Otta Seals and Gravseals as Low-Cost Surfacing Alternatives for Low-Volume Roads: Experiences in South Africa

2003 ◽  
Vol 1819 (1) ◽  
pp. 338-342 ◽  
Author(s):  
Simon Oloo ◽  
Rob Lindsay ◽  
Sam Mothilal
Keyword(s):  
South Africa ◽  
Low Cost ◽  
Cost Savings ◽  
Cost Effective ◽  
Field Trials ◽  
Low Volume Roads ◽  
Kwazulu Natal ◽  
Traffic Volumes ◽  
Low Volume ◽  
To Come

The geology of the northeastern part of the province of KwaZulu–Natal, South Africa, is predominantly alluvial with vast deposits of sands. Suitable gravel sources are hard to come by, which results in high graveling and regraveling costs brought about by long haul distances and accelerated gravel loss. Most gravel roads carry fewer than 500 vehicles per day of which less than 10% are heavy vehicles. The high cost of regraveling has led to consideration of upgrading such roads to surfaced standard, even though traffic volumes do not justify upgrading. Traditional chip seals are expensive and cannot be economically justified on roads that carry fewer than 500 vehicles per day. The KwaZulu–Natal Department of Transport is actively involved in efforts to identify cost-effective alternative surfacing products for low-volume roads. Field trials were conducted with Otta seals and Gravseals, which have been used successfully in other countries, as low-cost surfacing products for low-volume roads. The Otta seal is formed by placing graded aggregates on a relatively thick film of soft binder that, because of traffic and rolling, works its way through the aggregates. Gravseal consists of a special semipriming rubberized binder that is covered by a graded aggregate. Both Otta seals and Gravseals provide relatively flexible bituminous surfaces suitable for low-volume roads. Cost savings are derived mainly from the broad aggregate specifications, which allow for the use of marginal materials.

Pavement Evaluation and Rehabilitation Design Methodology Currently Used on Low-Volume Roads in Southern Africa

2003 ◽  
Vol 1819 (1) ◽  
pp. 343-352 ◽  
Author(s):  
J. A. Grobler ◽  
A. Taute ◽  
I. Joubert
Keyword(s):  
Southern Africa ◽  
Design Methodology ◽  
Low Cost ◽  
Cost Effective ◽  
Past Performance ◽  
The Road ◽  
Low Volume Roads ◽  
Pavement Evaluation ◽  
Wide Range ◽  
Low Volume

A pavement evaluation and rehabilitation design methodology is currently employed in southern Africa on relatively light pavement structures used for low-volume roads. The pavements normally consist of natural gravel materials in most layers and thin bituminous surfacings. When nearing the end of their design lives, they exhibit distresses ranging from minor deformation through aging of the surface to structural cracking and potholes. Rehabilitation options normally involve light stone seals or other inexpensive and cost-effective treatments. The phases of investigation for pavement evaluation and rehabilitation designs start with desk study to establish the history of the road and its past performance from pavement management system outputs. Detailed visual evaluations are then conducted of road features and extent of various forms of distress. These data are presented followed by a decision-making process to select areas for more detailed testing. All the information is used to determine the causes of distress and likely rehabilitation alternatives. Further destructive and nondestructive testing is carried out to predict performance of rehabilitation designs and equivalent annual cost comparisons. Rehabilitation design is also done with use of the dynamic cone penetrometer. Decision criteria are set for use of tests undertaken in the assessments, and test results are evaluated. This procedure normally results in a wide range of rehabilitation options, from application of a diluted emulsion as a surface rejuvenator to more extensive patching and resealing to major rehabilitation and overlays. This process effectively produces cost-effective solutions that maximize limited budgets. It is essential that the road authority be prepared to share the risks of the low-cost options with the designer. In this way benefits of low-cost solutions are realized, whereas, in a limited number of instances, premature distress may have to be repaired under routine maintenance.

Application of Epoxy Resin for Improvement of the Banana Stem-Acoustic Panel

2021 ◽  
Vol 15 ◽  
Author(s):  
Mohd Azril Riduan ◽  
Mohd Jumain Jalil ◽  
Intan Suhada Azmi ◽  
Afifudin Habulat ◽  
Danial Nuruddin Azlan Raofuddin ◽  
...  
Keyword(s):  
Oleic Acid ◽  
Kinetic Modelling ◽  
Low Cost ◽  
Cost Effective ◽  
Performic Acid ◽  
High Yield ◽  
Renewable Materials ◽  
Runge Kutta Method ◽  
To Come

Background: Greener epoxidation by using vegetable oil to create an eco-friendly epoxide is being studied because it is a more cost-effective and environmentally friendly commodity that is safer than non-renewable materials. The aim of this research is to come up with low-cost solutions for banana trunk acoustic panels with kinetic modelling of epoxy-based palm oil. Method: In this study, the epoxidation of palm oleic acid was carried out by in situ performic acid to produce epoxidized palm oleic acid. Results: Banana trunk acoustic panel was successfully innovated based on the performance when the epoxy was applied. Lastly, a mathematical model was developed by using the numerical integration of the 4th order Runge-Kutta method, and the results showed that there is a good agreement between the simulation and experimental data, which validates the kinetic model. Conclusion: Overall, the peracid mechanism was effective in producing a high yield of epoxy from palm oleic acid that is useful for the improvement of acoustic panels based on the banana trunk.

Chilean Structural Design Guide for Low-Volume Roads

2003 ◽  
Vol 1819 (1) ◽  
pp. 306-313 ◽  
Author(s):  
Guillermo Thenoux ◽  
Alvaro González ◽  
Felipe Halles
Keyword(s):  
South Africa ◽  
Structural Design ◽  
Engineering Application ◽  
Climate Conditions ◽  
Design Charts ◽  
Low Volume Roads ◽  
Mechanistic Analysis ◽  
Design Guide ◽  
Low Volume ◽  
Selection Of

The practical and theoretical principles used for development of the Chilean Structural Design Guide for Low-Volume Roads 2002 and the guide’s conceptual model and hypotheses are presented. The design guide is a simplified methodology for selection of different pavement structure alternatives for a variety of conditions (traffic, soil support capacity, and climate). The design guide provides solutions for four traffic ranges, six ranges of soil support capacity, and three climate conditions (dry, normal, and saturated). The design charts contain more than 150 solutions. Pavement structural design was solved by mechanistic analysis with the BISAR computer program and fatigue models developed in South Africa. The design guide may be considered an engineering application with upto- date research tools and results.

scholarly journals Improving the Design of Low Volume Sealed Roads in Tanzania

2008 ◽  
Vol 31 (2) ◽  
pp. 21-30
Author(s):  
David A. Mfinanga ◽  
Lusekelo A. Mwakyami
Keyword(s):  
Conventional Method ◽  
Southern Africa ◽  
Research Laboratory ◽  
Design Method ◽  
Cost Savings ◽  
Cost Effective ◽  
Dar Es Salaam ◽  
Pavement Design ◽  
Secondary Sources ◽  
Low Volume

The main objective of the study was to identify appropriate road designs for Low Volume Sealed Roads (LVSRs) with the aim of improving the design of such roads in Tanzania. The study was conducted in Dar es Salaam and Morogoro regions in Tanzania where data for LVSRs were collected from primary and secondary sources in the two regions. The study found that by using an improved pavement design method specifically meant for LVSRs results in cost savings for LVSRs of up to 51% compared with the conventional method of pavement design in Tanzania. The study recommends that the pavement design method for lightly trafficked sealed roads in southern Africa developed by Transport Research Laboratory, which was found to be most cost-effective, be used to design (or develop a procedure for design of) LVSRs in Tanzania and that the roads be preferably sealed with Otta seal or Surface dressing. The study also recommends that LVSRs in Tanzania be defined by a maximum traffic volume of 400 vpd.

scholarly journals Breakout Session: Leveraging Licensing to Increase Access

2018 ◽  
Vol 2 (1) ◽  
Author(s):  
Michelle Polchow
Keyword(s):  
Los Angeles ◽  
Low Cost ◽  
Cost Savings ◽  
Cost Effective ◽  
Convincing Evidence ◽  
Open Educational Resources ◽  
Breakout Session ◽  
Diverse Range ◽  
Course Materials ◽  
Library Resources

The Affordable Course Materials Initiative (ACMI) is a library-driven program established by University of California, Los Angeles (UCLA), designed to leverage existing library resources, encourage open educational resources (OER) content creation, identify cost-effective digital projects and modify existing license agreements in order to create reduced cost course materials for students, as an alternative to rising commercial textbook costs.  The faculty incentivized program encourages instructors to partner with the library to leverage free or low-cost resources, adjusting syllabi and assignments as needed.  ACMI’s two-year pilot resulted in convincing evidence that the service supported a broad and diverse range of campus disciplines, achieved substantial cost savings, served as a catalyst for community building with multiple stakeholders, and gained campus administration recognition with an ongoing commitment of financial support to permanently integrate the initiative as an ongoing component of library services. 

scholarly journals Online appendix 1:Collection stewardship constrained by resources: The management of religious archives in Pietermaritzburg, KwaZulu-Natal region

2013 ◽  
Vol 34 (1) ◽  
Author(s):  
Francis Garaba
Keyword(s):  
South Africa ◽  
South African ◽  
African Society ◽  
The South ◽  
South African Society ◽  
Online Appendix ◽  
Kwazulu Natal ◽  
To Come ◽  
The Voice

A survey using questionnaires, observation and interviews was conducted in 2011 to ascertain the collection stewardship strategies of archival repositories with religious archives in Pietermaritzburg. The study concluded that there was a need to establish a religious archives group in order for the voice of ecclesiastical archives to resonate across South Africa. Through this group, it is hoped that there will be greater coordination and networking amongst the archival repositories. The help of associations such as the South African Society of Archivists, the Oral History Association of South Africa and the South African Preservation Group could greatly assist in fostering best practices in archival management. To champion this worthwhile cause, it would be ideal to come up with an Open Day on religious archives to serve as an advocacy platform. These recommendations are made against a backdrop of the poor state of religious archives in Pietermaritzburg, resulting from acute underfunding and which threatens the survival of this record in the long term.

scholarly journals Online appendix 2:Collection stewardship constrained by resources: The management of religious archives in Pietermaritzburg, KwaZulu-Natal region

2013 ◽  
Vol 34 (1) ◽  
Author(s):  
Francis Garaba
Keyword(s):  
South Africa ◽  
South African ◽  
African Society ◽  
The South ◽  
South African Society ◽  
Online Appendix ◽  
Kwazulu Natal ◽  
To Come ◽  
The Voice

A survey using questionnaires, observation and interviews was conducted in 2011 to ascertain the collection stewardship strategies of archival repositories with religious archives in Pietermaritzburg. The study concluded that there was a need to establish a religious archives group in order for the voice of ecclesiastical archives to resonate across South Africa. Through this group, it is hoped that there will be greater coordination and networking amongst the archival repositories. The help of associations such as the South African Society of Archivists, the Oral History Association of South Africa and the South African Preservation Group could greatly assist in fostering best practices in archival management. To champion this worthwhile cause, it would be ideal to come up with an Open Day on religious archives to serve as an advocacy platform. These recommendations are made against a backdrop of the poor state of religious archives in Pietermaritzburg, resulting from acute underfunding and which threatens the survival of this record in the long term.

Quantification of Reduction in Hydraulic Conductivity and Skid Resistance Caused by Fog Seal in Low-Volume Roads

2017 ◽  
Vol 2657 (1) ◽  
pp. 99-108 ◽  
Author(s):  
Readul Mohammad Islam ◽  
Shams Arafat ◽  
Nazimuddin M. Wasiuddin
Keyword(s):  
Hydraulic Conductivity ◽  
Low Cost ◽  
Surface Friction ◽  
Application Rate ◽  
Application Rates ◽  
Low Volume Roads ◽  
Before And After ◽  
Road Type ◽  
Rate Of Recovery ◽  
Low Volume

Fog seal increases pavement life and postpones major rehabilitation. The reduction of permeability caused by fog sealing will reduce moisture-induced damage, but this benefit comes with a temporary loss of surface friction. However, quantifying the effectiveness of fog sealing by measuring permeability is a difficult task. Although fog seal may be a good low-cost maintenance option for low-volume roads, the rate of recovery of friction may be very slow because of less rubbing action between the fog-sealed surface and tires. Four low-volume parish roads in Caddo Parish, Louisiana, were selected for this study. Two emulsions, CSS-1H and E-Fog, with three application rates, were used to evaluate the reduction in hydraulic conductivity and to assess the characteristics of friction over time. Results showed that fog seal can be expected to be fully cured within 2.5 to 3.5 hours for an application rate of 0.2 to 0.4 gallons per square yard (gal/yd2). The same field cores were tested before and after fog sealing to quantify exactly the reduction in hydraulic conductivity. It was observed that fog seal has a significant potential to reduce hydraulic conductivity. Considering all four pavements and application rates of 0.1 to 0.22 gal/yd2, the average reduction in hydraulic conductivity was 38.5%. Reduction in hydraulic conductivity shows very slight sensitivity to the application rate. Irrespective of road type, emulsion, and application rate, fog seal causes a sudden drop in the International Friction Index parameter F60 by 20% to 40%. A fog-sealed surface does not return to the original level of friction after three months; however, the rate of recovery was the highest for the busiest of the observed Caddo Parish roads.

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