Technical - Construction Technology & Environmental Services Flashcards
(41 cards)
What is substructure and superstructure of a building?
These are the main two components of a building.
The substructure of a building is that which site below the ground level and its purpose is to transfer the load of the superstructure through the foundations and onto the soil.
The superstructure is the structure of the building which site above the ground level and it creates the frame for the purpose of the building including floors, elevations, columns and roof.
Name some different construction methods?
Traditional / Conventional Construction
Such a Brick and Blockwork and Steel whereby fabrication, assembly and construction are done on site.
Modern Method of Construction (Off Site)
- Timber Frames
- 3D Volumetric Construction
- Precast panels
What is the RIBA Plan of Works?
The RIBA Plan of Work is a model for the design and construction phases of buildings. It was updated in 2020 since its last update in 2013.
The model separates the construction and occupation of a building into 8no. stages.
Stage 0 – Strategic Definition
Stage 1 – Preparation and Brief
Stage 2 – Concept Design
Stage 3 - Developed Design
Stage 4 – Technical Design
Stage 5 – Construction
Stage 6 – Handover and Close Out
Stage 7 – In Use
Can you describe a type of traditional construction and its benefits?
Cast in-situ concrete using formwork:
Flexible, cost-effective, easy to transport.
Can you describe a modern method of construction and its benefits?
Off-site manufacturing:
Faster construction, QA products, less waste of materials.
You mention historic construction methods, can you describe some to me?
Pre-18th Century Box and Cruck Timber Frames with Thatched Roof design
Solid masonry with shallow footings.
What are O&Ms?
This stands for Operation & Maintenance manuals.
Each building should have an O&M manual and it should contain details and plans on the as built construction, subsequent alterations and salient H&S documentation such as FRA and Asbestos Registers
How do you consider EPC in building design?
Energy efficiency of design and materials.
Insulation in cavities, LED lighting, PIR sensors, installation of solar panels, thermal performance of elements.
How would you assess the design life of building elements?
- British Standards EN 1990-1999 provides indicative design lives for structures.
- Manufacturer’s specification sheets should give details on design lives of materials.
- BCIS Life Expectancy of Building Components Guide
What factors can impact the anticipated design life of a building component?
Environmental factors e.g. rain, wind, temperature fluctuations, pollution, solar radiation
Maintenance throughout the lifespan
Intensity of use e.g. increased loadings
Kings Road, Brighton
(Filler Joist Floor)
What was the construction of the building?
The superstructure comprised a reinforced concrete frame.
Kings Road, Brighton
(Filler Joist Floor)
What is a Filler Joist (Clinker) Floor?
A filler joist floor is an early form of reinforced concrete floor slab construction used commonly between the 1880s – 1920s. Iron or Steel ‘I’ Beams were spaced 0.6-1m apart and in-filled with lightweight concrete which often including the fines left over from blast furnaces. The load was applied to the concrete and transferred the ‘I’ Beam joists. Used as it was thought to provide fire protection.
Kings Road, Brighton
(Filler Joist Floor)
What issue is known to affect Filler Joist (Clinker) Floors?
Not the structural concept but the lack of corrosion protection offered to the metal joists.
The concrete mix containing unburnt coal or coke breeze is high in sulphur. When moisture is present the sulphur through chemical process produce sulphuric acid which can attack the steal causing corrosion and expansion. Leading to failure of the floor.
Kings Road, Brighton
(Filler Joist Floor)
What is the risk of a Filler Joist Floor?
Expansive corrosion can lead to the blowing and cracking of the concrete infill and ultimate failure of floor slab construction.
Kings Road, Brighton
(Filler Joist Floor)
How would you identify Filler Joist Floor and how would you know if it was defective?
Distinctive underside of the ‘I’ beams with concrete infill between, if not plastered/ Visual inspection can identify expansive rusting of the beams and blowing and cracking of the concrete cover and infill. These cracks are usually found on the top, long cracks following the joists/beam lines.
Kings Road, Brighton
(Filler Joist Floor)
What is the risk of a Filler Joist Floor getting wet?
The reaction of moisture with the clinker concrete results in the product of sulphuric acid combustion products and unburnt coal in the clinker concrete; due to the porosity/and lack of corrosion protection of the concrete the acid has a corrosive effect on the steel joists.
Kings Road, Brighton
(Filler Joist Floor)
How would you test the condition of the concrete?
Visual inspection
Test floor loads/physical opening up
Kings Road, Brighton
(Filler Joist Floor)
What are other forms of remedial works?
Expose the steel beams, remove the rust and treat with a protective paint coating or cathodic protection.
Kings Road, Brighton
(Filler Joist Floor)
How would test if the steel is corroding?
- Physical opening up
Non-destructive (Specialist)
* Infrared thermography
* Resistivity and hygrometry
* Linear polarisation resistance (LPR)
Kings Road, Brighton
(Filler Joist Floor)
You reference resin injection within your example as a form of remedial repair, can you explain this?
Yes, I am referring to a form of specialist repair which would only be specified following the findings of a structural engineer’s report.
This is early preventative measure. The specific method is a type of vacuum injection whereby the voids from the concrete infill around the steel ‘I’ beam are injected with a resin to consolidate the clinker concrete providing encapsulation minimising the risk of future corrosion.
Gracechurch Street, London
(R22 Refrigerent)
What is a R22 Refrigerant?
It is a HCFC (Hydo-Chloro-Flouro-Carbon) type of heating/cooling gas refrigerant used in air conditioning units.
It was banned in new units in 2004 and then banned further in 2015, preventing top-up the air conditioning unit. The substance was banned as it is an ozone depleting substance.
Gracechurch Street, London
(R22 Refrigerent)
What are the options?
A conversion of the unit to use a drop in replacement such as R417A. But the engineer advised me it was not feasible to do so. Instead, replacement equipment using R410A refrigerant should be installed which is more efficient.
Beach Avenue, Barton on Sea
(Flat Roof Repair vs Replacement) Mineral Felt Roof
Describe how you would go about inspection of a flat roof?
Gather any available information about the building, including details of any previous issues and repairs on the roof. Make arrangements for access and prepare necessary RAMS. Identify the age of the roof, period of defect, when does it leak (consistently or times of heavy rainfall), does water pond, what is the use of the are directly below the roof. Carry out a visual inspection during or after rainfall.
Beach Avenue, Barton on Sea
(Flat Roof Repair vs Replacement) Mineral Felt Roof
When considering the remedial works to the flat roof, what did you consider?
The age and condition of the roof covering, the extent of the defect, the cost involved with repairs, the use of the area below the roof and any disruption associated with repairs.
