HKIA Exam Paper 2 Quiz 62

The thermal conductivity (k), Watts per Metre Celcius of steel, carbon is 50
(Code of Practice for Overall Thermal Transfer Value in Buildings 1995 – Table 1)

The absorptivity of optical flat black paint is 0.98 (Code of Practice for Overall Thermal Transfer Value in Buildings 1995 – Table 4)

Cement mortar cement and sand 1:3 (General for Building 2017 Edition – Section 9 – Brickwork and Blockwork – Proportion – 9.22).

Rock filling material shall consist of pieces of concrete or hard and durable rock of which the maximum size shall not be greater than three times the minimum dimension of individual pieces (General Specification for Building 2017 Edition – Section 3 – Excavation and Earthwork – Definitions – 3.01).

Design and construct formwork and falsework to withstand the worst combination of the following without causing bulging or deflection:
i. Total weight of formwork, reinforcement and wet concrete.
ii. Construction loads, including dynamic effects of placing, compacting and construction traffic.
iii. Wind loads (General Specification for Building 2017 Edition – Section 6 – Structural Concrete Work – Loadings for Design and Construction – 6.03).

The use of swinging ball, drop ball and blasting shall not be permitted for demolition work
(General Specification for Building 2017 Edition – Section 2 – Demolition, Site Clearance, and Alterations – Methods of Demolition – 2.19).

The weight of a hammer used during the final set shall not be less than 70% of the weight of the pile (General Specification for Building 2017 Edition – Section 5 – Piling Work – Minimum Spacing/Number of Piles – 5.08).

No grout vents shall be provided at an interval greater than 15 m (General for Building 2017 Edition – Section 7 – Prestressed Concrete Work – Grout Vent – 7.21).

For the purpose of simplicity in Overall Thermal Transfer Value calculations, this shading effect is taken into account as an external shading multiplier which should be accessed as follows
a. Overhang projections to windows
b. Sidefin projections to windows
c. Combination of overhang and sidefin projections (Code of Practice for Overall Thermal Transfer Value in Buildings 1995 – 7 – Calculation of Components Coefficients and Parameters of Overall Thermal Transfer Value – External Shading Multiplier(ESM) – 7.6).

Immediately after compaction, protect finished concrete against harmful effects of weather, running water and drying out. Apply the protection by either:
i. Application of a liquid curing membrane.
ii. Covering with plastic sheets/wet sacks.
iii. Flooding with water (General for Building 2017 Edition – Section 8 – Concrete for Minor and Non-Structural Work – Protection of Immediately Finished Concrete – 8.15).

Concrete shall be of quality not inferior to Grade 20 with a minimum cement content of 300 kg/m3 (General Specification for Building 2017 Edition – Section 5 – Piling Work – Percussion Cast In-situ Concrete Piles – 5.17).

Fine filling material shall be “suitable material” capable of passing through a 75 mm BS sieve (General Specification for Building 2017 Edition – Section 3 – Excavation and Earthwork – Definitions – 3.01).

Protection shall be maintained for a minimum period of 4 days (General for Building 2017 Edition – Section 8 – Concrete for Minor and Non-Structural Work – Protection of Immediately Finished Concrete – 8.15).

When precast prestressed tubular piles are proposed, the SO will order at least one pile of each serial size from each batch, to be subjected to the following destructive tests:
a. Taking Test Cores
b. Assessment of Core Strength (General Specification for Building 2017 Edition – Section 5 – Piling Work – Precast Prestressed Tubular Piles – 5.16).

The floor tile adhesive remover used in the asbestos vinyl floor removal works shall be the type of low volatile organic compound (VOC) content and shall comply with the following requirements:
– biobased
– VOC content of less than 5% (General Specification for Building 2017 Edition – Section 2 – Demolition, Site Clearance, and Alterations – Floor Tile Adhesive Remover – 2.49).

The thermal transmittance of an opaque wall or roof should be derived using the following
Thickness of building material of the wall or roof or part thereof
Thermal conductivity of the building materials
Surface film resistance of the internal surface of the wall or roof
Surface film resistance of the external surface of the wall or roof
Air space resistance (Code of Practice for Overall Thermal Transfer Value in Buildings 1995 – 7 – Calculation of Components Coefficients and Parameters of Overall Thermal Transfer Value – Thermal Transmittance of Opaque Construction (U) – 7.1)

Concrete bricks and blocks to be to BS EN 771-3 & BS EN 772-2. The mean compressive strength to be not less than 7.0 MPa. Concrete bricks to be of the same size as clay bricks (General for Building 2017 Edition – Section 9 – Brickwork and Blockwork – Concrete Bricks and Blocks – 9.06).

Water/Cement ratio shall not exceed 0.44 (General for Building 2017 Edition – Section 7 – Prestressed Concrete Work – Mix Proportions of Grout – 7.06).

Dynamic Pile Test (DPT) is a test applied to a pile by impact, using falling weight, hammer or other percussive devices (General Specification for Building 2017 Edition – Section 5 – Piling Work – Minimum Spacing/Number of Piles – 5.08).

The special filling material shall have the following characteristics:
a. The liquid limit shall not exceed 45%.
b. The plasticity index shall not exceed 20%.
c. The coefficient of uniformity shall be greater than 50.
d. The percentage passing a 63 µm BS sieve shall be less than 45% by mass (General Specification for Building 2017 Edition – Section 3 – Excavation and Earthwork – Definitions – 3.01).

Saturation coefficient cannot exceed 0.78 (General for Building 2017 Edition – Section 9 – Brickwork and Blockwork – Facing Bricks – 9.03).

Ducts for prestressing tendons shall be an approved proprietary type with permanent sheathing or extractable core. All ducts shall be:
a. Strong enough to withstand all forces acting on them during construction.
b. Impervious, to prevent penetration of laitence which might subsequently hinder the movement of the tendons.
c. Rigidly supported at 450 mm centres maximum (General for Building 2017 Edition – Section 7 – Prestressed Concrete Work – Ducts – 7.18).

For piles bearing on bedrock as defined in Clause 5.19 (iv), the minimum clear spacing between the shaft surfaces of adjacent piles or edge of bell-outs shall be 1000 mm (General Specification for Building 2017 Edition – Section 5 – Piling Work – Minimum Spacing/Number of Piles – 5.08).

The Overall Thermal Transfer Value of the external walls of a building tower or a podium, should be calculated using the following
Area of opaque wall, m2
Thermal Transmittance of opaque wall, W/m2
Absorptivity of the opaque wall
Equivalent temperature difference for wall, degree Celcius
Area of fenestration in wall m2
Shading coefficient of fenestration in wall
External shading multiplier
The solar factor for the vertical surface W/m2
Gross area of the external wall (Code of Practice for Overall Thermal Transfer Value in Buildings 1995 – 5 – Overall Thermal Transfer Value of External Walls).

Grouts shall be non-shrink, low bleeding in the plastic state and be fluid (General for Building 2017 Edition – Section 7 – Prestressed Concrete Work – Properties – 7.06).

Props shall be spaced at no more than 2 m centres in both directions and shall be adequately cross-braced (General for Building 2017 Edition – Section 6 – Structural Concrete Work – Props – 6.09).

Trial mixes shall be completed 35 days before the grout mix is used in permanent work (General for Building 2017 Edition – Section 7 – Prestressed Concrete Work – Trial Mixes of Grout – 7.08).

Release agents containing mineral oil shall not be used. These include barrier paint, polyurethane varnish, or wax (General Specification for Building 2017 Edition – Section 6 – Structural Concrete Work – Release Agents – 6.04).

Falsework is defined as any temporary structure used to support a permanent structure during erection until the permanent structure is self-supporting (General Specification for Building 2017 Edition – Section 6 – Structural Concrete Work – General – 6.01).

Where the inclination exceeds 15 degrees from the horizontal, formwork to the top surface shall be provided (General for Building 2017 Edition – Section 6 – Structural Concrete Work – Sloping Formwork – 6.10).