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 New-age (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.

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.

Nanotechnology is the term used to cover the design, construction and utilization of structures with at least one dimension measured in nanometers. Compared with typical civil engineering structures the two fields operate on hugely divergent dimensional scales. Nanotechnology initially developed in the fields of physics and chemistry, and most fundamental developments still occur in these fields.However, for the technology to affect society at large, it needs to be applied in areas such as the engineering field. This paper focuses specifically on current and potential developments in pavement engineering where the unique properties of nanomaterials may be utilized to deliver a better environment to society, based on identified needs and challenges in the pavement engineering field. It is demonstrated that there are essentially two areas where nanotechnology can complement pavement engineering. These are in the development of improved materials and the use of characterization methods to improve the understanding of materials. Examples of current and planned research in these areas are cited and discussed. Finally, current challenges in exploiting the unique properties of nanomaterials in pavement engineering are indicated and discussed. The paper demonstrates that although the majority of the fundamental developments in nanoscale science and technology are occurring in the fundamental physics, chemistry and typically electronic engineering fields, the potential for this technology to impact on the quality of life of society at large is huge.

Nanoscale organofunctional silanes have been developed, tested and successfully applied to protect stone buildings in Europe against climatic effects since the 1860s. The same nanotechnologies can also be used in pavement engineering to create strong chemical bonds between a stabilising agent and granular material. The attachment of the organofunctional silane to a material also changes the surface of the material to become hydrophobic, thereby considerably reducing future chemical weathering. These properties allow naturally available materials to be used in any pavement layer at a low risk. In the built environment, scientists soon determined that the successful use of an organo-silane depends on the type and condition of the stone to be treated. The same principles apply to the implementation of applicable nanotechnologies in pavement engineering. Understanding the basic chemistry, determining the properties of the stabilising agent and the organofunctional modifying agent and the chemical interaction with the primary and secondary minerals of the material are essential for the successful application of these technologies in pavement engineering. This paper explains some basic chemistry, which fundamentally influences engineering outputs that can be achieved using New-age (Nano) Modified Emulsions (NME) stabilising agents with naturally available granular materials in all road pavement layers below the surfacing.

Phosphor-based polymer composites were prepared using a melt mixing and extrusion method. Morphology, luminescent properties, and Hamburg wheel test (HWT) of synthesized hybrid material were studied using various polymer matrices. The intensities of the luminescence of the strontium aluminates phosphors (SrAl 2 O 4 : Eu,Dy and Sr 4 Al 14 O 25 : Eu,Dy) were substantially changed when incorporated into structurally and chemically different organic matrices. HWTs were performed to evaluate the durability of the polymers against simulated wheel loads and the effect of these wheel loads on the luminosity of the polymers. The decay slopes of various polymer-phosphor composites suggests that the simulated wheel load of the Hamburg test did not have a profound effect on the luminosity as such but the duration of luminescence was found to be shorter for the polymer-phosphor hybrid after the Hamburg test.