Introduction of stones and rock

Rocks:

I. A lump or mass of hard consolidated mineral matter.II. Material consisting of the aggregate of minerals like those making up

the earth’s crust.

Stones:

I. A lump or mass of hard consolidated mineral matter.II. Building material consisting of a piece of rock hewn in a definite

shape for a special purpose.

In construction:

Rocks:

An definite mixture of naturally accuring substance , mainly minerals .its composition may vary in containment of minerals and organic subtances, and are never exact .

Stones:

Small piece of rocks , may or may not refer to ornamental materials.To ease the understanding of this topic ,rock = stones

Properties of stones and rocks

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(metamorphic rock)

Metamorphic :

Igneous or sedimentary rock transformed by heat and pressure into another rock.

Marble:

Recrystallized limestone, colour varies from white throught grey and black, red , violet ,pink , yellow, and green – presence of oxides of iron , silica, graphite , carbonaceous, matter, and mica produce these colour variations.

Quartzite:

It is a variety of and stones composed of mainly granular quartz cemented by silica , colour varies from brown , buff, tan, ivory, red throught grey.

Schist:

Made of silica with smaller amounts of iron oxide and magnesium oxide. Colour varies from blue , green , brown, gold, white, grey , and red.

Slate:

Consists mainly of clays and shales – major ingredients are silicon dioxide, iron oxide , potassium oxide , magnesium oxide, and sometimes titanium, calcium and sulfur – slate found in parallel layers , which enables it to be cut into thin sheets.

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(crushed stones)

Construction aggregate:

Or simply “ aggregate” , is a broad category of coarse particulate material used in construction , including sand , gravel, crushed stone , slag, recycled concrete and geosynthetic aggregates.

Aggregate are a component of composite material such as concrete and asphalt concrete , the aggregate serves as reinforcement to add strength to the overall composites material.

Aggregates are used as a stable foundation or road or rail base with predictable, uniform, properties, (e.g to help prevent differential settling under the road or building), or as a low-cost extender that binds with more expensive cement or asphalt to form concrete.

Constituents of stones

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Types of stones

Granite

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Granite is igneous – meaning it is formed by extreme heat and volcanic action. Its characteristic colors include a huge variety and mixes of color. Granite can take a high polish.

Limestone

Limestone is sedimentary – meaning it is formed by the action of water and great pressure. Its characteristic colors include neutrals, off-white, beige, tan, taupe, light blue grey. The look of limestone is created by the interaction of sediment deposits and shells with geological activity. Limestone finishes are usually honed and typically do not hold a high gloss polish.

Marble

Marble is the metamorphic product of limestone – meaning it is formed when heat and great pressure are applied to limestone. Its characteristics include a huge variety and mixture of colors. The veins found in marble are created by the interaction of mineral deposits with geological activity. Marble can take a high polish due to its hard surface.

Slate

Slate is metamorphic – meaning it is formed under great pressure from sediment. It has a huge variety of characteristic colors that often vary widely. Slate has a natural cleft finish.

Travertine

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Travertine is a banded, compact variation of limestone. Its characteristic colors include neutrals, off white, beige, tan, and yellow. The look of travertine is created by the interaction of gas, shells and water with geological activity. Travertine finishes are usually honed, but some will hold a polish.

Rock and stones

Rock and stones (origin)

o In geology , rock is a naturally occurring solid aggregate of minerals and / or mineraloids

o The earth’s outer solid layer , the lithosphere , is made of rock . in general rocks are of three types, namely, igneous, sedimentary, and metamorphic.

o The scientific study of rock is called petrology , and petrology is an essential component of geology.

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Manufacturing of stones

Manufactured Stone

People have been building with stone for thousands of years. Normally stone must be found in the ground, quarried or mined out, and then refined into a certain shape. With the advances in technology, however, people can now manufacture stone to fit their specifications. Called cast stone, this product can be mixed to fit any color or hue and to resemble a variety of different types of stone, including limestone, granite, slate and marble. This unusual product is made in a way that's remarkably similar to regular cement, with a few additional steps and additions.

Mixing

The basic materials that make up cast stone are water, cement, fine crushed stone, coarse crushed stone, color pigments and a variety of chemical admixtures. These components are all mixed together and stirred so that they're well mixed. This slurry is then poured into a mold and left to dry. As it hardens, it takes on the look of natural, carved stone. The color will vary with the pigments put into it, and the type of stone it mimics will change with the types of coarse and fine stone that are added to the mixture.

Reinforcement

Since cast stone is a slurry before it dries, this presents several opportunities for enhancing the structural integrity. Like concrete or cement, cast stone may be reinforced with steel bars or with other,

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similar means when it's poured into a mold. This way the stone can take more weight, but it still maintains the look of the stone that it's

trying to imitate. Additionally, the cost of cast stone is usually a lot less, and it can be molded to be exactly what a person wants. Oftentimes it can be molded in a way that natural stone simply couldn't be carved.

1-Selection of the right Quarry and the Big Block

Geologists check the soil with the latest technology using sonograms, samples and digging to make sure that the stone is of the highest quality and that there is sufficient reserve of this specific material. Then experts identify and mark the blocks to be processed.

2-Cutting down the Block to Slabs

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The blocks are brought to the processing factories and sliced down to slabs using top of the line Italian technology. Slabs with even the tiniest defect are rejected on site.

3-Sizing of the Slabs

The slabs are sized down and rectified to the required dimensions. The sizes are checked with a digital measuring device to avoid even the smallest size difference.

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4. Filling Process

Fillers are prepared by color experts to match the natural color of the stone in laboratories.

5. Polishing or Honing

The tiles are polished and honed with top quality Italian abrasives and processed repeatedly until the desired surface finish is met.

6. Final Quality Check and Shade Selection

Selection teams eye check every single tile based on our defined shade restrictions. Out-of-shade tiles are carefully eliminated.

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Selection of stones This Stone Federation Great Britain guide is based on relevant

sections of a number of British Standards, Codes of Practice and trade documents. It sets out the current best practice for the selection of natural stone for larger cladding, flooring, paving and masonry projects. It considers the important issues relating to the interpretation of samples, the role of the quarry/mine/factory visit in the assessment of the stone selection and the relevant factors appropriate to the evaluation of the technical properties of the stone, and if necessary, to a successful testing regime. It aims to identify the common misunderstandings and is designed to help the specifier to make an informed selection of a suitable stone for their project.

1.Samples All samples should be labelled in accordance with BS EN 12440

Natural Stone – Denomination Criteria, ie. they should have their traditional name, quarry location andcountry of origin and the petrological family declared, together with a sample reference number. This information will allow you to comparethis sample with previous samples andwith buildings using these stones and will also allow you to access previous technicalinformation which will give you an indication whether the stone is suitable in your proposedapplication.

Some stones are given commercial names but it is vital that the traditional name of the stone is established so that all appropriate historical information can be found. If the supplier is unable or unwilling to provide information we advise that an alternative stone is selected. All samples should be marked with the surface finish that has been applied to the sample, ie. If fine rubbed or honed, it should have the grit size used so that the specifier can accurately specify the

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finish of the stone. The wording should also reflect the requirements of the relevant product BS EN Standards.

Indicative Samples

An indicative sample shows the general colour, tone and texture of the stone, but cannot and should not attempt to show the range of geological characteristics that will be naturally present in all stones. These indicative samples are typically small stones, say 150mm x 150mm, so that they can be posted to various members of the project team for presentation to the planners (if appropriate). A short list of acceptable stones is normally made from viewing the indicative samples.

Range/Control Samples

The range/control samples may be specifically prepared for the project, or there may be panels of current production already established at the quarry/mine showing the typical range of features normally found in the bed of stone. The range/control samples should be of sufficient size to indicate the general appearance of the finished work. Normally about 10 large stones at least 600mm x 400mm or the sizes of the common stones on the project. These samples should include the typical variations in colour, texture, veining, shell content, grain size and the distribution, character and frequency of these, and all other features that are deemed to be part of the geological characteristics of the stone.

Selecting the Correct Stone

If processing of the stones typically involves the use of patching, fillers or other similar products for natural holes, faults or cracks, then they should be declared by the quarry/mine or the production

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facility completing this operation and the reference samples should include any such feature. It is ultimately the quarry or mine’s responsibility to select a suitable number of samples from various blocks from the chosen bed to show the typical range of geological variations that are present in the stone or the bed of stone. Invariably this inspection should take place at the extraction site but if in exceptional circumstances this is not possible, then confirmation that the source of the stone has been closely consulted in the sample selection must be sought.

You should view these samples and agree an acceptable range of samples for the project, remembering that rejection of characteristics typically found in the stone will potentially result in abortive cutting, prolonged procurement and possibly increased costs. All characteristics accepted in these samples should be considered to be typical of the normal production and not as flaws and therefore should not become a reason for rejection, unless their concentration becomes excessive and the typical character of the stone is lost.

Any comparison between the range/control samples and the actual production should be conducted in normal daylight for external stone work. For internal stone work the samples should wherever possible, be viewed in light conditions similar to those anticipated for the project. Wherever possible, samples should be viewed from a distance of 2m as stated in all the relevant British Standards and in the orientation in which the stone will be used. This will allow for an accurate comparison similar to the conditions on site.

Building Inspections

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It is advisable, if possible, to confirm the selection of the stone by viewing a number of buildings built in the vicinity or in a similar environment of the proposed project using the same stone or bed of stone and in the same application and exposure conditions. The stones on these buildings should be examined closely, noting the geological characteristics in the individual stones compared to the samples provided. It is important to remember that some of these characteristics may dull as part of the weathering process, so it may be advisable to retain the services of a stone consultant/experienced geologist to explain the process. After examining the stone in detail it is suggested the entire façade is viewed from a reasonable distance, perhaps from across the street, to see the stone as part of the overall building structure and to note the characteristics that are still visible or dominant.

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Suitability/ applications of stones

Igneous rock

Stones masonry

Building stones obtained by quarrying from the rocky strata of earth and reducing it to the required shapes and sizes for construction.

Granite

Consist mainly of quartz , feldspar , mica and other coloured mineals, colour include black , grey, red , pink , brown , buff and green.

Serpentine

Main ingredient is serpentine colour ranges from olive green to greenish black , is fine grained and dences.

Basalt

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Colour ranges from grey to black , used mainly for paving stones and retaining walls.

Granite

o Non-porous , hard , strong , durableo Colour rangeo Surface textureso Plimary uses

 

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Sepertine

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Basalt

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Suitability/ applications

(sedimentary rock)

Sedimentary

Sediments deposited by the action of water of wind gets consolidated to a rock.

Sandstones

Sedimentary rock composed of sand sized grains made of silica , iron oxide and clay – colours include grey , brown, light brown , buff , russet ,red , copper, and purple.

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Shale

Derived from clays and silts , weak along planes and is in thin laminations- high in limestones and colour varies from black to red, yellow, and blue.

Limestones

Sedimentary rock composed of calcite and dolomite - three types, oolitic , dolomitic , and crystalline – has high compressive streght- used for building stones and for paneling.

Sandstones

o Porous, relatively weako Colour rangeo Surface textures

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Shale

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Limestones

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