Hasil untuk "Highway engineering. Roads and pavements"

Avinash Talkeri, Raghuram Chinnabhandar, Harish Sagar

The performance of roller compacted concrete (RCC) was greatly influenced by variations in material proportion, optimum moisture content, density of mixes and methodology adopted making it different from conventional concrete mixes. Even though RCC has gained popularity, the complex phenomenon involved in developing the RCC mixes limits it from large-scale applications. In this study, reclaimed asphalt pavement (RAP) incorporated roller-compacted geopolymer concrete (RGC) mixes were developed herein with different compaction techniques such as vibratory hammer (VH), modified proctor (MP), vibration table (VT) and compression machine (CM) are studied and compared with control mixes of natural aggregates. Initially, the effect of alkali solutions such as sodium hydroxide (SH) and sodium silicate (SS) on the physical properties. During, the second phase mechanical properties such as dry density, compressive, flexural and split-tensile strength, modulus of elasticity and microstructure properties will be investigated. The test results revealed that compaction efforts were greatly influenced by the alkali solution. Furthermore, the poor bond characteristics between RAP and the binder matrix had a significant effect on strength properties. Also, the various compaction techniques affected the mechanical properties of mixes developed herein. In Comparison with various compaction efforts, VH and MP produced comparable results, whereas the VT method underestimated and overestimated the various strength properties. Although, the CM method reports comparable results but difficult to maintain consistency in strength aspects. Therefore, optimization of various parameters influencing the concrete properties needs to be achieved for field density.

Andrii Vozniuk, Bohdan Stasiuk, Mykhailo Dulia

Introduction. This article aims to outline the main stages of creating an information support system for Ukraine’s road infrastructure, with a view to further developing effective mechanisms for justifying and rationally planning road construction, reconstruction, repair, and maintenance works. Problems. Without reliable information about the road network and its traffic congestion, it is impossible to adequately justify the allocation of funds for road maintenance and repair. The road network is constantly undergoing significant changes, both due to destruction caused by the full-scale invasion of the Russian Federation and natural degradation, as well as a result of changes in logistics routes, which necessitates the processing of dynamically changing information in order to make the most optimal decisions.

Merley Misriani, Enita Suardi, Liliwarti Liliwarti et al.

Konstruksi infrastruktur jalan tol dapat mengalami kerusakan sebelum masa layanan yang direncanakan tercapai. Penurunan tanah dapat terjadi apabila infrastruktur transportasi dibangun di atas lapisan tanah lunak, sehingga menyebabkan kerusakan struktur dan geoteknik yang cukup besar. Penelitian menjadi sangat penting dengan mengambil studi kasus pada Jalan Tol Palembang-Indralaya STA 1+670 yang berada di atas lapisan tanah dengan nilai N-SPT < 10 dan tanah lunak mencapai kedalaman 16,95 m. Penelitian bertujuan untuk menguji efektivitas aplikasi preloading dan prefabricated vertical drain (PVD) dalam mempercepat proses penurunan tanah dasar pada jalan tol tersebut. Metode yang digunakan dalam penelitian adalah dengan mengombinasikan metode preloading dan PVD. Metode preloading menggunakan sistem surcharge, menempatkan beban timbunan pada tanah dasar dengan tinggi desain 5 m. Metode PVD dengan memasang alat vertical drain ke dalam lapisan tanah lunak. Data yang diperlukan meliputi layout lokasi dan data tanah dasar, yaitu data tanah hasil uji lapangan dan laboratorium. Hasil penelitian menunjukkan bahwa penurunan yang terjadi sebesar 1,556 m dengan derajat konsolidasi 90% selama 2,149 tahun. Selanjutnya, setelah memasukkan metode PVD, waktu penurunan tanah dasar dengan derajat konsolidasi 90% menjadi lebih cepat, yaitu dua bulan dengan pola pemasangan segitiga dengan jarak 3 meter. Pada jalan tol dari Palembang menuju Indralaya, pendekatan gabungan antara preloading dengan PVD terbukti bermanfaat dalam mempercepat proses penurunan tanah dasar. Penelitian mengimplikasikan bahwa kombinasi metode preloading dan prefabricated vertical drain (PVD) dapat dipilih sebagai metode perbaikan tanah lunak untuk mempercepat penurunan tanah dasar.

Natalia Popovych, Olha Belenchuk, Yevhen Tepliuk

Introduction. A significant share of traffic accidents occurs precisely at intersections and junctions Therefore, there is a need to increase road safety on them, taking into account modern requirements and best global practice, namely the organization of roundabouts at intersections Problem Statement. The increase in the car fleet is significantly ahead of the rate of growth of the road network. In this regard, traffic conditions worsen, the number of traffic accidents increases, the capacity of roads decreases, which leads to a decrease in road efficiency and an increase in the cost of road transportation. In such conditions, the issue of increasing road safety, in particular at intersections, becomes especially urgent. Purpose. Study of traffic safety at intersections, determination of the causes of traffic accidents and formulation of proposals to reduce their number. Materials and methods. In the article, the method of statistical data processing was used to analyze traffic safety on highways. Results. The causes of traffic accidents were analyzed, in particular at intersections, and it was determined that roundabouts are safer than other types of intersections.

João Santos, Massimo Pizzol, Hessam Azarijafari

Elvis Siaway Kwado Mensahn, Surajo Abubakar Wada, Lameck Lugeiyamu

: Transport and international agencies invest millions of dollars on road projects to support countries develop their infrastructure; therefore, it is important to ensure longer service life and value for money. The primary function of the pavement structure is to keep distresses, including fatigue cracking and permanent deformation, to an acceptable limit so that the pavement can withstand applied vehicle load and repetitions during the service duration. Furthermore, the layered structure of the pavement is intended to ensure that the vehicle contact pressure is distributed in such a way that critical responses at the bottom layer of the pavement are low enough to avoid severe damage. Two typical procedures associated with roadway pavement design are empirical-based and structural analysis methods. However, the empirical-based methods have significant shortcomings, as predicting the mode and extent of pavement performance becomes a major challenge. Alternatively, the structural analysis methods have advanced extensively with computers since they consider crucial factors such as traffic loads, material characteristics and environmental conditions. The imputation of these parameters into the computer algorithm contributes to a better understanding of the mechanical performance of constituent pavement material responses. The predicted responses enable highway engineers to select appropriate pavement compositions that will deteriorate at a satisfactory level during the time of service. The most common structural analysis approaches are analytical modelling and numerical simulation. On the other hand, differences in analysis results generation using these approaches have been a notable concern. This review article presents a synopsis of typical pavement design methods and the problem connected with them; structural approaches to identify factors influencing their accuracy. Furthermore, computer algorithms use due to their usefulness, and the assumptions of layered theories employed in pavement structural design are discussed to uncover potential drawbacks for future upgrades.

Rolands Izaks, Liga Gebauere, Raivis Sparans et al.

The research has been conducted to test the asphalt produced in Latvia using local mineral materials and local recycled modifiers (fiberglass, crumb rubber), as well as the recycled asphalt used in the production of high-modulus asphalt mix, which will meet the local Latvian road construction specifications and will be economically, environmentally and technically more attractive. In the theoretical part, the available sources were studied to establish a theoretical framework, assess possibilities for using recycled materials, define the concept of fiberglass, and consider its performance in asphalt mixes. During the experimental stage of the research, different asphalt mix formulas with glass fiber, crushed rubber, RAP, and other additives used to stabilize asphalt mixtures for surface and base layers were designed in the laboratory; they were compared to the reference mixes using performance tests. Then the mixtures with the best results were used in the test section of a high-intensity local road. The samples of the asphalt layers of the paved test section were tested as well. Two asphalt mixes were designed according to local Latvian road-building specifications, using fiberglass reinforcement 0.15% + 30% RAP for the base layer and crushed rubber 15% and RAP 30%+EVOFLEX CA© variable for the surface layer. The aim of the research is to offer solutions for reducing new asphalt pavement production allowing for the use of recycled asphalt mixes in local road building. The performance tests of the test asphalt mixes showed that recycled asphalt pavement fully meets the requirements of the local Latvian road-building specifications.

Anoop Bhardwaj, Satyendra Mittal

The development of reinforcements for soil has made an impact in most of the civil engineering sectors especially transportation. The use of geogrids is frequent in roadways but they are also finding use in railways. The major impact that geogrids could have is providing desired stiffness to a section by reducing material and serving as a proper reinforcement material. In the current study, an attempt has been made to redesign the railway embankment economically with the help of geogrids. Biaxial geogrid is used to substitute the blanket layer (thickness up to 100 cm) in the railway embankment by fulfilling the strain modulus requirement of the embankment, calculated using a plate bearing test as per DIN 18134. The experiment is performed on the embankment replicated in a metallic test chamber with granular soil as subgrade and geogrid is placed beneath the ballast. The experimental study is validated by a 3-D numerical model using Midas GTS NX software. The experimental analysis shows an improvement of 31.47% in the second modulus of the earth embankment. For the implementation of this study, a design section of Indian railways is adopted. With the help of geogrid, a reduction of 50% is observed in the embankment height, thereby reducing the overall costs.

Andrii Koretskyi, Artur Onyshchenko, Borys Ostroverh et al.

ntroduction. The article presents the results of the study of irregular bottom river forms and foundations of structures, as well as coastal forms under the action of surface channel currents. It is assumed that the development of channels occurs due to the action of natural hydromorphodynamic river processes during the long stages of rivers existence formed in accordance with topographic, geological and hydrometeorological conditions. Problem Statement. Flow velocities are determined by a system of equations for the kinematics of channel flows and sediment transport, which is built on the basis of averaging the depth of flow. Purpose. Application of the developed methods of solving problems in the spatial dimension for the study of turbulent effects in the interaction with structural elements. The development of methods for applying the spatial model will be carried out at the next stage. Methods of research. Differential equations describing a nonstationary depth-averaged flow are solved using the FST2DH numerical model, which implements the finite element method. The steps typically performed when using FST2DH to study surface water flow and sediment transportation require the general necessary geographic information systems to build a network and assign boundary conditions. The equations for calculating channel erosion and erosion of bridge piers in bound soils are also considered, where it is shown that erosion depends more on soil properties than for the case of incoherent sediments, but can reach the same erosion depths with longer multi-flood calculations hydrographs. Results. Calculations of the flow kinematics of the calculated floodplain on the example of crossing the floodplain along the highway showed that the presence of a large angle of the overpass to the flood flow leads to additional conditions for increasing local erosion of supports in the form of solid rectangular columns. Significant local erosion is observed in the area of supports near the channel part. Conclusion.

Ivan Kopynets, Mykola Stulii, Tetiana Protopopova

Introduction. Decision the tasks of effective functioning of surface dressing of roads of Ukraine with the use of modern methods carried out in European countries, in particular tests in accordance with EN 12272-1: 2021 (EN 12272-1: 2002, IDT) Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and chippings. Problem statement. One of the prerequisites for the effective functioning of the road network of Ukraine is, first of all, the introduction of the road industry the requirements of the Association Agreement between Ukraine and the EU. In order to implement the requirements of this Agreement, which are the key principles of economic modernization and sustainable development of the country, «DerzhdorNDI» SE has prepared a comprehensive set of national standards with an identical degree of compliance with European requirements in the direction of solving the problems of effective functioning of the surface dressing of the pavement. Purpose. The purpose of this work is to promote the implementation in the road industry of Ukraine of the requirements of the national standard DSTU EN 12272-1:2021 (EN 12272-1: 2002, IDT) «Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and chippings» which is being prepared for publication by the National Standardization Body of Ukraine and enter into force with 01.07.2022. The related requirements of this standard DSTU EN 12271:2021 (EN 12271:2006, IDT) «Surface dressing. Specifications» discussed in the article «European practice of solving the problems of effective functioning of surface dressing. Part 1. Materials and methods. Analysis of the national standard DSTU EN 12272-1:2021 (EN 12272-1:2002, IDT) Surface dressing - Test methods - Part 1: Rate of spread and accuracy of spread of binder and chippings with an identical degree of compliance with EN 12272-1:2002 (version en) «Surface dressing — Test methods — Part 1: Rate of spread and accuracy of spread of binder and chippings». Results The requirements of the national standard for the effective functioning of the surface dressing of roads in Ukraine are considered, further use of which provides an opportunity to improve the performance of works for its arrangement. Conclusion. The use of this standard will be promote the introduction of various on test methods used to rate of spread and accuracy of spread of binder and chippings, as well as indirect assessment of the quality of equipment for their distribution in the case of surface treatment. Requirements provide an opportunity to use quite simple toolkit, under consideration in this article, and which should be used in the road industry of the country.

V. Papavasiliou, A. Loizos

A. Galkin

The thermal regime of road surface and basements is an important factor determining their reliable and safe operation in the cryolithozone. The aim of the research was to quantify the possibility of replacing the layered environment of the road's soil base with an equivalent homogeneous soil with an average coefficient of thermal conductivity when calculating the depth of the road's thermal influence zone. Two methods of averaging the thermophysical properties of a layered medium are considered: weighted average and arithmetic average. Dependences are obtained for determining the degree of deviation of the properties and thicknesses of the layers of the soil base, in which both methods are acceptable for engineering calculations. As an example, the two-layer medium of the road base is considered. For the analysis, the classical formula of the depth of thermal influence was used, obtained from the solution by the integral method of the one-dimensional equation of unsteady thermal conductivity. Simple engineering formulas are given for the relative error in determining the values of the depth of thermal influence when using an equivalent layer of pavement in calculations. A concrete example of calculating the depth of the zone of thermal influence in the two-layer soil of the road base is considered. The equation of the functional relationship between the parameters characterizing the degree of deviation of the thickness and thermophysical properties of individual layers from each other is obtained, which provides an error in the calculations of the depth of the zone of thermal influence less than the permissible value. The results of numerical calculations are presented in the form of 2D and 2D graphs, which allow us to visually assess the influence of the range of changes in the values of the thermal conductivity coefficients of individual soil layers on the legality of using various methods of constructing an equivalent single-layer road foundation structure.

Deru Li, Z. Duan, Xiaoyang Hu et al.

This study develops and tests an automatic pixel-level image recognition model to reduce the amount of manual labor required to collect data for road maintenance. Firstly, images of six kinds of pavement distresses, namely, transverse cracks, longitudinal cracks, alligator cracks, block cracks, potholes, and patches, are collected from four asphalt highways in three provinces in China to build a labeled pixel-level dataset containing 10,097 images. Secondly, the U-net model, one of the most advanced deep neural networks for image segmentation, is combined with the ResNet neural network as the basic classification network to recognize distressed areas in the images. Data augmentation, batch normalization, momentum, transfer learning, and discriminative learning rates are used to train the model. Thirdly, the trained models are validated on the test dataset, and the results of experiments show the following: if the types of pavement distresses are not distinguished, the pixel accuracy (PA) values of the recognition models using ResNet-34 and ResNet-50 as basic classification networks are 97.336% and 95.772%, respectively, on the validation set. When the types of distresses are distinguished, the PA values of models using the two classification networks are 66.103% and 44.953%, respectively. For the model using ResNet-34, the category pixel accuracy (CPA) and intersection over union (IoU) of the identification of areas with no distress are 99.276% and 99.059%, respectively. For areas featuring distresses in the images, the CPA and IoU of the model are the highest for the identification of patches, at 82.774% and 73.778%, and are the lowest for alligator cracks, at 14.077% and 12.581%, respectively.

A. Ariyo, Anosh Joseph, Busari Ayobami et al.

Rosinta Sidabutar, Y. Saragi, Humisar Pasaribu et al.

axle vehicles with the aim of shortening the distance and travel time from one place to another, as well as an infrastruture that is needed to support development. The design of the Sisingamangaraja – Lubuk Pakam road pavement consisting of a cement concrete slab as a foundation layer and a foundation laver above the subgrade. The purpose of this study was to evaluate the thickness of the pavement using the Highways Method. The research method used is the secondary data collection method. The data collected include traffic data, concrete data, soil data, vehicle axle free data, CBR modulus of subgrade. Plaanning the thickness of the road pavement concrete slab using the Highways Method obtained 300 mm. A planner is expected to have “felling engineering” supported by extensice knowledge and experience gained in the field.

Mieszko Kużawa, Aleksander Mróz, Maksymilian Kliński et al.

Abstract: The paper presents a method and results of numerical simulations of dynamic interactions between vehicles and the bridge structure, which has defects in the form of excessive permanent deflections of their spans. The simulation analyzes were carried out on the example of a real motorway bridge, on which the presence of such defects was found. A typical 5-axle truck with a total weight of 40 tons was modeled as a moving load. During the analyzes, the main attention was paid to the values of vertical displacements and accelerations of vibrations of the bridge spans generated by heavy vehicles as a function of the intensity of permanent deflections of the structure and the vehicles speed. Keywords: Dynamic analysis of bridges; Bridge vibrations; Finite Element Method; Structure deformations

Iwona Chmielewska

Organic soil is characterised by high compressibility and should be improved so that it can be used for construction. The use of every method of soil improvement requires knowledge of the compressibility parameters. One of these parameters is the constrained modulus. The constrained modulus can be determined using laboratory or in-situ tests. In this study, the constrained modulus of organic soil was determined using oedometer and piezocone tests (CPTU). The author analysed subsoil under an approximately 250 m section of a designed road in north-eastern Poland. The constrained modulus of organic soil sampled from four different depths was determined in oedometer tests. Piezocone tests were conducted at 18 points located every 15 m along the length of the section concerned. To determine the constrained modulus based on the cone resistance from CPTU tests, the knowledge of the α and αM coefficients is needed. For the tested soil, the optimal range of the α coefficient from 0.4 to 0.7 was determined. The αM coefficient ranged from 0.4 to 0.8. The value of the constrained modulus of organic soil obtained from the oedometer tests, depending on the effective stress, ranged from approximately 100 kPa to 400 kPa. The constrained modulus of the tested soil decreased with depth, which both research methods proved.

Priyank H. Patel, V. Patel, M. VedwalaKhushbu

Bagus Hario Setiadji, Hariadi Dewabrata, Han Ay Lie et al.

Era kini ditandai dengan penekanan pada konsevasi energi, beton ramah lingkungan dan beton hijau. Semen merupakan bahan utama pembentuk beton, dan juga penyumbang pencemaran udara terbesar di antara bahan penyusun material tersebut. Semen slag atau Ground Granulated Blast Furnace Slag (GGBFS) yang merupakan hasil pengolahan limbah industri baja menjadi salah satu alternatif yang diminati karena proses produksi dan lebih ekonomis bila dibandingkan dengan Portland Cement (PC). Material yang mempunyai sifat cementitious ini berpotensi untuk menggantikan sebagian semen dalam campuran beton dengan tetap mempertahankan kelebihan sifat mekanis beton. Penelitian ini dilakukan di laboratorium dengan pengujian benda uji yang telah didesain dengan komposisi substitusi semen slag sebesar 0%, 10%, 20%, 30%, 40%, dan 50% dari berat semen yang dibutuhkan dan pada umur 28 hari. Sebagai benda uji kontrol beton direncanakan dengan kuat tekan f’c = 38 MPa. Semen slag yang digunakan berdasarkan referensi memiliki activity index grade 80. Penelitian dilakukan untuk mengetahui kinerja semen slag pada beton melalui pengamatan kuat tekan (f’c), hubungan tegangan-regangan (fc - ε) dan modulus elastisitas (E) beton. Pengujian menunjukkan bahwa substitusi slag menyebabkan terjadinya penurunan kuat tekan beton, regangan dan modulus elastisitas pada umur 28 hari karena adanya proses kimia yang lebih lamban daripada PC.

K. Ojha