Fundamental principles ensuring successful implementation of new-age (Nano) modified emulsions (nme) for the stabilisation of naturally available materials in pavement engineering

Good transportation systems are pre-requisites to economic development. Empirically developed, archaic test methods are traditionally used for materials classification used in road construction. This system normally classifies naturally available materials subjected to chemical weathering conditions, as unsuitable for use in the load-bearing road pavement layers. Consequently, design standards normally require the use of imported materials at considerable costs, severely restricting road network development under scenarios of limited funding. The introduction of applicable nanotechnologies has been shown to enable the use of naturally available materials in all pavement layers at a substantial reduction in costs. The successful roll-out of these nanotechnology solutions depends on a sound, scientifically based approach. Aspects such as toxicity, health and safety, etc. must be addressed in a holistic approach together with material compatibility and fundamental engineering requirements. The successes achieved over the last decade, introducing material compatible New-age Modified Emulsions (NME), are based on fundamental concepts that need to be considered in a holistic test, evaluation and implementation strategy. This paper identifies fundamental concepts related to nanotechnology implementation in the context of road pavement engineering, which needs to be addressed to ensure successful implementation. Ad hoc implementation of new-age technologies without adequate scientific evaluation could prove detrimental.http://www.mdpi.com/journal/applscipm2021Civil Engineerin

Practical application of nanotechnology solutions in pavement engineering : construction practices successfully implemented on roads (highways to local access roads) using marginal granular materials stabilised with new-age (nano) modified emulsions (NME)

The introduction of any new disruptive technology in a traditionally well-established industry, such as the road construction industry, is usually associated with considerable resistance. This is especially relevant when the new technology is based on the use of granular materials traditionally considered to be of an unacceptable quality in combination with relatively new concepts such as New-age (Nano) Modified Emulsions (NME). In such cases, the fact that the material design methods are based on fundamental scientific principles and have been proven in both laboratories and through Accelerated Pavement Testing (APT) may be of little influence. However, the general acceptance of new disruptive technologies, e.g., telecommunications and Information Technologies (IT), have been based on the considerable advantages it presented. The same principles are applicable to the general acceptance and use of the NME stabilisation/enhancement of materials in the road construction industry. This article is aimed at the practical cost-effective demonstration of the general application of the use of nanos-silane-modified emulsions in the construction of the highest order roads, i.e., inter-city multi-lane highways, lower-order roads (including Low-Volume Roads (LVR)), and even local accesses to farms and in villages/townships. The implementation of NME technologies is directly associated with ease of use, time, and cost savings, and with the addressing and reduction of risks applicable to the use thereof.https://www.mdpi.com/journal/applsciCivil Engineerin

Practical application of nanotechnology solutions in pavement engineering : identifying, resolving and preventing the cause and mechanism of observed distress encountered in practice during construction using marginal materials stabilised with new-age (nano) modified emulsions (NME)

New-age (Nano) Modified Emulsions (NME) for stabilising marginal materials used in the upper-pavement layers of roads have been proven in laboratories, through accelerated pavement tests (APT) in the field as well as in practice. In addition, materials design methods have been developed based on the scientific analysis of granular material mineralogy and the chemical interaction with the binder to design a material-compatible anionic NME stabilising agent for naturally available (often marginal) materials. However, any new disruptive technology that is introduced into a traditionally well-established industry, such as the road construction industry, is usually associated with considerable resistance. This is especially relevant when the new technology enables the use of granular materials traditionally considered to be of an unacceptable quality in combination with relatively new concepts such as an anionic NME stabilising agent. In practice, few road construction projects are without problems. New technologies are obviously easy targets to blame for any nonrelated problems that may arise during construction. In this article, we aim to assist in pre-empting, recognising, preventing, and resolving material or non-material related construction problems by correctly identifying the cause of the problems and recommending the best, most cost-effective ways to correct any deficiencies on site.https://www.mdpi.com/journal/applsciam2023Civil Engineerin

Nanotechnology incorporation into road pavement design based on scientific principles of materials chemistry and engineering physics using new‐age (Nano) modified emulsion (NME) stabilisation/enhancement of granular materials

The use of naturally available materials not conforming to traditional specifications or standards in the base and sub-base layers of road pavement structures and stabilised with Newage (Nano) Modified Emulsions (NME) have been tested, implemented and successfully verified through Accelerated Pavement Testing (APT) in South Africa. This was made possible through the development and use of a materials design procedure addressing fundamental principles and based on scientific concepts which are universally applicable. The understanding and incorporation of the chemical interactions between the mineralogy of the materials and an NME stabilising agent (compatibility between the chemistry of the reactive agents and material mineralogy) into the design approach is key to achieving the required engineering properties. The evaluation of the stabilised materials is performed using tests indicative of the basic engineering properties (physics) of compressive strengths, tensile strengths and durability. This article describes the basic materials design approach that was developed to ensure that organofunctional nano-silane modified emulsions can successfully be used for pavement layer construction utilising naturally available materials at a low risk. The enablement of the use of naturally available materials in all pavement layers can have a considerable impact on the unit cost and lifecycle costs of road transportation infrastructure.https://www.mdpi.com/journal/applsciam2022Civil Engineerin

Nanotechnology applications towards sustainable road surface maintenance and effective asset protection, generating rapid employment opportunities in a post COVID-19 era

The developing world has been faced with high rates of unemployment, exasperated by extended enforced lockdowns due to the Pandemic. Pressure is mounting for drastic intervention to accelerate economic growth and to provide employment opportunities. Most of these countries are faced with inadequate road transport facilities in support of economic growth. The construction of high-order roads in support of economic growth, require high degrees of compliance with limited opportunities for increased the labour content. However, many of the existing surfaced roads are notoriously lacking periodic preventative maintenance operations needed to preserve the integrity of road surfaces to protect pavement structures against water ingress and resultant rapid deterioration. This article demonstrates the ability of available, proven nanotechnologies to restore the waterresistant properties of already compromised road surfacings. It is shown that traditionally used road products can substantially be improved (in terms of strength properties and resistance to environmental factors) through the addition of applicable nanotechnology modifiers. These modified products can be applied at ambient temperatures, ideally suited for labour intensive applications as demonstrated, showing several examples of actual applications. A combination of modified existing technologies is recommended to partially restore severely compromised road surfacings, especially applicable to secondary, tertiary and urban road networks. The implementation of the recommended restoration programmes can go a long way towards road asset preservation, while simultaneously, addressing the urgent need for rapid employment generation.http://www.mdpi.com/journal/applsciCivil Engineerin

Development of a digital twin of a local road network : a case study

Virtual replicas of infrastructure can be used to run simulations and optimize the construction, management, and maintenance of such assets throughout their entire lifecycle. These digital twins (defined as integrated multi-physics, multiscale, and probabilistic simulations of a complex product) mirror the behavior and environmental responses of its corresponding twin. Digital reconstruction techniques using optical sensor technologies and mobile sensor platforms are providing viable, low-cost alternatives to develop digital twins of physical infrastructure. In previous work, the digital twinning of asphalt pavement surfacings using visual simultaneous localization and mapping and the initiation of a digital twin of a local road network were investigated and successfully demonstrated. In this article, the further development of the concept, incorporating road surface temperatures collected over a 1-month period, as well as potential inferences based on these data, in the micro- and macro-twinning of a local road, are discussed. Light detection and ranging, unmanned aerial vehicles, and traffic counting artificial intelligence allows for quantification of the road geometry and infrastructure utilization over large areas (macro-twinning), whereas the photogrammetric reconstruction technique based on a neural network, a proprietary environmental condition sensor (SNOET, or SNiffing Omgewing / Environmental Tester) and commercial temperature sensors were used to acquire the surface texture and environmental conditions respectively (micro-twinning), as well as surface temperatures at four locations and different surfacing materials. The combination of advanced environmental monitoring data, physical data, and surface temperature data provide management data that can assist in the maintenance of such roads. This article expands (with the permission of the conference organizers) on a GeoChina 2021 article through the addition of further temperature data collected on the discussed digital twin, with substantial additional data analysis and discussion.https://www.astm.org/products-services/standards-and-publications/journal-of-testing-and-evaluation.html2022-06-16am2022Civil Engineerin

Continuous, response-based road roughness measurements utilising data harvested from telematics device sensors

Roads need to be continuously monitored and maintained to ensure that they offer a driving surface that effectively address the safety and comfort needs of road users. Well maintained roads are also vital for freight transport companies, assisting with minimising vehicle and goods damage that can occur during transportation. Vehicle telematics is technology that is advancing in terms of complexity, diversity and data volume. Hundreds of thousands of these devices are installed in vehicles throughout South Africa and worldwide. The technology is predominantly used for the recovery of hijacked or stolen vehicles, driver behavioural insurance and monitoring and management of vehicle fleets. This paper demonstrates that vehicle telematics provides additional potential in terms of estimating road roughness (similar to a Class 3 level). This is demonstrated by utilising the global positioning system (time, latitude, longitude and speed) and vertical (z) acceleration data harvested from telematics device sensors. Road roughness data obtained from telematics technology can be used as ‘screening’ devices to measure road roughness on a real-time basis. It can also help close the gap between Class 1, Class 2 and Class 4 road roughness measurements.The University of Pretoriahttp://www.tandfonline.com/loi/gpav202019-06-18hj2019Civil Engineerin

Performance of thermoplastic road-marking material

The most important aspect of road markings is that they must be retroreflective. The minimum night-time visibility (retroreflectivity) (RL) for white and yellow road markings must be 100 mcd/m2/lx and 70 mcd/m2/lx respectively. There are also other important parameters to which road markings should conform, such as the day-time visibility (luminance) (Qd), colour and skid resistance. The South African Bureau of Standards (SABS) regulations on plastic road-marking materials are insufficient, and therefore road-marking applicators could be applying inferior quality plastic road-marking materials. Since the European specifications are widely adopted by many countries, the BS EN 2007 specification was used in conjunction with the available South African standards in this study to determine the performance of thermoplastic road-marking materials. Retroreflectivity testing is important in controlling the final road-marking product. The objectives of this study were: ■ To determine the RL and Qd service lives of various road-marking paints and road-marking materials on asphalt and chip seal road surfaces. ■ To determine if there are significant differences in RL, Qd and the colour of the road markings when washed with liquid soap mixed with water and hard brooms. ■ To check if the colour and skid resistance of the applied road markings comply with the specification. Based on the data obtained from the study, the following conclusions were drawn: ■ The RL and Qd service lives of various road-marking paints and road-marking materials on asphalt and chip seal road surfaces were determined as between 1 and 48 months, and 1 and 30 months respectively. ■ There was no significant increase in RL or colour compliance of the washed road markings, while there was generally an increase in Qd after washing the test markings. ■ White road markings generally complied with the colour specification, while yellow road markings did not comply with the specification. ■ The initial skid resistance of white and yellow 1.2 mm thermoplastic road markings complied with the specification, while all other road markings did not comply with the specification.http://www.journals.co.za/ej/ejour_civileng.htmlCivil Engineerin

Telematics-based technology and the development of road condition trends from cloud-sourced data

Road related telematics encompasses a combination of road transportation, in-vehicle electronics and telecommunications. It is continuously evolving in terms of complexity and diversity, and contains high volumes of sensor data. Telematics-based technology is mainly used for the recovery of hijacked/stolen vehicles, insurance purposes and vehicle fleet monitoring and management. In this paper, it is demonstrated that telematics-based technology may offer capabilities in terms of predicting road condition. This is based on a project where some simple statistical analysis techniques were used to interpret existing data originating from standard vehicle telematics units. The paper mainly evaluates the z-direction (up / down) acceleration for a few different vehicle types and x-direction (lateral), y-direction (longitudinal) and z-direction acceleration for the identification of road anomalies/defects. Roads are currently monitored using Class 1 profilometers, which provides a detailed but relatively costly indication of road condition. The use of vehicle telematics may provide a more cost-effective solution to monitor a wider road network and on a continuous basis, albeit on a Class 3 profilometer level. Telematics units are currently installed in numerous vehicle types throughout South Africa, and this paper focuses on achieving a reliable Class 3, real-time response-type measurement which can be used as a screening device and which is able to accurately produce an indication of road roughness, as well as major road distresses. This may assist in ensuring that agencies without direct access to funding for Class 1 road condition data may be able to obtain an indication of their road network conditions. It also contributes towards the safety and comfort of road users.Paper presented at the 34th Annual Southern African Transport Conference 6-9 July 2015 "Working Together to Deliver - Sakha Sonke", CSIR International Convention Centre, Pretoria, South Africa.The Minister of Transport, South AfricaTransportation Research Board of the US

Evaluation of microclimate effects on surfacing seal performance

Surfacing seals consist of a combination of bitumen and aggregate, and are used to provide an all-weather surfacing to protect underlying layers and provide safe access to vehicles traveling on a road. Analysis of a number of sections in Gauteng, South Africa, has shown that surfacing seals lost a large proportion of their aggregate where the road was crossed by a bridge. As all original properties of the seal components as well as the traffic on the road were similar, it was deduced that the micro-climate where the road traveled underneath the bridge should have caused this localized failure condition. In this paper the phenomenon is investigated through analysis of the micro-climate underneath the bridge, the material properties of the surfacing seal, and the combined effect of these factors on the performance of the seal. It is shown that the micro-climate can affect the performance of an otherwise suitable surfacing seal to such an extent that the performance of the seal is severely compromised. A procedure for the analysis of potential micro-climate effects is described in the paper.http://www.asce.org