APJ Abdul Kalam Technological University, India - B. Tech. in Civil Engineering - 4th Semester CE 204 Construction Technology - Module 3

1. CONSTRUCTION
TECHNOLOGY
Module 3
Fr. Dr. Bennet Kuriakose
Department of Civil Engineering

2. Syllabus
• Building construction Preliminary
considerations for shallow and deep foundations
• Masonry Types of stone masonry – composite
walls – cavity walls and partition walls -
Construction details and features – scaffoldings
• Introduction to Cost-effective construction
principles of filler slab and rat-trap bond masonry
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3. Components of Building (Review)
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4. Components of Building (Review)
1. Masonry Construction (Unframed)
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5. Components of Building (Review)
2. Framed Construction
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6. Introduction
Preliminary Considerations for Building
Construction
1. Locality to be suitable for the purpose
2. Availability of construction materials.
3. Soil conditions
4. Existence of water bodies
5. Should not be constructed across natural runoff way
6. Avoid slopes
7. Seismicity and seismic zones
8. Minimum disturbance to nature
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7. FOUNDATIONS
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8. Introduction
• Lowest manmade part of the structure
which is in direct contact with ground and
which transmit the load to the ground is
known as foundation.
• Foundations forms part of substructure
• Soil on which foundation is resting is
called “foundation soil” – should be strong
enough to bear the load (bearing
capacity)
• Foundation is chosen based on the type
of building, load and soil conditions
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9. Preliminary Considerations
1. Location: The foundations to be carefully located so as to
get the required bearing capacity and stability for a building.
On a sloping ground, the foundations are to be located
based on careful engineering calculations.
2. Stability: The foundation should be suitable to provide
enough stability to the building under service loads, wind
loads and earthquake loads.
3. Settlement: The foundation should be capable of resisting
settlement and differential settlement. The settlement
should be within the limits (normally <20 mm)
4. Scouring: Foundation soil should not score and destabilise
the structure.
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10. Preliminary Considerations
5. Depth: should be sufficiently deep to provide stability and
resting on soil strata enough to bear the loads.
6. Estimation of Loads: Accurate estimation of loads are
essential for existing building and possible future expansion.
7. Should not affect adjacent structure: The excavation and
drilling of foundation should not affect the adjacent structure
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11. Foundation Failures…
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12. Classifications
• Foundations are selected based on the loading, building type, soil
conditions, construction methodology etc.
• Classification:
– Shallow Foundations: Depth less than equal to its width
(least dimension)
• Strip footing
• Isolated footing
• Combined footing
• Strap footing
• Rafts
• Circular Raft
• Grillage foundations
– Deep Foundations: Depth greater than its width
• Pile
• Pile-raft
• Well (Caissons)
• Hollow box 12

13. Classification
Shallow Foundations
• Depth is considerably less compared to width
• Also called as open foundations – since excavation is done
and later foundation is made – ground is open and the entire
stages of construction is open before eye
• Also called footings – acts and look like foots of buildings
• Transfers very near to soil surface
• Preferred if sufficient hard strata of soil (safe bearing
capacity / SBC of ~300 kN/m2) is available near to soil
surface (not greater than 2 m)
• If water logging is prevailing at site, difficult to excavate and
shallow foundations are not preferred.
• Not preferred on reclaimed land.
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14. Classification
1. Strip Footing (Continuous Footing)
– Normally provided for load – bearing walls and
retaining walls
– Also provided for a row of columns is isolated footing
option overlaps one another
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15. Classification
2. Isolated Footing (spread or pad footings)
– Support individual column
– Shape
• Square  column with BM same along both directions
• Rectangular  column with BM different in both directions
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16. Classification
– Variation of thickness (footing is designed to resist
bending moment, shear force and punching shear – all
the three cases, more thickness is needed near to
columns)
• Regular – Thickness is small
• Tapered – Thickness is fairly small
• Stepped – Thickness is high and tapering not possible
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17. Classification
3. Combined Footing
– Supports two or more columns
– When columns are so close and their individual footing
would overlap
• Rectangular
• Trapezoidal
• Arbitrary shape
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18. Classification
4. Strap/ Cantilever Footing
– Two isolated footing connected with a structural strap
– Strap added as a rigid beam to carry bending moment
when one or both of the footings are provided in eccentric
fashion
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19. Classification
5. Raft/ Mat Foundation
– Entire bassement floor act as foundation.
– Raft  foundation „float‟ in the sea of soil
– Provided when the area of individual footings exceed 50%
of the total floor area
– Mat foundations are provided when SBC is very low
– Reduce differential settlements
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20. Classification
7. Circular Raft
• Provided for structures circular in plan – Circular water
tank (Intze type), Chimneys, cooling towers..
• Two types – (a) Full Circular (b) Annular (Ring)
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21. Classification
8. Grillage Foundation
– Form of spread footing
– Consist of a number of layers of
beams laid at right angles to each
other – disperse load to the ground.
– Normally used under steel columns
(stanchions)
– Used when bearing capacity is very
low.
– Types:
• Steel
• Concrete precast
• TimberDepartment of Civil Engg., SJCET Palai 21

22. Classification
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23. Classification
Deep Foundations
• Posses considerably greater width
• Provided when good soil capacity is not available at shallow
depths (~ 2 m) from ground level
• Also provided when excavations are impossible because of
elevated water table
• Deep foundations transfer load to strata at considerable
depth.
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24. Classification
1. Pile Foundations
– Long load transfer member
– Used when
1. upper strata is soft and water logged
2. Excessive differential settlement (when soil has
nonuniform spread or structure has non uniform
distribution of load)
3. Construction on slopes susceptible for failure (landslide)
4. When the top soil is susceptible for erosion (bridge
foundation)
5. When the lateral loads (wind or earthquake) are very
heavy
6. Some structures are subjected to uplift (transmission
tower, wind turbine, chimneys)
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25. Classification
Classification of Pile foundations:
I. Based on Load transfer
a) Bearing Pile
b) Friction Pile
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26. Classification
II. Based on Material
a) Timber (wooden) piles – less bearing capacity, damage
during driving, low cost
b) Steel piles – rolled section (I, tube or box) or fabricated –
driven by giving torque
c) Concrete
• Precast type (driven)
• Cast in-situ (bored) – (i) Cased (ii) uncased
d) Sand Piles – boring a hole  fill sand  compact. Can
handle only less loads. Not suitable for earthquake
prone areas
e) Composite Piles  steel + concrete, timber+ steel
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27. Classification
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Timber pile Steel pile (joist) Steel pile (pipe)
Steel pile (sheet) Precast concrete pile
Bored Concrete pile

28. Classification
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Cased bored Piles
III. Based on Installation Mechanism
a) Driven
b) Bored
• Cased
• Uncased
c) Underreamed

29. Department of Civil Engg., SJCET Palai 29
Uncased bored piles
Underreamed piles

30. Classification
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IV. Based Application
a) Tension Pile (Anchor Piles) – Anchorage
to pull (tall chimneys, suspension
bridges, retaining walls etc.)
b) Batter (Racked) Piles – Placed with
inclination to horizontal
c) Fender Piles – protect water-front
structures from impact
d) Sheet Piles – retains soil

31. Classification
2. Pile- Raft Foundations
– When loads are very heavy and cannot be bared by raft
alone or pile alone
– Used normally for sky-scrapers
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32. Classification
3. Caisson Foundations
– The term „caisson‟ is derived from the French word caisse
which means box or chest.
– box like structure, round or rectangular, which is sunk
from the surface of either land or water to some desired
depth.
– Two types:
• Box type:
– It is open at the top and closed at the bottom
– used where bearing stratum is available at shallow
depth.
• Open Type (Well):
– box opened both at top and bottom
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33. Classification
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34. Classification
4. Box Raft (Buoyancy Rafts)
– When soil is very weak and water table is at near ground
level
– If the place is susceptible for flood
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35. MASONRY
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36. Taxonomy of Stone Masonry
• Based on the arrangements of stones and degree of finish,
stone masonry can be classified broadly to
(a) Rubble Masonry (b) Ashlar Masonry (c) Gabion
Rubble Masonry
• A stone masonry in which either undressed or roughly
dressed stones are laid
• The joints of mortar are not of uniform thickness
• Stones of irregular size and shape are taken in the same
form or broken approximately to required size using simple
hammer
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37. Taxonomy of Stone Masonry
• Types of Rubble Masonry:
1. Random Rubble Masonry
(undressed or hammer
dressed stones are used)
• Coursed
• Uncoursed
2. Square Rubble Masonry
(stones having straight
sides – roughly dressed)
• Coursed
• Uncoursed
37
Coursed RR Uncoursed RR
Uncoursed SRcoursed SR

38. Taxonomy of Stone Masonry
3. Polygonal rubble masonry (stones are hammer dressed
and of polygonal shape. Requires skilled labour)
4. Flint rubble masonry (Flint is a hard grey rock with pure
silica. Available as nodules. Irregularly shaped)
5. Dry rubble masonry (Stones laid without mortar)
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Polygonal R Flint RDry R

39. Taxonomy of Stone Masonry
Ashlar Masonry
• Finely dressed regular shaped stones are used.
• Costlier than rubble masonry
• Stronger compared to rubble masonry
Types of Ashlar Masonry:
1. Ashlar fine tooled masonry
2. Ashlar rough tooled
3. Ashlar chamfered
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Ashlar rough tooled
Ashlar fine tooled Ashlar chamfered

40. Taxonomy of Stone Masonry
Gabion Masonry
• Gabionne in italian means “cage”
• Used mainly as retaining walls
• Wire cages provide shear strength by “Confinement”
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41. Composite Walls (masonry)
• When the facing and backing of wall are constructed using
different types of masonry or of different materials, then the
masonry is called composite masonry.
• Provided when:
– architectural beauty is required with cost effectiveness
– If one of the faces need more strength and weathering
resistance
– Conceal inferior works
• Combinations:
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Facing Backing
1 Ashlar Rubble/ brick
2 Stone slab Concrete/brick
3 Brick Rubble
4 Brick Concrete
5 Brick Hollow blocks

42. Composite Walls (Masonry)
• For integrity (prevent peeling apart and unequal settlement) :
– Staggered pattern with through stones is followed
– Ties are sometimes provided
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43. Cavity Walls
• Cavity walls (hollow walls) consist of two separate walls
(leaves / skins) with a cavity or gap
• ~ 50 to 100 mm
• Can be load bearing or non-load bearing
• Sometimes styrofoams or any heat resisting substances are
given inside the cavity
• Advantages
– Better thermal insulation
– Sound insulation
– prevent efflorescence and dampness into the room.
– Conduits and plumbing pipes can be placed in the cavity
• Disadvantages
– Workmanship required
– Rodents usually venture into the cavity
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44. Cavity Walls
• Types:
– Full cavity walls
– Partially filled cavity walls
– Filled cavity walls – insulators are filled
• Composite Cavity walls are also common
• Weep holes are drainage holes left in the exterior wall of the
cavity wall, to provide an exit way for water in the cavity.
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45. Partition Walls
• A dividing or a screen wall constructed to enclose an area
• Generally partition walls are non-load bearing
• Height normally restricted to 2 m. If more height is required,
lintel is must.
• Constructed after the construction of load carrying structure
• Types:
1. Brick Partition: Half brick
2. CMU partions: Hollow blocks are normally used
3. Clay block partition: from terra-cotta clay . Can be solid or
hollow
4. Concrete Partition: normally single set of rebars. < 50 mm
thick. Can be precast or cast-in-situ.
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46. Partition Walls
5. Ferrocement Partition – thickness ~ 20 mm – placed in
position and joined by cement mortarr
6. Glass partition: Steel or aluminium framework is provided to
support. Type of glass provided depending on the use
7. Timber Partitions – stiffened by horizontal and vertical
members - costly
8. Market form timber partitions
• Plywood
• Particle board
• Fibreboard
8. Metal partitions: Mild steel, aluminium are common
9. Gypsum board partitions
10. AC sheet partitions – placed in position and joined by
cement mortar
11. Fibre Cement Board (Eboard) – Paper waste + cement
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47. Partition walls
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48. SCAFFOLDING
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49. Scaffolding
• Process of providing temporary framework
• Uses:
1. To provide safe working platform for labourers
2. To provide space for storage of building materials
3. To provide platform for repair and maintenance work
• Should support material load, workers weight and wind load
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50. Scaffolding – Components
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51. Scaffolding – Components
1. Standards (H) – Vertical members of the framework –
supported on ground or drums
2. Ledgers (I) – Horizontal members parallel to wall
3. Transom (B) – Horizontal members perpendicular to wall,
supported on ledgers
4. Putlogs - Horizontal members perpendicular to wall, one
side supported on ledger, other on wall
5. Braces ( C and D) – Diagonal pieces fixed to standards to
provide integrity and stability
6. Guard Rail (E and F) – provided at working level, preventing
falling off.
7. Toe Board/ Guard Board (G) – Supporting workers from
falling off
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52. Scaffolding - Types
1. Single/ Brick Layer’s/ Putlog Scaffolding
– parallel to the wall at a distance of about 1.2 m.
– Distance between the standards is about 2 - 2.5
m.
– Cost-effective compared to other scaffoldings
– Main component is putlog
– One row of standards
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53. Scaffolding - Types
2. Double / Mason’s / independent
Scaffolding
– Supported on standards alone – no
connection with wall
– Normally stabilised by rakers
– Two rows of standards (~1.2 m gap)
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54. Scaffolding - Types
3. Cantilever/ Needle Scaffolding
– Standards are not supported on ground, but on needles
which are pinned to the floors.
– Uses:
• Ground is weak to support the scaffolding
• Higher stories
• Avoid obstruction of roads or other amenities.
– Types:
• Single framed
• Double framed
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55. Scaffolding - Types
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56. Scaffolding - Types
4. Suspended Scaffolding
– A platform suspended from any floor (normally terrace)
– Used for painting, pointing or any other finishing /
maintainance work
– No obstruction to ground.
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57. Scaffolding - Types
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58. 5. Trestle Scaffolding
– Movable scaffolding attached to tripods or ladders with
wheels
– Suitable for minor repair works or finishing works inside
room.
– Limited to ~ 5 m height
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59. COST-EFFECTIVE
CONSTRUCTION
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60. Introduction
• 80 % of people are of lower income group in India
• 100 million (10 Crore) people are homless world wide (UN,
2005)
• 610,042 in USA are homeless
• There are ~2 million (20 lakhs) of homeless people in India.
• ~3000 homeless families are there in Kerala.
• Houses with affordable cost is of crucial importance.
• Cost effectiveness is achieved by:
– Usage of locally available low cost materials
– Minimising ornamental works
– Alternative construction methods
– Proper planning and implementation
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61. Introduction
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Laurie Baker

62. Introduction
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G. Shankar

63. Introduction
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64. Alternative Construction Methods
1. Gypsum Panel Technology (Rapid Wall Technology)
2. Soil – Cement Block technology
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65. Alternative Construction Methods
3. Interlocking Blocks
4. Precast Construction
5. Filler Slab Technology
6. Rat Trap Bond Masonry
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66. Filler Slab Technology
• Based on the principle than the concrete on the tension side
of the bending member is not at all necessary!!!
• it is not easy to remove, the concrete from the tension zone,
hence we try and replace (partially); that part of concrete
using light weight and low cost filler material. This method of
construction is called filler slab
• These filler materials placed do not to compromise the
structural strength, stability and durability
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67. Filler Slab Technology
• Advantages achieved:
1. Reduction in consumption of high cost concrete (~ 15 to 20 %
of cost reduction)
2. Reduction in high energy (embodied energy) cement, thereby
reducing carbon footprint
3. Waste materials can be utilised as fillers (ex: used mangalore
tiles, used bricks etc.)
4. Cost saving as the dead weight of the slab is reduced.
5. More earthquake resistant as the seismic mass is reduced.
6. Thermal efficiency (improved thermal comfort in rooms) due
to internal cavity
7. Better aesthetics without finish
• Materials commonly used: Mangalore tiles, special filler tiles,
burnt clay bricks, hollow concrete blocks, clay pots, coconut
shells
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68. Filler Slab Technology
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Burnt Clay Bricks Burnt Clay Bricks Filler Tiles
Clay Pots Mangalore Tiles Coconut Shells

69. Filler Slab Technology
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70. Filler Slab Technology
• Filler material should be soaked in water before use
• Filler should not misplace during the compaction process
• Filler material shall be light weight when compared to
concrete.
• Filler material shall have less water absorption capacity (<25
% of its weight)
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71. Voided Slabs (Content beyond Syllabus)
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Bubble deck slab U-boot Technology
Hollow Core Slabs
Cobiax Slab

72. Rat-Trap Bond Masonry
• Bricks are placed in vertical position (shiner) instead of
conventional horizontal position (stretcher) within the wall
• Total wall thickness 230 mm (standard thickness)
• An internal cavity is created between the brick layers (facing
and backing)
• For 1 m3 of Rat trap bond, 470 bricks are required compared
to conventional brick wall where a total of 550 bricks are
required.
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73. Rat-Trap Bond Masonry
• Advantages achieved:
1. Cost effectiveness (25 % bricks and 30 % of mortar is
saved)
2. Strength and stability of the wall is not compromised
3. Reinforcement can be provided inside the cavity for better
seismic resistance.
4. Cavity provides sound and thermal insulation.
5. Electrical conduits or plumbing pipes can be placed
inside the wall.
6. Inherent integrity (no need of ties)
7. Rodents will not be able to venture into cavity of the wall
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Rat-Trap Brick Lay Schematic

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