Post 687 –by Gautam Shah
. Part 1 of Two articles
We today have greater capacity to search over wider terrains and also reach at sub surface locations. Exploitation of stones as collection from the surface or extraction from various depths is not a major technological problem. There are other issues that are forcing reappraisal of Stone as the viable material of construction. The issues are > economics of transportation, wastage in production, and reuse of the material as debris and production residues.
Stones, like the clays-soils are universal materials of construction and require very simple technology. There are Three essential sources of stone: 1 Surface collected stones, 2 Extracted stones, 3 Wastes and debris stones. Use of the surface collected stones in original size-form is easiest. Such stones, however, require down sizing and form dressing, before carriage to a place of use. Extracted stones are surface protruding and subterranean mass. These are often stratified or layered. Stone extraction causes ecological devastation due to removal of the top burden, large volume of reject-mass, and wastage of local cleaning, cutting and size dressing. Wastes and debris stones are man-made endeavours. Wastes occur at points of extraction and location of constructions, whereas debris occurs due to the demolition of structures. These need sorting, cleaning and transportation.
To make Stones viable now, Technological Developments and Materials Management are required. Stones are used for their mass, surface and structural strength. These can be exploited further by new design, joint technology, assembly methods, formation of composites, improved structural geometry and conversion to different materials (chemicals).
1 Extend the Surface Area: Stones are valued for their surface qualities and the prime need is to increase the surface area. The extended surface reduces the mass / weight of the stones. The surface area of the stones can be enlarged by two basic methods: by Thin Sectioning and by Amalgamation of bits and pieces, which otherwise end up as a collection and production wastes. Other methods of optimizing the surfaces are to endow new sensory qualities and surface properties. Many exciting technologies are now available.
2 Exploring structural properties: Stones have certain directional structural properties which can be exploited and reinforced. The efforts start with new ways of excavation, extraction and conversion of the material. Other common processes are selection, orientation, rational sectioning and controlled aeration-seasoning. Structural potential of stones can also be exploited by developing new areas of usage and new techniques of construction.
3 Stone’s Combinative formations: Traditionally stone composites have had lime and cement as the matrix component. The explorations now relate to composites with new forms of filler arrangements and new types of a matrix.
4 Designing geometrical or spatial compositions: Stones shows great promise in offering radically different materials’ combinative formations. The formations include various ways of combining or ‘synthesizing’ materials of diverse nature, such as, with metals, polymers, ceramics etc.
Stones have naturally variegated constitution and surfaces. These, provide with inexhaustible opportunities to work to many different forms, sizes, and finishes. Though, qualitative consistency of man-made materials poses a great challenge to multifarious nature of stone materials. Stones have structural attributes, often called Engineering characteristics, which regulate their usefulness for conversion to: Building or Dimension stones, Veneered or thin slabs and for crushing. Similarly stones also exhibit very distinctive sensory properties that govern their use as a facing material in the form of building blocks, cladding and flooring slabs.
The opportunities of intervention operate on two fronts: Improvisations over existing methods and Adoption of radically different technologies.
Part 1 of 2 articles