Temperature and Moisture Variation in Pavement Structures of the Test Road

AbstractEnvironmental conditions (temperature, moisture, intensity of sun, etc.) influence variation in asphalt pavement strength during the year. Lithuania is situated in a zone of cool average climate characterized by average warm summers and average cold winters. One of the most important climatic factors is the air temperature variation per day. In order to evaluate the dependence of road pavement strength on temperature and the dependence of Eo modulus of separate layers on seasonal factors a comprehensive research was carried out on the unique Test Road section that was constructed in 2007 in Lithuania and is operated almost for 8 years. This road is affected by real climatic conditions and high intensity heavy vehicle traffic. It consists of 27 different flexible pavement structures with the same class of pavement structure but the different type and composition of materials and all necessary electronic sensors (loop profilers, temperature and moisture sensors, stress and strain transducers). Temperature and moisture sensors are installed in 4 different pavement structures. In order to analyse behaviour of asphalt pavement structure under Lithuanian climatic conditions, taking into account temperature and moisture, as one of the most important climatic factors influencing structural strength of road asphalt pavement, the experimental research was carried out and results are presented in the article

Research of Asphalt Pavement Structures on Lithuanian Roads (I)

The rapid growth of heavy traffic, the increase in the standard axle load make scientists to look forward for new durable road constructing materials and their mixes. The continuously increasing need for strengthening the road pavement structures induces to use new road reconstruction technologies, to search for new methods in constructing pavement structural layers and investigate pavement structures under real conditions. The article presents construction of experimental pavement structures for the first time in the road history of Lithuania. The article also describes the installation process of stress and strain transducers in different layers of experimental pavement structures and initial results of stress and strain measurements. These measurements will be carried out each time after passed 20 000 ESAL’s calculated to 100 kN

Improvement of Road Pavement Maintenance Models and Technologies

The roads as main national assets maintenance costs increase dramatically but budgets stays as it is or even decrease over the years. However, at the same time, it is required to maintain road pavements condition at high level. These trends make asset owners and administrators to search for new ways and methods for more efficient roads maintenance management. As the new road is build or old one reconstructed performance indicators should be identified for whole life cycle as it is defined by design. Pavement condition evaluation by indicating present performance indicators level should be done timely and accurate at road level and whole network level. Ongoing support of pavement condition under network level, with a long-term strategy, allows to prolong the life of the pavement, improve traffic safety and meet public expectations. The comprehensive analysis of road maintenance and management systems recommendations for their improvement and application are presented in the article

Radionuklidų pasiskirstymo Ignalino AE poveikio zonos dirvožemyje tyrimai

Santr. angl., rusBibliogr.: p. 55 (13 pavad.)Vytauto Didžiojo universitetasŽemės ūkio akademij

A Test Road Section of Experimental Pavement Structures in Lithuania (I)

The rapid growth of heavy traffic, the increase in the standard axle load from 10 to 11,5 tonnes on the main roads of Lithuania make the scientists to look for new durable road building materials and their mixes. The continuously increasing need for the strengthening of road pavement structures induces to use new road reconstruction technologies, to search for new methods in constructing pavement structural layers, to investigate pavement structures under real conditions. The article gives the program of experimental investigations of a test road section constructed for the first time in the road history of Lithuania and consisting of 24 different pavement structures. The article also describes the initial results of investigations. Further investigation results, their analysis and evaluation will give a possibility to choose road pavement structures the most suitable to Lithuanian climatic and traffic conditions

Research on the Dependence of Asphalt Pavement Stiffness Upon the Temperature of Pavement Layers

The falling weight deflectometer (FWD) is the device most commonly used for the measurement of strength of road pavement structure. Using this device the impact of the wheel of heavy vehicle to the pavement is imitated for the assessment of pavement strength. The stiffness of asphalt pavement layers, as well as E0 modulus values, measured using the FWD, strongly depend on the pavement temperature. When we use deflectometer for measuring asphalt pavement strength at different environmental conditions and in different season the values of E0 modulus should be reduced to the assumed standard temperature. During this research at the experimental asphalt pavement structure the temperature correction factor was revised. The use of this factor enables to reduce the values of the stiffness of asphalt pavement layers measured by the falling weight deflectometer to the standard temperature of +20 °C. In this way the influence of the temperature of asphalt pavement layers upon asphalt stiffness and E0 modulus could be evaluated

Comparison of Greenhouse Gas Emissions Associated with Reconstruction of Low-volume Road – Lithuania Case Study

Europe faces the ambition to drastically reduce greenhouse gas (GHG) emissions. In road sector, most of the carbon footprint emissions are generated by vehicles. The remaining emissions are generated during the different stages of road life cycle. Therefore, European and other countries use methods to calculate GHG emissions and evaluate the impact of road construction and maintenance methods, and technologies on the environment. In Lithuania there is a little experience in using such tools, but it has committed itself to reduce GHG emissions not less than 40% comparing with the level of 1990 till 2030. Different modern and innovative techniques are available in road construction and maintenance, but their contribution achieving national goals is unknown. The aim of this research is to compare GHG emissions associated with reconstruction of low-volume road using different construction techniques. Analytical analysis was performed using Highways England Carbon calculation tool. This study showed that soft asphalt and warm asphalt technologies are more efficient than hot asphalt in terms of GHG emissions, which are respectively lower by 20.3% and 5.2%

The Road of Experimental Pavement Structures: Experience of Five Years Operation

The road of experimental pavement structures was constructed in 2007 and still continues its operation. The road consists of 27 different pavement structures with the same class of pavement structure but the different type and composition of materials. The experimental pavement structures were laid on the road to the query, one traffic lane is used by loaded traffic and other – by unloaded traffic. In May, 2012 totally 320 000 ESAL’s (100 kN) passed the road. Annually – about 70 000 ESAL’s. This article gives the research results of the bearing capacity and surface characteristics of experimental pavement structures after five years of their service