Name: WILLARD MULENGA.

Subject: BUILDING CONSTRUCTION.

Date of submission: 13/12/2020.

Lecturer: WORLD CLASS EDUCATION.

Question: EXPLAIN THE PROCESS OF SELECTION OF STONE AND HOW TO BUILD A STONE WALL.

Page 1 TABLE of CONTENTS

Page INTRODUCTION...... 4

Traditional building system of Uttarakhand...... 4

Impact of recent earthquakes...... 4

MAIN BODY...... 5

Materials...... 5

Dimensions...... 5

Selection of stones for Building Construction...... 5

Good Construction Stone Selection...... 5

The criteria is based upon the following parameters:...... 5

1.Chemical composition of stones:...... 5

2. Strength and hardness:...... 6

a) Hardness or softness of the components...... 6

b) Proportion of hard and soft materials ...... 6

c) Size and shape of the minerals in stones ...... 6

d) Cohesion...... 7

e) Porosity:...... 7

f) Density:...... 7

g) Cementing materia...... 7

3.Resistance to heat ...... 7

4. Bio-deterioration:...... 8

5. Appearance...... 8

Page 2 How to build a stone wall...... 8

1.Set Course of the Wall...... 8

Types of Building Walls ...... 8

Masonry wall...... 8

Monolithic wall...... 9

Frame wal...... 9

Membrane wall...... 9

Factors which will determine the type of wall to be used ...... 9

2. Dig Trench with Depth and Width Guide ...... 10

a. Start Building Foundations by Marking Out a Level Datum Point ...... 11

b. Calculate Material to be Removed...... 11

c. Use String Lines to Mark Out Your Building Foundations...... 11

d. Mark Out the Trenches for Your Building Foundations...... 12

3. Place and Level Stones...... 12

4. Saw old level stonec...... 12

5. Put in drainage with PVC pipe...... 13

CONCLUSION...... 13

REFERENCES...... 15

Page 3 BUILD A STONE WALL

INTRODUCTION

Stone walls are a kind of masonry construction that has been used for thousands of years. The first stone walls were constructed by farmers and primitive people by piling loose field stones into a dry stone wall. Later, mortar and plaster were used, especially in the construction of city walls, castles, and other fortifications before and during the

Middle Ages. These stone walls are spread throughout the world in different forms. One of the best example is the Cyclopean Wall in Rajgir, India.

Traditional building system of Uttarakhand;

People have been constructing stone buildings for their house and other service needs for hundreds of years in the hill areas of Uttarakhand, since stone has been the most abundantly found building material. Not only have they been using the stone for walls, but also for roofing. Timber, being the second most abundantly found material in the area, has also been in use in combination with stone for roof construction. In other words, the construction system based primarily on these two materials has been the backbone of the traditional construction of the region.

Impact of recent earthquakes;

In the decade of 1990's the state witnessed two destructive earthquakes. Both the earthquakes witnessed severe damage to many stone buildings. As a consequence, peoples' confidence in the traditional construction got badly shaken. This resulted in many house-owners switching over to modern cement, steel and brick based construction which many find expensive.

These guidelines will be helpful in designing earthquake resistant buildings with stone as the principal material in all parts of the State of Uttarakhand including those falling in Page 4 the Seismic Zones IV and V.

Materials

Stone walls are usually made of local materials varying from limestone and flint to granite and sandstone. However, the quality of building stone varies greatly, both in its endurance to weathering, resistance to water penetration and in its ability to be worked into regular shapes before construction. Worked stone is usually known as ashlar, and is often used for corners in stone buildings. Granite is very resistant to weathering, while some limestones are very weak. Other limestones, such as Portland stone, are more weather-resistant.

Dimensions

Large structures are usually made of very thick walls, so that castles and cathedrals possess walls which may be up to 12 feet thick. They normally consist of a layered stone exterior and rubble infill.

Selection of stones for Building Construction:

Good Construction Stone Selection;

Being cheap, hard, durable and naturally good looking, stones are often used in construction but keeping in view the variable properties of stones of different types, there must be some criteria for the selection of stones for construction. The criteria is based upon the following parameters:

The criteria is based upon the following parameters:

1. Chemical composition of stones:

Using/selecting a stone for construction, its chemical properties and composition must

Page 5 be tested and verified because different elements and compounds in stones have different properties. For instance, Magnesium in Limestone causes it to be more stronger and is called Dolomite. Feldspar, in large quantities in stone is a source of weakness because CO2 dissolves Potassium, Sodium, and even Calcium in the Feldspar leaving pure white clay behind.

Presence of Mica, even less than 2-3% makes stone unsuitable for building purposes.

Stones with silicates as cementing materials are resistant to weathering.

2. Strength and hardness:

The more compact grained and heavier a stone, the more stronger it is. A crystalline stone is superior to a non-crystalline texture. The specific gravity of good stone should be above 2.7. Stones used for road metal, paving blocks, floor slabs and railway ballast have to withstand mainly abrasion or wear and tear. Stone wall subjected to vibrations of machinery and moving loads should necessarily possess toughness. Strength and hardness itself depend on some factors such as: a) Hardness or softness of the components:

The composition of the compounds determines its hardness or softness. Stones containing Si, Na, K are poor while that containing Mg, Ca, and Fe are good, as they are harder. If the stone is composed of soft and unhardened materials it will result in a soft materials and vice versa. b) Proportion of hard and soft materials:

The amount of soft and hard material in a specific sample of stone also matters.

Greater the amount of hard materials more will be the resistance to weathering. c) Size and shape of the minerals in stones:

Page 6 Crystalline solids are hard and compact, thus superior to non-crystalline. Finer the crystals, stronger the stones and vice versa, This property i.e fineness reduces the pores in the stone. d) Cohesion:

It is the property of atoms or particles to attract each other. The fine grains have more cohesive power than the coarser grains. Greater the cohesion in stone causes increase in the hardness, strength and toughness of stones. The property of compactness also depends deeply on cohesion. e) Porosity:

Stones in wet conditions and having pores in them allow a lower crushing strength than normal. Porosity can reduce the strength upto 30 - 40% e.g limestone and sandstone are affected by this property. Porosity is the property of a substance in which it contains pores i it. It also reduces the resistance to a concentrated (point) load. f) Density:

If a stone is compact, dense, it would also be non-porous and strong , thus toughness also depends upon density. g) Cementing material:

Stones with silicates as cementing material will be resistant to weathering than those with calcareous or ferruginous binding material. So, cementing material also affects the choice of stone selection.

3. Resistance to heat:

Resistence to heat means that the stone must have a very low amount of expansion due to large increase in temperature. Silicious materials are good at areas where

Page 7 resistance to fire is required.

4) Bio-deterioration:

Certain trees and creepers thrust their roots in the joints of stones and have both mechanical and chemical adverse effects. Special microbes can grow on the surface and in minute fissures, their by-products cause flaking and discoloration.

5) Appearance:

The aesthetic aspect that is color, appearance and show of stones must also be considered when being used in a project. Appearance depends on the color and the ease with which the stone can be dressed, rubbed or polished.

How to build a stone wall

1. Set Course of the Wall

To lay out the curve of the wall and to define the area that needs to be dug out for the trench, or foundation, we're going to use a household extension cord as our marker.

Some other things that work just fine are a garden hose or even a length of rope. If the wall were to be straight, we could have used string and stakes, but the hose works great for laying out a curved wall.

Types of Building Walls:

There are various ways to construct a wall and many different materials can be used, but they can be divided into four main groups.

Masonry wall, Apart from certain forms of stone walling, all masonry consists of rectangular units built up in horizontal layers called courses. The units are laid up with mortar in specific patterns called bonding in order to spread the loads and resist overturning and in the case of thicker walls, buckling.

Page 8 The material in the masonry units can be mud or adobe bricks, burnt clay bricks, soil blocks (stabilized or unstabilized), concrete blocks, stone blocks or rubble. Blocks can be solid or hollow. in which the wall is built of individual blocks of materials such as brick, clay or concrete blocks, or stone, usually in horizontal courses bonded together with some form of mortar. Several of the earth derived products, either air dried or fired, are reasonable in cost and well suited to the climate.

Monolithic wall, in which the wall is built of a material placed in forms during the construction. The traditional earth wall and the modern concrete wall are examples. The earth walls are inexpensive and durable if placed on a good foundation and protected from rain by a rendering or wide roof overhangs.

Frame wall, in which the wall is constructed as a frame of relatively small members, usually of timber, at close intervals which together with facing or sheething on one or both sides form a load-bearing system. Offcuts are a lowcost material to use for a frame wall covering.

Membrane wall, in which the wall is constructed as a sandwich of two thin skins or sheets of reinforced plastic, metal, asbestos-cement or other suitable material bonded to a core of foamed plastic to produce a thin wall element of high strength and low weight.

However, another form of construction adapted for framed or earth buildings consists of relatively light sheeting secured to the face of the wall to form the enclosed element.

These are generally termed 'claddings'.

Factors which will determine the type of wall to be used are:

The materials available at a reasonable cost, as well as Availability of craftsmen

Page 9 capable of using the materials in the best way, also Climate, and The use of the building functional requirements.

The height of walls should allow people to walk freely and work in a room without knocking their heads on the ceiling, beams etc. In dwelling houses with ceilings is 2.4m a suitable height. Low roofs or ceilings in a house create a depressing atmosphere and tend to make the rooms warmer in hot weather..

2. Dig Trench with Depth and Width Guide;

After laying out the marker extension cord, it's time to dig out the trench. Skim off any grass, and set the dirt of the trench aside for later use. If your wall is going to be long, a backhoe or tiller rental can be a back-saving investment, but since this wall isn't going to be all that long, the long-handled shovels and some good old-fashioned sweat get the job done.

A good rule of thumb when digging the trench is to dig it about 6" deep and fill it with about 3"-4" of fill gravel. Then tamp it down to about 2". To determine the width of the trench, add 6" to the width of the stones you're using. This enables you to place your stones with 2" left up front and 4" left behind. Because Building foundations can often be the most perilous element of a building project for even the most seasoned of self builders.

Therefore, Building foundations is the crucial starting point when it comes to building a house. Your foundations will safely distribute the weight of your new home and prevent the subsoil from spreading, avoiding an unequal settlement of the structure, which could lead to structural issues down the line.

Mistakes at this stage could prove costly so it’s vital to double check all measurements, mark them on the plans and make sure everyone is working from the same set of plans.

Page 10 Be prepared to be flexible if the excavation process reveals some surprising ground conditions (setting aside a healthy contingency budget is essential for this stage).

If you aren’t sure which foundation system to choose or what type of soil you’re dealing with, then make sure you take a look at our guide to foundation systems and soil types. a. Start Building Foundations by Marking Out a Level Datum Point;

First you will need a level datum point. If you are building an extension this is usually the finished floor level or damp-proof course (DPC) of the existing building. For new builds, this will be marked on the plan as a fixed point such as a manhole cover or a marker in the road or pavement.

The datum point is important: all your height measurements are relative to this point, so any errors could cause problems later on, particularly if there is a height restriction placed on the building. b. Calculate Material to be Removed;

Next, calculate how much material needs to be removed from the site to end up back at finished floor level once all the layers of flooring materials (insulation, concrete, screed, etc) have gone down. Time taken with a site level at this stage will make things easier later on when the digger may not be able to reach any areas that have not been dug deep enough. c. Use String Lines to Mark Out Your Building Foundations;

Start marking out for the walls. Set up timber hurdles at the end of each wall, out of the way of where the digger will need to be. These carry the string lines that represent the wall faces of your building. Where space is limited, use corner pins instead and set up the hurdles after the concrete is in.

Page 11 d. Mark Out the Trenches for Your Building Foundations;

Begin lining up your footings by referring to your datum point. When it comes to extensions, never assume an existing building is square; pick the side you need to be square to and set up a line, then square off that line.

3.Tamp Down Gravel:

The trench is the solid foundation on which to build a wall, so make sure that the fill gravel is put into the trench and really tamped down until it is compacted and level.

Note: To tamp down as solidly as is necessary, you will need to use a tamper. There are two types, a hand tamper and a power tamper. Use the one with which you are most comfortable.

3. Place and Level Stones:

Place the stones so that they touch side by side; they should be fairly snug as they're laid down. Level each stone as it's put in. Use a torpedo level to check the side-to-side level of the stones as well as the front to back level. Use the gravel to help level the stones. Finish the first course of stones.

4. Saw Odd Stones:

It may be necessary to cut some of the stones as the wall comes together: that's where the wet saw comes into play. The wet saw is the perfect tool to rent when building a retaining wall. With its diamond blade, it cuts the stones pretty easily. Simply mark your stone at the desired size and cut. But if you're going to be cutting only a few stones, that can be done with a hammer and mason's chisel as well.

Page 12 5.Put in Drainage With PVC Pipe:

Now that the first row of stones is in, get ready to install the drainage in the wall. The first step is to add gravel to the back of the first run of stones. Put the gravel into the trench and tamp it down lightly. The gravel acts as an aid in drainage.

PVC drainpipe is laid on top of the gravel with the drain holes facing down to evenly distribute the draining water. It runs the length of the wall and out into the yard. The ends will be coupled with PVC pipe outlets for the drainage. This serves the purpose of moving water away from the wall, minimizing any damage that it might cause.

Once the drainpipe is in place, cover it with more gravel. Then lay down a layer of GEO textile fabric (Image 3) to line the back of the wall and trench. This fabric serves as an erosion barrier as well as keeping fine particles from seeping through the stones of the wall.

CONCLUSION

In conclusion, The building construction industry like in Ghana, particularly the urban housing sector, is dominated by the use of the conventional sandcrete block for wall construction. Various forms of waste have however been observed to be associated with the process of erecting walls using the conventional sandcrete block. This has lead to the need to explore the possibility of adopting other walling systems towards making the wall construction process lean in order to reduce waste and maximise value.

Therefore, a comparative study was conducted between the use of the conventional sandcrete block and the use of the interlocking block to establish the possibility of bringing wall construction process closer to the principles of lean thinking through the adoption of the interlocking block system. The focus of the study was to particularly Page 13 identify some non-value adding steps in wall construction process associated with the use of the conventional sandcrete block so that those steps could be eliminated through the use of the interlocking block.

Furthermore, the study revealed that a number of non-value adding steps like spreading of base mortar for various courses, vertical mortar jointing and levelling, which are associated with the use of conventional sandcrete block, could be eliminated when the interlocking block is used for build a stone wall construction. Such various forms of waste as over-production, unnecessary movement, unnecessary processing, inventories and waiting, seen to be associated with the use of the conventional blocks, are minimised to a large extent when the interlocking block is in use.

Not only that, The interlocking block is in no doubt a worthy tool towards making wall construction process lean due to the establishment of its elimination of non-value adding steps in wall construction, as well increasing speed of construction while reducing labour and material requirements. One challenge to its adoption from some countries is however the fact that the interlocking block work technology is not common and skilled labour for its application is not readily available. This may call for the need for more training of artisans in this technology. The curricula of Technical and

Vocational Educational Training (TVET) institutions offering training in masonry work needs to be revised to include training models in the interlocking block work. A modular approach to building design, using the interlocking block as the basic module, also needs to be adopted for an effective and efficient use of the interlocking block in building construction.

Page 14 REFERENCES

"The Cyclopean Wall Rajgir". Travel News India. 2017-03-07. Retrieved 2017-03-09.

Alarcon, J. V., 1993, Input- Output Analysis with Special Reference to Developing

Countries, Institute of Social Studies, The Hague, the Netherlands.

Ballard, G. and G. Howell., 1994, Implementing Lean Construction: Stabilizing Work

Flow. Second Annual Conference on Lean Construction, Catolica Universi- dad de

Chile Santiago, Chile, September 1994.

Ballard, G., 1999, Improving Workflow Reliability, IGLC-7 proceedings University of

California, Berkeley, CA, USA276.

Bansal, D., 2010, Interlocking Dry Stacked Masonry, 8th International Masonry

Conference, Dresden

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