness and diameters, and spacing of dowels. Modifications of the thickness of the plates, diameter and spacing of dowels, and base rigidity were considered by assessing the level of stress and displacement in the analysed concrete plate, as well as normal and tangential stresses in dowels by using finite element method. On the basis of an analysis of examples, an optimal solution of dowelling connections in concrete plates with established loads was proposed. The results of the calculations were presented as a contour level distributions and comparison tables.

The aim of the paper was to analyse the possibility to use waste material which is created during the production of mineral-asphalt mixes as a side effect of the process of drying and dedusting diabase aggregate in high temperature. Experimental studies included the analysis of the influence of the addition of diabase dust on the improvement of the properties of cement concrete destined for the construction of local roads. The mineral additive in the form of diabase dust, which constitutes natural waste, was inserted into the concrete mix as a mineral additive substituting a part of the aggregate with the constant amount of cement and water, and additionally as the substitute for cement. The performed studies resulted in the conclusion that adding diabase dust significantly increased the tightness and density of concrete, which impacts the increase of compressive strength by 7, 21 and 28% in reference to model concrete. The insertion of the waste diabase dust into the concrete mix significantly improved the freeze-thaw resistance of concrete after 150 cycles of testing and reduced the water absorption by 6, 15 and 21%. Using diabase dust as a substitute in the following amount: 50, 100 and 150 kg/m3 did not cause significant changes in the scope of density and water absorption, whereas the reduction of the compressive strength was from 8, 23 and 33% in reference to the model concrete. The application of dust as the substitute for cement resulted in the reduction of the costs of concrete by 6, 12 and 18% and resulted in the possibility to fully apply waste material, which confirms the justness of undertaking implementation research. Concrete with the use of waste rock dusts may be qualified as concrete that is environmentally friendly and compliant with the sustainable development of modern construction materials.

One of the main causes of road pavement distress are low temperatures, and hence the need to thoroughly study the low temperature performance of all bituminous materials used in road construction. The purpose of this studywas to determine the performance of alternative and conventional bituminous mixtures in the temperature range between –25˚C and –10˚C using for this purpose the Tensile Creep Test (TCT). The low-temperature performance data were evaluated using the Burgers model, a tool that is widely used for evaluation of bituminous mixtures. This research focuses on bridge paving mixtures. These included both conventional (mastic asphalt) and alternative (SMAMA) materials. It was established, based on the test results and their analysis, that low temperature performance of a bituminous mixture is influenced, in the first place, by the characteristics of the asphalt binder it contains. Furthermore, SMA-MA mixtures showed better low temperature performance than conventional, mastic asphalt type mixtures.

The paper analyses the influence of seasonal temperature variations on fatigue strength of flexible and semi-rigid pavement structures chosen for KR4 traffic flow category. The durability of pavement determined assuming a yearly equivalent temperature of 10˚C and assuming season-dependent equivalent temperatures was compared. Durability of pavement was determined with the use of Asphalt Institute Method and French Method. Finite Element Method was applied in order to obtain the strain and stress states by the means of ANSYS Mechanical software. Obtained results indicate a considerable drop in pavement durability if seasonal temperature variations are considered (up to 64% for flexible pavements and up to 80% for semi-rigid pavements). Durability obtained by the French Method presents lower dependence on the analysed aspect.

One of the common defects of flexible road pavement is the loss of bonding between two layers of asphalt concrete: the base course and the binder course. The occurrence of this phenomenon has a major impact on the observed state of deflection and deformation of the pavement. This effect affects the results of non-destructive tests which are used to calculate material parameters and then are used in the diagnostics of the pavement condition or design of structural strengthening. This paper discusses the influence of the various level of bonding on the result of backcalculation and the obtained elastic moduli. For the obtained values of moduli, calculations of key deformations and pavement durability were performed. Improper assumptions about the interaction between the layers affects the observed results. Additionally paper discusses the effect of pavement displacement discontinuity on the observed deflection basin and compares the results with those for a model with continuity. Numerical calculations were carried out using Simulia Abaqus software, the computational model was verified using analytical solution.

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.

Pavements made of cement concrete, used for road constructions, are damaged during use. This applies to both the pavements of rural and forest roads with very low traffic loads, as well as road pavements with high traffic loads. One of the most effective ways of repairing damaged concrete cement pavements is through placing an asphalt overlay on a concrete slab. In order to increase the fatigue life of the asphalt overlay, asphalt mixtures are modified with fibres. One technological solution is to use FRP (Fiber Reinforced Polymer), an innovative material with improved properties.

The aim of this paper is to assess the impact of asphalt overlays modified with a new type of fibres to strengthen the durability of weakened cement concrete pavement structures.

On the basis of the conducted analyses, it was shown that the use of an asphalt layer reinforcement increases fatigue life, for both 15 cm thick prefabricated slabs and a typical road pavement for average traffic made of 25 cm doweled and anchored concrete slabs. There was a significant increase in the fatigue life of the concrete pavement structure as a result of modifying the overlaid asphalt mixture with FRP fibres.

This paper develops an automatic method to calculate the macrotexture depth of pavement roads, using the tire/road noise data collected by the two directional microphones mounted underneath a moving test vehicle. The directional microphones collect valid tire/road noise signal at the travel speed of 10–110 km/h, and the sampling frequency is 50 kHz. The tire/road noise signal carries significant amount of road surface information, such as macrotexture depth. Using bandpass filter, principal component analysis, speed effect elimination, Gaussian mixture model, and reversible jump Markov Chain Monte Carlo, the macrotexture depth of pavement roads can be calculated from the tire/road noise data, automatically and efficiently. Compared to the macrotexture depth results by the sand-patch method and laser profiler, the acoustic method has been successfully demonstrated in engineering applications for the accurate results of macrotexture depth with excellent repeatability, at the test vehicle’s travel speed of 10-110 km/h.

Road construction relies on natural material exploitation and it is necessary to find new ways of reducing its negative environmental impact. Simultaneously, number of tyres placed on Croatian (and world) market is constantly growing and the need for waste tyres management will begin to increase due to the wear and tear of tyres in use at the moment. This paper presents a review of latest international and domestic researches on waste rubber application in road construction with special emphasize on Croatian researches within this topic. Preliminary results of ongoing research on waste rubber application in cement bound mixtures are also presented.

The article presents a results of study on the impact of replacing CEM I SR3/NA by CEMIII/A LH/HSR/NAon the mechanical properties and durability of pavement concrete with exposed aggregate. Was used granite aggregate and washed sand. Water/cement (w / c) ratio in the tested concretes constituted 0.35 and 0.4 and part of the cement was replaced with a 5% addition of natural pozzolana – zeolite. Compressive strength tests were performed after 3, 7, 28 and 56 days, tests of tensile strength test by splitting method and flexural strength two-point loading tests. The characteristics of the air pores and the rate of water absorption by concrete surface of the samples cut out from the slabs with exposed aggregate were presented. The resistance of the surface to exfoliation after 56 cycles of freezing-thawing in NaCl solution was tested. Based on the results obtained, it was found that when designing the composition of the concrete intended for the upper layer of the pavement, it is necessary to ensure high tensile strength, appropriate in the XF4 environment and with the decrease in the w / c < 0.4, a reduction in capillary porosity of the cement paste is obtained, and the same the durability of concrete is increased due to the improved strength parameters in the contact zone between coarse aggregate grains and cement paste. The research also showed a significant influence of proper cure on the mechanical properties and durability of pavement concrete.

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].

A review of mechanical models of road pavements in the form of a proposal of classification of these models is presented. It is assumed an autonomy of the following elements of pavement model: the models of structural layers, the subgrade model, the interlayer bonding models, including bonding of pavement structure with its subgrade, the models of external impacts on pavement layers, including load of heavy traffic, the models of pavement environment impacts on structural layers’ borders (lateral) and subgrade borders (including the lower one) – according to the selected criteria such as structural criterion, material criterion (physical criterion), dimension criterion and model scope (purpose) criterion − in the frame of assumptions of the classical Newtonian deterministic mechanics. The presented attempt to classify mechanical models of road pavements supports to orientate the roadmen community within a scope of the mechanistic modelling of these structures.

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.

One of the factors that affects the safety of flight operations is to maintain the airport infrastructure in an appropriate condition, due to importance of proper infrastructure management, including funds and human resources management in particular. Currently applicable methods for determination of surface condition are mainly based on visual assessment of surface deterioration. An innovative approach to assessing the cement concrete airport pavement's technical condition based on the APCI (Airfield Pavement Condition Index) is presented in the article. The method of APCI index determination is based not only on the visual assessment of the airfield pavement's surface condition and the calculation of its deterioration, but also includes parameter of load capacity, evenness, roughness and tensile strength of the surface layer. The presented method can be used as a tool for forecasting the technical condition of cement concrete airfield pavements in the context of planning funds for future maintenance purposes. The impact of considering individual model parameters on the value of APCI index, basing on the results of field tests carried out as part of military airports inspections was presented.

An enormous number of structures and roads are put on expansive subgrade soils and may be exposed to the swelling and shrinkage risk. To prevent the expanding weight of the subgrade layer under loaded pavement, one of the following strategies may be utilized are geogrid layer. Reinforced pavement layers have been propagated in the field of civil engineering because of their profoundly adaptable and diversified use. In this study, axisymmetric models of pavement layers have been created by 2-D Plaxis software and all of these models included geogrid layers at various positions concentrated to research the impact of geogrid on the critical pavement responses. Geogrid was placed at the bottom of asphalt layer, bottom of base layer, tope and middle of the subgrade layer. All models are loaded with incremental contact pressure between 50 and 600 kPa. Analysis processes have been made for all models and the obtained investigation results show a significant effect on pavement behavior when the a geogrid layer was used under various tire pressures. Also, there is an increase in the bearing capacity of a model that includes geogrid at the top and middle of the subgrade layer by about 35% and the resistance of the asphalt layer to deformation and cracking failure was improved.

The paper presents a design and performance analysis of a photosensor device enabling the measurement of the visible light illuminance. The sensor is designed for use in the light metering matrix of a mobile measurement platform allowing the correct operation of in-pavement airport lamps. This kind of control can be required by regulations and must meet the standards defined by the European Union Aviation Safety Agency (EASA). An important assumption of the solution was to obtain the highest possible speed of a measurement acquisition so that the control process would take place in a relatively short time. The proposed module concept is dedicated to the task of testing the quality of airport lamps, due to the characteristics of the photosensitive elements matching the light beams emitted by luminaries. The device is based on a VTP1220FBH photodiode and an ATmega328P microcontroller, which, in addition to the analogue-to-digital conversion and correction, sends the results back to the master unit via the I ²C bus.