STONES -a next generation perspective

Lecture presented by Gautam Shah at Stone Workshop Faculty of Design CEPT University Ahmedabad
 

Stones like many other natural materials are abundantly available.

Most rocks that we are likely to encounter are within the top 16 kilometres of Earth's face. This mass is made up of 95% Igneous rocks and rest consisting of widely spread cover of Sedimentary and Metamorphic rocks.

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, but economics of transportation limits its commercial usage.

There are 3 essential sources of Building Stone Materials:

● Surface collected stones

● Extracted stones: surface protruding and subterranean mass

● Waste and recycled stones

The stones occur in many forms and sizes:

             1           Large pieces which can be further down sized or cut into smaller units,

             2           Units that are used without any other processing,

             3           Pieces which are crushed or disintegrated into finer particles,

             4           Rejected material from mining and collection processes,

             5           Wastes from stone sizing and dressing operations,

             6           Debris material recovered from demolition of old buildings and other structures.

SURFACE COLLECTED STONES

Surface collected stones from a single geographic region show only minor qualitative and size variations. Further quality equalization can be done location-based sourcing, visual selection, grading, separation. Surface collected stones can be further quality equalized through many types of ‘processes’.

● Surface collected materials are naturally formed such as boulders, pebbles, gravel, sands, etc. These are very tough materials and equally weathered on all faces.

● Other surface collected materials are broken by natural disintegrating forces like weather, chemical reactions, land mass movements, internal stresses, etc. These stones may show up with varied weathering on their faces. Such materials are fractured along the plane of shearing force or across the weakest plane, and so show unpredictable structural properties, inconsistent colour and grain structure (texture) on different faces. These stones due to their long exposure are either the toughest remains or the weaker fractures. In the first instance further dressing or downsizing is difficult, and in the second case consistent shaping is not possible.

● Such materials are found spread or located over a difficult to access terrain. Collection unless manual involves a large amount of useless mass.

EXTRACTED STONES

Extracted materials are buried (loaded) under the same or different nature of materials’ mass. The over burdening mass protects, as well as contaminates the deposit. The water leaching through the organic soil burden is nominally acidic and affects the alkaline stone mass. Typically Lime stones are not exposed to Carbon Dioxide due to the overburden and so are soft and porous when freshly extracted, but begin to harden on aeration.

● Igneous and metamorphic rocks are not strongly stratified and do not present distinctive layers or strata. Sedimentary rocks are stratified, generally in horizontal layers. However, due to movements in the earth mass inclined and curved formations also occur. Sedimentary rocks show grains intervened by a cementing medium.

● Igneous and metamorphic rocks are often made of many different substances, some of these components, as remnants, are nearly crystalline compounds.

● Sedimentary rocks are comparatively formed of uniform constitution though with streaked colouration due to seepage of dissolved substances and stratification.

● Extracted rocks, require dressing, and often downsizing. The cleavage or fracturing during dressing and fracturing depends not only on the basic classification of the stone and also on constituent minerals such as silica, quartz, feldspar, mica, etc. These aspects also define the types of tools used for working and the nature of surface finish possible.

Igneous rocks, such as Granite and Trap are formed with the solidification of molten materials. Mineral gases and liquids penetrated into the stone and created new crystalline formations with various colours. Sedimentary rocks such as Lime stone, Sand stone, Soap stone Travertine, are formed from the bonding of deposition under pressure and heat over a very long period. Metamorphic rocks are formed by the transformation of igneous or sedimentary rocks, due to influence of heat or chemical action. Metamorphosed form of stones: Marble (of lime stone), Schist (of sand stone) and Slate (of mud-stone).

Amorphous Solid is any material which does not have its molecules arranged in a lattice, or crystalline structure. Amorphous solids make up only 10 % of solids in the world. A well-known example of amorphous solid is glass, and that is why these solids are often termed glass. Amorphous solids' structures have similarity to liquids, and so are also called supercooled liquids. Plastic is made from polymers, long strings of molecules purposefully chained together and is technically an amorphous solid.

Crystalline Solids constitute nearly 90 % of all solids in the world. Crystalline solids have a lattice of molecules. The ordered pattern repeats substantially through the mass.

Stones are classified as Siliceous when silica is the principal earthy constituent, Calcareous have carbonate of lime as the predominant material, and Argillaceous have alumina is the main component.

WASTES AND RECYCLED STONES

Stone extraction or collection creates large quantity of rejected and broken mass. Site based dressing and downsizing, mainly done to reduce the mass for transportation, also generates large quantity of wastes. As stone sites are very remote from the point of use or application, it is uneconomic to transport and use such waste materials. Downsizing and cutting workshops are located near urban localities, and have an advantage that the wastes originating here have consistent one face or dimension. Machines that dress a block with rotary or stripe saws create wastes with smooth finish on one or more faces. Similarly slabs’ end or edge cuts have a uniform thickness profile. Stone polishing machines provide ground particles which are used as filler media.

Angular cut wastes can be tumbled with iron bits in a rotary drum to achieve rounded edged pebbles. Stone wastes can be used to create cement and resin-based composites, and for ‘synthesizing’.

Stone buildings that are demolished in urban areas end up as debris for land fill for lack of man power required for separation and re-use. However, in rural area, it is possible to separate and reuse the material. Older stone flooring units are thicker in comparison to modern supplies. This can be split into two or more units and use the cut-face as the new face. Similarly masonry or building blocks can be cut to thinner blocks for use in cladding or surfacing. The advantage in reuse is free supply of mature (weathered-seasoned) stones.

STONE PROCESSES AND TECHNOLOGICAL DEVELOPMENTS

Stones, for cost of transportation, need to be in lightest possible units. Stones of only good surface quality and appropriate structural properties are brought at the point of use or application. However, quality parameters and economics of transportation rarely match at many locations. As such, whatever supplies are locally available must be exploited. Stones are exploited through following basic processes:

Subtractive processes are about removing material by sculpting, dressing, engraving, grinding, polishing, etc. The concept may be to ‘dress’ a surface or ‘sculpt’ a shape or size.

Formative processes are ‘non-mass adding’ procedures that change the spatial or physical character of the stone mass and alter its nominal behaviour. The treatments include impregnation, edge reinforcing, various types of chemical treatments through acid, alkali, solvent and other oxidative compounds. Heat and flame treatments, sintering, spluttering, dying, bleaching, etc.

Additive processes add to the stone mass. Till very recently technologies involved were of Surface layering by way of coating or cladding. But now ceramic formation, metal alloying and deposition, surface synthesis, surface molecular treatments are on the horizon.

DRIVERS FOR THE TECHNOLOGICAL DEVELOPMENTS

The technological developments of these processes are driven by following basic issues.

1           Extend the Surface Area: Stones are valued for their surface qualities and 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 2 basic methods: by Thin Sectioning and by Amalgamation of bits and pieces, which nominally end up as a collection and production wastes. Other methods of optimising the surfaces are to endow new sensory qualities and surface properties. Many exciting technologies are now available.

2           Exploring structural properties: Stones have certain structural properties which can be improvised and reinforced. These 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 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. Designing geometrical or spatial compositions of stones shows great promise. Materials’ technology front is also offering radically different materials’ combinative formations. The formations include various ways of combining or 'synthesizing' materials of diverse nature. (Like for being attempted with ceramics + metals / metals + synthetics / ceramics + synthetics etc.).

OPPORTUNITIES OF INTERVENTION

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.

1 Different species of stones

2 Local variations

3 Exposure to environment

4 Depth of deposit

5 Position or integrity of the strata

6 Technologies for excavation and collection

7 Angle of cut or rupture

8 Tools and techniques of down sizing

9 Size and shape

10 Dressing and Finishing

11 Treatments

12 Application or Usage

13 Life cycle

These opportunities of intervention operate on two fronts:

• Improvisations over existing methods

• Adoption of radically different technologies.

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. 

Dimension stones are selected or converted from natural rock material for the purpose of obtaining blocks or slabs of different shapes and sizes.

Veneered or slab stones occur naturally as thin body materials or converted into thin sections for the purpose of cladding, surfacing and floorings.

Crushed stones are naturally found, separated as small sized pieces, manufacturing wastes or ground materials for use as aggregates or as additives.

● Determinants at mining or collection level: Condition of the stone mass (integrity, fractures, consistency of colour, grain and pattern), over burdening materials, access to the deposit, exposure to weather, possibilities of size extraction and carriage, applicable technology for sizing.

● Use related selection criteria: Durability, weight bearing capacity, shear strength, ability to maintain the distinctive sensorial characteristics, resistance to decay and appearance.

● Mine or collection level operations: The stone materials if only relevant are carried off the place. This requires elimination of crust or weathered surfaces, uneconomic fractured or separated mass, removal of odd portions (in terms of constitution, colour, grain, etc., form or shape regulation extras, quality equalization selection).

● Workshop level primary processes: These are carried out at places where power, labour, equipment and markets are available, rather then at a mine or collection locality. These include sizing, cutting, dressing, finishing, splitting, sectioning or veneering, polishing, forming of edge or profile.

● Workshop level Subtractive or Mass removal processes: Surface treatments such as: sculpting, crafting, polishing, honing, engraving, inlaying, etching, sand blasting.

● Workshop level Additive processes: Resin or cement impregnation, crack filling, reinforcing mass with applique materials, sandwiching, edge binding and reinforcing.

● Workshop level formative processes: Colouring, staining, bleaching, flame-burnishing, Acid and Laser etching, printing. 

● Craft processes: This requires human ingenuity (design-concept) and intervention of men & machines. These are one or few pieces to mass-produced items. Craft pieces are inspired by the form possible through a material or its combination, potential finish that can substantiate the form, and expression through aggregation of form and finish. 

● Reconstructive processes: These processes use stone as a component raw material while keeping its physical form in tact. Particulate composites are formed with a matrix of resin or cement, and fillers of stone materials in various grades of fineness and shapes, such as: dusts, sands, gravels, pebbles, flakes, chips and lumps. Layered composites formed with sheets or slabs and also with such forms made as of particulate stone composites. Amalgamation done by lamination, co-extrusion and sheet forming with the use of polymers, metalizing, ceramic forming, etc.

● Surface altering processes: Washing, waxing, sintering, burnishing, heat treatments, laser and other radiation treatments.

● Masonry constructions: Techniques of stone masonry are very mature and scope for improvisation is seemingly very low. Yet, new forms of buildings, parts and components, require new concepts for masonry design. New methods of stone works are also required to manage specific distribution and transmission of stresses, fitment provisions, carriage and placement conditions, condition of the stone units. 

● Bonds and arrangements in masonry structures: Romans were the first innovators of stone arrangements in masonry structures, since then nothing much has evolved except re learning of the lessons post disasters and mishaps.

● Structural Joints and Joining: Cement less to cemented systems have been used for years. Cement-less joinery now involves metal, polymer and elastomer in the form of inserts, cleats and seam channels. Many of these items and technologies are proprietary (patented) designs. The range mechanical joining systems include auto-fit, perma-fit and re-use systems. New cementing systems are like: pressure injections, film bonding, gel gumming, powder melt adhesions, reactive and electrical charge bonding.

● Substrates: Substrates are very important in levelling, fixing and stabilizing stones along the plane of gravity (horizontal). However, stones with flatter (a larger surface) and levelled bottom is naturally stable, and this is now explored as a way of creating foundation bases, road beddings, gravity dams, retaining walls and porous structures. New substrate material combinations are available to replace lime and cement materials. These include cement and chemical foams, thixotropic compounds, expanded aggregates, a polymer sprays of organosols, and rubber and polymer underlays of plain, corrugated and bubble sheet formations. 

● Cladding and Surfacing: Traditionally cladding and surfacing (veneer) stones have been adhesion fixed with cements and gums. The traditional applications were in the form of water bound pastes, but now solvent bound pastes, catalyst activated bonding compounds, heat softening materials, pressure sensitive film-gums are available.

● Surface Patterns: The patterns are natural on the stone, through the colour and grain variations, which are explored by regular stamping, mirroring, or randomization. Stone patterns are also formed by the techniques of dressing, material combinations, surface finish combinations, joints design, form direction and scaling.

● Patterns and their meanings: Natural patterns due to colour and grain variations are often unavoidable in large stone masses. The patterns, their contrast and intensity (frequency) of distribution, and the form of pattern body (granular or spotty, linear -straight, angular, curved, consistent or varying widths and massive) mean different things to different users.

● Plastering and Rendering: Stones in various form and sizes constitute a substantial and very important mass with the cement and polymeric media. The stone additives determine renderings’ effects such as colour, and textures like granulated, coarse, rustic, angulated, etc. Other effects are achieved by tools and techniques of application and post application treatments. Post application treatments include green washing, pre-set blasting, dry blasting, chipping, grinding, colouring, etc.

● Make-believe stone effects: Such effects replicate sensory qualities of stones, with and without the use of stone ingredients. 

When stones are the constituent, these are used as fillers, or to take advantage of only one or few aspects of sensory qualities. 

Stones may be used for texture, but coloured differently, patterns are masked by another design, feel is altered by a treatment or applique material, or water absorption is curtailed. 

Similar make-believe effects are also created without the use of stone ingredients in any manner. Materials used for textural effects are mainly polyurethane-based polymeric compounds, which are hazardous in production, ‘life-cycle’ usage and disposal.

Wall papers, tiles, cladding panels, paper laminates, furnishing fabrics, textured painting compositions, etc. emulate real stone like effects. Palladio was one architect who extensively used stone like effects for building’s decorations from ceramics, and stones like masonry surfaces through plaster renderings.

● Plaster-based renderings are often created using tools and applicators’ skills. These are comparatively benign effects. However, such craft-applications over an extensive surface are not uniform.

● Effecting other materials’ through stones: These effects emulate other materials, but through stones as the ingredients. The stones are used for their structural properties, and physical characteristics, like grain form and size, low cost and easy availability.

● Dreaming wildly: The Opportunities of Intervention for stones are of following types:

Stones alone

Stones with other earth-based materials

Stones with natural organic materials: such as plants

Stones with man-made materials such as Ceramics, Metals, Polymers (plastics and elastomers)

Stones alone: Stones present one of the largest resource of earth-based materials. We have not touched even a small fraction of its top layer of mass. Ecologically its use or disposals are manageable. Only problems with stones supply are its inconsistency of sensorial and often qualities and difficult to predict structural properties. This is where man-made materials prove to be superior and reliable. Man-made materials require complex and costly processing whereas stones as a natural resource though unlimited in supplies have high costs of extraction and transportation. Man-made materials are highly custom created and so are not reused extensively, but stones have nine lives and can be used till conversion to form of a dust particle. Man-made materials are produced through multiple-processing, making them difficult to recycle or dispose off safely.

Stones with other earth-based materials: Stones combined with other earth-based materials provide many opportunities of usage. However, stones by themselves or with other earth-based materials have limited scope for combinations. These are mainly by positioning such as spreading, layering or stacking with gravity, by using electro-magnetic forces or by kinetic method of tying-knotting. Few earth-based cementing materials such as mud, pozolana or plant gums are insufficient in supplies and technically inadequate. Yet use of natural materials with very small proportion of man-made of joining materials and technologies can achieve outstanding results.

Stones with natural organic materials: Use of organic materials such as plant-based resources (Jungle, Farm produce) has not been explored adequately. Primitive man started using wood in combination of wood, which has been extended to buildings. Its use is limited as wood is a scarce resource (not easy to replenish). Other organic products require several levels of processing before qualifying their application with stones. Every single new application is worth its wait and expense.

Stones with man-made materials: Stones have been used with man-made materials like metals etc. But most technologies involve non-mixing combinations, such as mechanical joining, adhesion fixing or coating. Stones and earth-based materials have been used in many synthesizing processes. Stones in their physical form and characteristics have been exploited, as fillers, for creation of composites. However, stones have been less frequently synthesized with man-made materials such as ceramics, metals and polymers. These are going to be the opportunities for the next generation.

The inspiration arrives from the successes achieved in combining Ceramics with Metals. Ceramics and metals individually have diverse temperature of forming. At a temperature a ceramic begins to evolve some metal either evaporate, liquidize or form oxides. A combination seemingly impossible is now being achieved, for example in electrical transmission equipments, electronic components, tools and cutting edges making. Similarly stones can be combined with many other materials.

Metal application technologies provide exciting results here. Metalizing a stone surface with metallic particulate or molecules, by plating and sputtering techniques is not farfetched. Synthetics are mainly made with organic (carbon-based) monomers in polymers but chaining. These have been used both as the matrix and fillers components in composites. And can we visualize stones, not in the role of filler but of matrix in composite forming?

    

MATERIAL PROCESSING

A material technologist may further classify Opportunities of Interventions in terms of stones with:

Primary processed materials:

A brick manufactured from a soil or a fabric created from cotton or wool is primary processing 

Secondary processed materials and composites:

A nitro-cellulose produced from natural material such as cotton is primary but a film out of it is secondary processing. Metal refined from ore and converted into an alloy is secondary processing.

Tertiary processed materials or multi material synthetics:

A monomer produced from petroleum is primary, a polymer out of it is secondary, a fibre spun out of a polymer is tertiary, and fibres fused as a layered sheet or used as a reinforcement make it multi-lateral processing. 

Molecular level build-up of materials or sub-nano technologies: These are completely different methods of creating materials combinations. Here materials are created at molecular level combinations or molecules are implanted over a base. Many pharmaceutical drugs, chemicals, stem cell technologies are based on such works.

2.07 PLACEMENT OF SPECIFICATIONS

Post -by Gautam Shah
.

Specifications derive their importance and relevance on How and Where these are presented. Specifications in Design Practice are placed in many different types of documents with peculiar formats to serve very exact intentions. The Document type, location (Placement) and the format of presentation, are all determined mainly by the nature of exposure the specifications are to have.

Document types: Design documents are essentially of Four types: in-house, clients’ eyes, for consultant’s and for job award or execution. Other minor varieties of design documents include: for public presentation, for government authorities.
Location or Placement: Specifications are placed in sketches, drawings, as write-up accompanying drawings, as part of Job awards, brief memos, long reports, signage, as product or packing labels.

Format of Presentation: Specifications are literary or worded, drawn, orally communicated. Specifications could be sketchy, detailed, independent and intricately linked. Specifications could be drawn, printed, digital, audio-video, signs, signals, original, facsimiles.

Exposure: Very personal, i.e. author's-eyes only (access restricted to its creator), In-house (available to office-staff only), Clients’ reference, Consultants' assignments, Bids invitations or Job awards, Contract documents, Operating agencies.

Contents: The contents of specification documents are often defined to serve very specific purposes. The contents are re validated to see if, the information is private vs. public, Data is freehold (public domain) or patent (copyright, intellectual property), subject is prosaic or engaging, presentation is brief or detailed, language is allegorical or straightforward, etc. 

SPECIFICATIONS IN A DESIGN OFFICE ARE PLACED:

Within a sketch or preliminary drawing: These drawings are prepared to initiate an idea. Sketch or preliminary drawings are too small in scale, lacking in details, and do not carry all the graphical views to convey the intentions. Similarly materials, components, procedures, and design parameters which have not yet been fully conceived, or not crystallized into a formal structure, are all placed as a write-up. Such write-ups are usually meant for the designer's personal reference, and very rarely for the client, so need not be a trade, technique or material specific. These write-ups may be just indicative or thin in content, as these are seedlings from which the total idea is to germinate.

Within a schematic drawing: At a schematic drawing's stage, the design has taken shape. Options regarding materials, finishes, techniques, are explored and indicated as write-up, in the drawing. Where parts / subsystems are yet to be conceived their design parameters are also indicted. More often than not a set (copy) of schematic drawings is submitted to the client. In such a case only the office copy (in-house set), carries the specifications’ write-up. Schematic drawings are exploratory so may also carry optional specifications. However, whatever is shown or implied, will be construed by a client to be a promise.

 

Within a Layout Drawing: Layout drawings as the name indicates are used for specifying the whole work. These are also used in laying out the work on a site, and so contain specifications for establishing the scheme on the site. Since this is the main or starter drawing it establishes links to other drawings and details. It is used for conveying methods of interpretation for this and other linked drawings. Measures (dimensions, tolerances, fitments, margins, and measures like weights /mass /speed /time), which cannot be graphically indicated or linked to any particular graphical view are presented as a common write-up or explanation. Being the basic drawing, it provides a common ground to indicate, when and how a part or parts of drawing become execution worthy. Limitations and responsibilities of various agencies' work, time schedules and inter linkups for start and completion of various items, parts, etc., are all specified in the layout drawing.

Within a Detail Drawing: Detailed drawings are generally large scale presentations of complex parts. These drawings are often used by several trades’ persons. Overlapping areas of several components are shown here. The detail drawing specifications include legends showing graphical vocabulary used for identifying various materials in sections and on their faces (elevations). It also includes graphical symbols to represent very small parts or standard components. The specifications on such drawings clearly indicate or establish relationships between the component and the concerned trades branch. Where several detailed drawing sheets are referred for a part or component, specifications need not be repeated on all sheets. However, if specifications are to be distributed over several sheets, a proper linkage must be established. These makes it easy to revise specifications or drawings, and convey such changes to the concerned parties, through other means of communications.

Within a Component Drawing: Components are conceived as self sufficient sub systems, and as a result their details consist of not only the fitment conditions, but operative parameters as well. Component specifications generally do not spread over to many drawings (Large/complex components will consist of sub assemblies, which can be detailed individually). Components, if presented with siting specifications, it will mean a non standard placement is proposed. Whereas for standard components, absence of siting specifications, will mean that standard conditions apply. Standardized components may also be indicated by referencing the Standards’ Documents.

 As a separate write-up but on the Drawing Sheet: Specifications as a separate write-up on drawings, generally relate to procedures and materials about several parts or whole of the object, e.g. siting of a building on land, preliminary-work to be carried out before the commencement of actual work, precautions regarding the start / continuation / completion of the work, etc. These are presented in a written format, because graphical formats are inadequate or inappropriate here. In situations where graphical presentations are likely to create ambiguities in interpretation (as in a court of law, or by lay people not conversant with graphical presentations, communication through inappropriate modes, etc.) details must be additionally specified in writing.

As a separate document accompanying Drawings: Where Specifications are not related to any particular drawing, and are describing common materials and procedures etc. that generally relate to the entire work, and when are very lengthy, are supplied on separate sheets of paper accompanying the drawing. If necessary, mention of such Sheets is made in the relevant drawings. Such sheets sometimes are bunched together as a catalogue of Specifications of Works.

As Memos and Short Messages: Site and Design Office have a continuous exchange of messages relating to inquiries, clarifications, confirmations, rejections, acceptance, corrections, reporting, etc. Some sections of such communications could have effect equal to a revision of a specification or initiation of a new specification. For this reason all messages, routed through whatever mode of communication must be Dated and Numbered with Author and Receiver's Identity. It is often more prudent to separate out Communications that could have Consequential Effect, and reconfirm them in the weekly or periodical reports. Communications relating to a specification, must mention the relevant part, component, subsystem or section of the project and exact location (drawing, communication, tender etc.) where it was earlier referred to.

 As part of the Job Award Document like Tender: Specifications are very often linked to the Quantities of various tasks or work items, by actual mention or sheer proximate placement. The contractor is than asked to quote for the items. Such specifications are divided into two classes:

General Specifications: General Specifications as the name suggests, relate to the whole of work or several items. These are subdivided into categories such as (a) materials (b) techniques / procedures (c) precautions (d) time schedules (e) mode of measurements (f) billing procedures (g) completion of a part/s or whole.

Special Specifications: Special Specifications relate to an item and its materials, techniques / procedures, precautions, time schedules, etc. Such specifications are sometimes trade or supplier specific, and as a result, are restricted and technical in nature. Often the supplier is allowed to offer own improvised scheme within the frame work of specifications. Such specifications instead of describing, how and with what a part is to be made, a list of Performance Parameters and Conditions of Fitments are provided.

When specifications occur with any quantities for work or job, these are often perceived by the contractor or vendor, to be the optimal quantity of work for cost calculation. To avoid such a perception minimal quantity per natural lot of work (e.g. RCC or masonry work per day or stage) may need to be indicated.

As a Public Declaration: Public organizations are required to be transparent in their dealings. Public organizations regularly or occasionally (synchronized with major endeavours) place a statement in a public domain. This could be legal requirement, tradition or a voluntary act. Such a declaration in the form a Statement of Work (SOW), is published when a new project is launched. It could also be an internal publication for all stack holders or one handed over to the contractor of a project.

As Description for Pro-forma Invoice: To avoid the technicality of specifications writing, many organizations, prefer to acquire items that are familiar, standardized or commonly available in the market. Commercial descriptions or simply the Brand Names are provided as a Pro-forma Invoice (an advanced bill / predefined bill). Such Pro-forma Invoices also include the conditions of delivery, installation, the quantity, sizes along with the tentative rates. Often the buyer indicates a tentative rate over which a supplier provides a quote which may be lower, equal or higher. Such a system obviates several office procedures. The Pro-forma Invoice Specifications in a way demand a particular product or its equivalent, with knowledgeable performance. Pro-forma specifications do not allow any revision of specifications.

Referencing Standards: Specification to be compact, reference Published (public domain) Standards. Most Standards for part or detail level clarity refer to many other standards. So when a standard publication is referenced only by its title and code (and by not quoting its text), intentionally the main standards document is attached, but unintentionally other linked standards also automatically getting attached. A sub condition of a standard may be referenced, but it is very difficult to make it really effective bereft of its natural attachments.

PERFORMANCE SPECIFICATIONS

 Post -by Gautam Shah 
.
 

General: Performance Specifications tell a manufacturer, vendor, supplier or provider: What is considered to be an acceptable product? And How will the product's acceptability be judged ? In other words performance specifications state requirements in terms of the results to be achieved and provide criteria for verifying the compliance. Such specifications define the functional requirements for the product, the environment in which it must operate, and the interface and interchangeability requirements. Performance specifications, however, do not state means or methods for achieving the results. It allows the supplier with freedom to not only choose but improvise materials and methods.

 

Systems specifiers like a designer deal with a product or system only occasionally and do not get frequent feedback. Whereas a system provider (such as the supplier, manufacturer, fabricator or installer) is consistently involved in supply field, and receives feedback from diverse sources. System suppliers as a result has better understanding and capacity to improvise the product. A system specifier may specify a technologically adequate system, but a system provider offers a technologically superior and economically most appropriate item.

A designer as a system specifier must work in close collaboration with the markets (represented as the supplier, manufacturer, fabricator or installer, etc.). To specify performance, ideally a system specifier and the parties capable of submitting the proposal or bid, both must have a consensus as to what the requirements are. But this type of neutral interaction is not possible or desirable in Government deals. So it is desired that requirements of performance are specified quantitatively rather than qualitatively. Qualitative data can provide varying interpretations and cause misunderstandings, but quantitative data is easily verifiable.

Performance and Verification: Any condition, characteristic, or capability that must be achieved, and is essential for item to perform in the perceived environment must be plausible and verifiable. For example, if a building is required to withstand certain measure of an earthquake, then methods how to verify this must be stated. Verification process is accompanied by definition of 'the extent of contractor or vendor's participation and their liability for providing corrective solution’. Warranties offered by the vendor can to some extent substitute the performance and verification requirements. However, very often warranties of the vendors are restricted to their own supplies. The warranties are also conceived like a risk management system for compensating a fault with something 'equivalent' or money, but not the for the affectations that occur in adjacent areas or systems.

 

In comparison to item or work specifications, performance specifications require fewer references, except for standard tests, interface drawings, etc. Due to the absence of procedures, performance specifications are less dependent.

Restrictions in Performance Specifications: Performance specifications must not limit a provider to specific materials, processes (including quality of man power or equipment), parts, etc. However, one can prohibit certain materials, processes, or parts when authorities have declared quality, reliability, or safety concerns such materials, techniques or processes, as for example environmentally harmful technologies. Upper and/or lower performance characteristics can only be stated as requirements, but not as goals or best efforts.

 

Writing performance specifications: A System specification writer must know: ‘Which requirements are absolute or threshold requirements? Definitions of such thresholds. All constraints governing operations or use through natural and induced environments, interface with other systems, operator and maintenance person's limitations, must be declared’‘.

Performance Specifications for Structural, Architectural and Interior Design jobs: Such jobs consist mainly of industrially produced and standard components, but their composition (fabrication, installation or siting) is a unique phenomenon. Performance specifications at parts or components level are not very difficult to implement. However, adopting a performance specification strategy for large complex systems, or whole projects is a very difficult proposition. Design professionals can overcome this problem by consciously moving towards self-sufficient systems like plug-in modules, rather then excessively customized products that remain one-time efforts. Performance specifications at lower levels such as for replaceable components and spares, should include essentials for interchangeability and interoperability.

Strategies for Creating Performance Specifications: It is very difficult to conceive a fresh set of exclusive performance specifications. But one can gradually and consciously reformat the traditional specifications with inclusion of performance parameters for standard parts and components.

 

Resources for Performance Specifications: Many resources are available to form performance specifications, such as: Government departments and large corporate groups which prepare indexed descriptions of commercial items for frequently or routinely required products. Such performance oriented descriptions are available in a public domain through their purchase bids. Trade associations, commercial organizations, or technical societies often develop coordinated standard specifications, for the warranted performance of items produced by their members. Government Departments design and publish Model Specifications for use by their own sub departments and other agencies. Performance specifications of well-organized departments like defense, telecommunications, etc. can be used for further understanding of the methodology. Market analysis as available in technical journals can show the ranges of performance that are currently possible. Market analysis also show the technologies involved and available alternatives.

Standard Performance Specifications: Standard performance specifications are intended to facilitate standardization and interchangeability of common equipment. Standard performance specifications specify product characteristics, dimensions, matters relating to form, fit, and functions.
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2.1 MEASURES

We measure lengths, areas, volumes, weights to define things. Measures when combined with Time show the changes that occur in things. We measure events or happenings, for their start, the rate at which these actualize, duration and termination. Measures are very important in recording and recreating events and happenings.

 

Measurement is finding size or amount of some quantity, and expressing it as a number of defined units. All measurements are based on comparisons. A thing to be measured is compared with something similar, or with a thing that has already been calibrated -measured against a known reference.

 

There was a time, when things were measured in terms of body sizes and body’s capacities. Long Distances were measured for the travel time required, like in lunch breaks or night halts. Short distances or Lengths were measured in arm lengths or foot steps. Smaller sizes were measured with the palm, length of a finger or width of a thumb. Finer widths were measured in terms barley grain. Volumes were measured as the holding capacity of limbs like pinch or palm. Weights were measured in terms of carrying or displacement capacity of a person or animal, such as head load, cart loads, horsepower.

 

Measures based on body sizes or capacities had many racial and regional variations. It was possible to equate out such differences in a barter trade between neighbours. But the same was proving to be very difficult for trade with far-off regions. There was an acute need for some common measure system. Gradually trading blocks concurred to a common tradition of Nominal measurements. Conversion of measures with adjoining trade regions was facilitated by intermediaries like brokers, caravan masters and shippers. The inconsistencies of the measure conversions were partly solved when monetary pricing replaced the bartered trading.

 

Over a period of time many units for measuring length came into practice in different societies. Lengths were measured in Angula, Danda, Goruta or Korsa, Dhanush, Inches, Cubit, Digit, Thumb, Hand, Arm, Feet, Yojan or Jojan, Yard, Chain, Link, Fathom, Rod, Furlong, Miles, Nautical miles, League, Stadia. Early metric system had several units @ 10^X such as Millimetre, Centimetre, Decimeter, Metre, Dekametre, Hectometre, Kilometre. To these were added micro measures like nanometre, micron and Angstrom.

 

Roman pes or foot was divided in 12 parts called unciae, from which the words inch and ounce have derived. Similarly yard (gird) can be traced back to early Saxon kings who wore a sash or girdle around the waist which was removed and used to measure lengths. Later King Henry decreed that a yard should be the distance from the tip of his nose to the end of his outstretched thumb.

 

During the French Revolution (1870) the National Assembly of France asked French Academy of Sciences to formulate a scientific and rational measure system. Such a system was expected to be: 1 Neutral and Universal, 2 Replicable anytime and anywhere, 3 to have Decimal Multiples, 4 to follow Common Prefixes and 5 be Practical and Simple to use. The rationale for such a system forced many countries of Europe to think on similar strategies.

 

Industrial Revolution period saw faster means of transport and better communication systems. It fostered trade between far off regions and different political domains. The producer and the consumer were very distanced. British, Spanish, French and Dutch empires through trading outposts and colonies controlled major part of the international trade. These Trading Blocks maintained their own measurement system. In spite of trading blocks, the need for a common, logical, definable, replicable and comparable system of measurements was acutely felt. 

 

Foot & Pound system was widely used in British colonies and their trading outposts besides USA and parts of Canada. Foot & Pound system was a well developed but not very coherent as relationships between measures were illogical. Metric System on the other was mathematical but had too many sub fractions. Different nations, regions, and trade groups favoured different sub fractions, creating confusion. This was perhaps the major deterrent for other countries (chiefly those following the FP system), desiring a change over to the Metric System. Historically Metric system has seen many versions: CGS or the Centimetre-gram-second system, MKS or the Metre-kilogram-second system, MTS or the Metre-tonne-second system.

 

First International effort to develop a worldwide policy for weights and measures was made during May 1875. Some 17 countries signed a Metre Convention or Convention du Mètre, an international treaty to create a ‘permanent mechanism to recommend and adopt further refinements in the metric system’. This was directed towards defining what constitutes a standard measure unit and means to replicate it in great accuracy anywhere and anytime and towards defining sub units for the main measures.

 

The metric convention was held at the time of heightened Industrial activity during the Industrial Revolution period across Europe and USA. Signatories of Treaty of Metric were: USA, Germany, Hungary, Belgium, Brazil, Argentina, Denmark, Spain, France, Italy, Peru, Portugal, Russia, Sweden, Norway, Switzerland, Turkey, Venezuela.

 

After the Convention du Mètre in France in 1875 a General Conference on weights and measures or Confèence gènvrale des poids et mesures CGPM was organised in 1889. Eight CGPM, at rough intervals of 4 years, were held till 1933, followed by an inactive period due to world war II. These meetings gradually evolved a worldwide policy on the advice of scientists and metrologists.

 

Conférence générale des poids et mesures (CGPM), an intergovernmental conference of official delegates of member nations and the supreme authority for all actions. It continued the deliberations of Convention du Mètre.

 

Comité international des poids et mesures (CIPM), consisting of selected scientists and metrologists, which prepares and executes the decisions of the CGPM and is responsible for the supervision of the International Bureau of Weights and Measures.

 

Bureau international des poids et mesures (BIPM), a permanent laboratory and world centre of scientific metrology, the activities of which include the establishment of the basic standards and scales of the principal physical quantities and maintenance of the international prototype standards.

 

Hectic reconstruction activities began everywhere in the post world war II (1945) period. Major impediments to this effort were the differing National Standards. To allow free flow of raw materials, equipments and technology a platform of common Standards and Specifications was required. In 1946, delegates from 25 countries met in London to create a new organization, to facilitate the international coordination and unification of industrial standards. The new organization, Organisation internationale de normalisation, ISO, officially began operations on 23 February 1947, in Geneva, Switzerland.

 

The word ISO was selected to represent the organization in all languages because it is derived from the Greek isos, meaning equal.

 

9th CGPM in 1948, meeting after 15 years gap due to WW II formally adopted a recommendation for writing and printing of measure unit symbols and numbers. The name Systeme International d'Unites (International System of Units), with the international abbreviation SI, was adopted for this New Metric System.

In 1960, the CGPM revised and simplified the measure system. Seven Base Units such as: meter (Length), kilogram (Mass), second (Time), ampere (Electric current), kelvin (Temperature), mole (Substance), and candela (Luminous intensity), were established. 

 

Acceptance of SI has been varied. For French and other European countries including their colonies, already using MKS system, adopting the new system (SI) was very easy. In 1965 Britain started using it. Canada, Australia, New Zealand, and South Africa quickly followed and soon exceeded the speed of change in Britain. In 1975, USA officially accepted the Metric system (in the form of SI system), but no specific schedule was set for the change over.

 

SI MEASUREMENTS: As a designer, we are concerned with formulating or creating new entities, and also using ready parts and components. For both the purposes, we need to specify the Measures. ISO has formulated rules for Writing and Specifying Measures in drawings, documents, specifications and other forms of communication. This is done to avoid any ambiguities in interpretation of information.

 

WRITING AND SPECIFYING MEASURES:

▪ All decimal numbers must be preceded by a zero if no other digit exists. e.g. 0.121 (and not as .121 )

 

▪ No thousand or hundred markers are to be used, e.g. 1000 (and not 1,000), but where large number of digits are involved a blank or space (equal to 1 digit or not less than ½ digit in width) may be used as a separator, in place of a marker. However, where only four digits are used no space as a separator need be provided. e.g. 100 000, 10 000 or 1000 (but not 1 00 000 or 1 000)

 

▪ For length units km / m / mm, all must be in small letters (Unit indicators may be used, only when necessary. e.g. architectural plans have nearly all measures in mm, so the mention of mm should be avoided. However, in the same drawing if weight or volume or such other measures are to be indicated then unit identifiers for such units may be indicated).

 

▪ Full names of units even when these are named after a person, are written in small letters: ampere, volt etc., with the exception W for watt and J for joule.

 

▪ For liquid measure however lt may be written as Lt (to differentiate between 1 and l ).

 

▪ Plurals need not be used. (kms, mts, kgs).

 

▪ Point or Full stop for abbreviation may not be used, for example as in m.m. or mm.

 

▪ Where cubic or square measures are to be shown: 3m3 = will mean three cubic metres and not 3³ i.e. 3 x 3 x 3 = 27cmt.

 

▪ Following common units are acceptable

Length mm m km (all 1000 factored)

Weight gm kg mt or t (all 1000 factored)

Liquid mlt Lt klt (all 1000 factored).

 

▪ Where traditionally only one unit is accepted, and if there are no chances of ambiguity, the measure nomenclature (mm, km, gm etc.) may not be mentioned. (E.g. cloth width = 1.200). If in one sheet of drawing (or a document) only one scale and one mode of measure are used, the nomenclature may be mentioned as a general instruction for the drawing.

▪Where drawings or details are likely to be reduced or enlarged in processing / copying, a graphical scale preferably showing 100 mm bar may be shown. If 100 mm size is not suitable due to micro reduction or macro enlargement, suitable multiples of 100 mm for upwards scaling and 10x fractions of 100 mm for downwards scaling maybe used.

 

MEASUREMENTS ON DRAWINGS

When both mt & mm are used on drawings, it will be less confusing if the dimension is always written to three places of decimals, i.e. 3.450. No unit symbol need be shown unless a lesser number of decimal places are used; i.e. 3.450 or 3.45 m and under some circumstances 3.5 m, are all correct. Of the options, 3450 and 3.450 both are preferred. Where no ambiguity can arise, symbols may be discarded, according to following rules:

 

▪ Whole numbers indicate mm

 

▪ Decimated fractions to three palaces of decimals indicate m (and also by implication, mm)

 

▪ All other dimensions must be followed by the unit symbol.

 

▪ Where dimensions refer to different types of measures (lengths, weights, temperature etc.), preferably all units should be indicated or all units other than the major one should be indicated.

 

▪ Main dimensions and the tolerance (fitments, limits, margins etc.) etc. should be in the same unit system.

 

▪ Where main dimensions are accompanied by + or - range, both should be in the same unit.

From Interior Design Notes : Interior Design Practice & Office Management - II

Origin of ISO 9000 Series of Standards

2.13     ISO 9000 STANDARDS

ISO began its work primarily with the formation of standards for measurements, such as: specifications for writing and coordinating measures. The Standards for Measurements offered a universal approach for measurement systems. Subsequently ISO began to evolve International Standards for Products, Services, Processes, etc. These were derived as a consensus based on many national standards. The international standards though universal in nature related to issues that were self contained within the product, service or process. The standards were upgraded and redefined every five years, and sometimes more frequently. Yet, to serve the user better, many individuals and organizations outperform the standards.

Today business is no longer just about making available an adequate product, service or process to a user alone. In all human endeavors every citizen (or a being) is considered a stack holder. So one has to be conscious and conscientious of all our actions. It was accepted that for a consistent and all-inclusive care, an attitude at personal level and a culture at organizational level is necessary. This can only be achieved if a person or the organization strives for continued excellence, and develops a synergistic system to achieve it. Many individuals and organizations have such ingrained mechanisms, but these are often not comparable in terms of their intentions or achievements.

It is very necessary to institutionalize the individual attitudes and organizational culture for ‘good management’ with support of right policies, procedures, records, technologies, resources, and structures. To achieve a Quality System of consistency, a Quality Conscience is required. The Quality Management  Systems created by ISO are meant to certify the processes and the system of an organization, not the product or service itself.

QMS or Quality Management Standards have their origin in the Product Liability Directives of European Community (EC) of July 1985. (also known as the single market directives) which state that manufacturers exporting to the EC and, eventually, to the European Free Trade Association, would need to have a well documented and implemented Quality Assurance System for certain regulated products.

In this direction ISO created a series of Quality Management Standards (QMS), designated as ISO 9000 series.