## 1 Introduction  
Silicon-based new-age nanotechnology products have been used in the built-environment since the early 1800s. At the time, scientists were tasked in Europe with the challenge to develop products to protect stone buildings, monuments and statues from deterioration due to the observed detrimental effect of water and pollution [1]. Conflicting results by various scientists soon led to the conclusion that the type of stone and the condition of the stone, play an important part in the successful use of a specific silicon-based product to be effective and achieve the required results. These conclusions were derived after decades of testing using a trial-and-error approach. The development of advanced investigation and observation equipment (such as the Atomic Force Microscope (AFM)) in the 1980/1990s enabled scientists to observe and manipulate the behaviour of nano-size particles which led to the science of nanotechnology, influencing basically all major industries [2; 3]. It follows that since the 1980s, the science of new-age nanotechnology products for use in the built environment have developed exponentially. These products are used throughout the industry to, inter alia, enhance and protect of all types of building products, including wood, gypsum-board, etc., as well as the relatively softer and vulnerable type of building blocks such as sandstone, limestone and marble. These products are widely used in the built environment mostly incorporate silicon as a basic element that exhibits \"excellent mechanical, optical, thermal and electrical properties\" [4]. Most of the naturally available materials found in global climatic zones that are subjected to weathering due to chemical decomposition (high temperatures associated with seasonal rainfall [5]) are classified by road pavement engineers as marginal or unsuitable for use in the load bearing layers (upper layers) of a road structure. This \"unsuitable\" classification is mainly due to the risk associated with the secondary minerals (e.g., clays, etc.) that are present due to chemical decomposition of the primary minerals. The same nanotechnology silicon-based products used in the built environment can also be utilised to change this scenario. These naturally available materials can be treated, enhanced, stabilised and the secondary minerals neutralised to enable these materials to be used in the load bearing layers of a pavement structure [6]. Testing has shown the potential of such stabilisation of materials of unsuitable quality for use on roads carrying low to relatively high traffic loadings (in excess of 30 million dual wheel standard 80 kN axle loads (E80s)) [7; 8]. These examples, have also shown that the use of nano-silane technologies, enabling the use of naturally available materials without comprising the integrity the road pavement structures, could result in the reduction of the unit costs of surfaced roads by 30 to 50 per cent or more. These savings are influenced by various factors, such as the availability and proximity of high-quality crushed stone, traditionally used in the upper structural layers of a road. Many alternative \"wonder\" products have been introduced onto the market to improve naturally available materials for use in roads over many a decade. These products were mostly based on a limited number of empirically based tests of a few selected materials. Invariably, these products did not meet expectations. As a result of these experiences, the engineering faternity developed a scepticism and resistance towards the introduction of new technologies. It follows that any new-age nanotechnology needs to be based on a sound scientific basis to limit the risks associated with new products. A scientific approach also requires that material testing be extended to include the scientific analysis of the mineralogy of the materials in order to determine the primary and secondary minerals that need to be accounted for [6; 9].