scholarly journals MINERALINIŲ MEDŽIAGŲ MECHANINIŲ SAVYBIŲ TYRIMAI, ANALIZĖ IR VERTINIMAS / RESEARCH, ANALYSIS, AND EVALUATION OF MECHANICAL PROPERTIES OF AGGREGATES

2018 ◽  
Vol 10 (0) ◽  
pp. 1-9 ◽  
Author(s):  
Lina Šneideraitienė ◽  
Daiva Žilionienė
Keyword(s):  
Mechanical Properties ◽  
Asphalt Pavement ◽  
Road Construction ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Test Results ◽  
Analysis And Evaluation ◽  
Baltic Countries ◽  
Research Analysis ◽  
Mineral Aggregates

The two Baltic countries, Lithuania and Latvia, use asphalt mixtures with granite slag that is imported from other countries to install the top layer of asphalt pavement, which is quite expensive. One of the requirements for aggregates used in road construction is mechanical properties. There are some differences between these countries based on national requirements. The article presents test methods for determining the mechanical properties of aggregates. According to them, the mechanical properties of aggregates were tested: resistance to fragmentation, wear, polishing and to wear by abrasion from studded tyre. Tested aggregates were Lithuanian dolomite quarry stone, which was made based on the developed and common technologies as well as imported granite from Ukraine. The analysis and evaluation of the test results have been carried out by the requirements for mineral aggregates of Lithuania and Latvia. Santrauka Dvi Baltijos šalys, Lietuva ir Latvija, asfalto dangos viršutiniam sluoksniui įrengti naudoja asfalto mišinius su granito skalda, kuri importuojama iš kitų šalių, o tai gana brangu. Vienas iš reikalavimų mineralinėms medžiagoms, naudojamoms kelių tiesyboje, yra mechaninės savybės. Jos minėtose šalyse pagal nacionalinius normatyvinius reikalavimus šiek tiek skiriasi. Straipsnyje pateikti mineralinių medžiagų mechaninių savybių nustatymo bandymo metodų aprašai. Pagal juos atlikti skaldų mechaninių savybių bandymai: atsparumas smūgiams, trupinimui, dėvėjimuisi, poliruojamumui (LST EN 1097-8:2009. Bandymai užpildų mechaninėms ir fizikinėms savybėms nustatyti. 8 dalis. Akmens poliruojamumo nustatymas) bei dygliuotoms padangoms. Ištirtos skaldos yra Lietuvos dolomito karjero skalda, pagaminta pagal patobulintą ir įprastą technologijas, bei granito skalda iš Ukrainos. Atlikta gautų bandymų rezultatų analizė bei vertinimas pagal Lietuvos ir Latvijos reikalavimus mineralinėms medžiagoms.

scholarly journals Evaluation of Short-Term Aging Protocol for Asphalt Mixtures

2019 ◽  
Vol 9 (14) ◽  
pp. 2783 ◽  
Author(s):  
Sirin ◽  
Paul ◽  
Kassem ◽  
Ohiduzzaman
Keyword(s):  
Mechanical Properties ◽  
Asphalt Pavement ◽  
Road Construction ◽  
Asphalt Mixtures ◽  
Pavement Performance ◽  
Design Stage ◽  
Construction Site ◽  
Short Term ◽  
Compaction Processes

Asphalt mixtures are subjected to short-term aging during the production, placement, and compaction processes. Proper evaluation of asphalt pavement performance relies on the accurate characterization of asphalt mixtures during the design stage. In this study, three different loose asphalt mixtures often used in Qatar were evaluated to develop a laboratory short-term aging procedure. Sample mixtures 1 and 3 were collected from a construction site, while mixture 2 was obtained from an asphalt plant. Virgin aggregates and binders were also collected to reproduce the mixtures in the laboratory. Laboratory-produced mixtures were conditioned at 135 °C using various time durations. The mechanical properties of laboratory-produced mixtures were compared to those of mixtures produced on site. The results of the mechanical and binder testing demonstrated that the proper short-term aging protocol for asphalt mixtures often used in road construction in the State of Qatar would involve heating asphalt mixtures for 4 h at 135 °C before laboratory compaction.

Application of Small Punch Test to Evaluate Tensile Properties of SA213T22 Grade Boiler Steel

2015 ◽  
Vol 830-831 ◽  
pp. 191-194
Author(s):  
M. Venkateswara Rao
Keyword(s):  
Mechanical Properties ◽  
High Temperature ◽  
Tensile Properties ◽  
Test Methods ◽  
Uniaxial Tensile ◽  
Test Results ◽  
Small Punch Test ◽  
Small Punch ◽  
Punch Test ◽  
Aging Phenomena

Conventional tensile test methods are used for service exposed high temperature boiler tubes to evaluate the deterioration in mechanical properties such as tensile strength, yield strength and percentage elongation. The mechanical properties are required to be evaluated periodically as the boiler components undergo material degradation due to aging phenomena. The aging phenomena occurs due to continuous exposure of tubes to high temperature & pressure steam prevailing inside the tubes and high temperature exposure to corrosive combustible gases from the external surfaces within the boiler.A recent developed new technique called small punch testing has been used to evaluate the tensile properties of SA 213T22 grade steel predominantly exists in super-heater and re-heater sections of boiler. The small punch tests have been carried out on the miniature disk shaped specimens of diameter of 8.0 mm and 0.5 mm thickness extracted from both the new and service exposed tubes. Conventional uniaxial tensile tests on standard specimens from the same tube material have also been performed for comparison. The service exposed tubes showed considerable loss in mechanical properties in both the conventional and small punch test results. Correlations of tensile properties have been obtained based on the comparative analysis of both small punch and uniaxial tensile test results. Further, the study showed that an appropriate empirical relation could be generated for new and service exposed materials between both the techniques. Conventional test methods require large quantity of material removal for test samples from in-service components whereas small punch test method needs only a miniature sample extraction. This small punch test technique could also be extended to evaluate the thicker section boiler components such as pipelines and headers in the boiler as a part of remaining life assessment study. Also this technique could be a useful tool to any metallic component where large quantity of sample removal may be difficult or may not be feasible.

Stabilization of clayey subgrade with waste pumice for road infrastructure

2015 ◽  
Vol 22 (5) ◽  
Author(s):  
Ömür Çimen ◽  
Mehmet Saltan ◽  
S. Nilay Keskin
Keyword(s):  
Mechanical Properties ◽  
Road Construction ◽  
High Plasticity ◽  
Test Results ◽  
Index Properties ◽  
Compression Tests ◽  
Unconfined Compression ◽  
Swelling Potential ◽  
Project Costs ◽  
High Plasticity Clay

AbstractHigh-plasticity clayey subgrade, which is unsuitable for road construction, may sometimes occur along highway routes. In such cases, engineers need to change the route of a highway project, resulting in an increase in road length and project costs. In this study, waste pumice was examined for stabilization of high-plasticity clayey subgrade, which is inappropriate for road construction. For this purpose, the physical and index properties of clay and pumice were determined. Then, the pumice was mixed with high plasticity clay at different ratios by weight. By performing standard Proctor compaction tests on the mixtures, the effects of adding pumice on compaction were also studied. Unconfined compression tests and California bearing ratio (CBR) tests were performed on all pumice-clay mixtures, and the test results and the CBR ratios were compared for each sample, respectively. The results showed that pumice stabilization improved the mechanical properties and reduced the swelling potential of high plasticity clayey subgrade.

scholarly journals Impact of Preheating Temperatures and RAP Characteristics on the Activation of RAP Binder

2020 ◽  
Vol 10 (23) ◽  
pp. 8378
Author(s):  
Yifu Meng ◽  
Liping Liu
Keyword(s):  
Mechanical Properties ◽  
Asphalt Pavement ◽  
Asphalt Mixtures ◽  
Reclaimed Asphalt Pavement ◽  
Reclaimed Asphalt ◽  
Central Plant ◽  
Preheating Temperature

Reclaimed asphalt pavement (RAP) is preheated to 120 °C or lower in hot central plant recycling due to specification and equipment limitations. However, the insufficient activation of reclaimed asphalt (RA) caused by low preheating temperature may affect the final properties of reclaimed asphalt mixtures (RAM) and lead to insufficient utilization of RA binder. This study evaluated the influence of preheating temperature and aging of RA binder on binder activation by producing specimens with 100% RAP. The volumetric and mechanical properties of specimens were analyzed to reflect the effect of activation. The results indicate that preheating temperature has a significant impact on the activation of RA binder. Regardless of the source of RAP, RA binder can be highly activated at 180 °C, while the degree of activation decreases significantly at 120 °C. By using an artificial RAP with different degrees of aging, the aging of RA binder is found to be harmful to activation only when the preheating temperature is low (such as 120 °C). Hence, if the equipment is capable of doing so, it is better to raise the preheating temperature of RAP to improve the activation of RA binder, especially for binder with a higher degree of aging.

Re-Examining the Bulge Test: Methods for Improving Accuracy and Reliability

1991 ◽  
Vol 239 ◽  
Author(s):  
Martha K. Small ◽  
Joost J. Vlassak ◽  
William D. Nix
Keyword(s):  
Thin Film ◽  
Mechanical Properties ◽  
Tensile Tests ◽  
Test Methods ◽  
Tension Test ◽  
Bulge Test ◽  
Test Results ◽  
Bulk Materials ◽  
Test Technique ◽  
Improving Accuracy

ABSTRACTSince its first application to thin films in the 1950's, the bulge test has had a prominent place in the field of thin film mechanical properties. The major appeal of the technique is that it is analogous to the familiar uniaxial tension test, which is commonly applied to bulk materials. At the same time, it avoids the sample tearing and alignment problems associated with micro-tensile tests. Unfortunately, bulge test results have been sometimes controversial and difficult to reproduce. In this paper we address possible causes for mese inconsistencies and describe a method by which the bulge test technique can be made to produce accurate and reliable results.

scholarly journals Analysis of Nanoindentation Test Results of Asphalt Mixture with Different Gradations

2021 ◽  
Vol 11 (17) ◽  
pp. 7992
Author(s):  
Yunhong Yu ◽  
Gang Xu ◽  
Tianling Wang ◽  
Huimin Chen ◽  
Houzhi Wang ◽  
...  
Keyword(s):  
Material Properties ◽  
Asphalt Mixture ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Nanoindentation Test ◽  
Test Results ◽  
Before And After ◽  
Mineral Powder ◽  
Powder Content ◽  
Interaction Surface

Nanoindentation has been applied in the field of asphalt mixtures, but, at the nano-scale, changes in the composition of the mixture and material properties can have a significant impact on the results. Therefore, it is necessary to investigate the feasibility of nanoindentation tests on different types of asphalt mixtures with different gradations and the influence of material properties and test methods on nanoindentation results. In this paper, the nanoindentation test results on three kinds of asphalt mixture (AC-13, SMA-13, and OGFC-13) with different aggregate gradations were investigated. The load-displacement curves and moduli obtained from the nanoindentation tests were analyzed. In addition, nanoindentation tests were carried out before and after polishing with different ratios of filler and asphalt (RFA) (0.8–1.6). On this basis, the morphology of asphalt specimens with different RFAs is observed by scanning electron microscopy (SEM) imaging. The results indicate that using the nanoindentation test to characterize the mechanical behavior of asphalt mixture, the confidence level of the dense-graded mixture is low, and non-dense-graded mixtures are used as much as possible. Moreover, results illustrate that the nanoindentation modulus tends to increase as the RFA increases. and the SEM chart shows that the higher the mineral powder content in the mastic, the more complex the bitumen and mineral powder interaction surface, confirming the influence of mineral powder content on the nanoindentation test results. Furthermore, the effect of polishing is almost insignificant.

scholarly journals Fundamental Approaches to Predict Moisture Damage in Asphalt Mixtures: State-of-the-Art Review

2020 ◽  
Vol 5 (2) ◽  
pp. 20 ◽  
Author(s):  
Hilde Soenen ◽  
Stefan Vansteenkiste ◽  
Patricia Kara De Maeijer
Keyword(s):  
State Of The Art ◽  
Asphalt Pavement ◽  
Flexible Pavements ◽  
Asphalt Mixture ◽  
Moisture Damage ◽  
Test Methods ◽  
Asphalt Mixtures ◽  
Moisture Susceptibility ◽  
The Individual

Moisture susceptibility is still one of the primary causes of distress in flexible pavements, reducing the pavements’ durability. A very large number of tests are available to evaluate the susceptibility of a binder aggregate combination. Tests can be conducted on the asphalt mixture, either in a loose or compacted form, or on the individual components of an asphalt pavement. Apart from various mechanisms and models, fundamental concepts have been proposed to calculate the thermodynamic tendency of a binder aggregate combination to adhere and/or debond under wet conditions. The aim of this review is to summarize literature findings and conclusions, regarding these concepts as carried out in the CEDR project FunDBits. The applied test methods, the obtained results, and the validation or predictability of these fundamental approaches are discussed.

Research of Mechanical Properties of Asphalt Pavement Materials with WMA and RAP

2012 ◽  
Vol 204-208 ◽  
pp. 3934-3937 ◽  
Author(s):  
Bao Yang Yu ◽  
Yu Wang ◽  
Min Jiang Zhang
Keyword(s):  
Mechanical Properties ◽  
Tensile Strength ◽  
Dynamic Modulus ◽  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Mixtures ◽  
Indirect Tensile Strength ◽  
Porous Asphalt ◽  
Compaction Energy ◽  
Indirect Tensile

The objectives of this paper are to characterize the mechanical properties of porous asphalt pavement mixtures containing RAP and a WMA additive using Super pave gyratory compactor and dynamic modulus testing. Four types of asphalt mixtures were evaluated in this study. This study evaluated compaction energy index, permeability, indirect tensile strength, and dynamic modulus for all types of porous asphalt mixtures. All of the asphalt mixtures meet the typical minimum coefficient of permeability in this study. In addition, only a slight decrease in was found when WMA additive was added to the porous asphalt mixture containing RAP. For indirect tensile strength testing, WMA containing RAP was found to have the highest tensile strength among all of the mixtures tested.

Research of Fatigue Behavior of Asphalt Pavement Materials with WMA and RAP

2013 ◽  
Vol 361-363 ◽  
pp. 1783-1786 ◽  
Author(s):  
Bao Yang Yu ◽  
Yu Wang ◽  
Zhong Hua Zhao
Keyword(s):  
Asphalt Concrete ◽  
Dynamic Modulus ◽  
Life Cycle Cost ◽  
Asphalt Pavement ◽  
Fatigue Behavior ◽  
Road Construction ◽  
Asphalt Mixtures ◽  
Traffic Load ◽  
Porous Asphalt ◽  
Form Of Life

With the development of chinas road construction, the increase of traffic and the traffic load the fatigue of asphalt pavement under the vehicle load has become one of the major disruption in the form of life of life of asphalt concrete directly affect the service life and the performance use of asphalt pavement ,it is a key factor to determine the life cycle cost of asphalt concrete pavement construction. The objectives of this paper are to characterize the fatigue behavior of porous asphalt pavement mixtures containing RAP and a WMA additive using Super pave gyratory compactor and dynamic modulus testing. Four types of asphalt mixtures were evaluated in this study. This study evaluated compaction energy index, permeability, indirect tensile strength, and dynamic modulus for all types of porous asphalt mixtures. All of the asphalt mixtures meet the typical minimum coefficient of permeability in this study.

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