Construction Texhnology & Environmental Services Flashcards
(26 cards)
Can you explain the key differences between modular construction methods and precast flat panel systems, including their advantages and disadvantages?
Modular construction involves assembling entire structures off site which are then transported to site.
Precast flat panel systems are individual elements, such as a wall, floor or roof system and are manufactured off site and assembled on site.
An advantage of modular is that it is faster overall and arrives nearly complete, however if elements of the modular unit is incorrect for installation this can be expensive to rectify.
Precast systems are quicker than traditional methods of construction, however may require specialist labour to install.
What is BIM and what levels are there?
It is a shared data model to capture and provide information on a building pre, during and post it’s construction.
The different levels are,
Level 0, basic 2D CAD drawings
Level 1, a mixture of 2D and 3D drawings and models
Level 2, 3D model where data can be exchanged and shared
Level 3, a full centralised model which can be shared
What are some types of foundation?
Traditional strip - Where typically the loadings of a building is transferred to the ground via it’s external walls
Raft foundation - a large concrete slab across the footprint of the building
Pile foundations - deep foundations where piles are driven into the ground to support heavy structures, can come as either steel tubular piles or concrete piles
Trench fill foundation - similar to strip, however the trenches are completely filled with concrete
What do you see as the most significant emerging trends in construction technology, and how do you think these will impact cost advice in the future?
The most significant emerging trends in construction at this time in my opinion is the integration of smart technologies, such as ai in construction.
Generally, I believe these elements will lead to greater cost certainty when advising clients and aid clients in being able to predict future maintenance costs etc, however I also believe that information provided by these elements should be carefully considered and checked for accuracy.
What is substructure?
All elements of work that are undertaken below the damp proof course that provides the basis for the superstructure to be constructed upon.
What is the external envelope?
The materials and components that form the external shell or enclosure of a building.
These may be load or non-load bearing.
What are the Building Regulations?
Statutory instruments that set out the minimum performance standards for the design and constructionof buildings.
Supported by the Approved Documents and other codes of practice.
What are the approved documents?
A. Structure.
B. Fire safety.
C. Site preparation and damp proofing.
D. Toxic substances.
E. Sound proofing.
F. Ventilation.
G. Hygiene.
H. Drainage and waste disposal.
I. Not in use.
J. Heating appliances.
K. Protection from falling, collision and impact.
L. Conservation of fuel and power.
M. Disabled access and facilities.
N. Glazing.
O. Not in use.
P. Electrical safety.
What are British Standards?
Publications issued by the British Standards Institution prefixed BS.
They give recommended minimum standards for materials, components, design and construction practices.
What are international standards?
Publications issued by the International Organisation for Standardisation – prefixed ISO.
They are compatible with and complement the British Standards.
What is superstructure?
All internal and external works items above the damp proof course.
This is made up of:
o External walls.
o Stairs.
o Roof.
o Structural walls.
o Suspended ceilings.
o Raised floors
What is a retained façade?
The facade of the building is retained whilst everything behind the front wall is demolished.
Allowances needs to be made for a temporary support structure and also cleaning & restoration works to the retained façade.
Retained facades are often required as a result of listed building requirements.
What are temporary works?
Temporary works do not normally appear on construction drawings but may be required depending on the construction methodology being used.
Temporary works may also be required as a result of health and safety requirements to ensure a safe method of construction for example temporary propping.
What is shoring?
Shoring is a form of temporary support given to existing buildings.
Its purpose is to provide a precaution against damage or injury due to collapse of the structure.
What are the main components of concrete?
Cement.
Aggregate (natural rock, crushed stone, gravel).
Water.
What is a borehole?
A borehole can be used for soil investigation or for geothermal heating solutions.
Boreholes are the most suitable method of soil investigation when foundations are over 3m deep.
Geothermal boreholes are permanent boreholes that use the Earth’s natural heat to raise the temperature of circulated water.
This is a closed system and can be used to heat the building above which is adopted as a sustainable technology.
What are piles?
A series of columns constructed or inserted into the ground to transmit the load of a structure to a lower level of subsoil.
They are used where no suitable foundations conditions are present near ground level or if there is a high water table.
What are the different types of piles?
Sheet piles.
o A deep trench is excavated and concrete is poured in situ.
o The piles can be used to form basement walls or act as retaining walls.
Secant piles.
o Interlocking piles (male and female, often different diameters and hardness) are bored to provide a combination of foundations and basement walls.
o They support in providing a waterproof structure and are often seen when a top down construction method is used.
Bored Piles.
o An auger is used to excavate the soil and then concrete is poured in once complete.
Pre-cast piles.
o Piles are and hammered into the ground. This is not often favoured due to the high noise levels associated with installation and the lack of flexibility in terms of depth required.
Under what conditions would you expect a raft foundation to be used
for a substructure?
A raft can be used for lightly loaded buildings on sites with poor soils.
Heavy loads to the raft have the potential to cause the raft to move sideways as a result of raft foundations not being very deep.
What is a strip foundation?
Strip foundations are formed by creating a shallow continuous excavation to support the perimeter and internal walls.
They are also referred to as strip footings and are suitable for most subsoils and a light structural design.
What are pad foundations?
Pad foundations provide a base for reinforced concrete or steel columns.
They are usually formed by making an isolated excavation in the shape of a square or rectangle.
They often have reinforcement mesh as part of the construction and spread the load to a layer of bearing soil or rock below.
What are the technical advantages of steel frames?
- Steel frames are often quicker to assemble in comparison to alternative methods.
- They are 100% recyclable and inorganic meaning they will not warp, split, crack or creep.
- They offer the highest strength to weight ratio of any building material.
- Steel frames are not vulnerable to termites or any type of fungi or organism.
- They are dimensionally stable and do not expand or contract with moisture or temperature changes.
- Due to strict manufacturing controls, consistent material quality can be obtained due to production taking place in line with strict standards.
- Steel is non-combustible so it will not contribute to the spread of a fire.
- Steel frames are lighter in comparison to concrete frames and will often benefit from a cheaper foundation solution.
What are the technical advantages of concrete frames?
- Fire protection is often provided inherently as part of the structure.
- Due to offering a slower form of construction in comparison to alternative methods, this will likely result in reduced cash flow expenditure early on in the development.
- Maintenance requirements associated with concrete frames are relatively low in comparison to alternative methods.
- Concrete frames often provide good sound and heat insulation properties in comparison to steel frame constructions.
What are the technical disadvantages of concrete frames?
- In comparison to steel frames, they are more time consuming to install.
- There may also be complications during the install resulting from colder and inclement weather conditions.
- The need for steel reinforcement can lead to issues around price fluctuations and cost uncertainty associated with steel frames.
- Concrete frames are often heavier and require larger foundations.
