scholarly journals Use of Road Stabilizers in Sensitive Environments

Road infrastructure is key for any developing country to enable its expansion such as those in Africa. Natural road construction materials can become depleted and increasing traffic loads produce higher maintenance requirements, leading to research to develop additives that can be used to enhance the engineering properties of available pavement soils. Providing all weather roads for large vehicles in rural areas, such as Northern Namibia, are often based only on the available soils, involving compaction and use of stabilizers, is required to both provide a suitable load bearing road surface and maintain the road network. The region is also environmentally sensitive to any potentially adverse impacts of chemicals that may be released into the environment during construction or as breakdown products. A number of road stabilizer products are available and the choice of stabilizer must take into account both its specific properties and the sensitivity of the environment where it is to be used to any environmental impacts. The main stabilizer types are cementitious, bituminous and chemical, with the latter broken down in a range of materials including synthetic polymer binders, organic and ionic compounds, salts, enzymatic products and combinations thereof. Twenty available stabilizer products were considered in terms of their environmental properties and assessed against the published literature and the general findings reported in terms of the overall ranking of the environmental impact of stabilizer types.

Author(s):  
Bizzar B. Madzikigwa

The road sector in Botswana continues to develop its road network throughout the country at a tremendous rate. When Botswana gained independence in 1966, it had only 10 km (16 mi) of bitumen road. By 1992 the total length of bituminous surfaced road reached 3500 km (2,175 mi) out of a total road network of 18 000 km (11,285 mi). These statistics clearly show that the majority of roads are not yet surfaced; these are low-volume roads that provide access to the rural areas where most of the country’s population is found, though in low density. In spite of the rapid improvement in the quality of the national road network in recent years, much remains to be done. In the early 1970s and early 1980s the rural roads unit was introduced in the Ministry of Works Transport and Communications, which was charged with the responsibility of design and construction of low-volume roads around the country in a bid to integrate the country’s road network. This unit was later disbanded in the 1990s, and all roads are improved through the conventional procurement system using private contractors. For these roads the justification of a surfacing project based on conventional economic return methods does not apply, and worse still, the road improvements have to compete with other amenities for the same limited resources. Three ministries in Botswana are responsible for roads: Ministry of Works Transport and Communications, Ministry of Local Government, and Ministry of Trade, Industry, Wildlife and Tourism. These ministries have different responsibilities for different roads within the country, and earth, sand, and gravel roads are found under the jurisdiction of each of the ministries. The major drawbacks concerning low-volume roads in Botswana are inadequate maintenance, poor road construction materials, and the environmental impacts of the roads. Since the budget and resources are inadequate to keep these roads in good condition, it would be prudent to find technological means that would improve the locally available road construction materials so as to minimize their effects on the environment and vehicle operating costs.


2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Ubido Oyem Emmanuel ◽  
Igwe Ogbonnaya ◽  
Ukah Bernadette Uche

AbstractInvestigation into the cause of road failure has been carried out along a 60 km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12 to 61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1–52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2–35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17–43.9%, maximum dry density ranges from 1.51–1.74 g /cm3, specific gravity ranges from 2.52–2.64 and CBR between 3 and 12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20–138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20 m – 240 m along the profile to a depth of 7.60 m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m − 120 m along the profile to a depth of 15 m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.


2003 ◽  
Vol 1819 (1) ◽  
pp. 161-165 ◽  
Author(s):  
Ali A. Selim ◽  
Kenneth O. Skorseth ◽  
Ratnasamy Muniandy

Gravel surfacing is commonly used on low-volume roads in rural areas of the United States to form farm-to-market networks that contain more than a million miles of unpaved roads. Some of these roads carry appreciable amounts of trucks and farm machinery. Some of these roads, if properly designed and constructed, can last a long time. One such road is in Hand County, South Dakota. This road was constructed in 1963 and has never been rehabilitated or reconstructed since its construction, and it has shown excellent performance for more than 37 years. This road normally carries less than 200 vehicles per day, but significant numbers of heavy trucks use the road. This exceptional performance led to an investigation of the reasons why that road lasted as long as it did without major maintenance or rehabilitation. Although this type of road construction is common in other nations, under different names, the practice of constructing this type of road in the United States was done without documented specifications. The main objectives of the study were to determine all factors that contributed to the longevity and the remarkable performance of this road through field and laboratory investigations. Field investigations with a dynamic cone penetrometer (DCP) revealed that both the quality and the quantity of aggregate base were more than adequate. Although the subgrade soil was classified as A6 according to AASHTO soil specifications, it provided good support according to DCP data. Tests of the flatness and elongation of the coarse aggregate and the angularity of the fine aggregate also revealed satisfactory results. Gradation tests also revealed compliance with specifications.


2021 ◽  
Author(s):  
OYEM EMMANUEL UBIDO ◽  
Igwe Ogbonnaya ◽  
Bernadette Uche Ukah

Abstract Investigation into the cause of road failure has been carried out along a 60km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12-61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1-52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2-35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17 – 43.9%, maximum dry density ranges from 1.51 -1.74g /cm3, specific gravity ranges from 2.52-2.64 and CBR between 3-12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20-138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20m – 240 m along the profile to a depth of 7.60m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m –120 m along the profile to a depth of 15m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.


2018 ◽  
Vol 4 (1) ◽  
pp. 19 ◽  
Author(s):  
Ademila Omowumi

Roads in Nigeria are usually constructed without in-depth knowledge of the subsoil that serves as the foundation for the road elements. Road failures are often associated to poor construction materials or inadequate design without cognisance of the underlying soils. Engineering properties of ten bulk soil samples collected from the subgrade of Arigidi/Oke-Agbe highway were investigated to determine their suitability for highway pavement. Results show that all the subgrade soils below the failed locations have higher plasticity indices, which is an indication of their high swelling potential, and they are classified as A-7-6 clayey soils with high-water adsorption capability (16.1 – 22.4%) compared to subgrade soils from the stable locations. Low compacted density (1325 – 1928 Kg/m3), extremely poor CBR values; 8 – 31% (unsoaked) and 3 – 8% (soaked) which indicate percentage reduction in strength of the soils up to 77% on exposure to excessive moisture and the predominance of fines (> 59%) in the soils are responsible for the degree of instability. Furthermore, soft to low stiffness (49 – 131 kN/m2) and poor permeability of the subgrade materials underlying the pavement result to the failure characteristics witnessed. This study shows that the suitability and behaviour of subgrade soil is dependent on its engineering properties.


2014 ◽  
Vol 13 (4) ◽  
pp. 091-100
Author(s):  
Anna Chomicz-Kowalska

The aim of the study was to analyze the properties of foamed bitumen produced from 50/70 bitumen in terms of the assessment of its usefulness to the road construction materials. In order to improve the foaming parameters the synthetic wax Fischer-Tropsch (FT) in an amount of 1.0%, 2.0% and 3.0% was used. Bitumen binder parameters were evaluated before and after the foaming process. The basic parameters were evaluated (before the foaming process): penetration, Fraass breaking point and softening point. The bitumen foam parameters were measured at the foaming water content (FWC) in the range from 1.5% to 4.0% with an increment of 0.5%. The tests allowed determining optimal application ranges for the FT and the FWC to produce asphalt at lower temperatures.


2015 ◽  
Vol 38 ◽  
pp. 86-92
Author(s):  
J.O. Fatoba ◽  
A.O. Sanni ◽  
A.B. Ayantunji

Ago-Iwoye –Ilisan road is the major road that links Abeokuta the state capital of Ogun –state to Ijebu towns. The road has always been experiencing pavement failure, which occurs inform of cracks and potholes. Being the major road, the effect of the failure has negative impact on the soico-economic growth of Ijebu –areas. The primary objective of the study was to determine the influence of the geotechnical properties of the sub-grade materials on the pavement performance of Ago-Iwoye – Ilishan Road. Eleven (11) soil samples were collected at eight (8) different locations with the aid of hand auger and were air-dried before taken to the laboratory for determination of engineering properties. The Liquid limit and the Plastic limits ranged from 13.9 – 46.2% and 8.1 – 32.7%, with the Plasticity index from 10.6 – 15.9% and Shrinkage limit from 6.2 – 27.7% respectively. The soaked CBR values of the subgrade materials is between 67% and 75% compared with 30% minimum specified by FMWH, 1997.The soils were classified by ASSHTO under the A-6 and A-7 category which shows that the soils are fair to poor as a sub-grade material and USCS classification shows that the soil falls into the SM and SC group.The comparison of all the results with the Nigeria specification (Federal Ministry of Works and Housing general guidelines) for the sub grade materials along the Ago-Iwoye-Ilisian road show that the materials underlain the pavement do satisfy the Nigeria standard. Therefore, the perennial failure frequently experience along the road route is not significantly influenced by subgrade materials. Hence, influence of other factors such as poor drainage courses, level of groundwater table, variation of geologic materials along the road route and poor construction materials should be thoroughly addressed before embarking on future rehabilitation of the highway.


2020 ◽  
Author(s):  
OYEM EMMANUEL UBIDO ◽  
Igwe Ogbonnaya ◽  
Bernadette Uche Ukah

Abstract Investigation into the cause of road failure has been carried out along a 60km long Sagamu –Papalanto highway southwestern Nigeria. Geochemical, mineralogical, geotechnical and geophysical analyses were conducted to evaluate the cause of failure along the study area. The results of the laboratory tests showed that the percentage amount of fines ranges from 12-61.3%, natural moisture content from 6.8 to 19.7%, liquid limit in the range of 25.1-52.2%, linear shrinkage between 3.96 to 12.71%, plastic limit ranges from 18.2-35%, plasticity index ranges from 5.2 to 24.6%, free swell in the range from 5.17 – 43.9%, maximum dry density ranges from 1.51 -1.74g /cm3, specific gravity ranges from 2.52-2.64 and CBR between 3-12%. The Cone Penetrometer Test (CPT) shows a resistance value of 20-138 kgf/cm2. The major clay mineral that is predominant in the studied soil is kaolinite. The major oxides present are SiO2, Al2O3, Fe2O3, K2O, Na2O, MgO and CaO. The result of the 2D Electrical Resistivity Imaging revealed a low resistivity values for profile 2 and 3 ranging from 100 Ωm – 300 Ωm, between a distance of 20m – 240 m along the profile to a depth of 7.60m and a low resistivity value ranging from 50 Ωm – 111Ωm, between a distance of 80 m –120 m along the profile to a depth of 15m. It was concluded that the low CBR, low MDD and the class of subsoils namely A-26, A-7, A-2-7 (clayey soils) which were identified are responsible for the cause of failure experienced in the study area. These makes the soils unsuitable as road construction materials and hence, there is need for stabilization during the reconstruction and rehabilitation of the road.


2021 ◽  
Vol 265 ◽  
pp. 04007
Author(s):  
N. G. Mitrofanov ◽  
A. Yu. Sushilova

The following paper presents some results of long-term research on the urgent problem of recycling waste products and their use in road construction. The studied new materials and technologies are justified by the developments of Tyumen Industrial University. The aim of this work is to prove the technique, checking the ecological safety of the road materials with the use of waste products. Research techniques and test subjects are quantitative chemical analysis and biological testing of road material samples with waste additives obtained during drilling and oil production. Along with the standard procedures for analyzing the contamination and toxicity of water extracts, the authors have proposed and tested the evaluation of repeated and long-term extractions, imitating the possible environmental impact of waste products. The obtained results showed the environmental safety of the road-building materials based on wastes.


2011 ◽  
Vol 261-263 ◽  
pp. 812-815
Author(s):  
Dong Xing Wang ◽  
Rachid Zentar ◽  
Nor Edine Abriak

In the context of sustainable development, traditional approaches such as ocean dumping and inland deposit are unsatisfactory for managing such large quantity of dredged marine sediments. The solidified sediments with cement as a new material for road construction are preferred to resolve the present issue for minimizing the impact to environment. Based on the basal characterization of dredged sediments, a series of tests, such as compaction tests, compressive strength and tensile strength tests and swell tests, are performed to explore the engineering properties of treated materials. The compressive and tensile strengths increase with cement content and curing time, while the swell percents of sediments decrease after immersion in water for 4 days. And this treatment method could be considered adaptive and acceptable for the road construction from the point of view of swelling property. Finally, the I-CBR index of cement-treated sediments increases due to the flocculation and cementation compared to the I-CBR index before immersion.


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