How to find Good qualities of Bricks for the construction work?

 The 10 Qualities of Good Bricks

1. Bricks Should have given perfect edges, must be adequately burnt, should be uniform color either Red or Copper, and should free from cracks.
2. Bricks should have a rectangular plane surface with parallel sides and sharp right-angled edges. The size of a standard brick is 190mm x 90mm x 90mm.
3. It should be hard enough and while scratching on bricks with our fingernails, it has no impression left on its surface.
4. Bricks should not break while falling from the 1m height.
5. Bricks should not more than 20% up to 12.5 class and not more than 15% for a higher grade of absorption of water by their weight.
6. Bricks will produce a ringing sound while hitting each other.
7. Bricks should be a homogeneous material and well compacted.
8. Bricks should free from efflorescence deposits.
9. Bricks should have less thermal conductivity and must be soundproof.
10. Brick should have a minimum crushing strength of 3.5 N/mm².

Classification Of Bricks

Bricks are classified into two categories by their manufacturing terms:-

Burnt Bricks

• 

  Sundried Bricks

  
  

Burnt bricks are widely used in Civil Engineering for Building constructions. It is classified under four categories by its qualities. They are,

1. First-class Bricks,
2. Second-class Bricks,
3. Third-class Bricks,
4. Fourth-class Bricks.

Un-burnt bricks or Sun-dried bricks also called Katcha bricks, These bricks are dried directly by sunlight after the process of De-moulding. These bricks are not encouraged to use in exposed conditions to the weather. Mostly for heavy rains. These bricks are menial in quality. So, its recommends for temporary buildings or structures.

Classification Of Common Clay Burnt Bricks As per Indian Standards. 

(Source: IS 1077:1992) Vth Revision.

TESTS ON BRICKS

Before recommending bricks for construction work, ensuring the Class Designation as per IS code and confirming the suitability of bricks by conducting the following tests:

1. Compressive Strength Test
2. Water Absorption Test
3. Efflorescence Test
4. Dimensional Tolerance Test
5. Hardness Test
6. Soundness Test
7. Structure Test

LABORATORY TESTS ON BUILDING MATERIALS

Laboratory tests on building stones consist of,
        1.The Attrition Test
        2.The Crushing Test
        3.The Freezing and Thawing Test
        4.The Impact Test
        5.The Laboratory Hardness Test
        6.The Microscopic Test.

1.The Attrition Test

This is also called The Abrasion Test. This test is conducted to determine the percentage of the water of stones that are used for road construction. This is carried out in Deval's Attrition Testing Machine.

        In this test, a certain quantity of stone is placed on Deval's Attrition cylinder. The cylinder is rotated about its horizontal axis at the rate of 30 rpm for 5 hours.

After the end of the rotation, the contents of the cylinder are sieved, and the quantity of material retained on the stone is weighed. The percentage weight is the ratio of loss in weight to the initial weight which is expressed as a percentage.

2.The Crushing Test

The Crushing test is performed on the stones which are to be subjected to compressive stress. In this test, a cubical specimen of a 40 mm side is tested in a compression testing machine. The maximum load at which the stone specimen fails by crushing is noted. Then the crushing strength of the stone is the ratio of maximum load at failure and area of bearing face.

3.The Freezing and Thawing Test

This test is conducted for the use of stones in freezing regions, which are temperature goes below freezing point. The test consists of keeping a specimen of stone in water for 24 hours and then placing it in a freezing mixture at 12℃ for 24 hours. The specimen is taken out and thawed (warmed) to atmospheric temperature. The procedure has repeated a minimum of seven times after which the specimen is examined for any damage.

4. The Impact Test

The toughness of a stone is determined by the impact test using an impact testing machine. Here, a stone specimen of 25mm diameter and 25mm height is placed on the machine. A steel hammer of 2 kg weight is allowed to fall down axially on the cylinder from 1 cm height for the first blow, 2cm height for the second blow, 3 cm height for the third blow, and so on. The blow at which the specimen breaks is noted, which is the Toughness Index of the stone.

5.The Laboratory Hardness Test

This test is different from the field hardness test and the attrition test. This test is carried out in Dorry's testing machine. A cylinder of 25mm of the stone is rubbed against a steel disc spindled with coarse sand. The Specimen is subjected to the pressure of 1.25 kg/mm². After 1000 revolution in the machine, the loss in weight is found, and the co-efficient of hardness is determined as,

Co-efficient of hardness = (20−Loss of weight in gm) ➗ 3

6.The Microscopic Test

In this test, a flake specimen of a stone is taken and placed on a microscopic to study the following properties,

1. Mineral constituents
2. Texture of stone
3. Average grain size
4. Nature of Cementing material
5. Presence of pores, fissures, and veins

This test is a Geologist's test.

Field Tests on Construction Materials

     

Cement sample for tests

    In general, Construction materials are should check their qualities and properties before use at the site. Because of the poor quality materials reduced the life of the building and it causes major hazards to the persons who are living or using the buildings.

So, It may the Organizations or the single persons all should check the construction materials in proper and maintain records for their buildings and safety. it is everyone's responsibility to be aware of the material's quality used in our buildings.

Tests on Building stones:-

    For the Building stones, some tests are simple to conduct in fields, and some tests can be done in Laboratory. Accordingly, they may be grouped as field tests and laboratory tests (IS:1121, 1974 and IS:1124, 1998).

Field Tests:

The simple tests or Field tests are,

1. The Absorption Test, 
2. Smith's test, 
3. The Toughness Test, 
4. The Hardness Test, 
5. The Acid Test and 
6. The Crystallization Test.

Laboratory tests:

The Laboratory tests on stones consist of,

1. The Attrition Test, 
2. The Crushing Test, 
3. The Freezing and Thawing Test, 
4. The Hardness Test, 
5. The Impact Test, 
6. The Microscopic Test.

Field Tests:

1. The Absorption Test,

    Usually, this test is called the water absorption test. This is a simple test conducted on all stones. It consists of keeping a cubical specimen of the stone of about 50gm weight immersed in water for 24 hours and finding the volume of absorbed water. This is represented as a percentage of absorption by weight. This percentage should not be more than 0.6%. This test is also called the electrical resistance test.

         2. Smith's test, 

    This test is conducted to find the presence of earthly matter or the deterioration of stones when immersed in water. A specimen of the stone is placed in a glass container with water and stirred vigorously. It is placed in water for at least 24 hours. If the water shows turbidity, then the stone is assumed to contain earthly substances. This test is to be conducted for all stones.

        3. The Toughness Test, 

               It is a rough test without any rigid specification or procedure. A stone is struck by a hammer to gauge its toughness of the stone. The force required to break the stone reflects the toughness of the stone.

        4.The Field Hardness Test, 

                This test is also called Moh's scale of hardness test. This is a simple test in which the hardness of the test is based on the hardness of the surface. The surface of the stone is scratched with the help of a penknife, and the hardness is gauged based on the relative abrasiveness of minerals (the soft being talc and the hardest being diamond). Such a classification is given by Mohs and the scale is divided into the ten following scales,

1. Talc
2. Gypsum
3. Calcite
4. Fluorspar
5. Apatite
6. Orthoclase feldspar
7. Quartz
8. Topaz
9. Corundum (sapphire)
10. Diamond

            Thus, if a marking has been done with a pen knife on the surface of the stone, will be equated to the hardness of the Calcite. Hence the hardness, H=3. A siliceous rock surface cannot be scratched which may be equated to that of quartz and in this instance, H=7.          

        5.The Acid Test 

            This test is performed to determine the presence of alkaline or lime content. This test consists of placing a cube of 50 to 100 gm weight in 1% hydrochloric acid for one week. If the corners of the cube show roundish and loose particles deposited on the surface, the stone has some alkaline content. If the stones exhibit fluorescence when subjected to the action of acids, then it reflects the presence of lime content. Stones that do not react to sulphuric acid are highly fire-resistant.

        6.The Crystallization Test.

            Due to crystallization on reaction with some chemicals, the stones may show a loss of weight and some defects. This test consists of immersing a cubical specimen of 40mm side in sodium sulfate solution for 2 hours and then drying it in an oven at 100℃. This procedure is repeated five times. The loss of weight and the presence of cracking on the surface are noted. The presence of visible defects and loss in weight should be minimal indicating high durability and good resistance to weathering.

Important terms For Civil Site Engineers and Front Line Supervisors

 Here are some important tips and data for the Civil site engineers and supervisors.

Generally, Engineers should have sound knowledge in their field will help them to shine their career. So, knowledge in Materials is most prior other than that.

Engineering materials:-

• Civil Engineering materials
• Electric Engineering materials
• Mechanical engineering materials

Cement

River Sand

Bricks

Civil Engineering Materials

• Building stones
• Bricks
• Clay products
• Lime
• Cement
• Concrete
• Mortar
• Timber
• Soils
• Metals
• Aggregates
• Alloys   Etc.,

Building Stones:-

Stones have to be selected for a specific work based on the strength and other properties including durability. Stones are used in General building works for Foundations, walls, and superstructure. Sandstone is generally used for high mechanical strength, pleasant colors, and also high durability.

High wind zone:-

Such buildings are constructed near the seashore or where more wind prevails. Granite and basalt may be used in these areas due to their high crushing strength and the presence of silica in addition to hardness should be preferred.

Industrial area:-

In Industrial area has a high polluted atmosphere and it contains harmful gases, acid, and moisture. This may lead the stone to deterioration. So, Granite and compact sandstone may be preferred to use because of their sustain in the effect of acidity and smoke.

Building exposed to Heat and Fire:-

In very Hot region, the weather conditions are prevalent throughout the year and chemical factories which may have hot air which is susceptible for frequent fires. For such cases, the stones should have high fire-resisting properties. In general, stones are from calcium carbonate can resist fire.

Road metals and Railway Ballasts:-

Are subjected to high compression and abrasion. Further, railway ballasts are exposed to the atmosphere throughout their lifespan. Stones selected for such purposes should be hard, tough, and highly abrasive resistant. Generally, igneous rocks are preferred for this purpose, viz., Granite and Basalt.

 

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Are You Planning to start a House construction for your Family?

 Wait Till study the following steps to be considered before Constructing a Home

General:-

    For any building, the prerequisite is formal planning. Good planning transmits the best living environment. A Good home means the building has been built and planned well for structured living with family as comfortable.

The Construction of a Building has two stages, they are, 

Pre-Construction Activities:-

• Site/Plot Selection
• Acquired Technical details/help
• Prepare the detailed budget
• Acquire the permissions from concerned departments
• Approach an architect/Engineer for Construction
• Material Selection and Brands for All Item of works

During Construction Activities:-

• Site Preparation and Land Development
• Setting out Or Line marking
• Excavation & P.C.C Bed laying
• Foundation Marking
• Reinforcement Placing and Tying
• Sub-structure works (Upto Plinth Level)
• Super-Structure up to Lintel Level
• Doors and Window Framing works and Fixation
• Super-Structure Lintel and Above
• Roofing works
• Finishing works

Principles of Site Selection:

        Site selection is the most important first step in this process for the good planning and designing of buildings. The following general principles to be kept in mind while selecting the plot/site for the building.

1. The site/plot should be located in a fully developed or fast developing locality.
2. Before selecting a site, we should study the bye-laws of the local authority. i.e. about the restrictions regarding proportions of plots to be built up, open spaces and margins to be left in front and sides, the height of buildings, etc.
3. The area of the plot should meet the requirement of the owner who wants to build the building there, after following certain restrictions of the local authority.
4. The site should be located in an elevated place and also levelled surface with uniform slopes from one end to the other to provide good and quick drainage of surplus water.
5. The soil in the site should be good enough with a high safe bearing capacity to provide an economical foundation.
6. The purpose of building and extent of privacy is desired.
7. The shape of the plot should be rectangular or squared in shape. Rectangular is preferrable.
8. The site should be located near the community services like clearing wastages, utility services like water supply, electricity, drainage, etc., and easy access to the hospitals, schools and transport facilities, etc.,
9. The site should get Govt approved authorities for building construction.
10. The site shouldn't be in the zone of quarries, kilns, factories, rivers/lakes, flood, waterlogged areas and badly maintained slopes for drainage.
11. The legal and financial aspects also should be given due consideration.

Acquired Technical details/help

    After selecting the site for our new home construction, our next step will be to make technical drawings of our dream house by an Architect or an Engineer with all amenities in our thoughts.

    For that first, we have to interact with a number of technical persons about the designs that they have done. If, so will see their completed projects and ongoing projects about their way of working and also get the detailed estimation about all item in work-wise. then start to discuss with the Engineer/Architect the materials that we are going to use for our building.

Prepare the detailed budget

    Get the lists of the building materials and the quantity which obtained for our building. If possible, ask them to make a model of our new constructing house for the preview for our satisfaction and avoiding any changes and reworks. It will help us to avoid any extra costs.

And get cleared about the contract details that what are the works are covered in the contracts. If any, not included items so, please make a page in contracts to add the items separately.

Acquire the permissions from concerned departments

    For the new home construction, after getting approved or signed drawings and detailed estimation, We get approval from the local govt bodies like Panchayat/Municipal/Corporation. Then we have to submit the application for a new Electric connection for the construction in commercial terms until we complete the house.

What are Documents to be maintained at working site?

 

The Project means an activity which has start time and end time. same while the location of project called as working site. In working site some of Documents to be maintain as mandatory.

The Documents are Highlighted in the followings,

• The Site should be well organized by a firm. And it has to be show the roles of each persons by the Organization chart.
• And at site the project has to be run in quick and also in SAFE. So, Maintaining EHS manual and Safety Register.
• In some times the project may get delay for some reasons. It should be recorded in the Hindrance Register.
• The Standard work instructions Register for Frontline Staff and Labours to be maintained.
• For Executing the works, the Technical DRAWINGS is must. It should be in proper files and separation as their types, Site Plans, Architectural Drawings/Structural Drawings, Set of Service Drawings, All working drawings and as built Drawings.
• Work Awarded copy or Sanctioned copy original and revised. If So, (Item wise Tendered rate can entered on Estimate to keep watch)
• Tender Agreement Certified Copy
• Site Register: For Recording Daily Reports, Daily Work Measurements and sketches.
• Site Order Book: It should maintain at site for the record about any High-Officials Site visits. The Inspection Officer will record his observations and queries, in Site order Book.
• Display the progress of Project and Timeline item-wise in the BARCHART.
• Expenditure Graph to showing Details of work.
• Corrected/Audited Bill copy in filing system.
• Regular updated record of Cement with Issue voucher No. and Date to be maintain in Daily Cement Consumption register.
• If so, at site The Item wise Cement consumption Register can be maintain, its useful for billing process.
• The materials using in projects are Assured by Assurance Engineer regularly by conducting required tests for the materials and maintain Material Testing Register and File.
• In execution, Site engineers or Surveyors can maintain FIELD BOOK for recording actual levels, co-ordinates and other measurements. And is should be signed by respective Engineers and contractors.
• Material Stack Register should be maintain for all materials Inward and Outward from site.
• Laborer's Attendees Register to be maintain for recording the Daily No. Of Labours.
• Daily Progress Report DPR to be made, with all materials usage and stack, labour engaged, Unit of work done per day.
• Weekly Progress Report WPR same as DPR but it should be record for during week with work done and attachment of photographs
• Commencement/Plinth checking Certificate. This Certificate for Completion of building upto Plinth Level. This certification has provided to the citizen by the government for confirming the completion of the building.
• N.A(Non Agricultural) Order and other Government Permissions.
• Approvals From all Concerned Authorities.