scholarly journals Analysis of the Behavior of SMA Mixtures with Different Fillers Through the Semicircular Bend (SCB) Fracture Test

Materials ◽  
2019 ◽  
Vol 12 (2) ◽  
pp. 288 ◽  
Author(s):  
Pedro Limón-Covarrubias ◽  
David Avalos Cueva ◽  
Gonzalo Valdés Vidal ◽  
Oscar Reyes Ortiz ◽  
Rey Adame Hernández ◽  
...  
Keyword(s):  
Fracture Energy ◽  
Asphalt Mixtures ◽  
Thin Layers ◽  
Concrete Slabs ◽  
Portland Cement Concrete ◽  
Fracture Test ◽  
Different Types ◽  
Different Temperatures ◽  
Stone Mastic Asphalt ◽  
Cracking Process

In most cases, stone mastic asphalt (SMA) mixtures placed in thin layers and subjected to stress develop early cracks (potentially resulting from being improperly affixed to the underlying layer, placed over previously cracked asphalt pavement, or placed over Portland cement concrete slabs). However, the filler used in SMA production is very influential on the performance of the mix. Fillers used in this type of mixture have a low plastic index or are inert (calcium carbonate or lime), so it is important to understand the effect of each material on the possible fissuring and cracking process of the SMA mixture. The objective of this study is to present an evaluation of the behavior of SMA asphalt mixtures with different types of filler and at different temperatures using the semicircular bend (SCB) fracture energy test. This research compares results between fracture energy and different types of filler in SMA asphalt mixtures at temperatures ranging from −10 to 25 °C.

scholarly journals Effect of Rubberized Bitumen Blending Methods on Permanent Deformation of SMA Rubberized Asphalt Mixtures

2016 ◽  
Vol 2016 ◽  
pp. 1-14 ◽  
Author(s):  
Herda Yati Katman ◽  
Mohd Rasdan Ibrahim ◽  
Mohamed Rehan Karim ◽  
Suhana Koting ◽  
Nuha Salim Mashaan
Keyword(s):  
Creep Behaviour ◽  
Permanent Deformation ◽  
Asphalt Mixtures ◽  
Creep Model ◽  
Materials Testing ◽  
Wet Process ◽  
Test Conditions ◽  
Dynamic Creep ◽  
Different Temperatures ◽  
Stone Mastic Asphalt

This study aims at comparing the permanent deformation of Stone Mastic Asphalt (SMA) rubberized asphalt mixtures produced by the wet process. In this study, rubberized binders were prepared using two different blending methods, namely, continuous blend and terminal blend. To study the creep behaviour of control and rubberized asphalt mixtures, the dynamic creep test was performed using Universal Materials Testing Apparatus (UMATTA) at different temperatures and stress levels. Zhou three-stage creep model was utilized to evaluate the deformation characteristics of the mixtures. In all test conditions, the highest resistance to permanent deformation is showed by the rubberized mixtures produced with continuous blend binders. This study also reveals that the permanent deformation of rubberized mixtures cannot be predicted based on the characteristics of the rubberized binders.

Material and Cost Solutions Used for Construction of Upper Layers of the Road Pavement Structures

2018 ◽  
Vol 878 ◽  
pp. 224-228
Author(s):  
Ewa Ołdakowska
Keyword(s):  
Asphalt Concrete ◽  
Cost Optimization ◽  
Weather Conditions ◽  
Asphalt Mixtures ◽  
Thin Layers ◽  
Mastic Asphalt ◽  
Road Pavement ◽  
Rigid Pavements ◽  
Stone Mastic Asphalt ◽  
Rigid Design

Availability and variety of materials and technologies used for construction of roads allows for searching for solutions which are the best and optimal in the economical range. The article presents the analysis of various design solutions (susceptible, semi-rigid, and rigid pavements) depending on material and cost solutions. In case of susceptible and semi-rigid pavements the first layer subjected to direct influence of traffic and weather conditions is the grindable layer. It may be made from various mineral and asphalt mixtures: stone mastic asphalt (SMA), asphalt concrete (AC), porous asphalt (PA), asphalt concrete for very thin layers (BBTM), and mastic asphalt (MA). The costs of realization of 4 cm of the grindable layer vary from 40.37 PLN to 50.65 PLN (1 PLN = 0.26 USD) depending on used mixture. Another layer in the susceptible and semi-rigid pavements is the binding layer, and the realization cost per 1m2 of the binding layer e.g. of type B is from 53.46 PLN to 71.37 PLN depending on used mixture and traffic category. The materials used for realization of the binding layer are the mineral and asphalt mixtures, in particular the asphalt concrete of three recommended graining - AC 11, AC 16, and AC 22. The material and cost optimization of the typical solutions of the pavement design, taking all layers into consideration, allowed for determining the “economical” solutions not only for a given traffic category, but also for a given type. Savings in case of the same design types are from approximately 11 PLN to over 12 PLN for the susceptible and semi-rigid design, and from 0.39 PLN to 0.49 PLN in case of realization of 1 m2 of the rigid design.

scholarly journals Evaluation of Fracture Resistance of Asphalt Mixtures Using the Single-Edge Notched Beams

2018 ◽  
Vol 2018 ◽  
pp. 1-9 ◽  
Author(s):  
Biao Ding ◽  
Xiaolong Zou ◽  
Zixin Peng ◽  
Xiang Liu
Keyword(s):  
Fracture Toughness ◽  
Fracture Energy ◽  
Viscoelastic Properties ◽  
Fracture Resistance ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Single Edge ◽  
Fracture Properties ◽  
Different Temperatures ◽  
Peak Value

To determine and compare the fracture properties of different asphalt mixtures, single-edge notched beam (SENB) tests using three types of asphalt mixtures were applied in this study under the conditions of different notched depths and different temperatures. The effects of notched depths and temperatures on the fracture toughness and fracture energy were analyzed. The results indicate that the notch depth has no significant effects on the fracture toughness and the fracture energy, but the gradation has relatively obvious effects on the fracture energy, which the larger contents of course aggregate leads to increase the discreteness of the fracture energy of the specimen. The temperature has significant effects on the ultimate loads, fracture energy, and fracture toughness. The ultimate loads of the SENBs reach the peak value at 0°C, which could be resulted in that viscoelastic properties of asphalt mixture depend with temperatures. The fracture toughness at −20°C of continuously graded asphalt mixtures are higher than those of gap-graded asphalt mixtures. On the contrary, the fracture toughness of gap-graded asphalt mixtures is higher at temperatures from −10°C to 20°C. The fracture energy increases with temperatures, and the fracture energy of SMA-13 is significantly larger than those of AC-13 and AC-16.

scholarly journals The Addition of a High Dosage of Rubber to Asphalt Mixtures: The Effects on Rutting and Fatigue

2021 ◽  
Vol 13 (17) ◽  
pp. 9718
Author(s):  
Amin Chegenizadeh ◽  
Pak Jing Shen ◽  
Indah Sekar Arumdani ◽  
Mochamad Arief Budihardjo ◽  
Hamid Nikraz
Keyword(s):  
Service Life ◽  
Asphalt Mixture ◽  
Road Construction ◽  
Crumb Rubber ◽  
Asphalt Mixtures ◽  
Maintenance Costs ◽  
Different Types ◽  
Stone Mastic Asphalt ◽  
Marshall Stability ◽  
Positive Effect

Bitumen is subjected to cracks and damage during its service life. Adding a material with the potential to increase the durability of bitumen can expand its service life and reduce maintenance costs. Previous studies indicate that adding crumb rubber into asphalt has a positive effect on the performance of the mixture. Using crumb rubber may solve environmental problems due to vehicle tire waste disposal by reducing maintenance costs needed to increase asphalt’s strength. Some studies have investigated the effect of bitumen mixed with crumb rubber; however, it seems that the effect of different types of rubber mixtures used has been overlooked. Therefore, this study aims to better understand the effects of the increasing amount of rubber addition in various types of asphalt mixtures and determine the optimal mixture that could be used in road construction. A series of experiment was conducted, incorporating various tests (such as Marshall stability, rutting, and fatigue), to test various mixtures of asphalt in the form of dense-graded asphalt (DGA), fine gap-graded asphalt (FGG), gap-graded asphalt (Stone Mastic Asphalt, SMA), and open-graded asphalt. The amount of added crumb rubber was 25% by weight of bitumen. All mixtures were classified as superior in rutting and fatigue resistance, since they all reached a maximum depth of rutting less than 15 mm and generated two times more failure cycles compared to the conventional asphalt. The most optimal performance asphalt mixture was showed by the SMA10 mixture, resulting in a minimum rut depth of less than 1.2 mm and producing 750% more fatigue cycles than conventional asphalt. The result indicates that the addition of 25% of the rubber particles in the binder can increase the properties and durability of asphalt mixtures.

scholarly journals GERMINATION AND VIGOUR IN SEEDS OF THE COWPEA IN RESPONSE TO SALT AND HEAT STRESS

2019 ◽  
Vol 32 (1) ◽  
pp. 143-151 ◽  
Author(s):  
Luma Rayane de Lima Nunes ◽  
Paloma Rayane Pinheiro ◽  
Charles Lobo Pinheiro ◽  
Kelly Andressa Peres Lima ◽  
Alek Sandro Dutra
Keyword(s):  
Salt Stress ◽  
Heat Stress ◽  
High Temperature ◽  
Low Temperature ◽  
Vigna Unguiculata ◽  
Salt Concentration ◽  
Dry Weight ◽  
Germination Percentage ◽  
Different Types ◽  
Different Temperatures

ABSTRACT Salinity is prejudicial to plant development, causing different types of damage to species, or even between genotypes of the same species, with the effects being aggravated when combined with other types of stress, such as heat stress. The aim of this study was to evaluate the tolerance of cowpea genotypes (Vigna unguiculata L. Walp.) to salt stress at different temperatures. Seeds of the Pujante, Epace 10 and Marataoã genotypes were placed on paper rolls (Germitest®) moistened with different salt concentrations of 0.0 (control), 1.5, 3.0, 4.5 and 6.0 dS m-1, and placed in a germination chamber (BOD) at temperatures of 20, 25, 30 and 35°C. The experiment was conducted in a completely randomised design, in a 3 × 4 × 5 scheme of subdivided plots, with four replications per treatment. The variables under analysis were germination percentage, first germination count, shoot and root length, and total seedling dry weight. At temperatures of 30 and 35°C, increases in the salt concentration were more damaging to germination in the Epace 10 and Pujante genotypes, while for the Marataoã genotype, damage occurred at the temperature of 20°C. At 25°C, germination and vigour in the genotypes were higher, with the Pujante genotype proving to be more tolerant to salt stress, whereas Epace 10 and Marataoã were more tolerant to high temperatures. Germination in the cowpea genotypes was more sensitive to salt stress when subjected to heat stress caused by the low temperature of 20°C or high temperature of 35°C.

scholarly journals Multi-Criteria Selection of Additives in Porous Asphalt Mixtures Using Mechanical, Hydraulic, Economic, and Environmental Indicators

2021 ◽  
Vol 13 (4) ◽  
pp. 2146
Author(s):  
Anik Gupta ◽  
Carlos J. Slebi-Acevedo ◽  
Esther Lizasoain-Arteaga ◽  
Jorge Rodriguez-Hernandez ◽  
Daniel Castro-Fresno
Keyword(s):  
Cellulose Fiber ◽  
Environmental Indicators ◽  
Asphalt Mixtures ◽  
Environmental Benefits ◽  
Modified Bitumen ◽  
Porous Asphalt ◽  
Different Types ◽  
Product Assessment ◽  
Polymer Modified Bitumen ◽  
Selection Of

Porous asphalt (PA) mixtures are more environmentally friendly but have lower durability than dense-graded mixtures. Additives can be incorporated into PA mixtures to enhance their mechanical strength; however, they may compromise the hydraulic characteristics, increase the total cost of pavement, and negatively affect the environment. In this paper, PA mixtures were produced with 5 different types of additives including 4 fibers and 1 filler. Their performances were compared with the reference mixtures containing virgin bitumen and polymer-modified bitumen. The performance of all mixes was assessed using: mechanical, hydraulic, economic, and environmental indicators. Then, the Delphi method was applied to compute the relative weights for the parameters in multi-criteria decision-making methods. Evaluation based on distance from average solution (EDAS), technique for order of the preference by similarity to ideal solution (TOPSIS), and weighted aggregated sum product assessment (WASPAS) were employed to rank the additives. According to the results obtained, aramid pulp displayed comparable and, for some parameters such as abrasion resistance, even better performance than polymer-modified bitumen, whereas cellulose fiber demonstrated the best performance regarding sustainability, due to economic and environmental benefits.

Recent advances in synthesis of organometallic complexes of indium

2020 ◽  
Vol 40 (3) ◽  
pp. 107-151
Author(s):  
Hira Anwar ◽  
Rosenani A. Haque ◽  
Rahman Shah Zaib Saleem ◽  
Muhammad Adnan Iqbal
Keyword(s):  
Material Science ◽  
Thin Film Transistors ◽  
Heterocyclic Carbenes ◽  
Organometallic Complexes ◽  
Organic Ligands ◽  
Group 13 ◽  
Indium Complexes ◽  
Different Types ◽  
Stirring Time ◽  
Different Temperatures

AbstractThe indium complexes are being used in many applications like catalysis, optoelectronics, sensors, solar cells, biochemistry, medicine, infrared (IR) mirrors and thin-film transistors (TFTs). In organometallic complexes of indium, it forms different types of complexes with single, double, triple and tetra linkages by coordinating with numerous elements like C, N, O and S and also with some other elements like Se and Ru. So, the present study comprises all the possible ways to synthesize the indium complexes by reacting with different organic ligands; most of them are N-heterocyclic carbenes, amines, amides and phenols. The commonly used solvents for these syntheses are tetrahydrofuran, dichloromethane, toluene, benzene, dimethyl sulfoxide (DMSO) and water. According to the nature of the ligands, indium complexes were reported at different temperatures and stirring time. Because of their unique characteristics, the organometallic chemistry of group 13 metal indium complexes remains a subject of continuing interest in synthetic chemistry as well as material science.

Kinetics of Ion-Pair Effect of Aquation of Bromopentaammine Cobalt(III) Complex in Different Dicarboxylate Media

2011 ◽  
Vol 324 ◽  
pp. 166-169 ◽  
Author(s):  
Farah Zeitouni ◽  
Gehan El-Subruiti ◽  
Ghassan Younes ◽  
Mohammad Amira
Keyword(s):  
Free Energy ◽  
Solvent Effect ◽  
Compensation Effect ◽  
Ion Pairing ◽  
Reaction Rates ◽  
Ion Pair ◽  
Free Energy Of Activation ◽  
Different Types ◽  
Different Temperatures ◽  
Kinetics Of

The rate of aquation of bromopentaammine cobalt(III) ion in the presence of different types of dicarboxylate solutions containing tert-butanol (40% V/V) have been measured spectrophotometrically at different temperatures (30-600°C) in the light of the effects of ion-pairing on reaction rates and mechanism. The thermodynamic and extrathermodynamic parameters of activation have been calculated and discussed in terms of solvent effect on the ion-pair aquation reaction. The free energy of activation ∆Gip* is more or less linearly varied among the studied dicarboxylate ion-pairing ligands indicating the presence of compensation effect between ∆Hip* and ∆Sip*. Comparing the kip values with respect of different buffers at 40% of ter-butanol is introduced.

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