Alfredas Laurinavičius

Monitoring the Mechanical and Structural Behavior of the Pavement Structure Using Electronic Sensors

Over the last decade, pavement instrumentation has become an important tool for monitoring the performance of pavement structures and materials under real climatic and traffic conditions. Stress, strain transducers, loop profilers, temperature, and moisture sensors could be reasonably used for sophisticated analysis of pavement performance. Commonly, such research projects involve only few pavement structures under accelerated loading tests. The unique experimental road section was constructed in 2007 in Lithuania. It consists of 27 different flexible pavement structures and all necessary electronic sensors. This road is affected by real climatic conditions and high-intensity heavy vehicle traffic. The aim of such research is to continuously monitor performance of different pavement structures and to elaborate on the most suitable and economically effective pavement structures.

Reduction of external rail wearing on road curves

Abstract Railway line curves restrict train speed. Besides, there is a high side wearing intensity in the external rail head on the curves. The main functions of cant are discussed in the article. Results of experimental research which was carried out in order to estimate the influence of cant and gauge increase on the curves of rail head side wearing intensity, are presented. Improved cant calculation methodology, which assures rail head side wearing intensity reduction and safe railway traffic, is suggested.

Research of snow melting materials performance efficiency for road winter maintenance

AbstractIn 2012, the Lithuanian Road Administration initiated a three-year research project ‘The study of effective winter road maintenance of national significance roads in Lithuania’. The main purpose of this research was to optimize road maintenance in winter and to determine the most effective means of combating slippery conditions. The research project was carried out by two institutions: the Road Research Institute of the Faculty of Environmental Engineering of Vilnius Gediminas Technical University and JSC ‘Problematika’. JSC ‘Problematika’ conducted exploratory experiments, which were divided into two phases. In the first phase of the experiment, five different snow melting materials (Slipperiness Reducing Materials – SRMs) were investigated in the laboratory. Different test methods were used in this investigation. In the second phase of the experiment, three SRMs with different properties were selected, and experimental road sections were set up to determine the road slipperiness and the change i...

The influence of treated oleo-chemical wastewater applications on the metal speciation forms in soils

Abstract This paper presents a developed method of pretreating wastewaters coming from small-tonnage oleo-chemical production and also the research results on the variability of concentrations of heavy metals (Cd, Cr, Cu, Ni, Pb, Zn) in the soil irrigated and fertilized with wastewater from this production. The processing wastewater pretreatment was carried out at two stages. The first stage eliminated fatty substances by using dispersed air flotation aided with hydrogen peroxide as an oxidizer. The second stage included coagulation and chemical precipitation with milk of lime, flocculation, final dissolved air flotation (DAF), and also oxidation with hydrogen peroxide. Field experiments, the aim of which was to compare variability levels for speciation fractions of heavy metals, were carried out according to Tessiers method for four years. The study revealed that the average concentrations of the given metals fractions in soil samples where raw wastewaters were directed did not significantly change duri...

Policy instruments for managing road safety on EU-roads

Abstract Directive 2008/96/EC on road infrastructure safety management requires the establishment and implementation of procedures relating to road safety impact assessments (RSIA), road safety audits (RSA), ranking of high accident concentration sections and network safety ranking (NSR) and road safety inspections (RSI). The aim of this article is to present the outputs of BALTRIS project. The goal of the international project BALTRIS is to elaborate the road and street infrastructure safety management procedures and teaching material consistently explaining the above mentioned infrastructure management procedures. Four Baltic Sea region countries (Sweden, Estonia, Latvia, and Lithuania), represented by universities and national road administrations participate in the elaboration of these procedures and teaching material. This article describes the scope of NSR, RSA and RSI procedures prepared in the frame of BALTRIS project, also article provides detailed implementation and execution of procedures for t...

CONTACT LOSS BETWEEN RAILWAY TRACK AND SUBGRADE IN VERTICAL PLANE DURING ROADBED RESEARCH

Abstract In the paper a new method of railway subgrade investigation is analysed. Contact loss between track and subgrade in vertical plane is considered. During the roadbed investigations the rail is jacked up using a plate called „VSS”. It is assumed that variable temperatures have influence on the rail which is laid on a curved roadbed. Elasticity of the railway roadbed is calculated. Finally formulas and dependences of various types of track structures are obtained.

Research on physico-chemical pretreatment of wastewater from the production of wood coating materials

Abstract This paper presents the results of the research conducted on the installation designed for physico-chemical pretreatment of technological wastewater in the volume of up to 5.0 m3/day discharged from the production of protective and decorative coating materials used for wooden surfaces. The subject-matter installation constructed on a mobile pallet, consisted of a storage-averaging tank where concentrations were equalised with the use of circulation aeration and mixing. A variant, preliminary pre-oxidation with the use of hydrogen peroxide was conducted in this tank. A substantial installation set for the wastewater treatment plant consisted of two preliminary tube reactors, one cylindrical-conical processing reactor, stations for preparing and dispensing reagents and the sediment dewatering station. Considerable reductions in main chemical indicators of water pollution were obtained in the installation: both total suspended solids (TSS) and ether extract (EE) - more than 98%, chemical oxygen demand (COD) - 46-54%, biochemical oxygen demand (BOD5) - 39-46%, and free formaldehyde (HCHO) - 14-27% due to the use of pre-oxidation and the acid - alkaine double coagulation by applying the ALCAT 105 - SAX 25 system. The use of pre-oxidation with hydrogen peroxide in doses 250.0-450.0 mg/l and then two-stage coagulation resulted in an increase in the reduction of: COD and BOD5 by ca 10-15%, and HCHO by ca 58-66% with reference to the water pretreatment without pre-oxidation. The assessment of sediments formed during the process of pretreatment was made determining the leachable forms of metals (Cu, Ni and Ti) according to methodology of TCLP in compliance with the US EPA Method 1311. Abstrakt Przedstawiono wyniki badań prowadzonych na instalacji zbudowanej na potrzeby fizykochemicznego podczyszczania ścieków technologicznych w ilości do 5,0 m3/dobę z produkcji materiałów powłokowych, ochronnych i dekoracyjnych, stosowanych na powierzchnie drewniane. Przedmiotowa, mobilna instalacja zbudowana na przenośnej palecie, składała się ze zbiornika magazynująco-uśredniającego, w którym wyrównywanie stężeń prowadzono za pomocą napowietrzania i mieszania cyrkulacyjnego. Wariantowo w tym zbiorniku prowadzono wstępne utlenianie za pomocą nadtlenku wodoru. Zasadniczy zespół instalacji oczyszczalni tworzyły reaktory: dwa wstępne rurowe i procesowy cylindryczno-stożkowy, stacje przygotowania i dozowania reagentów oraz stacja odwadniania osadów. Stosując preutlenianie oraz podwójną koagulację kwaśno-alkaliczną układem ALCAT 105 - SAX 25, na instalacji uzyskiwano ponad 98% redukcję zawiesin ogółem (ZO) i ekstraktu eterowego (EE), 46-54% chemicznego zapotrzebowania na tlen (ChZT), 39-46% biochemicznego zapotrzebowania na tlen (BZT5) i 14-27% wolnego formaldehydu (HCHO). Zastosowanie wstępnego preutleniania za pomocą nadtlenku wodoru w dawkach 250,0-450,0 mg/dm3, a następnie dwustopniowej koagulacji skutkowało wzrostem redukcji ChZT i BZT5 ca 10-15%, a HCHO ca 58-66%, w relacji do wariantu bez preutleniania. Oceny powstających osadów po procesie podczyszczania dokonano, oznaczając wymywalne formy metali (Cu, Ni and Ti) według metodyki TCLP zgodnie z procedurą US EPA Method 1311.

INVESTIGATION OF AUTOMOBILE ROADS PAVEMENT DETERIORATION TRENDS IN LITHUANIA

Abstract Currently there are three pavement management systems (PMS) used in Lithuania for planning and management of road maintenance and repair activities: HDM-III, HDM-4 and DAVASEMA (Lithuanian PMS). HDM pavement deterioration models are used in all of them. With the purpose of calibration and adaptation of those models in 1997 Lithuanian Pavement Deterioration Research Project was developed. The research data gathered in four years of the Project gives an opportunity to draw some conclusions on asphalt pavement deterioration in Lithuania. This article presents the main HDM asphalt pavement deterioration models, and describes the most important steps in adaptation of some input data to those models and calibration of the models to the local conditions.