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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
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Consruction Techniques, Equipment And Practice UNIT I - CONCRETE TECHNOLOGY PART-A
1) What are all the types of cement? o Ordinary Portland cement o OPC33,OPC43 and OPC53 grade o Rapid hardening cement
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o Extra rapid hardening cement
Portland slag cement
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o Sulphate resisting cement
o Low heat cement
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o Quick setting cement
o Portland pazzolona cement
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o Colored cement
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o Air entraining cement
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2) Differentiate dry process and wet process of manufacturing cement?
Lime stone and clay are ground to fine powder separately and are mixed together Water is added to make a thick paste which contains 14% of moisture The paste format are dried and off charged into a rotary kiln The product obtained often calcinations in rotary kiln
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Process
Process o The crushed raw materials are fed in to a ball mill and a little water is added o The steel balls in the ball mill pulverized the raw material which form a slurry with water o The slurry is passed through storage tanks where the proportioning of compound is adjusted to ensure desired chemical composition
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
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3) Define batching, what are all the methods of batching? The measurement of materials for making concrete is known as batching. Methods of batching Volume batching Weigh batching 4) What are all the raw materials of the cement? Lime Silica Alumina Calcium sulphate Iron oxide Magnesium oxide Sulphar ti oxide alkalis
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5) Write notes on steam curing.
This approach is widely used in precast concrete units.here the precast units are kept under warm and damp atmosphere of a steam chamber.
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6) Define non destructive testing. Non destructive testing is done on haredend concrete in non destructive testing methods soe properties of concrete are used to estimate strength durability ,elastic parameters,crack depth micro cracks and progressive deteriotion of concrete.
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7) What are all the types of concrete test? Slump test compressive test split tensile strength
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
h h h h h[ Ty pe here] [Ty pe here ]
[Ty pe here ]
PART-B 1) Explain the manufacturing of cement with neat sketches and flow chart Raw materials used
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Calcareous Argillaceous Calcareous materials used are Cement rock Lime stone Marl Chalk Marine shell
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Argillaceous materials used are Clay shale slate blast furnace slag
Process manufacturing cement Dry process Wet process
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Dry process
Adopted when the raw materials are quite
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General
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hard The process is slow an the product is
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costly Process
Lime stone and clay are ground to fine powder separately and are mixed togetherWater is added to make a thick paste which contains 14% of moisture
The paste format are dried and off charged into a rotary kiln
The product obtained often calcinations in rotary kiln
The clinker I obtained as a result of incipient fusion and sintering at a temp about 1400◦c to1500◦ c
The clinker is cooled to preserve the meta stable compounds and there solid
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solutions Dispersion of one solid with another solid which made the clinker again P.JAGATEESH
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
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heated Clinker is again cooled and grounded in tube mills where 2-3% gypsum is added
The purpose of adding gypsum is to coat the cement particle by interfering the process of hydration of cement particles
Wet process
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The operations are
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Process
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Mixing Burning Grinding
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The crushed raw materials are fed in to a ball mill and a little water is added
The steel balls in the ball mill pulverized the raw material which form a slurry with water
The slurry is passed through storage tanks where the proportioning of compound is adjusted to ensure desired chemical composition
The corrected slurry having moisture about 40%,is then fed into rotary kiln Where it loses moisture and form on to lumps
These are finally burned at 1500◦ to 1600 ◦cIt becomes clinker at this stage, the clinker is cooled and then grounded in tube mills
While grinding the clinker 3% gypsum I added this is stored in silos and packed
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
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2) Explain briefly about the chemicals used in concrete and their advantages Water-reducing admixture / Plasticizers: These admixtures are used for following purposes:
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1. To achieve a higher strength by decreasing the water cement ratio at the same workability as an admixture free mix. 2. To achieve the same workability by decreasing the cement content so as to reduce the heat of hydration in mass concrete. 3. To increase the workability so as to ease placing in accessible locations 4. Water reduction more than 5% but less than 12% Actions involved:
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1. Dispersion:
2. Lubrication:
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Surface active agents alter the physic chemical forces at the interface. They are adsorbed on the cement particles, giving them a negative charge which leads to repulsion between the particles. Electrostatic forces are developed causing disintegration and the free water become available for workability.
As these agents are organic by nature, thus they lubricate the mix reducing the friction and increasing the workability.
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3. Retardation:
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A thin layer is formed over the cement particles protecting them from hydration and increasing the setting time. Most normal plasticizers give some retardation, 30–90 minutes Super Plasticizers:
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o The commonly used Super Plasticizers are as follows:
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o These are more recent and more effective type of water reducing admixtures also known as high range water reducer
Sulphonated melamine formaldehyde condensates (SMF) Give 16–25%+ water reduction. SMF gives little or no retardation, which makes them very effective at low temperatures or where early strength is most critical.
However, at higher temperatures, they lose workability relatively quickly. SMF generally give a good finish and are colorless, giving no staining in white concrete.
They are therefore often used where appearance is important.
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
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Sulphonated naphthalene formaldehyde condensates (SNF)
Typically give 16–25%+ water reduction. They tend to increase the entrapment of larger, unstable air bubbles. This can improve cohesion but may lead to more surface defects.
Retardation is more than with SMF but will still not normally exceed 90 minutes. SNF is a very cost-effective.
Polycarboxylate ether super plasticizers (PCE) Typically give 20–35%+ water reduction. They are relatively expensive per liter but are very powerful so a lower dose (or more dilute solution) is normally used.
In general the dosage levels are usually higher than with conventional water reducers, and the possible undesirable side effects are reduced because they do not markedly lower the surface tension of the water.
Accelerators:
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An admixture which, when added to concrete, mortar, or grout, increases the rate of hydration of hydraulic cement, shortens the time of set in concrete, or increases the rate of hardening or strength development.
Accelerating admixtures can be divided into groups based on their performance and application:
1. Set Accelerating Admixtures,
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Reduce the time for the mix to change from the plastic to the hardened state.
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Set accelerators have relatively limited use, mainly to produce an early set.
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Which increase the strength at 24 hours by at least 120% at 20ºC and at 5ºC by at least 130% at 48 hours. Hardening accelerators find use where early stripping of shuttering or very early access to pavements is required.They are often used in combination with a high range water reducer, especially in cold conditions.
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2. Hardening Accelerators,
Set Retarders:
The function of retarder is to delay or extend the setting time of cement paste in concrete. These are helpful for concrete that has to be transported to long distance, and helpful in placing the concrete at high temperatures.
When water is first added to cement there is a rapid initial hydration reaction, after which there is little formation of further hydrates for typically 2–3 hours.
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IV Year/ VII Semester
CIVIL ENGINEERING
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The exact time depends mainly on the cement type and the temperature. This is called the dormant period when the concrete is plastic and can be placed. At the end of the dormant period, the hydration rate increases and a lot of calcium silicate hydrate and calcium hydroxide is formed relatively quickly. This corresponds to the setting time of the concrete.
Retarding admixtures delay the end of the dormant period and the start of setting and hardening. This is useful when used with plasticizers to give workability retention. Used on their own, retarders allow later vibration of the concrete to prevent the formation of cold joints between layers of concrete placed with a significant delay between them.
The mechanism of set retards is based on absorption. The large admixture anions and molecules are absorbed on the surface of cement particles, which hinders further reactions between cement and water i.e. retards setting.
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Air Entrained Admixtures:
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An addition for hydraulic cement or an admixture for concrete or mortar which causes air, usually in small quantity, to be incorporated in the form of minute bubbles in the concrete or mortar during mixing, usually to increase its workability and frost resistance.
Air-entraining admixtures are surfactants that change the surface tension of the water. Traditionally, they were based on fatty acid salts or vinsol resin but these have largely been replaced by synthetic surfactants or blends of surfactants to give improved stability and void characteristics to the entrained air.
Air entrainment is used to produce a number of effects in both the plastic and the hardened concrete. These include:
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Resistance to freeze–thaw action in the hardened concrete.
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Increased cohesion, reducing the tendency to bleed and segregation in the plastic concrete.
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Compaction of low workability mixes including semi-dry concrete.
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Stability of extruded concrete.
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
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3) Explain the procedure of compression test on concrete
The compression test shows the compressive strength of hardened concrete.
The compression test shows the best possible strength concrete can reach in perfect conditions. The compression test measures concrete strength in the hardened state. Testing should always be done carefully. Wrong test results can be costly.The testing is done in a laboratory off-site. The only work done on-site is to make a concrete cylinder for the
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compression test.
The strength is measured in Megapascals (MPa) and is commonly specified as a characteristic strength of concrete measured at 28 days after mixing.
The compressive strength is a measure of the concrete’s ability to resist loads which tend to crush it.
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Apparatus for compression test
Small scoop Bullet-nosed rod (600 mm x 16 mm) Steel float Steel plate
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1. 2. 3. 4.
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Cylinders (100 mm diameter x 200 mm high or 150 mm diameter x 300 mm high) (The small cylinders are normally used for most testing due to their lighter weight)
Procedure for compression test of concrete
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Clean the cylinder mould and coat the inside lightly with form oil, then place on a clean, level and firm surface, ie the steel plate. Collect a sample.
Fill 1/2 the volume of the mould with concrete then compact by rodding 25 times. Cylinders may also be compacted by vibrating using a vibrating table.
Fill the cone to overflowing and rod 25 times into the top of the first layer, then top up the mould till overflowing.
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Level off the top with the steel float and clean any concrete from around the mould.
Cap, clearly tag the cylinder and put it in a cool dry place to set for at least 24 hours.
After the mould is removed the cylinder is sent to the laboratory where it is cured and crushed to test compressive strength
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
UNIT-II CONSTRUCTION PRACTICES PART A
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1. What are the general specifications for first class building? Foundation and plinth. superstructure. damp-proof course. lintels. roofing. plastering. doors and windows. distempering and colour wasting. painting.
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2. What are monolithic wall? write its classifications? Monolithic walls:-Walls built of a material requiring some kind of shuttering in the initial stages. Masonry can be classified into the following types stone masonry. brick masonry. hollow block concrete masonry. reinforced masonry. composite masonry.
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3. Define plinth. Plinth:- It is the horizontal course of stone or brick provided at the base of the wall above ground level. It indicates the height of the ground floor level above the natural ground level. It protects the building from dampness.
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4. What are classifications of stone masonry There are two types ,they are rubber masonry. ashlar masonry.
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5. What is rubber masonry and ashlar masonry? Rubber masonry:Stones of irregular sizes are used. stones may be undressed or roughly dressed. using hammer having wider joints. Ashlar masonry:This is a costlier, high grade and superior quality of masonry. The work built from accurately dressed stones with uniform and very fine joints of about 3mm. thickness is termed as ashlar masonry.
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IV Year/ VII Semester
CIVIL ENGINEERING
6. Compare English bond and Double Flemish bond. English bond double Flemish bond. More compact and stronger for walls Less compact and stronger. having thickness more than 1(1/2) bricks. Better appearance in the facing. Not pleasing appearance of the facing. Good workmanship and careful No strict supervision and skill required supervision is required. for its construction. Cheaper in cost-because number of More in cost than Double Flemish bricks bats are used. bond.
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7. What are the defects in brick masonry. Defects in brick masonry:Sulphate attack. Crystallization of salts from bricks. Corrosion of embedded iron or steel. Shrinkage on drying.
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8. Mention the common sizes of building blocks. The common sizes of building blocks are 390x190x300 mm- standard size hollow block. 390x190x200 mm- hollow building tiles. 390x190x100 mm- hollow concrete blocks for partition.
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9. What the types of flooring commonly used. mud flooring muram flooring cement concrete flooring mosaic flooring tiled flooring marble flooring
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10. Define damp proof course., what are its causes of dampness. Definition :-The courses which are laid to check the entry of water or moisture into the building are called damp proof courses. Causes:faulty design of structure faulty construction or poor workmanship use of poor quality materials in construction. 11. Define roofs. Roof:-A roof is defined as the uppermost part of the building which is constructed in the form of a frame work to give protection to the building against rain , heat wind etc..
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12. What are the uses of water proofing compounds. Uses:- When water proofing compounds is added to cement during construction it prevents leakage. It is available in powder form. It is mixed with cement by hand before cement is mixed with aggregate.
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13. what are the condition for filters. Condition for filter:It should remove harmful particles from air. It should be workable under different velocity. It should have very low frictional resistance. It should not cause contamination of incoming air. it should be easy to clean.
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14. Define fire resistance Fire Resistance:- It is the time during which an element of structure fulfils its function in building safely in the event of fire of known intensity. Fire resistance is also defined as an index of fire safety of buildings.
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15. Define acoustics Acoustics:-The term acoustics is defined as the science of sound, and it describes the origin ,propagation and sensation of sound.
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16. What are the conditions for good acoustics of an auditorium:Conditions for good acoustics of an auditorium:The initial sound should be of adequate intensity or loudness. It is important for a speaker to be heard over a long distance. The sound produced should be evenly spread over the whole area covered by audience. If the sound is not evenly distributed echoes will be established. the initial sound should be clear and distinct. For music hall ,the initial sound should reach the audience with same frequency and intensity. All undesired sound should be reduced.
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17. Define scaffolding:Scaffolding:-It is defined as the temporary structure employed in the building construction for supporting workers, materials and tools etc., during its construction alteration, demolition, painting and repair etc., 18. Write the types of scaffolding. Types of scaffolding:Single scaffolding or Brick layer scaffolding. Double scaffolding or Masons scaffolding. Ladder scaffolding. Cantilever or Needle scaffolding.
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IV Year/ VII Semester
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19. Write any some materials used for joints. bituminous felt Metal strips Fibre board these are some of the materials used for joints. 20. Define flooring Flooring:- The properly supported horizontal surfaces which divide the building into different levels for providing accommodation one above the other within space are called floors.
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
1) Explain the various types of foundation with neat sketches The foundation is he lower portion of the building, usually located below the ground level, which transmit the load of super structure to sub soil Functions of foundation Reduction of load intensity Even distribution of load
Provision of level surface
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Lateral stability
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Safety against undermining
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Shallow foundation Deep foundation Shallow foundation
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Protection against soil movements Types of foundation
If the depth of foundation is less than or equal to width of foundation it is called as shallow foundation
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Types of shallow foundation
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Spread footing
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Combined footing
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Strap footing
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Mat foundation Spread footing
Spread footing is those which spread the super imposed load to of a wall or column over the large area Spread footing support either a column or a wall It has the following types
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Single footing Stepped footing Sloped footing Wall footing with out step Stepped footing for wall Grillage foundation
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Combined footing
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A spread footing which supports two are more columnsis termed as combined footing It has the following types Rectangular combined footing
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Trapezoidal combined footing Combined column wall footing
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Trapezoidal footing
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If the independent footings of two columns are connected by a beam it is called as strap footing
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A strap footing may be used where the distance between the columns is so great that a combined trapezoidal footing becomes quite narrow
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The strap beam does not remains in contact with soil and thus does not transfer any pressure to the soil
A raft or mat is a combined footing that covers the entire beneath a structure And supports all walls and columns
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Mat foundation
It is used when the allowable soil pressure is low are the building loads are heavy It is used to reduce the settlement above highly compressible soil
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Rafts may divided into three types o Solid slab system o Beam slab system o Cellular system Deep foundation If the depth of foundation is equal to or more than the width of the foundation is called deep foundation Types Deep strip rectangular or square footing
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Pilefoundation
Pier foundation or drilled caisson foundation
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Well foundation or caissons
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Deep strip footing
Whenever the depth of strip footing is more than the width it is called as deep strip footing Pile foundation
Types of pile foundation End bearing pile
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it is a type of deep foundation in which the loads are taken to a low level by means of vertical members which may be timber or concrete or steel
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Friction pile
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Combined end bearing and friction pile
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Compaction pile
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End bearing piles
End bearing piles are used to transfer load through water or soft soil to a suitable bearing stratum Such piles are used to carry heavy loads to hard strata Multi storied buildings are invariably founded on end bearing piles, so that the settlements are minimized
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Friction piles Friction piles are used to transfer loads to a depth of a friction load carrying material by means of skin friction along the length of the pile These piles mostly used in granular soil Combined end bearing and friction pile
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These are the piles which transfer the super imposed load both through side friction as well as end bearing Such piles are more common, especially the end bearing piles are passed through granular soil
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Compaction piles
Pier foundation
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These piles are used o compact loose soil thus increasing there bearing capacity The pile tube driven to compact the soil is gradually taken out and sand is filled in its place thus forming the sand pile
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A pier foundation consist of a cylindrical column of large diameter to support transfer large super imposed loads to the firm strata below
It has two types
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Generally pier foundation is shallower in depth than the pile foundation
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Drilled caissons
Caisson foundations are used for major foundation work such as
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Well foundation or caissons are box like structures –circular or rectangular which are sunk from the surface of either land or water to the desired depth
Bridge pier and abutments in river Wharves and quay walls docks Large water front structures such as pump houses, subjected to heavy vertical and horizontal loads
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IV Year/ VII Semester
CIVIL ENGINEERING
2) Make a comparison between stone masonry and brick masonry Definition: The art of building a structure in stone with any suitable masonry is called stone masonry. Types of Stone Masonry:
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Stone masonry may be broadly classified into the following two types:
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1. Rubble Masonry 2. Ashlar Masonry
1. Rubble Masonry:
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The stone masonry in which either undressed or roughly dressed stone are laid in a suitable mortar is called rubble masonry. In this masonry the joints are not of uniform thickness.
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Rubble masonry is further sub-divided into the following three types:
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Random rubble masonry Squared rubble masonry Dry rubble masonry
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1. Random rubble masonry: The rubble masonry in which either undressed or hammer dressed stones are used is called random rubble masonry. Further random rubble masonry is also divided into the following three types:
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a. Un coursed random rubble masonry: The random rubble masonry in which stones are laid without forming courses is known as un coursed random rubble masonry. This is the roughest and cheapest type of masonry and is of varying appearance. The stones used in this masonry are of different sizes and shapes. before lying, all projecting corners of stones are slightly knocked off. Vertical joints are not plumbed, joints are filled and flushed. Large stones are used at corners and at jambs to increase their strength. Once "through stone" is used for every square meter of the face area for joining faces and backing.
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Suitability: Used for construction of walls of low height in case of ordinary buildings. b. Coursed random rubble masonry: The random rubble masonry in which stones are laid in layers of equal height is called random rubble masonry. In this masonry, the stones are laid in somewhat level courses. Headers of one coursed height are placed at certain intervals. The stones are hammer dressed. Suitability: Used for construction of residential buildings, go downs, boundary walls etc.
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Squared rubble masonry:The rubble masonry in which the face stones are squared on all joints and beds by hammer dressing or chisel dressing before their actual laying, is called squared rubble masonry
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There are two types of squared rubble masonry. c. Coursed Square rubble masonry: The square rubble masonry in which chisel dressed stones laid in courses is called coarse square rubble masonry. This is a superior variety of rubble masonry. It consists of stones, which are squared on all joints and laid in courses. The stones are to be laid in courses of equal layers. and the joints should also be uniform. Suitability: Used for construction of public buildings, hospitals, schools, markets, modern residential buildings etc and in hilly areas where good quality of stone is easily available. d. Un coursed square rubble masonry: The squared rubble in masonry which hammer dressed stones are laid without making courses is called un coursed square rubble masonry. It consists of stones which are squared on all joints and beds by hammer dressing. All the stones to be laid are of different sizes. Suitability: Used for construction of ordinary buildings in hilly areas where a good variety of stones are cheaply available.
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2. Dry rubble masonry: The rubble masonry in which stones are laid without using any mortar is called dry rubble masonry or sometimes shortly as "dry stones". It is an ordinary masonry and is recommended for constructing walls of height not more than 6m. In case the height is more, three adjacent courses are laid in squared rubble masonry mortar at 3m intervals. 2. Ashlar masonry: The stone masonry in which finely dressed stones are laid in cement or lime mortar is known as ashlars masonry. In this masonry are the courses are of uniform height, all the joints are regular, thin and have uniform thickness. This type of masonry is much costly as it requires dressing of stones.
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Suitability: This masonry is used for heavy structures, architectural buildings, high piers and abutments of bridges. Ashlars masonry is further sub divided into the following types: Ashlars fine or coarse ashlar masonry Random coarse ashlars masonry Rough tooled ashlar masonry Rock or quarry faced ashlars masonry Chamfered ashlars masonry Block in coarse masonry Ashlar facing
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Ashlar fine or coursed ashlar masonry: In this type of stone masonry stone blocks of same height in each course are used. Every stone is fine tooled on all sides. Thickness of mortar is uniform through out. It is anexpensive type of stone masonry as it requires heavy labor and wastage of material while dressing. Satisfactory bond can be obtained in this type of stone masonry. Random coursed ashlar masonry: This type of ashlar masonry consists of fine or coursed ashlar but the courses are of varying thick nesses, depending upon the character of the building Rough tooled ashlar masonry: This type of ashlar masonry the sides of the stones are rough tooled and dressed with chisels. Thickness of joints is uniform, which does not exceed 6mm. Rock or quarry faced ashlar masonry: This type of ashlar masonry is similar to rough tooled type except that there is chiseldrafted margin left rough on the face which is known as quarry faced. Chamfered ashlar masonry: It is similar to quarry faced except that the edges are beveled or chamfered to 450 for depth of 2.5 cm or more. Block-in course masonry: It is the name given to a class of ashlar masonry which occupies an intermediate place between rubble and ashlars. The stones are all squared and properly dressed. It resembles to coursed rubble masonry or rough tooled ashlar masonry.
Ashlar facing: Ashlar facing is the best type of ashlars masonry. Since this is type of masonry is very expensive, it is not commonly used throughout the whole thickness of the wall, except in works of great importance and strength. For economy the facing are built in ashlars and the rest in rubble.
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CIVIL ENGINEERING
Brick masonry This bond is weak in strength but it is economical Brick masonry is made up of brick units bonded together with mortar
Components of brick masonry
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Brick Mortar
Types of mortar
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Traditional bricks Modular bricks Traditional bricks It has not been standardize in Sze Dimensions varies from place to place
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Cement mortar Lime mortar Cement-lime mortar Lime surkhi mortar Mud mortarTypes of bricks
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x10cmx10cm Actual size is 19x9x9
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bis The nominal size of the modular brick is 20cm
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Any brick which is the same uniform size as laid down by
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Thickness varies from varies from cm to 7.5cm,widthvaries from 10to13 cm and length varies from 20to25 cmModular brick
Classes of brick First class brick Second class brick Third class brick Bonds in brick work Stretcher bond
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Header bond English bond Flemish bond Facing bond English crossing bond Brick on edge bond Dutch bond Racking bond Zigzag bond Garden wall bond
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Stretcher bond
The length of the brick its along with the face of the wall\
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This pattern is used only for those wall which have thickness of half brick Header bond
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The width of the bricks are thus along the direction of the wall This pattern is used only when the thickness of the wall is equal to one brick English bond
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It is the most commonly used methodthis bond is considered to be the strongest
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This bond consist of alternate course of stretchers and headers
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Alternative courses will show either headers or stretchers in
centrally over the joint between two stretchers in corse in below
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elevation There is nop vertical jointEvery alternative header come
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Since the number of vertical joint in the header course twice the number of vertical joints in stretcher course ,the joints in the header course are made thinner than the joints in the stretcher course Flemish bond Inthis type of course is comprised of alternative headers and stretchers Types of Flemish bond Double Flemish bond Single Flemish bond
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Double Flemish bond Every course consist of headers and stretchers placed alternatively The facing and backing of the wall in each course have the same appearance Single Flemish bond Single Flemish bond is comprised of double Flemish bond facing an English bond backing and hearting in each course Facing bond
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This bond is used where the bricks of different thickness are to be used in the facing and backing of the wall
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The nominal thickness of facing brick is 10 cm and that of backing bricks is 9 cm the header course tis provided at a vertical interval of 90 cm English cross bond
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This is he modification of English bond to improve the appearance e of the wall Brick on edge bond
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IV Year/ VII Semester
CIVIL ENGINEERING
UNIT III SUB STRUCTURE CONSTRUCTION PART A 1. What are the techniques used in Box/Pipe Jacking? Techniques used in Box/Pipe jacking requires the construction of just two pits: The Trust Reception pits Dimensions of the pits vary according to site conditions.Excavation of soil can be by manual or mechanical means depending on the type of machines used.
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2. Give the applications of Box Jacking? The applications of Box Jacking are: Underground Pipes Ducks and culverts 3. Give the advantages of Box/Pipe Jacking? The advantages of Box/Pipe Jacking are: Environmentally friendly with minimal damage to the surface. Highly accurate and cost effective. Suitable for all kinds of profiles for a wide variety of soil conditions. Traffic congestion and additional pollution will not cause. Extremely suitable for all kinds of underground utility infrastructure. 4. List the disadvantages of Box/Pipe Jacking? The disadvantages of Box/Pipe Jacking are: Limited tunnel run resulting in more required shafts (approximately every 1000 ft). Relatively straight alignment required (minimum radius of curvature approximately 400ft). Difficulty in replacing damaged pipe. 5. When is Diaphragm walls used? A diaphragm wall is basically a deep trench excavated in soil in to which reinforced concrete is placed.Diaphragm walls are used in permanent and temporary foundation walls for deep basements in earth retention schemes for highway and tunnel projects,as permanent walls for deep shafts for tunnel access,and as permanent cut-off walls through the care of earth dams. 6. Give the uses of diaphragm walls? To provide structural support for the construction of building basements with underground parking. To provide stability to landslide ,highway cuts,and deep building excavations including shafts. To provide retaining walls in areas where severe limitations may be posed by noise,vibration,geology,water table and schedule. 7. What is a tunnel?Give the advantages? A tunnel is defined as an underground passage for transport of passengers,water,sewage,minerals,gas,etc. Advantages:The society of tunnel construction is increased by the improved modern methods of construction. It is more economical than open cuts beyond certain depths.
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8. What are the factors you will consider while selection of route in tunneling? a) Geological conditions b) Right of way 9. Give the various methods of tunneling through rock . The various method of tunneling through the rocks are: Full face method Heading and bench method Cantilever car pump method Drift system Pilot tunnel method 10. Give the various methods of tunneling through soft ground. The various methods of tunneling through the soft ground are: a) Fore paling method b) Needle beam method c) Five piece set method d) Linear plates method e) Other methods • Casting methods • Square sets and logging method • Horse cups method 11. What is cofferdam? A cofferdam is defined as a temporary structure which is constructed.So,as to remove water/soil from an area and make it possible to carry on the construction work under reasonably dry conditions. 12. What are the uses of cofferdams? To facilitate pile driving operations. To place grillage and raft foundations. To construct foundations for piers and abutments of bridges,dams,locks,etc, 13. What are the factors you will consider while selecting cofferdams? The factors considered while selecting cofferdams are: The area to be protected by a cofferdam. The depth of coater to be dealt with i.e, shallow depth of deep depth. The possibility of overtopping by floods,tides,etc. The nature of bed on which the cofferdam is to test,(i.e;) previous layer or an impervious layer. 14. What are the types of cofferdams? The types of cofferdams are: Dikes Single wall construction Double wall construction Cellular cofferdam Rock-filled Concrete cofferdam Suspended cofferdam 15. Give the different types of piling? Rotary board technique Continuous flight Augur piling Low head room continuous Augur pile
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16. What is grouting?
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Grouting is an engineering and art combined to fill up the voids or cavities in rock or soil masses with fluid that will increase the overall strength and impermeability of the mass. 17. Give the types of grouting. Chemical Cement Jet grouting 18. Give the characteristics of grouting materials. The characteristics of grouting materials are: The grouting material has high permeability. No vibrations are used. Application requires no additional structure used. The properties are measurable. It has high strength and low deformability. 19. What is caisson ? The word caisson is derived from the French word ‘caisse’ meaning a box. In civil Engineering, a caisson is defined as a structure which is sunk through ground or water. They exclude water and semi fluid material during the process of excavations of foundations and which subsequently becomes an integral part of the substructure.
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20. Give the uses of caissons. The uses of caissons are: To reach the hard bearing structure for transferring the load coming on support for bridge piers and building columns. To serve as an impervious core wall of earth dams.When placed adjacent to each other. To provide an access to a deep shaft or a tunnel. 21. What is the difference between cofferdams and caissons? The difference between cofferdams and caissons are: The main difference between a cofferdam and a caisson is that the former is a temporary structure while the latter forms the part of the permanent work. A cofferdam becomes uneconomical in cases where the place of the foundation work and small as compared to the depth of water under such circumstances ,caissons are most suitable. The places at which cofferdam cannot be dewatered successfully,caissons are used. 22. What are the materials used for the construction of caissons? Cast iron Reinforced Cement concrete Steel Timber
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23. Give the classification of caissons?
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24. What are the uses of sheet pile? The uses of sheet pile are: To protect river banks. To retain the sides of foundation trenches. To resist flow of underground or loose soil or of both. To resist bending abrasion or other stresses which may arise in use. 25. Give the different types of sheet piles? The types of sheet piles are: Concrete sheet pile Steel sheet pile Timber sheet pile 26. What is shoring?Why is it provided? Shoring is the construction of a temporary structure to support temporarily an unsafe structure. 27. Why is shoring provided in foundation? When a wall cracks due to unequal settlement of foundation and the cracked wall needs repair.So,shoring is provided in foundation. 28. Give the types of shoring in foundation. Types of shoring foundation are: Sheet piling Stay Bracings Box sheeting Vertical sheeting
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29. What is dewatering? The process of removal of water from an area where the ground water table is high . 30. Give the methods of dewatering. Ditches Well point system Shallow well system Deep wall system Vacuum method (forced flow method) Electro osmosis method
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IV Year/ VII Semester
CIVIL ENGINEERING
PART-B 1) Explain under water construction of diaphragm walls with neat sketches.
Diaphragm Wall
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In structural engineering, a diaphragm is a structural system used to transfer lateral loads to shear walls or frames primarily through in-plane shear stress . These lateral loads are usually wind and earthquake loads, but other lateral loads such as lateral earth pressure or hydrostatic pressure can also be resisted by diaphragm action.
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The diaphragm of a structure often does double duty as the floor system or roof system in a building or the deck of abridge, which simultaneously supports gravity loads.
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Diaphragms are usually constructed of plywood or oriented stand board in timber construction; Metal deck or composite metal deck in steel construction; or concrete slab in concrete construction.
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Parts of a diaphragm include:
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The two primary types of diaphragm are flexible and rigid. Flexible diaphragms resist lateral forces depending on the tributary area, irrespective of the flexibility of the members that they are transferring force to. On the other hand, rigid diaphragms transfer load to frames or shear walls depending on their flexibility and their location in the structure.
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the membrane, used as a shear panel to carry in-plane shear the drag strut member, used to transfer the load to the shear walls or frames The chord, used to resist the tension and compression forces that develop in the diaphragm, since the membrane is usually incapable of handling these loads alone.
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02) Explain the various types of sheet piles. Sheet Piles It is the type of pile that is made of concrete, steel or wood The thickness of the pile is very less when compared to the length and width of the pile To prevent the entry water in construction the sheet piles are used, this is also used to separate the vertical member of the building
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The piles are inserted by some machine the depth of the piles can be increased by proper joints in successive installment
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To enclose the site or part to prevent escape of loose soil To retain the sides of trenches or excavation
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To construct retaining wall in the marine structures
To prevent seepage below the dams or hydraulic structures to construct coastal defense work
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To protect the foundation from scouring action of nearby river
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Concrete sheet piles
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Reinforced precast unit having the width of 50 to 60 cm and thickness 2to 6cm and the depth can be increased by further installment Timber sheet piles
t it is used only for temporary works ,the width of the pile varies from 225to 280 cm the thickness shall not be less than 50mm
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3) Explain the methods of piling Pile Driving This is the process of inserting the pile inside the soil It is a process by way of which a pile is forced in to the ground with out excavating the soil Pile driving an be done by two methods
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Using hammering Using pile driver Hammering
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Heavy bl0w is given by means of a hammer
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Drop hammer
The hammer is lifted by a winch and dropped down
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The hammer is connected to the rope by a hook
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Variety of hammers available to perform some of the acion Drop hammer Single acting hammer Double acting hammer Diesel hammer and Vibrating hammer
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When it is lifted up after reaching a particular height it is dropped down
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Single acting hammer
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Hammer is lifted by stream and dropped then it will fell down in the top of the pile by gravitational force Double acting hammer
It is the same as that of single acting but here both the lifting and dropping is done by steam engine
Diesel hammer The process of lifting and dropping is done by diesel engine
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Vibrators If the soil condition is loose ,then using some vibrators the pile is inserted 04) Write notes on Dewatering and stand by Plant equipment for underground open excavation. Dewatering
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Definition When water table exists at a shallow depth below ground surface, it is essential to lower the water so as to carry out construction of foundation, basement, and metro tunnels etc.This is achieved by pumping out water from multiple wells installed at the site. The process is called as dewatering.
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Types of dewatering method
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Dewatering can be done by adopting one of the following four strategies Dewatering of soil by temporary lowering of water table using wells and pumps prior excavation as depleted in figure Allowing water to reap into excavation area, collecting it in sumps and pumping it out. Before that adequate steps have to be taken to support the soil on sides of the excavated area, to prevent washing away of fines and have sufficient space for the work area.
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Instalation Technique
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Making the soil around excavated zone impermeable by technique such as grouting are freezing so that inflow of water is stop are minimized.
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Sufficient size and capacity of dewatering system is necessary to lower and maintain ground water table and to allow material to be excavated in a reasonable dry condition. Excavation slopes to be stabilized where sheeting is not required
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Dewatering system is to be operated continuously until backfill work has been completed.Then, the structure to be constructed at the excavated area has to be finished
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The complete stand by have to be available for immediate operation as may be required, to adequately maintain dewatering on continuous basis and in the event that all or any other part of the system may become inadequate or fail The water removed from the excavation to be disposed in such a manner as will not endanger portions of work under construction or completed. For dewatering purpose, well points deep well, caissons and tunnels are used.
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When construction operation have to be excited below the ground water table level. Dewatering of soil can be done by the following methods Collecting water in sumps and pumping it out. Installing well points small or deep wells and pumping out ground water Using special technique in fine grained soils such as vaccum dewatering and electro-osmosis
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Well Points To pump out the ground water small sized wells called well points are used for a more dry working area the two methods used most often for lowering water table below the excavation level are the well point method and the deep well method.
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Well Point Method : This is economical and useful for lowering the water table by 15m or less. Incase of well point method or deep well method it is based on the fact that removal of water by continuous pumping from a well causes the water table level to become depressed and result in the formation of draw down. When a series of wells are placed close to each other, the overall effect is lowering of the water table level. Well points, being smaller, are easy to install.
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Deep Well Method
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Well points, can lower the water table by only 6.7m because the pump, is located at the ground surface and connected to group of well points through a pipe, cannot lift water from greater depth. Beyond 7m, multistage well points are used.
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This method is useful for lowering the water table by more than 15m. Deep wells have
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larger diameter more depth and greater spacing.
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The pump is located at the bottom of well and hence can pump out water from greater depth. Deep wells
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become more economical if more points are required.
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IV Year/ VII Semester
CIVIL ENGINEERING
UNIT IV SUPER STRUCTURE CONSTRUCION PART A
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1.What are the uses of offshore platform? The uses of offshore platform are: Connect the offshore pipeline grid. Provide an efficient means to platform maintenance Locate compression,separation,production handling and other facilities. Conduct drilling operations during the initial development phase of an oil and natural gas property. Oil & gas exploration Navigation aid towers. Bridges and causeways Ship loading & unloading facilities. 2. What are the types of offshore platforms? The types of offshore platforms are: Converted jackup barges Fixed tower structures Tension leg platforms (TLP’s) Stationary floating SPAR’s 3. What are the classifications of bridge? Segmental bridges are in two general categories.They are: Precast bridge Cable bridge A cable stayed bridge is suspended by multiple cables.Main component of cable stayed bridge are inclined cables,towers,piers and the deck.The cable stayed deck is in compression,pulled towards the towers,and has to be stiff at all stages of construction and use.
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4. What are skyscrapers? Skyscrapers are the multistoried building.The construction of multi-storied building dependenton availability of materials,technology and the availability of services like elevators. 5. Give the uses of silos. Silos are used to store large quantities of granular bulk solids and to store the green crops and converting them into sillage. 6. What are the types of cooling tower? The types of cooling tower are : Mechanical draft cooling tower Natural draft cooling tower 7. What is Transmission Tower? Transmission tower is a steel structure constructed to transmit the signals.Generally ,it is used as towers for Television,Radio & Cell phones.
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1) Explain the types of bridge decks with sketch Bridge Decks The principal function of a bridge deck is to provide support to local vertical loads (from highway traffic, railway or pedestrians) and transmit these loads to the primary superstructure of the bridge, Figure 1(1). As a result of its function, the deck will be continuous along the bridge span and (apart from some railway bridges) continuous across the span. As a result of this continuity, it will act as a plate (isotropic or orthotropic depending on construction) to support
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Continuity ensures that whether or not it has been designed to do so, it will participate in the overall structural action of the superstructure.
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IV Year/ VII Semester
CIVIL ENGINEERING
2) What are all the types of off shore platforms?
Off shore platforms Off shore platforms are self contained platforms with adequate facilities for drilling, derrick, drilling mud electric power, pumping equipment for the offshore construction these are artificial facilities above the elevation of off shore platforms
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Off shore platforms can be classified as Fixed Off shore platforms
Bottom supported structures
Compliant platforms and floating platforms
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Construction principles of offshore platforms Selection of operational criteriaSelection of environment Environmental factors like Storming wind velocity Storming wave height Tidal conditions o Before analysis and design of foundation it is necessary to determine the soil characters of the sea shore. Capacities of the available crains will influence the operational activities of platform constructions.
The fixed platforms can be classified into Jacket or template structures Gravity structures
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IV Year/ VII Semester
CIVIL ENGINEERING
03) What are all the light weight components of tall structures? Erecting Light Weight Components On Tall Structures Besides high raise buildings the usage of steel element is also popular with construction of hospital and commercial complexes
Light weight blocks are used for patricians to reduce the dead load building
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Instead of concrete beams and columns more than 6100 tonnes of steel have been used to build the main frames
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The usage of permanent concrete form works and structural steel elements will be the main constituter for erecting light weight components on tall structures results rapid speed of constructions. Hence the erection of steel beams and columns as well as the installation of concrete form work consumes only less time
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Self drilling tapping screws are the most prevalent fasteners. Steel to steel connections can be carried out to connect struts or joist and track together Entire can be erected manually with out the use of heavy equipment
All these structures require few battery powered screw gunes and some ropes and pulleys
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No scaffoldings is require for assembly and disc assembly of the structures because the structure itself provides the scaffoldings as it goes up or comes down Almost any number of column sections can be added to make it any height we desire
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During the construction of tall structures the following equipments areused for the aerial transporting and handling
Aerial cable way Helicopter
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IV Year/ VII Semester
CIVIL ENGINEERING
UNIT V CONSTRUCTION EQUIPMENT PART A
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1. On what basis you will select the equipment for the construction? Volume of the material to be removed Size of the machine used Depth of excavation Height to be lifted Soil type Duration of period Rented or purchased Production cost Spares availability Skilled operation 2. List some excavation equipment? Tractor a) Crawler or track type b) Wheel or pneumatic type Bull dozer & Angle dozers Grader Scraper a) Crawler-drawn scraper b) Two-axle scraper c) Three-axle scraper Power shovels 3. Bring out some difference between crawler and pneumatic type of wheels? Pneumatic type wheels
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1.It moves on pneumatic tyres.
2.They are slow speed.
2.They are faster in speed.
3.They are used for uneven & rough ground.
3.They operate best on smooth roads.
4.They have a speed of about 12 Km/h.
4.They have a speed of about 50 Km/h.
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1.The crawler moves on an endless chain.
4. What are the three types of scraper? Crawler-drawn scraper Two-axle scraper Three-axle scraper
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5. What is the power shovel? It is used to excavate the earth of all classes and load it into wagons.They are mounted on crawler tracks.It consist of a mountain ,cab,boon,dipper ,stric,hoist line.
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6. Name some compaction equipment? Towed static smooth compactors Static sheep foot or pad foot compactors Static three wheel self propelled compactors Static tandem compactors Three axle static compactors Rubber tyred compactors Vibrator compactors a) Tandem vibrator compactors b) Towed vibrator compactors c) Sheep foot & tamping foot vibrator compactors d) Self-propelled vibrator compactors e) Hand guided vibrator compactors 7. What are the types of conveyors? Belt conveyors Roller conveyors Chain conveyors Pipe conveyors Elevating conveyors 8. Give some advantages of belt conveyor? Its suitable levels eliminate a good deal of lifting and lowering of material. It require no stopping or standing but is continuous operation. Transportation is affected by friction between material being transported and the belt. It largely saves labor cost. No noise Carry the material horizontal,vertical,inclined. It can withstand 1600 C. 9. How do you calculate the output of the scraper? Size & Mechanical condition of the scraper Hauling device Condition of the haul road Characteristics of soil & work area Efficiency Output of scraper in bank volume/hr =Optimum loose volume loaded/trip x S x 60/t x efficiency o Where ,S= Swell factor T =cycle time/trip in miniutes.
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IV Year/ VII Semester
CIVIL ENGINEERING
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10. What are the uses of excavators? It have various earthmoving jobs,like laying pipes,removing trees,excavation of drains,general earth moving jobs of cleaning area,loading,etc,It is also used for excavation of houses & building foundation,trenches for irrigation,sewage,cables,gas & oil pipe lines.Maintenance & cleaning of rivers,cannals,irrigation.It is also used for loading of material like earth,coal,aggregate,etc. 11. What are the types of excavators? Crawler mounted excavators Truck mounted excavators Self propelled excavators Excavators mounted on barge or rail Hydraulic excavators Excavators loader Bucket wheel excavators 12. Give the advantages of elevating scraper? Better loading ability It is self loading one in addition to self propelled capabilities. The chain rotated by power independent of the travel of the scraper. It has a variable speed It has a very good finishing ability. Pusher not required It gives uniform compaction They are capable of loading most materials except rock and boulders. 13. List the factors which will affect the output of the scraper? When working in hard ground the surface should be pre broken by a ripper or scarifier and assistance in cutting should be given by a pushing vehicle. Where possible the cutting operation should take place down hill to take full advantage of the weight of the unit. Haul roads should be kept smooth to enable the machine to obtain maximum speed. Recommended tyre pressure should be maintained. Size, distance,Road condition,soil type,Efficiency of engine. 14. What is grader?Give its uses? It is used for leveling and smoothening the earth work.Spreading and leveling the base course in the construction of roads and air fields.This blade can be rotated at 3600 and also used as ditching and trenching operation. Gravel road repairing Ditch filling or digging Level or sloped ground finishing Snow clearance Land clearance Base course of spreading and leveling
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
15. What are the types of tractors?
Crawler type Wheel type Two wheeled Four wheeled
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16.What is grad ability? The maximum slope of the tractor that can work K= 11660 x T x G _ N RxW 40 K=Gradability G=Clear reduction W=Wt. of vehicle T=Torque R=really radian N=Rolling vehicle
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17.What is the application of dozer? Road cleaning Stripping Back filling Ditching Spreading Side fills & cuts 18.What does the output of dozer depend on? The output of the dozer depends on: Size & condition of the dozer. Distance travelled by the dozer. Speed of operation. Characteristics of soil being handled. Surface on which dozer is operating, soil condition, etc Efficiency
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19.Give some importance of excavators? Excavators are basically used for soil, it is a digging machine. The hydraulic system is very productive and efficient. It is rotated at 3600 This can be fitted with various multipurpose attachments for various works like laying pipe, removing trees, excavating drain, clearing, loading, etc. 20.Give the application of trenchers? Trenchers are the equipment used for excavating trenches or ditching of variable depth. It is used to trench the water lines, pipe lines, oil line cables, drainage and sewer. These are usefull for digging canal works.
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IV Year/ VII Semester
CIVIL ENGINEERING
PART-B 1) Types of earth moving equipment Classified into following types Production equipment Equipment used for digging and moving Service equipment
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Dozers and motor girders
Tractors are machine which change the engine energy into tractive energy These are primarily used for pull or push the loads They are also used for different purposes by mounting many types of accessories
Types of tractor
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Tractors
Crawler type or track type Rubber tired or wheel type
The tractor is multi purpose machine
Light models are used for agricultural or short haulage works Heavy models are employed in earth moving works, cranes, shovels or special rigs
Wheeled types or employed in light but speedy jobs
Main constituents of tractor are engine ,clutch ,transmissonsystem,ground drive and controls
Factors should be considered while selecting a tractor dozer
Size of the dozer for given job the type expected from the track to dozer
The type and condition of haul
distance to be move
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
CIVIL ENGINEERING
Bulldozers Dozers are machine designed primarily for cutting and pushing the material over short Distance.
They consist with a front mounted blade controlled by hydraulic cylinder to vary the depth of cut and rate of leveling depending on the material and application a dozer is frame mounted unit with a blade, curved in its section, extending in front of the tractor
Bulldozer is most versatile and most important equipment on construction project
Basically its pushing unit but its widely used as multipurpose equipment and can perform large number of operations with minor changes
Scrapers
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Scrapers are the devices to scrap the ground and load it simultaneously, transport it for the required distance and dump it and then spread it for the required area
The scrapers are designed to dig,load,haul,dump and spread
The scrapers are of three types
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Towed type
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towed type conventional type self loading or elevating scrapers
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Self loading scrapers
These are twin engine scrapers It can work completely independently of all other plants
It has the following parts
Bowl Cutting edge Apron
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These are generally manufactured from 10to 25cubicmetres
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The towed type scrapers are provided with either cable or hydraulic control It can be operated in extremely adverse condition Conventional scrapers
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Construction Techniques, Equipments and Practices
Tail gate or ejector
Following or three major operations of scrapers
Loading or digging Transporting Unloading
IV Year/ VII Semester
CIVIL ENGINEERING
Selection Of Equipment Proper selection of construction equipment place a vital role in the speedy and economical completion of the construction
Following are the main points which should be considered while selection off the construction equipments
Suitable for job condition The equipment must meet the requirement of the work climate and working condition
Size of the equipment Size of the equipment it should be such that must be able to be used with other equipments If the
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equipment selected for larger size it will remain idle inmost of the time Standardization
Availability of spare parts
Multi purpose equipments the selected equipments must be capable of performing various operations
Availability of know how
The equipments selected should be satisfactorily handled by the available operators and machine
Use in future projects The economical
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It is better to have same type and size of equipment in a construction then it is easy to have spare parts, and to understand its operations Availability of equipment
aspects Reliability of the equipments Service support
Operating requirements
Past performance
Reputation of the manufacturer
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Construction Techniques, Equipments and Practices
IV Year/ VII Semester
Warranty and guaranty offered by the manufacturer
Adequacy of drive mechanism
CIVIL ENGINEERING
Excavators Excavators are basically digging machines having three major components
An under carriage to give mobility
A super structure with operators cabin mounted on either a sloe ring to traverse through 360◦or on a rigid frame
Hydraulically articulated boom or tipper arms with bucket
Types of excavators Crawler mounted excavators Truck mounted excavators Self propelled excavators Excavators mounted on barge or rail Compactors
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Compaction is the process where by material particles are constrained to pack more closely together through a reduction of air void content generally by mechanical means
pneumatic tired rollers
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sheep foot and pad foot rollers
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static smooth wheeled rollers
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Types of compactors
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vibratory rollers Static compaction equipment It has several types
towed static smooth compactors
static sheep foot or pad foot compactors
static three wheel self propelled compactors
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static tandem compactors
three axle static compactors
IV Year/ VII Semester
CIVIL ENGINEERING
Towed static smooth compactors
Smooth rolls where the first type of rolling compaction equipment usedThese where pulled by men or horses and were first used by Romans to smoothen there roads
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