scholarly journals Characteristics of the fatigue life (IT-FT) of the recycled base course at the controlled stresses state

2014 ◽  
Vol 13 (4) ◽  
pp. 109-116 ◽  
Author(s):  
Marek Iwański ◽  
Przemysław Buczyński ◽  
Grzegorz Mazurek
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Indirect Tensile Test ◽  
Road Pavement ◽  
Indirect Tensile ◽  
Base Course ◽  
The Impact ◽  
Fatigue Life Test

The paper presents the results of the base coarse made in the cold deep recycling technology with the emulsion in aspect of its durability for a different tensile stress level. The recycled base design simulated a deep recycling process with materials from existing crushed bituminous pavement layers("in-situ" technology). While assessing the quality of the designed MCE mixture, the following physical and mechanical parameters were considered: void contents Vm, indirect tensile strength ITSDRY at 25oC, tensile strength ratio TSR, stiffness modulus Sm. Additionally, the evaluation of fatigue was done at three stress cases: 250 Pa, 400 Pa, 500 Pa. The impact of the vehicle axle load on the stress state in the base course was simulated. For the purpose of determining the pavement durability, one of the method of fatigue life test was used. The tests were done according to IT-FT, based on an indirect tensile test (ITT). This method was choosen because it exhibits good equivalence to the real road pavement behaviour.

scholarly journals Indicadores do desempenho de misturas asfálticas determinados através do ensaio de compressão diametral

TRANSPORTES ◽  
2008 ◽  
Vol 16 (1) ◽  
Author(s):  
Lélio Antônio Teixeira Brito ◽  
Jorge Augusto Pereira Ceratti ◽  
Daniel Ramos Victorino
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Fatigue Life ◽  
Cyclic Loading ◽  
Tensile Test ◽  
Resilient Modulus ◽  
Phase Lag ◽  
Asphalt Mixes ◽  
Indirect Tensile Test ◽  
Indirect Tensile

<p>Os ensaios de compressão diametral são amplamente usados no Brasil para determinação das propriedades mecânicas de misturas asfálticas, tanto através de ensaios monotônicos para determinação da resistência à tração, quanto sob carregamentos cíclicos para determinação do módulo de resiliência e da vida de fadiga. Este trabalho teve como objetivo mostrar que com instrumentação adequada destes ensaios, indicadores adicionais àqueles usualmente determinados podem ser obtidos. A energia mobilizada durante o ensaio de resistência à tração, bem como o monitoramento da rigidez ao longo do ensaio de fadiga e a defasagem medida entre o pulso de carga e o deslocamento no ensaio de módulo de resiliência, mostram-se promissores para este propósito.</p><p><em><strong>Abstract</strong> Indirect tensile test (IDT) are broadly used in Brazil for the assessment of mechanical properties of asphalt mixes, not only under monotonic loading to determine the tensile strength, but also under cyclic loading to determine resilient modulus and fatigue life. This study tries to demonstrate that with adequate instrumentation of these tests, additional indicators to those usually determined are possible to be obtained. The mobilized energy during the IDT test, as well as the monitoring of the stiffness during the fatigue test and the phase lag measured between load and displacement pulses in the resilient modulus test are promising for this purpose. </em></p>

Performance Comparison of Asphalt Emulsion Stabilized Granular Base Modified with Cement or Asphaltenes

2021 ◽  
Author(s):  
Muhammad Misbah Uddin ◽  
Farshad Kamran ◽  
Leila Hashemian
Keyword(s):  
Tensile Strength ◽  
Oil Sands ◽  
Performance Comparison ◽  
Indirect Tensile Strength ◽  
Asphalt Emulsion ◽  
Performance Properties ◽  
Low Temperature Cracking ◽  
Indirect Tensile ◽  
Base Course ◽  
The Impact

Asphalt emulsion is a common material used for pavement base course stabilization, and cement is usually added as an active filler to improve the stability of asphalt emulsion mixtures further. However, using cement in these mixes has several drawbacks, including high material costs and environmental issues. On the other hand, asphaltenes is a waste by product derived from the processing of Alberta oil-sands bitumen that could be used for the same purpose. This investigation compares the impact of cement and asphaltenes as additives to asphalt emulsion-stabilized layers. To compare the performance properties, cement- and asphaltenes-modified mixtures are prepared at different concentrations. The performance properties of the modified mixtures are investigated by conducting a series of tests including Marshall stability, indirect tensile strength, IDEAL-CT, and tensile strength ratio. In addition, to evaluate low-temperature cracking resistance of the mixtures, indirect tensile strength test is conducted at 0 °C and −10 °C.

Effect of combined drink cans and steel fibers on the impact resistance and mechanical properties of concrete

2020 ◽  
Vol 14 (2) ◽  
pp. 6734-6742
Author(s):  
A. Syamsir ◽  
S. M. Mubin ◽  
N. M. Nor ◽  
V. Anggraini ◽  
S. Nagappan ◽  
...  
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Compressive Strength ◽  
Reinforced Concrete ◽  
Impact Resistance ◽  
Fiber Reinforced Concrete ◽  
Steel Fibers ◽  
Fiber Reinforced ◽  
Indirect Tensile ◽  
The Impact

This study investigated the combine effect of 0.2 % drink cans and steel fibers with volume fractions of 0%, 0.5%, 1%, 1.5%, 2%, 2.5% and 3% to the mechanical properties and impact resistance of concrete. Hooked-end steel fiber with 30 mm and 0.75 mm length and diameter, respectively was selected for this study.  The drinks cans fiber were twisted manually in order to increase friction between fiber and concrete. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the strength performance of concrete, especially the compressive strength, flexural strength and indirect tensile strength. The results of the experiment showed that the combination of steel fibers and drink cans fibers improved the compressive strength, flexural strength and indirect tensile strength by 2.3, 7, and 2 times as compare to batch 1, respectively. Moreover, the impact resistance of fiber reinforced concrete has increase by 7 times as compared to non-fiber concretes. Moreover, the impact resistance of fiber reinforced concrete consistently gave better results as compared to non-fiber concretes. The fiber reinforced concrete turned more ductile as the dosage of fibers was increased and ductility started to decrease slightly after optimum fiber dosage was reached. It was found that concrete with combination of 2% steel and 0.2% drink cans fibers showed the highest compressive, split tensile, flexural as well as impact strength.    

The Effect of Yarn Linear Density on Mechanical Properties of Plain Woven Kenaf Reinforced Unsaturated Polyester Composite

2013 ◽  
Vol 465-466 ◽  
pp. 962-966 ◽  
Author(s):  
Mohd Pahmi bin Saiman ◽  
Mohd Saidin Bin Wahab ◽  
Mat Uzir Wahit
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Linear Density ◽  
Unsaturated Polyester ◽  
Composite Panel ◽  
Composite Yarn ◽  
Polyester Composite ◽  
The Impact ◽  
Woven Kenaf

To produce a good quality of dry fabric for reinforced material in a natural-based polymer composite, yarn linear density should be in consideration. A woven kenaf dry fabric with three different linear densities of 276tex, 413.4tex and 759tex were produced. The fabrics with different linear densities were been optimize with the assistance of WiseTex software. The optimized dry fabrics were infused with unsaturated polyester to produce composite panel using vacuum infusion process. The composites properties were tested on the tensile strength, flexural strength and the impact strength. The result shows that the mechanical properties of the composite increased when the yarn linear densities increased.

scholarly journals Stability Assessment of Mining Excavations: the Impact of Large Depths

2018 ◽  
Vol 40 (3) ◽  
pp. 180-187
Author(s):  
Tadeusz Majcherczyk ◽  
Zbigniew Niedbalski ◽  
Łukasz Bednarek
Keyword(s):  
Rock Mass ◽  
In Situ Monitoring ◽  
Stability Assessment ◽  
Underground Excavations ◽  
Deformation Prediction ◽  
Large Depth ◽  
Coal Deposits ◽  
The Impact

AbstractBack in the early 1980s, coal deposits occurring at depths of ~700 m below surface were already regarded as large-depth deposits. Meanwhile, today the borderline depth of large-depth mining has extended to >1,000 m. Design, excavation and maintenance of mining roadways at the depth of >1,000 m have, therefore, become crucial issues in a practical perspective in recent years. Hence, it is now extremely important to intensify research studies on the influence of large depths on the behaviour of rock mass and deformation of support in underground excavations. The paper presents the results of the study carried out in five mining excavations at depths ranging from 950 to 1,290 m, where monitoring stations with measurement equipment were built. The analysis of data from laboratory and coal mine tests, as well as in situ monitoring, helped to formulate a set of criteria for stability assessment of underground excavations situated at large depths. The proposed methodology of load and deformation prediction in support systems of the excavations unaffected by exploitation is based on the criteria referring to the depth of excavation and the quality of rock mass. The depth parameter is determined by checking whether the analysed excavation lies below the critical depth, whereas the rock mass quality is determined on the basis of the roof lithology index (WL) and the crack intensity factor (n)

scholarly journals The Impact of Slicing Softwares on the Mechanical Properties of 3D Printed Parts

2020 ◽  
Vol 9 (2) ◽  
pp. 487-494
Keyword(s):  
Mechanical Properties ◽  
Surface Roughness ◽  
Tensile Strength ◽  
Ultimate Tensile Strength ◽  
3D Printer ◽  
Stl File ◽  
3D Printed ◽  
Intersection Curves ◽  
The Impact

“Slicing tool” or “Slicing Software” computes the intersection curves of models and slicing planes. They improve the quality of the model being printed when given in the form of STL file. Upon analyzing a specimen that has been printed using two different slicing tools, there was a drastic variation on account of the mechanical properties of the specimen. The ultimate tensile strength and the surface roughness of the material vary from one tool to another. This paper reports an investigation and analysis of the variation in the ultimate tensile strength and the surface roughness of the specimen, given that the 3D printer and the model being printed is the same, with a variation of usage of slicing software. This analysis includes ReplicatorG, Flashprint as the two different slicing tools that are used for slicing of the model. The variation in the ultimate tensile strength and the surface roughness are measured and represented statistically through graphs. An appropriate decisive conclusion was drawn on the basis of the observations and analysis of the experiment on relevance to the behavior and mechanical properties of the specimen.

scholarly journals Stiffness Modulus of Asphaltic Concrete Incorporating Coir Fibre and Subjected to Aging

2018 ◽  
Vol 65 ◽  
pp. 02003
Author(s):  
Abdullahi Ali Mohammed ◽  
Ramadhansyah Putra Jaya ◽  
Étienne Joseph Marie Delbrel ◽  
Choong Wee Kang ◽  
Sien Ti Kok ◽  
...  
Keyword(s):  
Stiffness Modulus ◽  
Modified Asphalt ◽  
Indirect Tensile Test ◽  
Coir Fibre ◽  
Performance Response ◽  
Short And Long Term ◽  
Indirect Tensile ◽  
Repeated Load ◽  
The Impact

The aim of this paper is to investigate the performance response of a set of coir fibre modified asphalt samples subjected different ageing conditions and containing three different fibre contents. The laboratory experimental programs are indirect tensile test at 25°C and repeated load axial test at 40°C. The results showed that the fibres improved the mixture’s performance. The main findings obtained at 25°C for short and long-term ageing reveal that low fibre content at around 0.3% per aggregate weight display a stiffness modulus up to 14% higher than that of unmodified mixtures, hence showing that fibres may improve the bearing capacity and rut-resistance of asphalt mixtures. Conversely, as the amount of fibre increases to 0.5% and 0.7%, the stiffness decreases to the point of becoming unacceptably low, almost 80% lower than unmodified mixes stiffness. However the data also reveal that high fibre contents at 0.5% and above completely neutralize the impact of ageing on the mixture, indicating that fibre-modified mixtures would yield longer lives.

Moisture Sensitivity of Bituminous Mixtures with Compound Fly Ash Modifier

2012 ◽  
Vol 509 ◽  
pp. 149-154
Author(s):  
Jun Xie ◽  
Jun Cai ◽  
Shao Peng Wu ◽  
Ling Pang
Keyword(s):  
Tensile Strength ◽  
Fatigue Life ◽  
Fly Ash ◽  
Moisture Damage ◽  
Moisture Sensitivity ◽  
Bituminous Mixtures ◽  
Primary Object ◽  
New Type ◽  
Indirect Tensile ◽  
Short Span

Bitumen pavement suffers from moisture damage mainly due to loss of durability and stability in a short span of service life. Filler is known to be capable of increasing the stiffness of bitumen binder, contributing to improvement of moisture sensitivity of bitumen mixture. In this paper a new type of filler named 'Compound Fly Ash Modifier' (CFAM) was introduced in order to enhance the bond strength between acidic aggregate with bitumen. The primary object is to determine the effect of CFAM on the moisture sensitivity of bitumen mixtures prepared by gneiss and granite respectively, which are termed acidic aggregate. Modified Lottman test and fatigue test were conducted. The results show that CFAM improves the resistance of mixes to moisture damage in the increase in indirect tensile strength and the extension of fatigue life. Finally the mechanism of modified effects for CFAM is discussed.

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