Unpaved Roads Research Articles

Use of Recycled Construction and Demolition Waste (RCDW) in Geosynthetic-Reinforced Roadways: Influence of Saturation Condition on Geogrid Mechanical Properties

Replacing natural aggregates in infrastructure with recycled construction and demolition waste (RCDW) works helps to meet the requirements established by sustainable development. This environmentally friendly proposal undoubtedly becomes better when it is carried out with geosynthetics, providing better technical performance and positive economic impacts. However, the chemical characteristics of RCDW may result in the degradation of the geosynthetics and, therefore, must be assessed and quantified. This study aims to assess the chemical degradation caused by RCDW for the mechanical properties of two types of polymeric geogrids (polyester and polyvinyl alcohol). The study evaluates the influence of the RCDW saturation condition in the chemical degradation and the possible synergism between the launching damage (drop height) and chemical degradation. Watertight tanks were constructed to maintain the geosynthetic reinforced layers in flooded, dry and open-to-environment conditions, simulating paved and unpaved roads. The occurrence of degradation was evaluated and quantified by reduction factors related to the properties of interest using statistical analysis. The results have shown a significant influence of chemical degradation on the geogrid characteristics (especially tensile strength and secant tensile stiffness), which increased when the specimens were subjected to prior launching process simulation. The reduction factor values reported herein encourage the combined use of these materials (geogrid and RCDW) and highlight the importance of assessing the chemical degradation for the design purposes of geosynthetic-reinforced roadways with alternative materials.

Updated distribution of the Texas kangaroo rat (Dipodomys elator) and patterns of rodent species associations from county road surveys in Texas

The Texas kangaroo rat (Dipodomys elator) is a rare species of conservation interest at both the state and federal level. Therefore, an updated understanding of distribution and abundance of D. elator is critical for initiating informed decisions about its conservation status and subsequent management strategies. We surveyed more than 850 locations along unpaved county roads across the historical range of this species in north-central Texas to identify sites of D. elator presence and examine patterns of rodent species associations. We determined that D. elator presently occurs in five counties in Texas within its historical range and was the eighth most abundant species of the 14 species that we captured. Moreover, we found that the majority of pairwise species associations, including those involving D. elator, were random and there was no strong evidence that pairs of rodents were aggregating or segregating with respect to each other. We did observe negative associations between D. elator and both Dipodomys ordii (Ord’s kangaroo rat) and Sigmodon hispidus (hispid cotton rat). Nonetheless, these patterns indicate that interspecific interactions do not play a strong role in influencing the distribution of D. elator. However, the restricted and temporally dynamic distribution of this species suggests that a metapopulation perspective should be considered when making future conservation considerations.

Component-based transfer path analysis on agricultural tractor

Agricultural tractors are special purpose machines that perform agricultural operation in harsh environments such as unpaved roads and farmlands, and generate high levels of noise and vibration. Eco-friendly tractors using electric drivetrains and hydrogen fuel cells are being developed to reduce exhaust gas in accordance with global environmental regulations. Unlike traditional tractor structures, these electrified tractors are being developed as modular and shared platforms. Therefore, it is changing into a system that is easy to apply component-based transfer path analysis (C-TPA) to reduce noise and vibration of tractors. In this paper, the noise and vibration contributions of an agricultural tractor were analyzed using C-TPA, and the blocked force usable as the excitation force of the virtual model was derived. The accuracy of transfer path analysis was improved by applying transfer functions including the rotational directions using virtual point transformation technique. The prediction result of developed experimental model were similar to the vibration response of the actual tractor, and the contribution of structure-borne noise could be quantitatively evaluated.

Indoor air quality in Hungarian Passive Houses

The indoor air quality (IAQ) was investigated in 15 Passive Houses in the heating and non-heating seasons between 2019 and 2021 in Hungary. The concentrations of volatile organic compounds (VOCs), aldehydes, ozone, nitrogen dioxide, PM2.5 mass, carbon dioxide, bacteria, fungi, and pollen were measured together with the monitoring of temperature, relative humidity and air change rate (ACR). The IAQ varied considerably among the investigated buildings. Significant seasonal differences were obtained for all physical parameters (temperature, relative humidity, ACR), certain VOCs (benzene, α-pinene, limonene), acetaldehyde, and airborne fungi. Considerable health concern was associated with the indoor concentrations of PM2.5 mass and nitrogen dioxide in many cases based on the evaluation of IAQ in relation to potential adverse health effects, while the peak concentrations of other pollutants (e.g. trichloroethylene, α-pinene, certain aldehydes, fungi) were also of concern in a couple of cases. The median indoor/outdoor concentration ratios of benzene, PM2.5 mass, nitrogen dioxide, ozone and fungi indicated that these pollutants are mainly of outdoor origin, while the other VOCs, aldehydes and bacteria showed higher concentration indoors. Overheating, the lack of proper particle filters in the mechanical ventilation system, and low ACR and relative humidity were identified as frequent problems related to the building characteristics. The emissions from building materials and furniture, the proximity of construction works and unpaved roads, and the allergenic vegetation might considerably influence IAQ. The results highlight that risk reduction measures are needed to create healthier indoor environment in the Passive Houses.

Modelling of washboard effect on unpaved roads experimental evidence on non-cohesive materials

Washboard or corrugation is a common phenomenon in unpaved roads. The washboard effect can be very uncomfortable for the driver, but it can also be very dangerous due to the loss of contact between the wheels and the road. There are few pieces of research about this topic, but undulations seem to emerge due to the caŕs velocity and mass. This work aims to identify the main physical variables controlling the appearance of the washboard effect. For this purpose, an experimental set-up of a multi-pass system was developed. This apparatus consists of a rotating wheel rolling over a sandy path. This model allows evaluation of the evolution of the undulations resulting from the washboard phenomenon and allows relating it to variables such as the dynamic forces and track profile. Different scenarios were evaluated, including wheel velocity, wheel mass, and soil density.

Territory establishment and microhabitat selection of Bachman's sparrows in a Mississippi pine forest

AbstractBachman's sparrows (Peucaea aestivalis) are an obligate southern open pine forest species linked to disturbance regimes (e.g., fire, windthrow) that reduce canopy cover and promote herbaceous groundcover needed for nesting, foraging, and concealment from predators. Early successional groundstory characteristics suitable for Bachman's sparrows are ephemeral in nature, raising questions about the perceived visual cues created by vegetation structural characteristics and how these characteristics influence multi‐scale habitat selection. We quantified habitat selection for 40 breeding and post‐breeding male Bachman's sparrows within 5 separately managed open pine management sub‐units at Sam D. Hamilton Noxubee National Wildlife Refuge in east‐central Mississippi, USA, from 2020–2021. We captured and color‐banded 20 individuals each year and used weekly resight locations and resource selection function models to assess factors influencing territory establishment (i.e., second‐order selection) within our study area, and microhabitat selection (i.e., third‐order selection) within territories. Bachman's sparrow territory establishment was positively influenced by evergreen cover and fire disturbance, and negatively influenced by tree canopy cover, and distance to unpaved roads. Within territories, sparrows selected areas with a greater basal area of pine (18 m2/ha), more available perching options (>9), and an abundance of native herbaceous groundcover (>36%). They also selected recently burned areas (1–3 yr) with low visual obstruction (<40 cm), and a low percent coverage of leaf litter (<33%). A better understanding of territory establishment and microhabitat selection of the Bachman's sparrow underscores the importance of frequent fire and is helpful in guiding conservation and management efforts for this declining species.

Five-Year Performance Evaluation of Geogrid Reinforcement in Low-Volume Unpaved Roads Using Dynamic Cone Penetrometer, Plate Load Test and Roadway Sensing

This paper provides a five-year performance evaluation of an application of geogrid reinforcement in low-volume unpaved roads using dynamic cone penetrometer (DCP), plate load tests (PLT), and roadway sensing method. A Forest Service unpaved road located in northern Arizona, USA, exhibited severe deterioration on the surface, creating an unsafe traffic environment for vehicles. A total of four structural sections (1–4; 4.3 m wide) were installed in the 40 m long test area. One additional section of existing subgrade/roadbed with native soil adjacent to the test sections was used for comparison purposes. The project was originally completed in November 2015, followed by five annual field visits to observe surface conditions of the five test sections. Based on DCP and PLT results (both conducted in 2015), and roadway sensing tests conducted in 2020, the section made of 30 cm thick aggregate with one geogrid layer appeared to have a better capacity for resisting traffic loading as compared with the other four sections. This paper concludes that, from a long-term point of view, the geogrid reinforcement improves the capacity of the unpaved roads, with significantly reduced rutting and damage from both roadway traffic loads and weathering effects.

Quantifying the effect of freeze–thaw on the soil erodibility of gully heads of typical gullies in the Mollisols region of Northeast China

The soil erodibility of gully headwalls is a critical factor influencing gully erosion. In some cold regions, the soil of gully headwalls is subjected to a bidirectional freeze–thaw effect (FT), while the quantification of the influence of FT on the soil erodibility of gully heads is unclear. Therefore, five typical and representative gullies developed in farmlands (GF1 and GF2), along unpaved road (GR), in the woodland (GW) and in stabilized gully bed (GS) were selected to quantify the influence of FT on the soil erodibility of gully heads reflected by five soil erodibility parameters including the K factor (K), soil disintegration rate (SDR), mean weight diameter (MWD), soil shear strength (SS) and saturated soil hydraulic conductivity (SHC). A comprehensive soil erodibility index (CSEI) was constructed by combining the above five soil erodibility parameters. This study revealed that FT significantly affected the five soil erodibility parameters and CSEI, of which the K and SDR increased by 22.7 % and 52.3 %, respectively, but the MWD, SHC and SS decreased by 29.3 %, 30.4 % and 26.1 %, respectively. The change in soil erodibility of the gully heads was closely related to the soil and root properties, of which the contribution of roots to the change in soil erodibility of gully heads was increased by 78.5 % after FT on average. Furthermore, FT significantly increased the CSEI at depths of 0–50 cm in GF1, GF2 and GR, and at depths of 0–80 cm in Gw and GS. FT increased the CSEIs of the five gully heads by 20.1 %-37.3 %, with an average of 26.1 %. Evidently, the organic matter content (OMC), soil texture and temperature dominated the change in the CSEI, of which the extremely low temperature and temperature rangeability during freeze–thaw period exhibited the greatest impact on the soil erodibility of the gully heads.

Identify Infrastructure Availability in Parit Tokaya Village South Pontianak District Pontianak City, West Kalimantan

This study aims to identify the availability of infrastructure in Tokaya Parit Village, South Pontianak Regency, Pontianak City, West Kalimantan. The method used in this study is a survey with data collection techniques through direct interviews with local communities and direct observation in the field. The results showed that the availability of infrastructure in Tokaya Parit Village is still inadequate, especially in terms of roads, clean water, and sanitation. Most of the roads in Tokaya Parit Village are still unpaved dirt roads and are badly damaged during the rainy season. The source of clean water available in this village is also still very limited, so people often have to take water from rivers or wells that do not meet health standards. In addition, sanitation in this village is also still inadequate, with most people still using squat-style toilets or mobile latrines. In conclusion, this study shows that the availability of infrastructure in Tokaya Parit Village still needs to be improved in order to meet the needs of the local community. There needs to be attention and support from related parties, both government and private, to increase the availability of infrastructure in this village, so that people can live properly and meet their basic needs

Study on Geosynthetics in Pavement Design

Geosynthetic reinforcement is one of the techniques adopted to improve their performance in pavement design.Geogrid are single line and multi-layer materials usually made by extruding and stretching high density polyethylene,or by weaving or knitting and coating high-strength polyester yarns.The resulting lattice structure has large holes that improve interaction with the soil aggregate. Roads having mostly the problems like the formation of potholes, ruts, cracks and localized depression and settlement, especially during rainy season. These are mainly due to the insufficient bearing capacity of the subgrade in water saturated condition.Geogrids are reinforcing elements to strengthen the ground in order to work on very soft and weak ground in the construction of asphalted or unpaved vehicle roads and areas where the high traffic flow is expected.Laboratory and simulated field CBR tests are conducted on soil samples with and without the inclusion of geogrid layer and also by varying the position of it in the mould. Use of geogrid increases the CBR value of the subgrade and thereby reduces the pavement thickness considerably up to 40%.This study will have positive impact as it will be reduce both project and road maintenance costs.

GEOLOGICAL FIELD GUIDE TO THE EARLY CRETACEOUS INHANDUÍ HOTSPRINGS AND THEIR HOST BOTUCATU PALEODUNES

Structures formed by geological processes that occurred during the Early Cretaceous are preserved in large areas of the Fronteira Oeste Rift in Rio Grande do Sul, Brazil. Among these areas, the Inhanduí Paleodune Field (IPDF), located in northeastern Alegrete, is part of the Botucatu paleoerg, the largest paleodune field in Supercontinent Gondwana. This area shows hundreds of circular and curvilinear dunes of silicified sandstone of variable sizes, which were covered by intraplate Paraná volcanic rocks. This field guide provides the information for a field trip from Porto Alegre, Brazil to two hills (Cerros) in the IPDF, Cerro Farrapo and Cerro Figueirinha. Important features formed by hot water, volcanic rock and sediment interaction are preserved in large outcrops in these hills, including extensive silicification and deformation of the buried dunes, injection of fluidized sand and explosive hydrothermal activity. Hydrothermal structures include preservation of subterranean conduits that emerged at the Earth’s surface to form surging hot pools, geysers and spouts. These features are preserved as bowls, rounded to polygonal cavities and prismatic and lozenge-shaped clasts and blocks. Access to the outcrops is mostly via paved roads, with 40 km in unpaved roads.

Rehabilitation Options and Guidance for Severely Distressed Low-Volume Paved Roads With a Focus on Conversion to Engineered Unpaved Surfaces

A large percentage of low-volume paved rural roads in the United States are in a severely distressed state, primarily owing to delayed maintenance because of limited funding. Road agencies are now faced with decisions on what to do with these roads under constrained budgets. Options include closing selected roads completely if more than one road can be used to access properties; converting the distressed paved road to an engineered unpaved road, pulverizing the existing materials to form a new base and applying a surface treatment (e.g., chip seal); or doing a full-depth recycle, potentially with supplemental aggregates, using bituminous or cementitious recycling agents (choice dependent on the properties of the recycled material) and then applying a surface treatment or thin asphalt overlay. Choice will depend on traffic volume, safety concerns, available materials, and available funds. Regardless of the choice, sound engineering procedures should be followed throughout the conversion or rehabilitation process to ensure that funds are used optimally and that the road provides satisfactory performance over its new design life. This paper provides guidance on converting roads to an engineered unpaved standard.

Melbourne's Suburban Landscapes: Administering Population and Employment Growth

As recently as fifty years ago, Melbourne's new suburban communities were constructed with unpaved roads and lacked many basic services. Today they often come not just with roads but virtually complete with most of the facilities and amenities needed on a daily basis. Yet architectural, planning and design professionals remain uneasy about the design and the environmental, social, and economic sustainability of the newest suburbs built in some instances up to 60 kilometres from the central business district. We locate this unease in the systemic nature of the planning and building of these new communities by an enormous public–private industry complex. Melbourne's outer suburbs could be thought to be administered rather than planned.

Evaluation of Geogrid in Unpaved Road Constructed on Sand Subgrade under Cyclic Loading

Evaluation of Geogrid in Unpaved Road Constructed on Sand Subgrade under Cyclic Loading

Air Pollution in South Texas: A Short Communication of Health Risks and Implications

Air pollution is a major public health concern. The region of South Texas in the United States has experienced high levels of air pollution in recent years due to an increase in population, cross-border trade between the U.S.A. and Mexico, and high vehicular activity. This review assesses the relationships between human health and air pollution in South Texas. A thorough scientific search was performed using PubMed, Science Direct, and ProQuest, with most of the literature focusing on the source apportionment of particulate matter that is 2.5 microns or less in width (PM2.5), Carbon Dioxide (CO2), carbon monoxide (CO), Black Carbon (BC), and associated health risks for children and pregnant women. Findings from the source apportionment studies suggest the role of industries, automobiles emissions, agricultural burning, construction work, and unpaved roads in the overall deterioration of air quality and deleterious health effects, such as respiratory and cardiovascular diseases. This review demonstrates the pressing need for more air pollution and health effects studies in this region, especially the Brownsville–Harlingen–McAllen metropolitan area.

Experimental Study on Monotonic Behaviour of Two-Layered Unpaved Road Model Reinforced with Treated Coir Geotextiles

Experimental Study on Monotonic Behaviour of Two-Layered Unpaved Road Model Reinforced with Treated Coir Geotextiles

Modeling Dust Generation on Low-Volume Roads Based on Vehicle Speed and Surface Fines Content

This study analyzes the role of vehicle speed and surface fines content on dust emission. Accordingly, fifty unpaved road sections in Iowa were evaluated; surface loose-aggregate samples were collected, and dust was collected using a Colorado State Dustometer at three speeds: 25 mph, 40 mph, and 55 mph. The data were analyzed using analysis of variance (ANOVA) test. Several dust-prediction models were developed utilizing multiple linear regression (ML), nonlinear regression with an interaction term (NLI), nonlinear beta regression (NLB), nonlinear curve-fitting regression (NLCF), and a multilayer neural network (MNN). The model predictors included vehicle speed and surface fines content. When models were evaluated using synthetic data and compared using post-hoc analysis, it was found that dust increases exponentially as vehicle speed increases and increases linearly as surface fines content increases. Also, at higher speeds, dust values will converge independently of the fines content in the surface materials. The ANOVA test results revealed that vehicle speed, surface fines content, and their interaction significantly affected dust emissions. The accuracy of models ranged from acceptable to good. The coefficients of determination ( R2) for ML, NLI, NLB, NLCF, and MNNTraining models were 0.703, 0.718, 0.689, 0.696, and 0.776, respectively. Evaluation of the models showed that independent of the R2 value, the MNN model was the most accurate in predicting dust emissions, followed by the NLCF model, the ML model, the NLB model, and lastly the NLI model. The post-hoc test showed that MNNTraining, NLCF, and ML models produced comparable results.

Muchkas-1 — a new reference complex of the Chuzh’yael’ Culture on the Mezen’ River

The results of the studies of the Muchkas settlement in 2020 are reported. The site is located on the right bank of the Mezen’ River in Udorsky District of the Komi Republic (northeast of the East European Plain). The exploitation of an unpaved motor road endangered the preservation of dwelling No. 1, which necessitated extensive excavation of an area of 82.5 m2. On the basis of the analysis of the complex of traces and remains, it has been determined that the studied structure is of a rectangular shape in plane, measuring 3.8m×5.5m with the area of 20 m2. Within the building, two hearths were used sequentially or concurrently. Related to them are two external horizontal heating-and-ventilating chimneys. Some information is preserved about the underground part of the structure. This was a frame strengthened at corners by bundles of thinner trunks of trees, possibly, pointed and stuck into the ground. Pine and to a lesser extent spruce, juniper, and birch were used to build the dwelling. The collection of Muchkas-1 con-tains 3819 objects, including 30 identifiable flint implements, a flint pendant, 21 implements made from non-siliceous rocks, fragments of three ceramic vessels, and debris of calcinated bones. Scrapers predominate in the flint toolset, while knives, awls, and arrowheads are represented to a lesser extent. As the result of the traceological analysis, it has been determined that the arrowhead and the pendant bear traces of long-term carrying in a container, or wea-ring on the clothing or on the body. Tools made of non-isotropic rock include mostly grinding stones. A hammer stone and an adze are represented by single specimens. Among the faunal remains, bones of reindeer, beaver, marten, wolverine, squirrel, black grouse, goose, and pike have been identified. This attests to the dominant role of hunting in the appropriating economy of the inhabitants of Muchkas-1 settlement. The specifics of the building struc-ture and technical-and-typological parameters of the pottery and stone tools allow attributing Muchkas-1 complex to the Chuzh’yael’ Culture of the final Neolithic period — the Chalcolithic. By virtue of 10 radiocarbon dates, the time of its construction is determined by the end of the 4th — first half of the 3rd mil. BC. The published data advance our understanding of the traditions of housebuilding, stone-working, and pottery-making of the prehistoric population of North-Eastern Europe and permit considering Muchkas-1 complex as a source of reference for the study of the Chuzh’yael’ Culture of the 4th — first half of the 3rd mil. BC.

The Amount of Tourist Waste in the Altai Mountains. Mongolia and Kazakhstan Cases

The article presents information about the result of the experiment that determined the amount of tourist waste in the Altai Mountains of Kazakhstan and the Altai Mountains of Mongolia. During the pandemic, traveling to the Altai Mountains became a trend for domestic tourism in both countries. Due to the low development of the infrastructure in this region, tourist vehicles drive on unpaved roads, build new branch roads, cross clay swamps to approach high mountains, damage the soil cover, and dump garbage into nature. The authors conducted a special experiment on the main tourist routes in the Altai Mountains and determined the amount of waste per tourist. Based

Condition Assessment of Unpaved Roads Using Low-Cost Computer Vision–Based Solutions

Unpaved roads are an important part of the road transportation system of many countries and they contribute to the accessibility of remote communities and businesses. Despite the importance of unpaved road networks on social and economic development of remote regions, research on semiautomated and automated assessment of these roads is limited. This paper proposes low-cost computer vision–based solutions for assessment of unpaved roads using two approaches: unmanned aerial vehicle (UAV) and participatory-based imaging methods. Both methods use deep neural network to process captured images and locate major road distresses, including potholes, rutting, and corrugations. In addition, a method is proposed to estimate the size of detected potholes in the UAV-captured video frames. Each of the proposed methods was evaluated using a set of experiments, which demonstrated promising performance in assessment of these infrastructure assets that are vital for reliable access of rural and remote communities.