construction and - aitsolutions.ait.ac.th/wp-content/uploads/2016/08/aits... · 2016-08-24 · 3...

Workshop on

Earthquake Resilient Construction for School Buildings

Chandani Chandra Neupane

Post-earthquake School Reconstruction Project

Construction and Construction Safety

Day-2Session 3

2

Construction

Construction is the process of constructing a building or infrastructure.

Construction Material

Quality Control (Material, Construction)

Construction Practices

Construction Site Safety

https://en.wikipedia.org/wiki/Process_(disambiguation)

https://en.wikipedia.org/wiki/Building

https://en.wikipedia.org/wiki/Infrastructure

3

Construction Materials• Affect the seismic performance of a building.

• Suitability of construction materials depends on

characteristics of the materials themselves

their combination with other materials

• If the materials perform well both in compression and in tension, it is helpful

to resists the internal forces caused by earthquake.

A building constructed of brick in cement mortar will behave much better

than brick in mud mortar, provided all other parameters remain the same.

4

Selection of Material

Construction Materials for earthquake safety

1. Highly suitable: steel, wood, RC

2. Moderately suitable: Brick, block, dressed stone masonry with good

mortar, compacted earth construction if appropriately reinforced

3. Slightly suitable: Unreinforced brick, block, stone masonry with good

mortar

4. Unsuitable: Unreinforced masonry with mud mortar, earthen walls

without reinforcement

5

Selection of Material

Brick/Stone in

mud mortar

48%

Timber

19%

Brick/Stone in

cement mortar

18%

Others

15%

BUILDING TYPOLOGY

6

Basic Materials & FinishesConstruction Material

Foundation

Brick on mud

Brick on cement

Stone on mud

Stone on cement

Concrete isolated footing

Wall

Brick on mud

Brick on cement

Stone on mud

Stone on cement

Interlocking Habitech blocks

Floor

RCC Slab

Wooden

Precast System

Openings

Timber

Aluminum

UPVC

CGI

Roof

CGI sheet on wooden joists

CGI sheet on steel truss

RCC slab

Roofing tiles on wooden joists

Roofing tiles on steel truss

Staircase

RCC

Timber

Steel

7

Sand• From rivers/quarries• Clean, free of mud &

organic materials

Gravel • From rivers/quarries• Clean, free from mud and

organic materials• Diameter 1-2 cm

Cement• Portland Cement• Not hardened• Dry• Uniform color• Not mixed with other

materials

Burnt Bricks• Completely burnt• Flat, not warping• Doesn’t break easily• Uniform size• Corners not damaged• Over-burnt, under-burnt &

deformed bricks should be avoided.

CRITERIA FOR CHOOSING APPROPRIATE CONSTRUCTION MATERIALS

8


Testing of sand

Sand for different uses:

a) fine sand for plaster construction;

b) coarse sand for mortar and concrete

construction, and

c) Excessively coarse sand

a b

c

9

Timber•Dry•Straight•No cracks•No notch•Treated against termite

Water• Clean • Clear and no smell• No oil, acid, alkali, salt, organic

materials that can affect the R.C. bars

• Potable

Concrete Block

• Best from concrete mix• No cracks• Corners not damaged

Habitech interlocking block

• Dry• Flat, not warping• Undamaged frogs• Corners not damaged• No cracks


10

Steel Bars• Uniform size• Conform with standard bars• Not rusted• Straight• Diameter in accordance with

drawings

Rubble Stone

• Size as uniform as possible• Hard, tough, compact

grained, uniform in texture

• Rough surface (not smooth)

CGI Sheet• Uniform corrugation• Not rusted• Thickness according to

drawing

Steel Bars• Uniform size• Not rusted• Straight• Diameter in accordance

with drawings


11

Quarry Stones• Easily breakable soft stones

should be avoided.• Only solid & strong quarry

stones with no obvious fractures should be used.

Boulder Stone• Round boulders don't provide

uniform binding when used in wall construction, resulting in movement of individual boulders and ultimate failure of the wall during earthquake.

• Round boulders should be avoided or broken into angular pieces.

Mud Mortar • Mud for mortar should be free from organic

materials, pebbles & other hard materials which will upset the mortar thickness.

• Dry mud should be thoroughly kneaded with water to prepare a dense paste.


12

Attributes

Fiber

Cement

Board

Gypsum

BoardPlywood/OSB CGI Sheet GFRG Panel

Shera Wall

Board

Fire Resistance <3 hours X XNon-

combustible

>3 Hrs/Non-

combustibleFire resistant

Water & Moisture

ResistanceGood X X Excellent Excellent Good

Mold & Mildew

FreeGood X X Excellent Excellent Excellent

Insect Resistant Good X X Excellent Excellent Excellent

Water Absorption ≤35% 10%34-46% (Plywood)

13-26%(OSB)X <4% ≤35%

Thermal

Conductivity0.15 w/mk

6.3-17.3

w/mk0.13 w/mk 38 w/mk

0.0918 w/mk

(Unfilled Panel)0.15 w/m.k

Density1300±50

kg/cu.m.

700

kg/cu.m.

500-650 kg/cu.m.

(pine plywood) 900

kg/cu.m. (hard

plywood)

7850

kg/cu.m.

1650-1795

kg/cu.m.

1300±50

kg/cu.m.

COMPARISION OF MATERIALS FOR WALL

13

Attributes

Fiber

Cement

Board

Gypsum

BoardPlywood/OSB CGI Sheet GFRG Panel

Shera Wall

Board

Bending Strength 7-8 MPa2.25-3.79

MPa1.2 MPa -- -- --

Compressive

Strength5-7 MPa 2.75 MPa 4.48-17.5 MPa -- 4.77 MPa --

Modulus of

elasticity

5500±50

MPa

1750-

2500

Mpa

100x103 MPa 207x103 MPa 3000-6000 MPa5500±50 Mpa

(Wet)

Nail Yes Yes Yes Yes X X

Cut/Saw-No

special toolsX Yes Yes Yes

Specific machine &

hammerX

Wallpaper over X Yes X X Yes

Sound & Heat

InsulationYes X Yes X

Good (Unfilled panel)

Excellent (concrete

filled panel)

Yes

Strong & Durable Yes X Yes Excellent Excellent Excellent

Light Weight X Yes X Yes Yes (40kg/sqm) Yes

Reusable X X X Yes X X

COMPARISION OF MATERIALS FOR WALL

14

Attributes Fiber Cement Board Gypsum Board Plywood/OSB

Fire Resistance <3 hours X X

Water & Moisture Resistance Good X X

Mold & Mildew Free Good X X

Insect Resistant Good X X

Water Absorption ≤35% 10% 34-46% (Plywood) 13-26%(OSB)

Thermal Conductivity 0.15 w/mk 6.3-17.3 w/mk 0.13 w/mk

Density 1300±50 kg/cu.m. 700 kg/cu.m.500-650 kg/cu.m. (pine plywood) 900

kg/cu.m. (hard plywood)

Bending Strength 7-8 MPa 2.25-3.79 MPa 1.2 MPa

Compressive Strength 5-7 MPa 2.75 MPa 4.48-17.5 MPa

Modulus of elasticity 5500±50 MPa 1750-2500 Mpa 100x103 MPa

Nail Yes Yes Yes

Cut/Saw-No special tools X Yes Yes

Wallpaper over X Yes X

Sound & Heat Insulation Yes X Yes

Strong & Durable Yes X Yes

Light Weight X Yes X

COMPARISION OF MATERIALS FOR FALSE CEILING

15

Attributes CGI Sheet Shera Wall Board

Fire Resistance Non-combustible Fire resistant

Water & Moisture Resistance Excellent Good

Mold & Mildew Free Excellent Excellent

Insect Resistant Excellent Excellent

Water Absorption X ≤35%

Thermal Conductivity 38 w/mk 0.15 w/m.k

Density 7850 kg/cu.m. 1300±50 kg/cu.m.

Modulus of elasticity 207x103 MPa 5500±50 Mpa (Wet)

Nail Yes X

Cut/Saw-No special tools Yes X

Wallpaper over X Yes

Sound & Heat Insulation X Yes

Environmentally 'Green' & Non-toxic X Yes

Strong & Durable Excellent Excellent

Light Weight Yes Yes

Reusable Yes X

COMPARISION OF MATERIALS FOR FALSE CEILING

16

Quality Control (Material, Construction)

Re

qu

ire

me

nts

Sa

tisf

ac

tio

n

Clie

nt/

Cu

sto

me

r

Product/service realization

Management responsibility

Measurement, analysis &

improvement

Resource management

Clie

nt/

Cu

sto

me

r

Continual Improvement of the Quality Control/Management System

InputOutput Product/

Services

17

Quality Control Concept

Quality Control

Covers all activities from

DesignDevelopm

entProduction Installation Servicing

Documentation

18

Quality Control Concept

Elements of Good Quality Control

i. Regular testing of construction materials at qualified

laboratories (at site or away)

ii. Periodic training of workmen at professional training houses

iii. On-site evaluation of the technical work

19

Quality Control

Need for Mason Training

• Key actors in every type of construction

• No awareness of earthquake resistant technology

• Unknown about reducing the earthquake risk

• Who recommend owner on materials selection & construction process

• Have greater role in building production in terms of quantity and quality

20

Quality of Material

• Material quality has to be ensured for good final quality of Construction

• Quality of material should be selected beforehand the construction is

started

• The standard practice of construction should be decided during the

planning and designing phase

• Quality depends according to construction type, structural element and

location of site

21

Use of Equipment

Manual Mixing of ConcreteMachine Mixing of Concrete at site

22

Use of Equipment

Needle VibratorCompactor

23

Service lines

1. Electricity line

2. Plumbing (Water supply and sewerage)

3. Telephone cabling

4. Gas pipe line

24


• Rapid growth of urban population: Doubling every 10-15 years

• Demanding high rate of building production.

Fig. Housing Scenario in Nepal

25


Masons

90%

Professionals

10%

Involvement in Construction

26


Key actors in Construction Practice

• Engineers or professionals

• Masons

27


• Most municipalities have a

system of building permits.

• But there is no provision in the

process to check the submitted

plans against the strength

criteria.

28

Prevailing Construction Practices in Nepal

Engineered Constructions: Buildings designed, supervised and constructed as per

standard engineered practices. Involvement of engineers and professionals throughout

the whole process of design, construction & completion.

Innovate l Integrate l Collaborate

29


Engineered Constructions

30


Engineered Constructions

Health Post constructed with Stone reinforced masonry in cement sand mortar, designed with

proper seismic bands and light weight roof, supervised by engineers.

31


Semi-engineered Constructions: Involvement of engineers and professionals only in

design stage. Masons with the contractors take the rest of the responsibility.

32


Semi-engineered Constructions

33


Semi-engineered Constructions: Poor Engineered construction

RC Building with brick masonry

34


Semi-engineered Constructions: Poor Engineered construction

RC Building with brick masonry

35


Non-engineered Constructions: No involvement of any professional at any stage.

Stone Masonry Brick Masonry

36


Residential Buildings in Hilly Region

Different types of Non-engineered Constructions in Nepal:

Stone Masonry

37



Stone Masonry

38



Stone Masonry

39

Unsafe buildings: Roots of Earthquake Risk

Main causes:

• Poverty

• Rapid population growth

• Lack of awareness, knowledge and skills for earthquake

resistant construction & earthquake risk

40

Initiatives for improving seismic performance of

new school constructions

• Efforts to build the capacity of local authorities (municipalities)

in adopting seismic provision of building codes in their building

permit process.

• Seismic intervention with community participation & with local

mason involvement to promote safe construction

41

Approaches to promote safe school construction

4 main strategies:

i. Raising awareness

ii. Improve capacity of engineering community, including

engineers, sub-engineers towards earthquake safety.

42

Approaches to promote safe school construction

iii. Improve the capacity of the main actors of the building

production process – the masons, the chief masons, and

the sub-contractors

iv. Institutionalize quality control of construction materials as

well as that of the construction processes

43

Construction Site Safety

No job is so important that it cannot be done safely

44

Construction Accidents

Fall from height56%

Trapped by collapsing or overturning

21%

Struck by moving vehicle

10%

Electricity5%

Falling object4%

Moving Machine3%

Hot or hamful substance1%

45

Safe Access On Site: Good practice

• Everyone can get to their place of work safely

• Edges from which people could fall are provided with double guard rails or other suitable edge protection

• Holes are protected with clearly marked and fixed covers to prevent falls

• Site is tidy

• Good lighting

• Fenced off from public

46

Working at Height: Good practice

• Using ladders or scaffolding with proper fixing

• Never use incomplete scaffolding.

• Make sure there are hand rails and toe boards at all edges

• Things fall on sites, wear your helmet

• Before starting work at heights check for clearance from any overhead power lines

• Always inspect a roof before you walk on it

47

Good practice

• All excavations deeper than 1.25 meters must be shored or battered.

• Make sure you know where any underground pipes and cables are before you hit them

• Remember: There is no safe ground that “will not collapse”

• Trench sides can collapse without warning

• Treat electricity with respect

48welders operate without and with welding goggles

49

Safety

Most construction sites require at least:

• Hard hat

• Safety Boots

• Safety jacket

• Safety Glasses

• Dust Mask

Wear them always for your safety

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