scholarly journals Fracture Performance of a Large-Stone Asphalt Mixture Based on a Monotonic Tensile Overlay Test

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Jianhui Wei ◽  
Tao Fu ◽  
Junlin Liang
Keyword(s):  
Constitutive Model ◽  
Fracture Energy ◽  
Asphalt Mixture ◽  
Test Results ◽  
Large Stone ◽  
Loading Mode ◽  
Disturbed State Concept ◽  
Study Results ◽  
Fracture Performance ◽  
Base Course

A large-stone asphalt mixture (LSAM) is usually used as the base course of asphalt pavement to prevent the generation of cracks. However, there are few studies on the fracture performance and crack resistance of LSAMs. Under the monotonic tensile loading mode, the overlay test (OT) was explored to investigate the influence of different test factors on the cracking resistance and fracture performance. The study results indicated that a change in temperature and aging results in a variation in fractal dimension, the fracture energy of crack growth is higher than that of crack initiation, and fracture energy is increased to a certain extent by decreased temperature, an increased loading rate or increased aging. Finally, a constitutive model is established based on the disturbed state concept (DSC), and the proposed constitutive model is consistent with the test results.

Measurement on Fatigue Cracking Thresholds of the Cast Steel for Chinese Railway Rolling Wagon Bogie Frames

2010 ◽  
Vol 118-120 ◽  
pp. 111-115
Author(s):  
Hai Bin Hu ◽  
Yong Xiang Zhao
Keyword(s):  
Growth Rate ◽  
Growth Rates ◽  
Cast Steel ◽  
Fatigue Cracking ◽  
Test Results ◽  
Present Material ◽  
Loading Mode ◽  
Study Results ◽  
Crack Growth Rates ◽  
Rate Requirement

Measurement on fatigue cracking thresholds is investigated to the grade B cast steel for China railway rolling wagon bogie frames. Compact tensional specimens are fatigued under a continuous decreasing loading mode for present study. Results reveal that the minimum test values have different crack growth rates without meeting the code-based rate requirement. Therefore, the test results can not be directly used for measuring the thresholds. A probabilistic modeling in the form of a non-linear law is developed for reflecting the scattered test data. The thresholds at specified reliability levels are then derived in meeting the threshold definition with a specified growth rate. The measurement for the present material has verified the availability of the present modeling.

Performance Evaluation of Large Stone Porous Asphalt-Rubber Mixture

2010 ◽  
Vol 150-151 ◽  
pp. 1184-1190 ◽  
Author(s):  
Wei Dong Cao ◽  
Zhan Yong Yao ◽  
Qing Sen Shang ◽  
Ying Yong Li ◽  
Yong Shun Yang
Keyword(s):  
Low Temperature ◽  
Asphalt Mixture ◽  
Rigid Base ◽  
Test Results ◽  
Rubber Mixture ◽  
Porous Asphalt ◽  
Large Stone ◽  
Asphalt Rubber ◽  
Temperature Performance ◽  
As Stress

Performance of Large Stone Porous Asphalt- Rubber Mixture（LSPARM）was studied in laboratory. Hamburg wheel tracking test, low temperature indirect tensile test and bending fatigue test were conducted to evaluate the high temperature performance of resistance to rutting, moisture susceptibility, low temperature performance of resistance to cracking and anti-fatigue performance of LSPARM and the test results were compared with the conventional large stone porous asphalt mixture using one polymer modified asphalt (control mixture). The test results indicate that LSPARM has better performance than the control mixture and it could be used as stress absorbing layers of semi-rigid base asphalt pavement.

scholarly journals Assessment of Lacrimal Duct Patency in Patients Undergoing Endoscopic Medial Maxillectomy

2021 ◽  
Vol 10 (2) ◽  
pp. 245
Author(s):  
Andrzej Sieśkiewicz ◽  
Tomasz Łysoń ◽  
Marek Rogowski ◽  
Marek Bielecki ◽  
Ewa Gindzienska-Sieskiewicz ◽  
...  
Keyword(s):  
Assessment Method ◽  
Test Results ◽  
Functional Disorders ◽  
Lacrimal Duct ◽  
Assessment Tests ◽  
Number Of Patients ◽  
Study Results ◽  
Assessment Techniques ◽  
Medial Maxillectomy ◽  
Comparison Of The Results

Purpose: The risk of epiphora after medial maxillectomy with lacrimal duct transection is difficult to assess. The data available in the literature are inconclusive due to various operating techniques used by the authors of medical publications, different additional procedures aimed at improving tear drainage after maxillectomy, and a variety of lacrimal duct patency assessment techniques. The aim of our work was to assess the anatomical and functional patency of lacrimal ducts after medial maxillectomy without performing additional procedures to improve tear drainage as well as comparison of the results obtained with different assessment tests. Materials and methods: 21 patients who underwent medial maxillectomy in the years 2016–2019 were assessed for discomfort and epiphora based on patients’ own reports and basic clinical examination, lacrimal duct rinse test, the Munk score, and a modified endoscopic Jones I test. Results: Gradually increasing the sensitivity of the assessment method resulted in an increase in the number of patients with potential tear drainage disorders, starting from 0% in the rinsing test, 4.8% self-reported tearing complaints, 14.3% Munk score, and 19% modified endoscopic Jones I test. Conclusions: The study results revealed that a small fraction of patients tend to report epiphora as a consequence of medial maxillectomy themselves. Subtle functional disorders, which are not particularly bothersome to patients, are more common. More sensitive lacrimal duct patency tests reveal more cases of tear drainage disorders. The results of studies assessing the incidence of epiphora after medial maxillectomy appear to depend on the type of test used.

scholarly journals Analysis of the Correlation between the Static and Fatigue Test Results of the Interlayer Bondings of Asphalt Layers

2016 ◽  
Vol 62 (1) ◽  
pp. 83-98 ◽  
Author(s):  
A. Szydło ◽  
K. Malicki
Keyword(s):  
Fatigue Life ◽  
Fatigue Test ◽  
Asphalt Mixture ◽  
Fatigue Tests ◽  
Test Results ◽  
Static Tests ◽  
Bonding State ◽  
Road Pavement ◽  
The Future ◽  
Pavement Structure

Abstract The bonding state of the asphalt layers in a road pavement structure significantly affects its fatigue life. These bondings, therefore, require detailed tests and optimization. In this paper, the analyses of the correlation between the results of laboratory static tests and the results of fatigue tests of asphalt mixture interlayer bondings were performed. The existence of the relationships between selected parameters was confirmed. In the future, the results of these analyses may allow for assessment of interlayer bondings’ fatigue life based on the results of quick and relatively easy static tests.

Improving The Student's Classroom Student's Reasoning Ability In Mathematics Lesson Through Problem Solving Efforts At Sdn 13 Kubang

2018 ◽  
Vol 1 (2) ◽  
pp. 149-158
Author(s):  
Zulfetriani Zulfetriani
Keyword(s):  
Learning Outcomes ◽  
Teaching And Learning ◽  
Basic Education ◽  
Mathematics Learning ◽  
Basic Knowledge ◽  
Test Results ◽  
Community Members ◽  
Maximum Value ◽  
Study Results ◽  
Daily Test

Basic education aims to provide basic skills to learners to develop their lives as individuals, community members, citizens and members of the human race and prepare learners to follow the next education. Primary education is organized to develop skills attitudes and provide the basic knowledge and skills necessary to live in communities and prepare learners who are eligible for secondary education (UU Sisdiknas No. 20 Year 2003 article 13). In teaching and learning activities, a teacher would have hope of desire for learners can get the maximum value possible, in accordance with the learning objectives created or desired but what can be in word, reality. For special mathematics subjects, field findings such as EBTANAS, summative test results and daily test scores and report scores indicate that the learners' learning outcomes are still below the numbers that may be unsatisfactory in both low and class high. From some study results and opinions of experts, the low mathematics learning outcomes of students is not because they are not able to perform calculations, but because they do not understand the problems contained in the problem. Hudoyo (in Laily Hasbullah: 2000: 1) states that questions related to numbers are not so difficult for learners, but the problems that use sentences are very difficult for learners who have less or less ability.  

Design and Analysis of a High Power Density, Low Temperature Waste Heat Recovery System Using an Oil-Free Turboalternator

2010 ◽  
Author(s):  
James F. Walton ◽  
Andrew Hunsberger ◽  
Hooshang Heshmat
Keyword(s):  
Output Power ◽  
Waste Heat ◽  
Maximum Output Power ◽  
Output Power Level ◽  
Working Fluid ◽  
Prototype System ◽  
Low Grade ◽  
Maximum Output ◽  
Test Results ◽  
Study Results

In this paper the authors will present the design and preliminary test results for a distributed electric generating system that uses renewable energy source for economical load-following and peak-shaving capability in an oil-free, high-speed micro-turboalternator system using compliant foil bearings and a permanent magnet alternator. Test results achieved with the prototype system operating to full speed and under power generating mode will be presented. A comparison between predicted and measured electrical output will also be presented up to a power generating level of 25 kWe at approximately 55,000 rpm. The excellent correlation between design and test provides the basis for scale up to larger power levels. Based upon the turboalternator test results a thermodynamic cycle analysis of a system using low grade waste heat water at approximately 100 C will be reviewed. The tradeoff study results for a series of environmentally friendly refrigerant working fluids will also be presented including sensitivity to vaporization and condensing temperatures. Based on the cycle and pinch point analyses predicted maximum output power was determined. Finally a preliminary turbine design for the selected R134a working fluid was completed. The results of this study show that a net output power level of greater than 40 kW is possible for approximately 240 l/m flow of water at 100C is possible.

scholarly journals Influence of Fiber Type on Low-Temperature Fracture Performance of Presawed Asphalt Mixture Beams

2018 ◽  
Vol 2018 ◽  
pp. 1-7 ◽  
Author(s):  
Jinrong Wu ◽  
Rongbao Hong ◽  
Chenbin Gu
Keyword(s):  
Low Temperature ◽  
Fiber Type ◽  
Asphalt Mixture ◽  
Basalt Fiber ◽  
Fiber Types ◽  
Horizontal Distance ◽  
Obvious Effect ◽  
Improvement Effect ◽  
Temperature Fracture ◽  
Fracture Performance

In order to improve the durability of asphalt pavement, low-temperature fracture performance of AC-13 asphalt mixture with different fiber types were studied by three-point bending fracture test under different temperatures and presawed positions. Test results show that the improvement effect of basalt fiber is obvious and stable. The improvement effect of polyester fiber is not obvious to resist I crack, and the resistance effect of I-II compound crack is obvious. Lignin fiber mixed in the asphalt mixture has no obvious effect on improving the crack resistance property under low temperature. Fiber cooperated with asphalt mixture can improve the ability of low-temperature fracture performance, while the improvement degree is effected by fiber type. Low-temperature fracture performance of asphalt mixture improves with the increase of temperature within a certain temperature range. The presawed position has significant effect on the low-temperature fracture performance of asphalt mixture. The larger the horizontal distance of the presawed position and center load is, the stronger the low-temperature fracture performance of asphalt mixture presents.

Coupled Numerical Analysis of Anti-crack Mechanism of Large Stone Asphalt Mixture

2010 ◽  
Vol 4 (2) ◽  
pp. 22-26
Author(s):  
Qingchang Lu ◽  
Jianmin Zi ◽  
Haijun Wang ◽  
Qiuxi Huang ◽  
Wei Wan
Keyword(s):  
Numerical Analysis ◽  
Asphalt Mixture ◽  
Large Stone

scholarly journals Long-Term Performance of Pavement Structures with Cold In-Place Recycled Base Course

2021 ◽  
Vol 16 (2) ◽  
pp. 48-65
Author(s):  
Audrius Vaitkus ◽  
Judita Gražulytė ◽  
Andrius Baltrušaitis ◽  
Jurgita Židanavičiūtė ◽  
Donatas Čygas
Keyword(s):  
Asphalt Pavement ◽  
Asphalt Mixture ◽  
Asphalt Pavements ◽  
Recycled Asphalt ◽  
Binding Agents ◽  
Pavement Structure ◽  
Pavement Structures ◽  
Base Course ◽  
Surface Distress ◽  
Foamed Bitumen

Properly designed and maintained asphalt pavements operate for ten to twenty-five years and have to be rehabilitated after that period. Cold in-place recycling has priority over all other rehabilitation methods since it is done without preheating and transportation of reclaimed asphalt pavement. Multiple researches on the performance of cold recycled mixtures have been done; however, it is unclear how the entire pavement structure (cold recycled asphalt pavement overlaid with asphalt mixture) performs depending on binding agents. The main objective of this research was to evaluate the performance of cold in-place recycled asphalt pavements considering binding agents (foamed bitumen in combination with cement or only cement) and figure out which binder leads to the best pavement performance. Three road sections rehabilitated in 2000, 2003, and 2005 were analysed. The performance of the entire pavement structure was evaluated in terms of the International Roughness Index, rut depth, and pavement surface distress in 2013 and 2017.

Sign in / Sign up

Export Citation Format

Share Document