Using jaw crushers in construction of gravel roads

2015 ◽  
Vol 3 (2) ◽  
pp. 249-252
Author(s):  
A. Leshchevich
Keyword(s):  
Gravel Roads ◽  
Jaw Crushers

Economics of upgrading gravel roads to Otta seal surface

2019 ◽  
Vol 51 (44) ◽  
pp. 4820-4832 ◽  
Author(s):  
Ali Nahvi ◽  
Yang Zhang ◽  
Ali Arabzadeh ◽  
Sharif Y. Gushgari ◽  
Halil Ceylan ◽  
...  
Keyword(s):  
Gravel Roads

scholarly journals INVESTIGATION INTO HEAVY METAL CONCENTRATION BY THE GRAVEL ROADSIDES / SUNKIŲJŲ METALŲ KONCENTRACIJŲ ŽVYRKELIŲ PAKELIŲ DIRVOŽEMIUOSE VERTINIMAS / ОЦЕНКА КОНЦЕНТР АЦИЙ ТЯЖЕЛЫХ МЕТАЛЛОВ В ПОЧВЕ ОБОЧИН ГРАВИЙНЫХ ДОРОГ

2011 ◽  
Vol 19 (1) ◽  
pp. 89-100 ◽  
Author(s):  
Audronė Mikalajunė ◽  
Lina Jakučionytė
Keyword(s):  
Heavy Metals ◽  
Heavy Metal ◽  
Metal Concentration ◽  
Road Dust ◽  
Heavy Metal Concentration ◽  
Concentration Limit ◽  
Roadside Soils ◽  
Oil Emulsion ◽  
Gravel Roads ◽  
The Impact

Vehicles release large amounts of heavy metals to the environment. There have been done a lot of investigations analysing the distribution of heavy metals in soils near intensive regional roads. However, there is lack of investigations into the impact of small-intensity gravel roads on roadside soil contamination with heavy metals. The object of this investigation is four gravel roads of local significance connecting small villages. The intensity of these roads is very low. The gravel roads are chosen according to application of dust-minimizing materials, for example, CaCl2 and oil emulsion. According to our results, none of the soil samples had an excess of heavy metal concentration limit. Besides, heavy metal concentrations were decreasing with a distance from the road increasing. We can make an assumption that road dust-minimizing materials do not have a significant impact on heavy metal distribution in roadside soils. The major factors of heavy metal pollution distribution in roadside soils are traffic intensity, roadside trenches, and topographic conditions. Santrauka Eksploatuojant autotransportą, į aplinką patenka daug sunkiųjų metalų. Atlikta nemažai tyrimų sunkiųjų metalų paplitimuidirvožemyje šalia intensyvių magistralinių kelių nustatyti, tačiau mažo intensyvumo keliai šiuo požiūriu tiriami mažai.Tirti pasirinkta 4 žvyrkeliai – vietinės reikšmvs keliai, jungiantys nedideles gyvenvietes. Eismo intensyvumas šiuose keliuose mažas. Žvyrkeliai pasirinkti pagal taikomas priemones dulkėtumui mažinti, t. y. du nagrinvjami žvyrkeliai apdorotiCaCl2, kiti du – naftos emulsija. Nė viename mėginyje sunkiųjų metalų koncentracijos neviršijo DLK, o tolstant nuo važiuojamosios kelio dalies sunkiųjų metalų koncentracijos buvo mažesnės. Galima daryti prielaidą, kad kelio apdorojimo medžiagos dulkėtumui mažinti žymios įtakos sunkiųjų metalų pasiskirstymui pakelių dirvožemyje nedaro, lemia transporto srauto intensyvumas, kelio grioviai pakelėse bei reljefo sąlygos. Резюме При эксплуатации автомобилей в окружающую среду попадает много тяжелых металлов. Проведено немалоисследований, посвященных анализу распространения тяжелых металлов в почве обочин интенсивно эксплуатируемых магистральных дорог, однако исследований, касающихся аналогичных проблем дорог малой интенсивности, в настоящее время имеется немного. В настоящей работе в качестве объекта исследований выбраны четыредороги местного значения с гравийным покрытием, соединяющие небольшие поселения. Интенсивность дорог небольшая. Гравийные дороги выбраны с учетом их обработки для уменьшения пыльности – две дороги обработаны с применением CaCl2, а две другие – с применением нефтяной эмульсии. Ни в одной пробе не былозафиксировано концентраций тяжелых металлов, превышающих допустимые нормами. С удалением от проезжей части концентрации тяжелых металлов уменьшались. На основании исследований можно сделать вывод о том,что материалы, применявшиеся для уменьшения пыльности дорог, большого влияния на распространениетяжелых металлов в почве обочин дорог не оказывают. На распространение тяжелых металлов в почве обочин оказывает влияние интенсивность транспортного потока, кюветы на обочинах и условия рельефа.

scholarly journals Revisiting gouging abrasion test for jaw crushers

2018 ◽  
Vol 71 (1) ◽  
pp. 111-115 ◽  
Author(s):  
Giuseppe Pintaude ◽  
Nilson Mar Bartalini
Keyword(s):  
Abrasion Test ◽  
Jaw Crushers

Optimizing Low-Volume Road Network Performance Through Improved Management, Design, and Construction

2003 ◽  
Vol 1819 (1) ◽  
pp. 299-305 ◽  
Author(s):  
G. D. Van Zyl ◽  
M. G. Henderson ◽  
H. G. Fourie
Keyword(s):  
Management System ◽  
Road Network ◽  
Performance Monitoring ◽  
Systems Design ◽  
Western Cape ◽  
Road Management ◽  
Gravel Roads ◽  
Low Volume ◽  
Gravel Road ◽  
Design And Construction

The Provincial Administration of the Western Cape in South Africa is responsible for 18,900 km of proclaimed roads, of which 10,500 km are unsurfaced. A formal gravel road management system has been in operation since 1989 that assists in prioritizing projects for regraveling and upgrading gravel roads to surfaced standards. Because of fund limitations for upgrading gravel roads to surfaced roads, there is a need to optimize performance of the gravel road network and maximize use of knowledge and latest research results for southern Africa. Staff shortages and loss of in-house expertise made external assistance necessary to improve service to road users. Processes formalized, implemented, and planned for this purpose included ( a) upgrading the gravel road management system to quantify benefits, prioritize activities, and select maintenance and improvement measures; ( b) appointing consulting engineers in each district to help manage borrow pits, materials design, training, construction supervision and quality control, maintenance planning and control, and performance monitoring; ( c) communication about project priorities, construction programs, work methods, construction team performance, and activity costs; and ( d) development of an operational web-enabled system to manage all activities related to unsurfaced roads. Within 1 year, a remarkable difference in gravel road performance was observed without a significant reduction in productivity. Total transportation costs were lowered with only a marginal increase in agency costs. Continuous communication among system operators, design engineers, project managers, and construction teams is considered one of the most important aspects in optimizing performance of the Western Cape low-volume road network. This study highlights the most important changes in management, systems, design, and construction and the practical innovations responsible for the successes achieved as a potentially valuable aid to those involved with providing and maintaining low-volume roads.

Identification and discussion on distress mechanisms of unsurfaced gravel roads

2019 ◽  
Vol 12 (1) ◽  
pp. 88-96
Author(s):  
Leandro Olivio Nervis ◽  
Washington Peres Nuñez
Keyword(s):  
Gravel Roads

Estimation of Gravel Roads Ride Quality Through an Android-Based Smartphone

2018 ◽  
Vol 2672 (40) ◽  
pp. 14-21 ◽  
Author(s):  
Waleed Aleadelat ◽  
Cameron H. G. Wright ◽  
Khaled Ksaibati
Keyword(s):  
Low Cost ◽  
Ride Quality ◽  
Initial Validation ◽  
Road Condition ◽  
Gravel Roads ◽  
Signal Demodulation ◽  
Smartphone Sensors ◽  
Quality Rating ◽  
Local Agencies ◽  
Gravel Road

This study demonstrated the ability of smartphone sensors in evaluating gravel roads conditions. Seventy gravel roads with various conditions, surface materials, and geometric features were included in this study. The analysis was based on signal demodulation and wavelet transformation to reduce the effect of many external factors (i.e., speed dependency, engine vibrations, and suspension system) that may affect the obtained measurements. It was found that the acquired signals from a smartphone accelerometer can reflect the actual conditions of a gravel road. In addition, the location and the severity of surface deteriorations such as potholes could be identified. A regression model ( R2 = 0.78) based on the acquired signals from smartphones was developed to predict the overall rating of the gravel road condition according to the Riding Quality Rating Guide (RQRG) system. An initial validation analysis, conducted on 35 new gravel roads, showed that this model was able to return reasonable ratings. Also, the statistical analysis showed that any difference between the predicted and the actual ratings of <1.3 was not significant. The proposed methodology can be considered as a baseline for building a low cost crowdsourcing platform that helps local agencies in managing their inventory of gravel roads.

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