The use of ANSS in road projects is recognized as an extremely cost effective method of converting poor quality soil into a strong impermeable layer. It permits the construction of pavement layers, embankments and reinforced earth structures in areas where they were not previously economically viable, while saving significant sums of money.

ANSS is a calcium driven, inorganic soil stabilizer patented worldwide. Its specific formulation allows for stabilization of a broad range of materials without compromising the quality of the result.

The main components that are used to formulate ANSS are a series of inorganic hydration activated powders. It is composed of a specific type of cement, a lime, several pozzolans, rate governing additives, and a unique polypropylene fiber. The specific formulation allows for the individuality of the components to contribute to the reaction process, but also act holistically contributing of the stabilization process.

The theory behind their reactivity is quite simple, but the chemistry of each individual powder differs and the collaborative reaction is quite complex. Each component reacts individually while also contributing to the broader stabilization reaction. Each component contained in ANSS has its own series of reactions that occur at varying rates, which can be broken down into initial, short term and long term reactions.

ANSS is mixed with the soil as a dry powder. Initiation of hydration will commence immediately upon addition of water. The importance of achieving the desired water content is required not only for hydration of the components contained in ANSS, but also for wetting the reactive soil particles sufficiently to allow for exchange reactions to take place.

Dissolution of Ca (OH)₂ will provide an excess of Ca-ions in the soil solution. These divalent ions will incorporate themselves into the clay structure, which provides a starting point for calcium silicate and calcium aluminate reaction products to form. Due to the cation effect, calcium is a difficult ion to replace on the exchangeable sites of clay. Therefore, it will remain in the clay structure. The presence of calcium in the crystal structure of clays allows for other clay particles to form bridging covalent bonds, forming insoluble calcium silicates and a starting point for aluminosilcate bridges. These bridges form an integral part of the inter-particle crystal matrix.

Due to the phases contained in ANSS, there is a considerable rise in the pH of the system. This increase in soil pH will activate the pH dependent sites on the surfaces and edges of clay particles. This will also provide a key site for combining with other soil particles creating a link between the micro and macro structure of the soil.

One of the first reactions to take place is flocculation of the clay particles, which is associated with an immediate reduction (or elimination) in the plasticity (PI) of the soil. The ‘aggregation’ of the fine fraction leads to stability within the layer. Following flocculation, medium to long term reactions begin and secondary reaction products form.