Initial Findings on Skid Resistance of Unpaved Roads

2007 ◽  
Vol 2016 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Jeremy D. Lea ◽  
David J. Jones
Keyword(s):  
Skid Resistance ◽  
Unpaved Roads

Relationships Between the Friction and Viscoelastic Properties of Rubber

2000 ◽  
Vol 28 (3) ◽  
pp. 178-195 ◽  
Author(s):  
N. Amino ◽  
Y. Uchiyama
Keyword(s):  
Viscoelastic Properties ◽  
Skid Resistance ◽  
Grain Sizes ◽  
Abrasive Grain ◽  
The Coefficient Of Friction ◽  
Tan Δ ◽  
Silicone Carbide ◽  
And Storage ◽  
Wet Skid Resistance ◽  
Frequency Curves

Abstract In this study, the relationships between friction and viscoelastic properties such as loss tangent tan δ and storage modulusE′ were examined. Wet skid resistance was measured using the British Pendulum Tester. The rubber specimens were rubbed againstfive silicone carbide cloths of differing abrasive grain sizes. The viscoelastic properties of the rubber specimens were measured with a viscoelasticspectrometer. From the data on wet skid resistance and viscoelastic properties, it is found that the coefficient of friction μ varies as follows:           μ = a + b · tan δ/E′ where a and b are constants. Tan δ/E′ was related to the hysteresis term of friction, and the μ-frequency curves were compared with the tan δ/E′ –frequency curves.

scholarly journals Sustainable Use of Waste Polypropylene Fibres to Enhance the Abrasion and Skid Resistance of Two-Stage Concrete

2021 ◽  
Vol 13 (9) ◽  
pp. 5200
Author(s):  
Rayed Alyousef
Keyword(s):  
Abrasion Resistance ◽  
Research Work ◽  
Sustainable Use ◽  
Plain Concrete ◽  
Skid Resistance ◽  
Two Stage ◽  
Polypropylene Fibres ◽  
Conventional Concrete ◽  
Carpet Industry ◽  
Waste Polypropylene

Two-stage concrete (TSC), also known as prepacked aggregate concrete (PAC), differs from traditional concrete in terms of site application and manufacturing process. Although this type of concrete is not a replacement for conventional concrete applications, it is an ideal option for unusual and difficult placing conditions, especially for repairing existing concrete structures. In other words, this type of concrete is a newly developed concrete and made by placing and packing coarse aggregates and fibres in a designed formwork, then injecting a cement grout mixture into the free spaces between the aggregate particles using gravity or a pump device. For the mentioned system and others, concrete components used as floors or pavements must have an adequate degree of roughness during service life when exposed to skid and abrasion. Thus, this research work introduced a new concrete method (prepacked aggregates fibre-reinforced concrete—PAFRC) with high abrasion and skid resistance reinforced with waste polypropylene (PP) fibres from the carpet industry. The effects of PP fibres at 0–1% dosages on the mechanical properties, abrasion resistance, and skid resistance of PAFRC mixes were studied. The results revealed that the addition of PP fibres reduces the compressive strength of concrete mixtures. Nonetheless, the presence of PP fibres results in PAFRC mixes having higher tensile strength, abrasion resistance, and skid resistance than plain concrete. It was detected that in both grouting methods (gravity and pump), with the addition of PP fibre up to a specific dosage, the resistance against abrasion and skid was increased by about 26% compared to plain PAC mix. Additionally, the outcomes indicated that PAFRC is a promising material for applications such as pavements with high abrasion and skid resistance.

Protected areas and unpaved roads mediate habitat use of the giant anteater in anthropogenic landscapes

2021 ◽  
Author(s):  
Natalia F Versiani ◽  
Larissa L Bailey ◽  
Nielson Pasqualotto ◽  
Thiago F Rodrigues ◽  
Roberta M Paolino ◽  
...  
Keyword(s):  
Habitat Use ◽  
Protected Areas ◽  
Native Species ◽  
Population Decline ◽  
Native Vegetation ◽  
Brazilian Cerrado ◽  
Anthropogenic Landscapes ◽  
Unpaved Roads ◽  
Relative Paucity ◽  
Model Average

Abstract The drastic reduction of the Brazilian Cerrado has transformed this savanna hotspot into vast swaths of commodity-based agriculture fields, mainly soybean, sugarcane, and beef-production pasturelands. The resulting habitat loss and fragmentation are the principal factors underlying population decline of native species inhabiting the Cerrado, particularly those with a high demand for space, low population density, and specialized diet, such as the endangered giant anteater (Myrmecophaga tridactyla). Although the species has been studied in protected areas, we know much less about its ability to endure in disturbed landscapes. Here, we analyzed camera-trapping data to estimate a proxy of habitat use (ψ^; occupancy) and detection probabilities of the giant anteater, identifying environmental covariates influencing these parameters in landscapes with intensive agriculture and commercial forestry. We found this species using about half of the study area (model average ψ^ = 0.51, CI = 0.40–0.62), with two predictors strongly influencing habitat use: protected areas and unpaved roads. In turn, detection probability correlates positively with area of open Cerrado and negatively with area of settlements. The species is more likely to use unpaved roads inside protected areas (ψ^ = 0.90, CI = 0.47–0.75), compared to off road sites in the surrounding areas (ψ^ = 0.19, CI = 0.10–0.34). Our findings indicate that giant anteaters are dependent on nature reserves and native vegetation areas existing on private properties, whose protection is regulated by the Brazilian Native Vegetation Protection Law. Given the relative paucity of state-owned protected areas in the Brazilian Cerrado, increasing the adherence of rural owners to this law is, therefore, key for the conservation of the giant anteater. The intense use of unpaved roads might reflect travelling and/or foraging optimization, a behavioral response that, nevertheless, may compound this species’ susceptibility to suffer mortality from roadkill.

Estimation of initiation thresholds and soil loss from gully erosion on unpaved roads on China’s Loess Plateau

2021 ◽  
Author(s):  
Yiyang Zhao ◽  
Yan Zhang ◽  
Mutian Yuan ◽  
Meng Yang ◽  
Jiayong Deng
Keyword(s):  
Loess Plateau ◽  
Soil Loss ◽  
Gully Erosion ◽  
Unpaved Roads

scholarly journals Degradation Prediction Model for Friction of Road Pavements with Natural Aggregates and Steel Slags

2019 ◽  
Vol 10 (1) ◽  
pp. 32 ◽  
Author(s):  
Bruno Crisman ◽  
Giulio Ossich ◽  
Paolo Bevilacqua ◽  
Roberto Roberti
Keyword(s):  
Residual Life ◽  
Steel Slag ◽  
Steel Production ◽  
Threshold Level ◽  
Skid Resistance ◽  
Concrete Pavements ◽  
Cumulative Number ◽  
The Road ◽  
On The Road ◽  
Natural Aggregates

Steel production wastes (steel slags) are used more often in asphalt concrete pavements as a valuable replacement for natural aggregates, which are becoming increasingly rare. In this paper authors investigate the polishing characteristics of aggregates, and in particular of steel slags, used in bituminous road surfacing, are a major factor in determining the resistance to skidding. The main purpose of the study is the identification of a suitable degradation model, based on friction indicators, in the laboratory, as well as the comparison of in-situ pavement skid resistance with the cumulative number of passing vehicles over the years. The model predicts the expected resistance to skidding of the road surface based on the knowledge of the polished stone value (PSV) of the aggregates and the expected traffic on the road. In this study, several types of aggregates were compared: steel slag, limestone, limestone and slag mixture, diabase, Criggion stone and basalt. Using a standard PSV test, it was found that the aggregates did not reach the lower value of skid resistance (equilibrium value). The analysis of the British Portable Number (BPN) data versus polishing time allowed to empirically derive a regression model for each investigated aggregate. Hence, it appears possible to define both an investigatory level and threshold level to predict the actual residual life of the pavement from the examination of skid resistance.

Mechanistic-based comparisons for freeze-thaw performance of stabilized unpaved roads

2017 ◽  
Vol 141 ◽  
pp. 97-108 ◽  
Author(s):  
Cheng Li ◽  
Pavana K.R. Vennapusa ◽  
Jeramy Ashlock ◽  
David J. White
Keyword(s):  
Unpaved Roads ◽  
Freeze Thaw

Annualized Road Works Cost Estimates for Unpaved Roads

2009 ◽  
Vol 135 (10) ◽  
pp. 702-710 ◽  
Author(s):  
George Huntington ◽  
Khaled Ksaibati
Keyword(s):  
Unpaved Roads ◽  
Cost Estimates

Study on the skid resistance of asphalt pavement: A state-of-the-art review and future prospective

2021 ◽  
Vol 303 ◽  
pp. 124411
Author(s):  
Fucheng Guo ◽  
Jianzhong Pei ◽  
Jiupeng Zhang ◽  
Rui Li ◽  
Bochao Zhou ◽  
...  
Keyword(s):  
State Of The Art ◽  
Asphalt Pavement ◽  
Skid Resistance
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