BE225 CONSTRUCTION METHODS & TECHNOLOGY
s
School of the Environment
Semester 2 Examinations 2009-2010
BE225
CONSTRUCTION METHODS
& TECHNOLOGY
Instruction to Candidates.
Time allowed: TWO hours
Section A is compulsory.
Section B. Attempt TWO questions.
Section C. Attempt ONE question,
Section A is a compulsory multiple choice set of questions which should
be answered by providing crosses within the template provided at the
end of this question paper.
Candidates are to attempt FOUR QUESTIONS.
All questions carry equal marks (25%)
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
June 2010, 2 hours
Section A. Candidates are to attempt all question within this section.
Identify the most credible answer to the following questions/statements by providing
one cross for each question within the template provided at the end of this question
paper. Please carefully remove the template at the rear of this examination paper
and ensure that it is affixed to your answer paper at the end of the exam.
Soils and Foundations.
1. A uniformly distributed loaded foundation exerts pressure on the soil:-
a) evenly over the footprint of the formation upon which the foundation
sits;
b) causing greatest settlement of the soil at its centre;
c) causing greatest settlement at its perimeter;
d) causes settlement to occur outside the area of soil upon which the
foundation actually sits.
2. Non- cohesive soils derive their greatest strength when:-
a) the soil is dry;
b) the soil contains particles which are spherical in shape;
c) the soil particles are angular and slightly damp;
d) the soil is damp and contains particles which are spherical in shape.
3. The sides of an unsupported excavation in a cohesive soils can:-
a) stand unsupported for an indefinite length of time;
b) stand unsupported for a sufficient length of time if cohesion of the soil is
sufficient such that the foundation could be constructed without the
need for support;
c) remain unsupported provide that the excavation is square on plan;
d) become unstable following unfavourable weather conditions which
reduces it’s cohesive properties.
4. Testing a cohesive soil to achieve an accurate safe bearing capacity can be
achieved by;
a) in-situ testing by way of a plate bearing test;
b) deducing the amount of sand present by detecting the grains in a
sample by means of ones tongue;
c) measuring the effort required to push a pencil into the soil;
d) deducing the plasticity of a soil sample.
5. Pad foundations of a framed building will:-
a) always be at the same formation level.
b) always be the same size.
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
c) vary in level and size.
d) always be constructed of reinforced concrete.
Soils and Foundations.
6. In-situ –bored piles formed principally through a cohesive soil but founding on
a non-cohesive soil will:-
a) be lined through their entire length.
b) be lined only through the non-cohesive strata.
c) not require any lining at all.
d) not be used.
7. ‘Backstop water-bar’ is used in basement construction because:-
a) it keeps ground water and water vapour from entering the building.
b) it protects reinforcement embedded in the concrete as well as keeping
water from entering the basement at construction joints.
b) it can be simply adhered to the structure after concreting.
c) It can be hidden by internal finishes.
8. Continuous Flight Auger piles are not used:-
a) because of possible vibration damage to adjacent buildings during their
formation in the ground.
b) to construct contiguous piled walls.
c) because of the need for lining of the piles prior to the pouring of
concrete.
d) in areas where limited headroom exists.
9. A reinforced concrete basement raft is constructed with a series of
down-stand beams in order to:-
a) allow a plastic soil to be contained below the raft.
b) make the overall raft structure lighter.
c) protect the soil below the edges of the raft from freezing.
d) allow a heavy cladding system to load the perimeter of the building.
Structure.
10. Steel framed structures have advantages over in-situ concrete reinforced
structures because:-
a) off-site fabrication allows for a safer system of working on site when
erecting the fame.
b) lead-in times are less than that for in-situ concrete framed
buildings.
c) fire proofing of the structure is no more complicated than that for
reinforced concrete structures.
d) such buildings have less dead weight than reinforced concrete
buildings.
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
Structure.
11. Confined masonry is a combination of bricks or blocks and mortar which is:-
a) load bearing and laid in between concrete floors, the dead load
sufficient to ensure stability of the structure;
b) load bearing and contained within integrally cast concrete columns,
beams and floors;
c) built in between a structural concrete frame;
d) simply reinforced with steel mesh within the bed joints.
12. High rise structures obtain their rigidity by:-
a) diaphragm floors being incorporated into the structure.
b) strategically placed shear walls constructed on alternate floors.
c) continuously rising shear walls forming core(s) which provide
load transfer.
d) continuously rising shear walls forming cores connected to
diaphragm floors.
13. Shear studs are used to:-
a) prevent shear failure in concrete floors.
b) provide structural continuity between steel beams and concrete floors.
c) allow for the fixing of profile metal decking.
d) allow the use of pre-cast concrete floor slabs to be used without the
need for ‘stitching’ reinforcement across the floor beams.
14. Wind acting on the gable ends of a Portal Frame is resisted by:-
a) building its short side into the prevailing wind.
b) using universal beam sections for stanchions attached to fixed- bases.
c) using universal beam sections for stanchions attached to pinned-
bases.
d) using rigid joints between roof and column members with
horizontal bracing in the end bays of the roof structure together with
vertical bracing to transfer loads into the ground
15. Correct water/cement ratio is an important factor in the mixing of concrete
because it:-
a) provides for easier mixing;
b) ensures the best compressive strength;
c) economises on the amount of cement;
d) provides concrete with a suitable workability.
16. Concrete newly cast to form a floor slab which will receive ceramic tiles laid
upon a levelling screed will receive:-
a) a power-floated finish;
b) a trowelled finish;
c) a tamped finish;
d) an integrally cast screed.
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
Enclosure.
17. Rainscreen cladding provides protection by:-
a) preventing wind and rain penetrating the cladding system.
b) absorbing kinetic energy so allowing no wind driven rain to impinge
upon the structure.
c) allowing a reduced quantity of rain to collect behind the rain-screen in
front of an airtight barrier and to drain away.
d) soaking up water and dispensing of it during dry windy conditions.
18. Movement joints are essential when detailing the external envelope of a
masonry cladding system for high rise concrete construction because:-
a) the structure to which the bricks are attached will expand during the
lifetime of the building;
b) clay bricks will expand upon laying;
c) their location is critical since the brickwork provides additional structural
stability to the frame to which it is attached;
d) rain water cascading down the face of the building will enter
poorly located movement joints.
19. Water can penetrate curtain walling by:-
a) wind pressure;
b) surface tension;
c) gravity;
d) all of the above.
20. Dense bricks used as the external skin of a masonry cladding system for high
rise construction:-
a) prevents frost damage to the cladding during freezing temperatures.
b) provides an impervious surface through which wind driven rain cannot
pass.
c) provides additional structural stability to the frame to which it is
attached.
d) allows rainwater to cascade down the face of the building which at
times of high wind speeds is likely to enter the cavity.
21. Load- bearing pre-cast concrete cladding is often employed to:-
a) dispense with edge protection during the construction of the structure.
b) allow the structure to proceed without the reliance on the continued
supply of the pre-cast panels.
c) reduce the number of columns poured and so reduce the cranage time
for each floor cycle.
d) allow intricate facings or tooling to be applied to a quality produce
manufactured in factory conditions.
22. Wind-posts are incorporated into an enclosing masonry walling system to :-
a) decrease the effective length of a wall between supports.
b) reduce the need for vertical expansion joints.
c) provide head restraint to the masonry wall by fixing the top of the post
to the concrete soffit above
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
d) provide resistance to the masonry system as well as adding extra
propping to the perimeter of the structure.
Finishes.
23. Intumescent mastic is:-
a) a carbon based product used to reduce the passage of sound through
service holes within ceiling voids.
b) used to maintain fire integrity by filling small voids within fire
compartment walls and floors.
c) used as a baffle to reduce the passage of impact sound between metal
ducting and the structural frame of a building.
d) a thixotropic material which cures with the presence of moisture.
24. The general rule for the component parts of a three coat sand/cement render
mix is to:-
a) ensure that the cement content is the same for all three coats with its
overall hardness being greater than the substrate,
b) ensure that each successive coat contains extra cement such that each
coat becomes harder, the final coat matching the strength of the
substrate.
c) ensure that the first coat is less hard than the substrate and each
successive coat is less hard than the previous coat.
d) ensure that each coat is applied and finished with a steel trowel.
25. Expansion joints in areas of ceramic floor tiling is recommended
because:-
a) aesthetically designers require a thin joint to be formed between tiles;
b) tiles will always be laid on a concrete substrate;
c) simply, like all clay products, the tiles will shrink on drying;
d) such joints will ensure longevity since the joints will enable
differential expansion and contraction to take place between the tiles
and the substrate upon which they are placed.
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
Section B. Construction Methods – Attempt TWO questions from this section.
B1. Discuss and justify one method (not formally risk assessed) for the demolition of
an unattached 4 storey Victorian warehouse, 32 x 6m on plan, with no
basement provision.
A survey has found it to be structurally safe, comprising 2B and 1 1/2B London
Stock bricks laid in lime mortar. Large windows, supported by gauged brick
arches, add an air of grandeur to the façade. Timber floors are of double floor
construction utilising cast iron girders. The roof is of king post design, covered
with slate.
The warehouse, located on the back edge of a pavement in a residential
redevelopment area, has a single storey loading bay feeding across the
pavement to a very busy thoroughfare.
(25 marks)
B2. The layout of a construction site is seen as crucial in the provision of a safe
and healthy environment for site operatives and visitors, as well as a means of
aiding production.
Addressing the above issues, consider the criteria to be applied for the
selection and location of the following preliminary items that would be utilised
on a congested inner city high rise building site.
a) Hoardings and viewing panels.
b) Site administration temporary buildings.
c) Site welfare facilities.
d) Storage lock-up compounds and sheds.
e) Major items of plant and equipment.
(25 marks)
B3. By way of annotated sketches, describe the manner in which a pile cap,
receiving loads from a reinforced concrete column and consisting of two
750mm. diameter piles is constructed after the piles have been cast and
excavation has been completed.
(25 marks)
B4. The foundations of a two storey detached house, of modern construction are
showing signs of differential settlement. The building is currently formed at
450mm below ground level, upon a non-cohesive soil, it now requires
underpinning to a depth of 1.5m below the existing concrete strip foundation
onto a formation of sound chalk.
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
Describe, by way of clear and well annotated diagrams, two suitable methods
of stabilising the structure.
(25 marks)
Section C. Attempt one question from this section.
C1. A steel framed building, 24m square on plan completely fills an available plot.
Existing load bearing masonry buildings abut it to either side.
Discuss (with the aid of sketches) an excavation support system utilising the
dumpling method of excavation suitable for the construction of a single storey
reinforced concrete basement of 3.00 storey height.
(25 marks)
C2
(a) Explain why it is necessary for the introduction of horizontal
movement joints in brick cladding to a six storey reinforced concrete framed
building.
(15 marks)
(b) Present how and why wind-posts are incorporated into a
concrete frame to stabilise enclosing brickwork.
(10 marks)
C3
a) Detail the manner whereby a timber or metal stud partition can be improved
with respect to sound transmission.
(15 marks)
(b) Write a specification for the fixing and finishing of tapered
plasterboard affixed to a 100mm x 50mm timber stud partition.
(10 marks)
C4. Relative to a storey height of 2.5m in a commercial building detail the
following:-
a) ceramic floor tiling laid upon a concrete substrate abutting ceramic wall
tiling affixed to a lightweight concrete block wall, within an office toilet;
(9 marks)
b) wall tiling as previously described abutting a false ceiling; and,
(8 marks)
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
c) marble cladding affixed to a concrete shear wall.
(8 marks)
Construction Methods and Technology - BE225 (2009/10)
Student number:………………………..
Section A. Multiple Choice Answer Template
(Place a cross X in the appropriate box(s) which relates to a correct solution to
questions posed).
Question a) b) c) d)
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BE225 CONSTRUCTION METHODS & TECHNOLOGY
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Please affix to your answer book
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