Field Evaluation of Surface Friction Performance of Chip Seals in Indiana

2012 ◽  
Vol 2295 (1) ◽  
pp. 11-18 ◽  
Author(s):  
Shuo Li ◽  
Todd Shields ◽  
Samy Noureldin ◽  
Yi Jiang
Keyword(s):  
Field Performance ◽  
Surface Friction ◽  
Field Evaluation ◽  
Field Testing ◽  
Factors Affecting ◽  
Pavement Condition ◽  
Chip Seal ◽  
Chip Seals ◽  
Friction Performance ◽  
On Chip

Chip seal has been widely used as an effective surface treatment for pavement preservation. The Indiana Department of Transportation (DOT) chip sealed a total of 373 lane mile pavements in 2008 and 700 lane mile pavements in 2009. However, many issues, such as the optimal use of local materials and new aggregates, remained unsolved. No original information was available at the time for Indiana DOT engineers to assess the performance of chip seal pavements. A research study was initiated by the Indiana DOT to evaluate the field performance of chip seal pavements, particularly the surface friction properties. Eighteen chip seal projects were selected as the test sections for this study. Field testing was conducted to measure pavement surface friction and texture properties. The true surface friction numbers were identified for chip seals after 12 months of service. The variation of surface friction on chip seals was analyzed. Factors affecting chip seal surface friction, such as aggregate, traffic volume, and existing pavement condition, were identified and examined. Three traffic levels were defined for better chip seal application. The international roughness index on the existing pavement affected chip seal friction performance. A criterion was recommended for assessing the friction performance of chip seal and identifying the possible failure of a chip seal.

Laboratory and Field Evaluation of Single Layer and Double Layer High Friction Surface Treatments

2019 ◽  
Vol 2673 (2) ◽  
pp. 552-561 ◽  
Author(s):  
Shuo Li ◽  
Peiliang Cong ◽  
Demei Yu ◽  
Rui Xiong ◽  
Yi Jiang
Keyword(s):  
Double Layer ◽  
Friction Surface ◽  
Single Layer ◽  
Aggregate Size ◽  
Surface Friction ◽  
Field Evaluation ◽  
The United States ◽  
Aggregate Gradation ◽  
State Highway ◽  
Friction Performance

High friction surface treatment (HFST) has been proactively used as a solution to extreme friction demands at locations such as horizontal curves, ramps, bridge decks, and intersections. Considerable efforts have been made to evaluate the use of HFST across the United States (U.S.) The American Association of State Highway and Transportation Officials (AASHTO) has issued a provisional specification, i.e., AASHTO PP 79-14, to help state Departments of Transportation (DOTs) to successfully apply HFST. This paper presents a further effort made by the authors to evaluate and compare the friction performance and durability of single and double layer HFTS systems with calcined bauxite aggregate. The laboratory accelerated polishing was conducted to evaluate the effects of aggregate candidate gradations on the friction performance, such as friction coefficient and macrotexture mean profile depth (MPD), and to determine the aggregate gradation for field evaluation. Field evaluation was conducted on both single and double layer HFST systems using test strips under actual traffic polishing over a time period of nine months that covered an entire snow season. It was found that larger aggregate size tends to yield larger MPD, but larger MPD does not necessarily imply larger friction. The double layer HFST did not outperform the single layer HFST with respect to friction and durability. If the properties of calcined bauxite aggregate are precisely defined, either surface friction or MPD can solely be utilized as the frictional metric for quality assurance (QA) of HFST.

scholarly journals Investigation of Durability and Performance of High Friction Surface Treatment

2021 ◽  
Author(s):  
Fulu Wei ◽  
Ce Wang ◽  
Xiangxi Tian ◽  
Shuo Li ◽  
Jie Shan
Keyword(s):  
Surface Treatment ◽  
Friction Surface ◽  
Coefficient Of Thermal Expansion ◽  
Good Condition ◽  
Surface Friction ◽  
Loading Test ◽  
System Integrity ◽  
Chip Seal ◽  
Friction Performance ◽  
And Performance

The Indiana Department of Transportation (INDOT) completed a total of 25 high friction surface treatment (HFST) projects across the state in 2018. This research study attempted to investigate the durability and performance of HFST in terms of its HFST-pavement system integrity and surface friction performance. Laboratory tests were conducted to determine the physical and mechanical properties of epoxy-bauxite mortar. Field inspections were carried out to identify site conditions and common early HFST distresses. Cyclic loading test and finite element method (FEM) analysis were performed to evaluate the bonding strength between HFST and existing pavement, in particular chip seal with different pretreatments such as vacuum sweeping, shotblasting, and scarification milling. Both surface friction and texture tests were undertaken periodically (generally once every 6 months) to evaluate the surface friction performance of HFST. Crash records over a 5-year period, i.e., 3 years before installation and 2 years after installation, were examined to determine the safety performance of HFST, crash modification factor (CMF) in particular. It was found that HFST epoxy-bauxite mortar has a coefficient of thermal expansion (CTE) significantly higher than those of hot mix asphalt (HMA) mixtures and Portland cement concrete (PCC), and good cracking resistance. The most common early HFST distresses in Indiana are reflective cracking, surface wrinkling, aggregate loss, and delamination. Vacuum sweeping is the optimal method for pretreating existing pavements, chip seal in particular. Chip seal in good condition is structurally capable of providing a sound base for HFST. On two-lane highway curves, HFST is capable of reducing the total vehicle crash by 30%, injury crash by 50%, and wet weather crash by 44%, and providing a CMF of 0.584 in Indiana. Great variability may arise in the results of friction tests on horizontal curves by the use of locked wheel skid tester (LWST) due both to the nature of vehicle dynamics and to the operation of test vehicle. Texture testing, however, is capable of providing continuous texture measurements that can be used to calculate a texture height parameter, i.e., mean profile depth (MPD), not only for evaluating friction performance but also implementing quality control (QC) and quality assurance (QA) plans for HFST.

scholarly journals Bioengineered Islet Cell Transplantation

2021 ◽  
Author(s):  
Kevin Bellofatto ◽  
Beat Moeckli ◽  
Charles-Henri Wassmer ◽  
Margaux Laurent ◽  
Graziano Oldani ◽  
...  
Keyword(s):  
State Of The Art ◽  
Diabetes Research ◽  
Islet Cell Transplantation ◽  
Β Cell ◽  
Cell Compartment ◽  
Factors Affecting ◽  
Insulin Activity ◽  
On Chip

Abstract Purpose of Review β cell replacement via whole pancreas or islet transplantation has greatly evolved for the cure of type 1 diabetes. Both these strategies are however still affected by several limitations. Pancreas bioengineering holds the potential to overcome these hurdles aiming to repair and regenerate β cell compartment. In this review, we detail the state-of-the-art and recent progress in the bioengineering field applied to diabetes research. Recent Findings The primary target of pancreatic bioengineering is to manufacture a construct supporting insulin activity in vivo. Scaffold-base technique, 3D bioprinting, macro-devices, insulin-secreting organoids, and pancreas-on-chip represent the most promising technologies for pancreatic bioengineering. Summary There are several factors affecting the clinical application of these technologies, and studies reported so far are encouraging but need to be optimized. Nevertheless pancreas bioengineering is evolving very quickly and its combination with stem cell research developments can only accelerate this trend.

scholarly journals Evaluation of Bleeding Resistance in Chip Seal and Asphalt Emulsion Residue Rheology

Coatings ◽  
2019 ◽  
Vol 9 (10) ◽  
pp. 670
Author(s):  
Preeda Chaturabong
Keyword(s):  
Influence Factors ◽  
Application Rate ◽  
Test Methods ◽  
Test Results ◽  
Asphalt Emulsion ◽  
Aggregate Gradation ◽  
Factors Affecting ◽  
Promising Tool ◽  
Chip Seal ◽  
Asphalt Emulsions

Chip seal bleeding is influenced by many factors, including design inputs, material properties, and project-specific conditions. It reduces the surface texture of the pavement and thus compromises the safety of the traveling public. Even though factors that bring about premature bleeding are known, currently, no laboratory test methods for evaluating bleeding in chip seals have been specified. The objective of this paper is to present the results of an investigation of the influence factors of asphalt emulsion residue properties measured by the ASTM D7405 multiple stress creep and recovery (MSCR) test, as well as other factors related to chip seal bleeding resistance as measured by the modified loaded wheel test (MLWT). In this study, the MSCR test was used as a tool for evaluating the performance of asphalt emulsions because it has been identified as a potential test related to bleeding in the field. In addition, MLWT was selected as a tool for evaluating chip seal bleeding performance in the laboratory. The results of the MLWT showed that the emulsion application rate (EAR), aggregate gradation, and emulsion properties were significant factors affecting bleeding. The MSCR test was found to be a promising tool for the performance evaluation of asphalt emulsion residue, as the test was able to differentiate between emulsion chemistries and modifications in terms of sensitivity to both temperature and stress. In relation to chip seal bleeding resistance, only the creep compliance (Jnr) obtained from the MSCR test results was identified as a significant property affecting potential for bleeding.

Field evaluation of tissue-cultured bananas in south-eastern Queensland

1990 ◽  
Vol 30 (4) ◽  
pp. 569 ◽  
Author(s):  
RA Drew ◽  
MK Smith
Keyword(s):  
Callus Culture ◽  
Field Performance ◽  
Field Evaluation ◽  
Ratoon Crop ◽  
Musa Sp ◽  
Planting Material ◽  
Lateral Buds ◽  
Conventional Material ◽  
Banana Cultivar ◽  
Plant Crop

Field performance is described for tissue cultured plants and conventional propagules of planting material of banana cultivar 'New Guinea Cavendish' (Musa sp., AAA group, Cavendish subgroup). Tissuecultured plants were produced by either regeneration of plants from callus culture or by micropropagation of plants following the release of dormant buds at the leaf axils of explants. The conventional material consisted of suckers and 'bits' (lateral buds and associated corm material). Tissue-cultured plants established more quickly, were taller, and had a shorter time to bunch emergence and harvest of plant crop than conventional planting material. They had significantly (P<0.05) higher yields in terms of bunch weight, which was a function of greater numbers of fingers and hands. These advantages did not extend to the ratoon crop. Sucker production on tissue-cultured plants was significantly (P<0.01) higher up to 8 months after planting, equal to conventional material from 8 months to harvest, and then significantly lower. Twenty-two per cent of the plants derived from callus were off-types compared with 3% in the line produced by axillary bud proliferation. No off-types were observed in conventional planting material.

Research on the Friction Performance of Bionic Surface Based on the Clamber Animal Foot Pad

2013 ◽  
Vol 427-429 ◽  
pp. 298-301
Author(s):  
Chun Jian Su ◽  
Zhou Yu Fu ◽  
Hui Sun ◽  
Xiao Shen
Keyword(s):  
Sliding Friction ◽  
External Surface ◽  
Surface Friction ◽  
Friction Mechanism ◽  
Micro Particles ◽  
Bionic Surface ◽  
Friction Performance ◽  
Foot Pad ◽  
The Mathematical Model ◽  
Center Distance

The clamber animal foot pads were researched by the Super Depth of Field3D Microscopic System marked VHX-600 and the flexible non-smooth surface friction mechanism of clamber animal foot pad was analysed through bionic tribology. The total friction includes two aspects: a) The sliding friction caused by the adsorbability between clamber animal foot pad and external surface. b) The embedding resistance caused by the external surface micro particles embedded into clamber animal foot pad. The mathematical model of single convex hull was built and the different center distance bionic surfaces were designed, the friction contact simulation of bionic surface was done by ANSYS and the friction performance of bionic surface was verified through the plane friction testbed.

Effect of Aggregate Size on the Retention of Conventional and Rubberized Chip Seal

2019 ◽  
Author(s):  
Alireza Pourhassan ◽  
Ahmed A. Gheni ◽  
Mohamed A. ElGawady
Keyword(s):  
Impact Load ◽  
Mechanical Energy ◽  
Aggregate Size ◽  
Crumb Rubber ◽  
Superior Performance ◽  
Natural Aggregate ◽  
Modes Of Failure ◽  
Chip Seal ◽  
Chip Size ◽  
On Chip

<p>A common defect of chip seals is chip loss or raveling. The previous studies showed uniform grading of aggregate will enhance the retention ability of the chip seal. Also, it was shown that using crumb rubber as an aggregate will enhance the chip seal behavior including aggregate retention. However, no specific study has been done focusing on the effect of aggregate size for rubber nor natural aggregate. This paper is evaluating the effect of chip size on aggregate retention of both natural and rubber aggregate. Standard and modified Vialit tests, and standard and modified Pennsylvania tests which apply different forms of mechanical energy in different temperature was used to assess the aggregate-binder bond interaction and study the chip seal retention. Test results showed different trends for the effect of size on chip retention under impact load versus dynamic load because of different modes of failure. However, rubber particles showed a superior performance rather than natural aggregate in all cases.</p>

Field performance of hot applied modified binder chip seal in california

2019 ◽  
pp. 411-417
Author(s):  
A. Rahim ◽  
S. Saadeh ◽  
O. Aljairi ◽  
D. Cheng
Keyword(s):  
Field Performance ◽  
Chip Seal ◽  
Modified Binder

scholarly journals Developing a standard methodology for testing field performance of residential greywater reuse systems: case study of a greywater reuse system installed in 23 homes in Southern Ontario

2021 ◽  
Author(s):  
Madeleine Jean Craig
Keyword(s):  
Water Quality ◽  
User Satisfaction ◽  
Residential Buildings ◽  
Field Performance ◽  
Field Testing ◽  
Single Family ◽  
Southern Ontario ◽  
Capital Costs ◽  
Reuse System ◽  
Greywater Reuse

Using shower wastewater to flush toilets decreases the potable water demand of residential buildings, reducing pressure on existing water supplies. “Off- the-shelf” greywater reuse systems intended for single-family residential dwellings have recently become commercially available, but have variable field performance. A standard field testing methodology was developed and applied to a greywater reuse system installed in 23 homes in Southern Ontario. Performance was quantified by measuring the water balance, water quality, energy consumption, durability, maintenance requirements, installation process, economics and user satisfaction with the system. The tested system was found to save, on average, 40.9 litres per household per day, occasionally meet water quality guidelines and generally have less maintenance and durability issues than previous generations, resulting in satisfied users. However, due to low water rates and high capital costs, there is a need for government subsidization of these systems which will ultimately, reduce pressure placed on centralized water infrastructure.

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