Stones

Contents

Classify Rocks: i. Geological Classification, ii. Physical Classification, iii. Chemical Classification 3

Geological classification of rocks : 3

Recall the following tests of stone: i. Acid test, ii. Hardness test, iii. Water absorption test iv. Crushing test, v. Attrition test 5

Recall the following qualities of a good building Stone: i. Crushing strength, ii. Appearance, iii. Hardness iv. Specific gravity, v. Percentage wear 7

Describe the following methods of quarrying: i. Quarrying with hard tools, ii. Quarrying with a channeling machine, iii. Quarrying by blasting 8

Define the term Dressing 9

Recall the purpose of Dressing 10

Recall the Deterioration of Stones 11

Describe the following causes of decay of stones: i. Alternate wetness and drying ii. Impurities in atmosphere iii. Rain water iv. Temperature variations 12

List and recall types of Preservatives: i. Coal tar, ii. Paint, iii. Linseed oil, iv. Solution of baryta 13

Recall the procedure for making an Artificial stone 15

Recall the forms of Artificial Stones 16

List and recall the advantages and disadvantages of Artificial Stones 17

Define Building Materials

Building materials are materials that are used in the construction of buildings, houses, and other structures. These materials are chosen for their durability, strength, and ability to withstand the elements and the wear and tear of daily use. They can be natural materials, such as wood, stone, and clay, or they can be man-made, such as concrete, steel, and plastic. Building materials are an essential part of the construction process, as they provide the foundation, structure, and finish of a building. They are also important in terms of energy efficiency, as certain materials can help to insulate a building and reduce energy consumption. Building materials are selected based on their suitability for the specific construction project and the needs of the end user.

Classify Building Materials

Building materials can be classified in a number of ways, including by their origin (natural or man-made), by their physical properties (such as density, strength, and durability), by their function (structural, insulation, finish, etc.), and by their cost and availability.

One common way to classify building materials is by their origin. Natural building materials are those that are found in nature and are not processed or altered in any significant way. Examples of natural building materials include wood, stone, clay, and sand. Man-made building materials, on the other hand, are those that are created through the processing of raw materials or the combination of different materials. Examples of man-made building materials include concrete, steel, brick, and glass.

Building materials can also be classified based on their physical properties. For example, materials that are strong and durable are often used for structural purposes, such as supporting the weight of a building. Materials that are lightweight and insulating are often used for insulation, to help keep a building warm in the winter and cool in the summer. Materials that are attractive and easy to maintain are often used for finishes, such as flooring, countertops, and wall coverings.

Another way to classify building materials is by their function. Structural materials are those that are used to support the weight of a building and provide its overall shape and stability. Insulation materials are used to reduce heat loss and gain, and to improve the energy efficiency of a building. Finish materials are used to cover surfaces and add decorative touches to a building.

Finally, building materials can be classified based on their cost and availability. Some materials, such as wood and brick, are relatively inexpensive and widely available, while others, such as marble and gold, are much more expensive and harder to come by. The cost and availability of building materials can be an important factor in determining which materials to use for a construction project.

Define the term Stone

Stone is a naturally occurring solid material that is composed of minerals, mineraloids, or organic materials. It is typically formed through the process of lithification, in which sediments are compacted and cemented together over time. Stone can be found in a variety of forms, including as boulders, cobbles, and pebbles, and it can be used for a wide range of purposes, including construction, landscaping, and decorative applications.

Classify Rocks: i. Geological Classification, ii. Physical Classification, iii. Chemical Classification

Rocks are naturally occurring solid materials that are composed of minerals, mineraloids, or organic materials. They can be classified in a number of ways, including by their geological, physical, and chemical properties.

Geological classification of rocks :

Geologists classify rocks into three main categories:

1. Igneous, primary, unstratified or eruptive rocks

Inner layers of earth are at such high temperatures that masses of silicates melt. This molten mass, known as magma, is forced up. Magma solidifies into rocks when it reaches the surface of earth and forms Basalts and Traps. If, however, the magma solidifies before reaching the surface of earth it forms solid crystalline rock known as Granite.

2. Sedimentary, aqueous or stratified rocks
Surface of earth is subjected to the destructive action of rain, frost, winds and chemical actions. These destructive agents break up the surface of earth which gets further broken up when carried down by rains and rivers. In the journey of river from mountains to sea the velocity goes decreasing as the river moves further. As the velocity of the river decreases so it goes on depositing the debris carried by it. The ones being the first to be deposited followed by the deposit of smaller and finer ones. Sand and silt get deposited in the voids of deposited debris-the latter having the binding properties.
Due to seasonal variations the materials are deposited in layers. The deposit in layers continues for millions of years in which period the deposited layers subjected to enormous pressure of overlying layers and of flowing water get consolidated forming stratified, sedimentary or aqueous rocks. Sandstones and limestones belong to this class.

Sedimentary rocks are often well stratified and show well-defined bedding planes. These rocks can be split and cleared easily both in the bedding direction and normal to the bedding planes giving building blocks of fairly regular shape. Properties of sedimentary rocks vary considerably depending upon the nature of sediment and the type of bonding that exists between the adjacent sediment grains. Sandstone formed by consolidation of sand deposits consists primarily of small rounded grains of silica. The sand stone will be relatively soft or hard depending upon the nature of binding material.

(iii) Metamorphic rocks

Due to structural changes in earth igneous or sedimentary rocks find their way deep in earth where they are subject to high temperature and heavy pressure which cause changes in texture or in mineral composition or in both resulting in the formation of new types of rocks known as metamorphic rocks; Following are some of the changes to “metamorphic rocks”: (i) Granite (igneous) changes to Gneiss, (ii) Sand stone (sedimentary) changes to Quartzite, (iii) Limestone (sedimentary) changes to Marble, and (iv) Shale (sedimentary) changes to Slate.

2. Physical Classification: In physical classification, rocks are grouped based on their physical properties, such as their density, hardness, and colour.
Physical classification of rocks

Physically rocks are classified as

Stratified rocks showing distinct layers along which it can be easily split into this labs e.g., Slate, Sandstone and Limestone,

Unstratified rocks

Unstratified rocks which show no sign of stratification and can not be easily split into thin layers e.g., Granite, Basalt and Trap.

All sedimentary rocks are essentially stratified whereas all igneous rocks are unstratified. Metamorphic rocks may be either stratified or unstratified depending upon the type of rock that has undergone transformation.

iii. Chemical Classification: In chemical classification, rocks are grouped based on their chemical composition. This can include their mineral content, as well as their pH and other chemical properties. For example, rocks that are high in silica are generally more resistant to weathering and are often used for landscaping purposes.

Recall the following tests of stone: i. Acid test, ii. Hardness test, iii. Water absorption test iv. Crushing test, v. Attrition test

Acid test: This test is carried out to understand the presence of calcium carbonate in building stone. A sample of stone weighing about 50 to 100 gm is taken. It is placed in a solution of hydrochloric acid having a strength of one percent and is kept there for seven days. Solution is agitated at intervals. A good building stone maintains its sharp edges and keeps its surface free from powder at the end of this period. If the edges are broken and powder is formed on the surface, it indicates the presence of calcium carbonate and such a stone will have poor weathering quality. This test is usually carried out on sandstones.

Hardness test: The hardness of a stone is a measure of its resistance to scratching, abrasion, and cutting. There are several methods for testing the hardness of a stone, including the Mohs scale, which uses a set of standard minerals to determine the relative hardness of a sample.
For determining the hardness of a stone, the test is carried out as follows:
A cylinder of diameter 25 mm and height 25mm is taken out from the sample of stone.
It is weighed.
The sample is placed in Dorry’s testing machine and it is subjected to a pressure of 1250 gm.
Annular steel disc machine is then rotated at a speed of 28 rpm.
During the rotation of the disc, coarse sand of standard specification is sprinkled on the top of the disc.
After 1000 revolutions, the specimen is taken out and weighed.

The coefficient of hardness is found out from the following equation:
Coefficient of hardness = 20 – (Loss of weight in gm/3)

Water absorption test: This test measures the amount of water a stone absorbs when it is immersed in water for a certain period of time. A stone with a high water absorption rate may be less durable and more susceptible to damage from freezing temperatures than a stone with a low water absorption rate.
Crushing test: A crushing test is used to determine the compressive strength of a stone, which is the maximum load it can bear without breaking. This test is typically performed on a sample of the stone that has been cut into a standard size and shape.
Attrition test: An attrition test is used to evaluate the resistance of a stone to wear or abrasion. It involves rubbing the stone against a surface or another stone under controlled conditions and measuring the amount of material that is worn away. This test is used to determine the suitability of a stone for use in applications where it will be subjected to repeated mechanical stress.

Recall the following qualities of a good building Stone: i. Crushing strength, ii. Appearance, iii. Hardness iv. Specific gravity, v. Percentage wear

Crushing strength: This refers to the ability of a stone to withstand the load or pressure of external forces without breaking. A stone with high crushing strength is essential for use in construction, as it can support the weight of the structure and any additional loads placed on it. Crushing strength of the stone should be more than 100 Nmm^-2

2. Appearance: The appearance of a stone refers to its colour, texture, and pattern. In some cases, the appearance of a stone is a key factor in its selection, as it can affect the overall aesthetic of a building or landscape.

Hardness: Hardness is a measure of a stone’s resistance to scratching, abrasion, and cutting. A stone with high hardness is typically more durable and less prone to wear and damage than a softer stone.
Hardness is measured by Mohs scale.
Coefficient of hardness = 20 – (Loss of weight in gm/3)
Specific gravity: This is a measure of the density of a stone relative to the density of water. A stone with a high specific gravity is typically denser and heavier than a stone with a lower specific gravity.

Specific gravity in natural stone ranges from 2 to 3, meaning that stone is two to three times denser than water.

4. Percentage wear: This refers to the amount of material that is worn away from a stone when it is subjected to mechanical stress or abrasion. A stone with a low percentage wear is more resistant to wear and will last longer in applications where it is subjected to repeated mechanical stress.
Percentage wear worked out as follows: Percentage wear = (Loss in Weight/Initial Weight) x 100

A percentage wear of stone is 3%

Describe the following methods of quarrying: i. Quarrying with hard tools, ii. Quarrying with a channeling machine, iii. Quarrying by blasting

Stone quarrying refers to the process of extracting natural stone from the ground for use in construction and other applications. This typically involves removing large blocks of stone from a quarry or mine site, which can then be cut and shaped into the desired size and shape for use in a specific project.

Quarrying with hard tools: This method of quarrying involves using hand tools or simple machines, such as chisels and hammers, to remove the stone from the quarry. It is a traditional method that has been used for centuries and is still used today in some areas where access to modern machinery is limited.
Quarrying with a channelling machine: This method involves using a machine that has a series of cutting teeth or blades, which are used to cut into the stone along a predetermined line. The machine then removes the cut stone in rectangular or square blocks. This method can be efficient and produce regular shape stone block
Quarrying by blasting: This method involves using explosives, such as dynamite, to break the stone into smaller pieces that can then be removed from the quarry. Blasting is typically used in larger quarries and is a more efficient method of removing large quantities of stone in a short period of time, but it also can have negative impacts on the surrounding environment and humans if not properly handled. The blasting method also requires proper permissions, planning, and safety measures.

Define the term Dressing

The term “dressing” in the context of stone refers to the process of shaping and finishing natural stone. This typically involves cutting and shaping the stone to the desired size and shape, and then smoothing and polishing the surface to create a finished surface that is suitable for use in construction and other applications. The process may also include additional steps such as chiselling, grinding, or honing to achieve a specific texture or surface finish.

Dressing of stone can be done using hand tools or machine tools depending on the size, shape and surface finish desired. In traditional methods, hand tools like chisels, hammers, hammers and chisels, and hammers and punches, etc. are used. But with the advancement of technology, diamond-tipped cutting and grinding machines are widely used for dressing.

Dressing can also include the process of cutting a stone into smaller pieces to create specific features such as lintels, arches, columns, sills and copings. The process is also used to create decorative elements such as sculptures and reliefs, or to produce specific architectural details such as mouldings and ornaments.

It is important to note that the dressing process can greatly affect the final outcome of the stone, and the quality and accuracy of the work are critical to ensure that the finished product is suitable for its intended purpose.

Recall the purpose of Dressing

The purpose of dressing in stone refers to the process of shaping and finishing natural stone in order to prepare it for use in construction and other applications.

Creating a desired size and shape: Dressing is done to bring the natural stone to the desired size and shape for the intended use. This could be for building walls, floors, roofs, stairs, countertops, monuments, sculptures, etc.
Improving aesthetic appearance: Dressing the stone can greatly enhance the aesthetic appearance of the natural stone. By polishing, honing or flamed finishing it can create different visual effects on the surface of the stone which can make it more attractive and appealing.
Improving Durability: Dressing process can also improve the durability of the stone. A well-dressed stone can withstand the rigours of weathering and other environmental factors better than an undressed stone.
Enhancing the functional capabilities: Dressing the stone can enhance the functional capabilities of the stone. By creating a smooth surface on the stone, it can be used for architectural ornaments, sculptures, monuments, and other decorative elements
Improving safety: Dressing the stone by creating a smooth surface can improve safety. For example, in a building with polished stone flooring, the floor is less slippery, thus reducing the risk of accidents.

Overall, the Dressing process is done to improve the functionality, appearance, and durability of the natural stone, and make it suitable for the intended use.

Recall the Deterioration of Stones

The deterioration of stones refers to the process by which natural stone materials degrade over time due to a variety of environmental factors. This can include changes in temperature, moisture, atmospheric conditions, and other factors. Natural stone materials such as granite, limestone, marble, and sandstone are used in a variety of architectural and construction applications, including building facades, monuments, statues, and pavements. However, these materials are susceptible to deterioration, which can affect both the aesthetic and structural integrity of the stone.

There are several types of deterioration that can occur in natural stone materials, including:

Physical deterioration: This type of deterioration is caused by weathering, freeze-thaw cycles, and other physical processes. It can lead to cracking, flaking, spalling, and other types of surface damage.
Chemical deterioration: This type of deterioration is caused by the chemical reaction of the stone with the environment. This can include acid rain, pollution, and salts, which can cause the stone to become discoloured, stained, and weakened.
Biological deterioration: This type of deterioration is caused by the growth of plants and microorganisms on the stone surface. This can include moss, lichens, and algae, which can cause discoloration and erosion of the stone.
Mechanical deterioration: This type of deterioration can occur due to human activities such as neglect, improper cleaning and maintenance or even in a few cases due to improper construction techniques. It can cause the stone to become chipped, cracked, and damaged.

It is important to note that these types of deterioration can often occur simultaneously and interact with one another, leading to an accelerated rate of deterioration. In order to prevent or slow down the process of deterioration of stone, regular cleaning, maintenance and preservation techniques need to be used. These include surface treatments, moisture control, and the use of protective coatings.

Regular inspections, documentations and monitoring of the conditions of stone structures are also important steps to identify any issues early on before it becomes a major problem. Consulting with the professionals and experts in the field of stone conservation can help to develop the appropriate plan to care for and maintain the longevity of the stone.

Describe the following causes of decay of stones: i. Alternate wetness and drying ii. Impurities in atmosphere iii. Rain water iv. Temperature variations

The decay of stones can be caused by a variety of factors, including:

i. Alternate wetness and drying: This occurs when a stone surface is repeatedly exposed to periods of moisture and then dryness. This can cause the stone to expand and contract, leading to cracking and erosion over time. Additionally, when water is absorbed into the stone, it can cause the formation of salt crystals. These crystals can grow over time, and can cause the stone to weaken and eventually crumble. The process of alternation of wet and dry conditions is known as freeze-thaw cycling, which results in physical and chemical weathering, and also known as frost-wedging. This occurs when water seeps into small cracks in the stone and then freezes, expanding and widening the cracks, which can lead to flaking, spalling, and other types of surface damage.

ii. Impurities in the atmosphere: The atmosphere is filled with a variety of pollutants, such as acid rain, industrial pollutants, and chemicals from car exhaust. These impurities can cause damage to the stone surface over time. Acid rain, in particular, can react with the calcium carbonate in the stone, causing it to break down and dissolve. Industrial pollutants can also cause discoloration or staining of the stone. The pollutants that contain sulphur and nitrogen can be responsible for the acid rain and can cause chemical weathering.

iii. Rainwater: Rainwater can be a significant cause of decay in stone structures. It can cause the stone to become weathered and erosion to occur. Rainwater can also carry dirt and other impurities with it, which can become trapped in the porous surface of the stone. Over time, this can cause discoloration and staining, and can also lead to the growth of moss and other vegetation on the stone. Rainwater can also cause physical weathering by expanding in the cracks of the stone and causing erosion.

iv. Temperature variations: Temperature changes can also cause damage to stone structures. Extreme temperature changes can cause the stone to expand and contract, leading to cracking and erosion. Additionally, temperature changes can cause the formation of freeze-thaw cycles, which can cause the stone to become weakened and eventually crumble. The process of temperature variations causing the stone to expand and contract is known as thermal cycling, which can cause physical weathering.

Overall, all these different factors can cause stone to slowly degrade and needs to be take into account while maintaining and restoration of building made of stones

List and recall types of Preservatives: i. Coal tar, ii. Paint, iii. Linseed oil, iv. Solution of baryta

It refers to the ability to list and recall different types of preservatives that can be used to protect and preserve natural stone materials. Preservatives are applied to the surface of natural stone in order to protect it from deterioration caused by environmental factors, such as moisture, pollution, and temperature changes.

The types of preservatives that can be used on natural stone include:

i. Coal tar: Coal tar is a thick, black liquid that is derived from the distillation of coal. It is commonly used as a waterproofing and protective coating for natural stone, due to its ability to repel water and resist the growth of microorganisms. However, Coal Tar has potential health hazards and is also considered harmful to the environment, its usage is gradually being phased out.

ii. Paint: Paints can be applied to natural stone as a form of protection. They can be used to seal the surface of the stone, and to prevent the penetration of moisture and pollutants. Paints also provide a good aesthetic look, but they often change colour and peel away over time, which can lead to discoloration of the stone surface.

iii. Linseed oil: Linseed oil is a natural oil that is derived from flax seeds. It is commonly used as a preservative for natural stone, as it can penetrate into the surface of the stone and provide a barrier against moisture and pollutants. Linseed oil is also environmentally friendly, but it has a tendency to darken the colour of the stone, and it may not be suitable for all types of stone.

iv. Solution of Baryta: Baryta is a chemical compound that is commonly used as a preservative for natural stone. It is a solution of barium hydroxide and is applied to the surface of the stone to provide a barrier against moisture and pollutants. Baryta solution also has a tendency to increase the whiteness and brightness of the stone but should be used with caution as it may discolour certain types of stones.

It is important to note that each type of stone material may have different properties and thus have different preservation needs, and not all preservatives are suitable for all types of stone. It is recommended to consult with professional conservators or stone experts for appropriate preservation methods for each specific stone type.

Recall the procedure for making an Artificial stone

It refers to the ability to recall the procedure for making an artificial stone. Artificial stone, also known as cast stone, is a type of building material that is made by mixing natural materials such as cement, aggregates, and pigments to create a product that mimics the appearance of natural stone. The procedure for making artificial stone typically involves the following steps:

Mixing the ingredients: The first step in making artificial stone is to mix the ingredients together. This typically includes cement, aggregates (such as sand and gravel), pigments (to provide colour and texture), and water. The ingredients are mixed together in a large mixer until a consistent, homogeneous mixture is formed.
Vibration: After the ingredients are mixed together, the mixture is poured into moulds and vibrated to help remove any air bubbles and to ensure a consistent density throughout the cast stone.
Setting and curing: The cast stone is then left to set and cure. This is the process by which the cement in the mixture reacts with the water to form a hardened, rock-like substance. The curing process can take several days or even weeks, depending on the type of cement and the ambient conditions.
Demolding: Once the cast stone has set and cured, it can be removed from the mould. The cast stone is then allowed to dry and cure further, until it reaches its final strength.
Finishing: After the cast stone is demolded and dried, the final finishing steps can take place. This includes cutting and shaping the cast stone to the desired shape, smoothing rough edges, and polishing the surface to achieve the final look of the artificial stone.

It is important to note that the procedure for making artificial stone may vary depending on the specific application and the desired properties of the final product. Different types of cement, aggregates, pigments, and curing methods can be used to achieve different colours, textures, and strength properties.

Also artificial stone may not have the same durability as natural stone and thus may require more maintenance and care. In addition, it can be difficult to match the colour and texture of natural stone exactly, therefore, it is important to have a clear understanding of the final look and qualities of the artificial stone when planning its production.

Recall the forms of Artificial Stones

It refers to the ability to recall the forms of artificial stone. Artificial stone, also known as cast stone, is a type of building material that is made by mixing natural materials such as cement, aggregates, and pigments to create a product that mimics the appearance of natural stone. There are several forms of artificial stone, each with their own unique properties and uses.

Precast stone: Precast stone is made by casting the mixture of cement, aggregates, pigments, and water into moulds in a controlled environment. The cured and finished product is then transported to the construction site for installation.
Architectural precast: This is a specific form of precast stone that is used for architectural elements such as balustrades, coping, and trim. Architectural precast can also be used to replicate ornate details, such as cornices and decorative mouldings, that would be difficult or impossible to replicate with natural stone.
GFRC (Glass Fiber Reinforced Concrete): Glass fibre reinforced concrete is a type of artificial stone that is made with a mixture of cement, aggregates, pigments, and water, along with the addition of glass fibres. It is typically used in architectural and decorative applications, where lightweight and thin sections are required.
GFRG (Glass Fiber Reinforced Gypsum): Glass fiber reinforced gypsum is similar to GFRC, but the cement is replaced by gypsum. It is used in architectural and decorative applications, but it has a higher fire resistance and better sound insulation properties than GFRC.
Artificial veneer stone: Artificial veneer stone is a thin layer of cast stone that is applied to the surface of a building or structure. It can be used to replicate the look of natural stone, but at a fraction of the weight and cost.
Artificial paving stone: It can be used in paving, sidewalks and other similar applications. It is usually made by moulding technique and its thickness is relatively thinner than precast stone.

It is important to note that while artificial stones can be used to replicate the look of natural stone, they may not have the same durability and resistance as natural stone. Therefore, they may require more maintenance and care. When choosing artificial stone, it is important to consider the properties of the final product, such as its strength, durability, and resistance to weathering, as well as the intended application and the desired aesthetic.

List and recall the advantages and disadvantages of Artificial Stones

It refers to the ability to identify and recall the pros and cons of using artificial stones as a building material.

Advantages of Artificial Stones:

Cost-effective: Artificial stones are typically less expensive than natural stones, making them a cost-effective option for building and construction projects.
Durable: Artificial stones are typically made from a mixture of cement, sand, and aggregate. This mixture is then pressed into molds and cured, creating a hard and durable building material.
Variety: Artificial stones can be made in a variety of shapes, sizes, and colors. This allows builders and designers more flexibility in their design choices.
Low maintenance: Artificial stones are not prone to decay, erosion, and weathering, making them a low-maintenance option for building materials.
Easy to Install: Artificial stones are relatively easy to install, which can save on labor costs.

Disadvantages of Artificial Stones:

Limited aesthetic appeal: Artificial stones lack the natural beauty and unique character of natural stones. They may be less visually appealing to some people.
Limited types: Some artificial stones can only mimic a limited set of natural stones types, and not all natural stones can be replicated by artificial stones.
Low thermal mass: Artificial stones do not store heat as well as natural stones, meaning that they may not be as energy-efficient.
Not environmentally-friendly: The production process of artificial stones can generate waste and pollution and may be less sustainable than natural stones, which are a renewable resource.
Susceptible to water damage: While artificial stones are resistant to weathering, they may be more susceptible to water damage than natural stones. If not properly sealed, water can seep into the porous surface of artificial stones and cause damage.

Overall, artificial stones can be a cost-effective and durable option for building materials, but they may lack the aesthetic appeal and environmental sustainability of natural stones.