What is another name for a Semi-Precast Slab?
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Sub-Slab.
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What is another name for a Semi-Precast Slab?
Sub-Slab.
What test is used to assess watertightness in precast facades?
ASTM E331 - 00.
How many facade units are mentioned in relation to joints?
4 facade units.
What is the numerical value associated with the exempted GFA?
What is a wet joint in precast construction?
A monolithic joint where in-situ concrete bonds the precast element with the structure.
What is a wet joint in precast construction?
A connection method where fresh concrete is applied to join precast elements.
What is flashing in the context of building construction?
A material used to direct water away from critical areas of a structure.
What is one way to reduce weather exposure on construction sites?
By using more machines or robots to substitute workers.
What tools are commonly used for trowelling?
Trowels, floats, and sometimes power trowels.
What is Modular Construction?
A construction method that involves prefabricating building sections off-site and assembling them on-site.
What is the significance of clearly identifying the location of a panel?
It ensures proper installation and alignment in construction.
What is trowelling in construction?
A finishing technique used to smooth and level surfaces.
What was the name of the pioneering project by the HK Housing Department?
Kwai Chung Flatted Factory Redevelopment.
What is the total area of the 3-bedroom apartment mentioned?
160 square meters.
What is a significant requirement for storing precast units?
Ample storage space.
Why are joints important in facade units?
They ensure structural integrity and proper alignment of the units.
Where is the Modular Construction project located?
At HKU, Science Park.
What is the benefit of casting window frames before concreting?
It results in consistent and higher quality with a lower risk of water leakage.
What is applied to the floor slab in precast toilets to reduce water leakage?
A waterproofing layer.
What is the purpose of trial production and testing in the factory production stage?
To test aspects such as water tightness before mass production.
What is a filled joint?
A type of dry joint that is filled to create a seal.
What does a monolithic precast element typically consist of?
Two sides and a top, with a dry joint at the bottom.
What is a gasket joint?
A type of dry joint that uses a gasket to create a seal.
What strategies can be employed to maximize space utilization?
Implementing modular designs and optimizing layouts.
What system did the HK Housing Department implement in their project?
Enhanced Precast and Prefabrication System (EPPS).
What is a key functional requirement of joints in construction?
They must allow for structural, thermal, and moisture movement.
What factors need to be finalized during the factory production stage for precast panels?
Panel size (dimensional, weight factors), joint (type, location), lifting and handling method, mould manufacturing production line.
What is the primary goal of maximizing space utilization?
To make the most efficient use of available space.
Which building was the first in Hong Kong to use prefabricated toilet cubicles?
HSBC headquarters.
What is an example of symmetrical shapes mentioned?
Flat D vs E.
What should be used for lifting precast elements?
Designated hoisting hooks (lifting inserts).
What is a common failure associated with filled joints?
Poor adhesion due to dirt, grease, or oil not being removed before applying sealant.
What is the primary function of a gasket joint?
To prevent leakage and ensure a tight seal between precast elements.
What is the purpose of a lifting frame?
To provide support and stability during the lifting process.
What is a disadvantage of traditional timber formwork staircases?
They are time-consuming due to irregular shapes.
What is a characteristic of symmetrical designs in this context?
Symmetrical is NOT considered repetitive.
What is the purpose of supporting frames during transportation?
To secure the position of elements and prevent overturning.
In what applications are lightweight concrete wall panels commonly used?
In residential and commercial buildings for walls and partitions.
What is precast concrete?
Concrete elements that are cast and cured in a controlled environment before being transported to the construction site.
What are the possible modes of transportation mentioned?
By sea, road, or both.
What are vertical joints in facade units?
Connections between the side edges of adjacent facade units.
How does a smooth concrete surface contribute to environmental friendliness?
It reduces or eliminates the need for finishes like plastering, allowing for direct painting or tiling.
What is an On-Site Casting Yard?
A designated area where precast concrete elements are manufactured directly at the construction site.
What is one advantage of an indoor working environment in precast construction?
It is shielded from heat and rain, leading to consistent and higher quality.
What is the purpose of using a wet joint?
To ensure a strong bond between precast elements.
What percentage of concrete elements were precast in the Kwai Chung project?
Up to 60%.
What is prefabrication?
The manufacture of different sections or components that can be assembled later on the site to form part of a building.
Where have precast beams and columns been used?
In HK Jockey Club HQ, KCR Hunghom extension, KMB Lai Chi Kok depot, PolyU Hunghom Bay campus, etc.
Why is it difficult to change the design in precast construction?
Because the design is often frozen once committed.
What is a key strategy to maximize space utilization in transportation?
Mounting frames on lorries.
Why is space utilization important in precast construction?
It enhances efficiency and reduces waste.
How does in-situ construction compare to precast construction in terms of flexibility?
In-situ construction is more flexible, allowing for last-minute changes.
What are horizontal joints in facade units?
Connections between the top and bottom edges of adjacent facade units.
What is a Monolithic Joint?
A joint where an in-situ wall is bonded with precast facades.
What is Metazeal?
Metazeal is an air seal used as a compressive joint material.
What is the significance of the number 165 in the context of Modular Construction?
It may refer to a specific project code or identifier related to the HKU, Science Park.
When is the placement by tower crane typically done in construction?
Before the overhead slab is cast.
What is the exempted Gross Floor Area (GFA) mentioned in the sales brochure?
Greater than 1,500 sq ft.
What are dowel bars used for in construction?
They are used to transfer loads between concrete slabs.
What number is associated with the location of the panel?
How many modules are needed to form a 3-bedroom apartment?
6 modules.
What is the purpose of slots in precast concrete?
Slots allow for the alignment and connection of precast elements.
What is the purpose of air sealing in construction?
To prevent air leaks and improve energy efficiency.
What is a major concern for structural precast elements?
Integrity and continuity of structural elements like rebars.
What is the primary structural element used in the Hong Kong Convention and Exhibition Centre?
Steel Truss.
What should be done if water leakage is found during trial production?
Modify the design, such as the joints.
How does standard design affect project coordination?
It simplifies communication among stakeholders and reduces the likelihood of errors.
When is trowelling typically performed?
After the concrete has been poured and has begun to set.
In which sector have prefabricated toilet cubicles become more popular?
Public housing.
How does reducing the demand on tower cranes affect construction?
It helps in lifting reinforcement, concrete, and formwork more efficiently.
What type of unit was included in the precast elements of the project?
Volumetric (3D) bathroom-cum-kitchen unit.
What is prefabrication in construction?
The process of assembling components of a structure in a factory before transporting them to the construction site.
What conditions are typically controlled in a curing chamber?
Temperature and humidity levels.
What issues can arise from having different companies handle various trades?
Conflicts can occur due to miscommunication and lack of coordination.
What type of prefabrication is very popular?
Precast concrete.
What are the benefits of modular construction?
Faster construction times, reduced waste, and improved quality control.
What is the cap percentage for GFA exemption?
10%.
What are mounting frames used for?
They are used to support and secure precast elements during construction.
What happens in the Site Assembly Stage?
The precast elements are assembled on-site.
What happens to substandard precast products before installation?
They are discarded.
What is the shape of a baffle mentioned in the context?
U-shaped.
What is a key feature of the semi-precast external wall?
One side of the panel is already tiled.
What does the Buildings’ Dept. Practice Note APP - 151 relate to?
It relates to the GFA concession cap of 10%.
What is the primary focus of the video linked?
The content of the video is not provided, so I cannot determine the primary focus.
How can safety be improved on construction sites?
By minimizing work at height and maintaining a tidier site through better housekeeping.
What is the first consideration in the Design & Decision Stage?
Financial feasibility (GFA exemption).
What is a major limitation of precast construction regarding layout?
Lack of flexibility to change layout once the design is committed.
Where were the prefabricated toilet cubicles for the HSBC headquarters made?
Japan.
What type of construction is affected by the defective precast slabs?
Public housing.
How is the air space inside splice sleeves filled?
With cement grout.
What is the benefit of using modules in apartment construction?
Efficiency and speed in building.
Where are top reinforcement bars typically placed?
At the upper section of concrete elements.
How does a precast factory help in managing construction elements?
It operates under the same management, allowing for better planning and coordination.
Why is closer supervision and quality control necessary for precast beams and columns?
Because they affect building stability.
What does a curing chamber provide in precast construction?
A controlled environment for temperature, humidity, and pressure.
How does the demand for skilled labor impact precast construction?
It requires lower labor costs due to the wage gap between Hong Kong and China.
How do lightweight concrete wall panels contribute to energy efficiency?
They provide better insulation compared to traditional concrete.
What is the updated GFA concession for MiC effective from 1 August 2022?
10% in Joint Practice Note No. 8.
What is a characteristic of modular construction mentioned?
3D/volumetric precast.
What is an important assembly characteristic of joints?
Joints should be easily assembled.
What is a key characteristic of modular construction?
It involves creating sections of a building off-site that are then assembled on-site.
How do non-structural prefabricated external walls benefit developers?
They allow developers to build more floor area for sale.
What activities must be completed during the lead time for precast production?
Prepare drawings, sample approval, mould/formwork preparation, and arrange trial production and testing.
What is the primary function of a baffle?
To control air flow.
What is poured on top of the Semi-Precast Slab to form monolithic joints?
Top layer of concrete.
What is essential for the structural integrity of a precast balcony?
It must bond to the structure with monolithic concrete.
What type of finishes do Semi-Precast Slabs provide?
Good soffit finishes.
What additional feature is required for a precast balcony?
Additional top reinforcement.
What is a potential issue with Semi-Precast Slabs?
Possibility of cracks.
What can happen if excessive pressure is applied to a gasket joint?
It may damage the joint material.
What is a standard design?
A design that follows established guidelines and specifications for consistency and efficiency.
Why is standard design important in construction?
It ensures safety, reduces costs, and streamlines the construction process.
What is the purpose of trowelling?
To achieve a smooth and even finish on concrete surfaces.
How does the use of robots or machinery contribute to precast construction?
It ensures consistent workmanship, such as in troweling.
What is a benefit of reducing the number of separate operations in construction?
It minimizes conflicts between different trades and subcontractors.
In what context is a wet joint typically used?
In lost form construction where the formwork is not removed.
What are lightweight concrete wall panels?
Panels made from lightweight concrete, designed for construction.
What is a drained joint?
A type of multi-stage dry joint designed to allow drainage.
What makes filled joints easy to apply?
The adhesion of sealant to seal off joints.
In which construction method are gasket joints commonly used?
In precast concrete construction.
What durability characteristic is required for joints?
Joints must be durable.
What is conventional staircase formwork typically made of?
Timber.
What is the GFA concession for MiC floor area as per PNAP APP-161?
6% of MiC floor area.
What is the primary purpose of formwork in construction?
To support and shape concrete until it hardens.
How many sides do monolithic joints have?
Two sides and at the top.
What is the focus of the Movement and Transportation Stage?
Transporting precast elements to the construction site.
How are precast staircases bonded to the structure?
By dowel bars or monolithic concrete.
What are the dimensional limitations for transportation?
Max. 4.6m tall, 2.5m wide, and 24 - 44 tonnes.
What is the purpose of a neoprene baffle in a drained joint?
To divide the joint into two parts.
What precast concrete element is used for privacy in restrooms?
Toilet cubicles.
Why are drained joints important in precast construction?
They help maintain structural integrity by preventing water-related damage.
What is a structural precast element that supports loads in buildings?
Beams.
Where is the filled joint located?
Between the facades of upper and lower floors.
What is a key advantage of on-site production?
Lower transportation cost.
What is involved in the site assembly stage regarding facade units?
Full-scale facade units are fitted on site.
What is a disadvantage of on-site production?
Higher labor cost.
What can be affected by improper construction sequencing?
Project timelines, costs, and safety.
What is a limitation of off-site production?
Weight and dimensional limits imposed by road traffic.
What is a Double Wall/Slab in Modular Integrated Construction (MiC)?
A structural element that consists of two parallel walls with an insulating layer in between.
How are rooms typically designed in hotel development?
Identical rooms.
What is the primary benefit of using Double Wall/Slab in MiC?
Enhanced thermal insulation and structural integrity.
Why is the precast balcony considered a green feature?
It is promoted by the government.
What is one benefit of using hollow units in construction?
Hollow units save materials.
How do external finishes like tiles improve safety during construction?
They are fixed at ground level rather than working at height on a scaffold.
What is a key consideration for proper storage in construction?
Avoid excessive stress.
How does air sealing contribute to indoor air quality?
By reducing the infiltration of outdoor pollutants.
What type of construction method is used to create the 3-bedroom apartment?
Modular construction.
Why was precast concrete unpopular in private development before?
Due to less repetition, lower flexibility to change, and longer design time.
How does an On-Site Casting Yard impact project timelines?
It can streamline the construction process by allowing for simultaneous casting and assembly.
How should precast elements be stacked?
According to installation sequence.
What event in 2001 contributed to the popularity of prefabricated external walls?
Government encouragement of green buildings.
Why is it important to set up quality control procedures during the factory production stage?
To ensure product quality and facilitate easy identification of defects later.
Why are traditional timber formwork staircases difficult to work with?
They are congested, making it hard to place concrete.
What is a major precast concrete element used for building exteriors?
Façades.
How should joints be maintained?
They should be easily maintained.
What type of precast element is used for external walls?
Semi-Precast External Walls.
What properties should joints maintain in relation to surrounding cladding?
They should maintain thermal and sound insulation properties.
What is a common characteristic of lightweight concrete?
It contains aggregates that are lighter than traditional concrete aggregates.
What is a key benefit of quality control in precast concrete manufacturing?
Reliable quality control in the factory.
What is a semi-precast external wall?
A wall panel that has one side already tiled.
What is the purpose of fixing a window frame before concreting?
To ensure proper alignment and support for the window during the concrete setting process.
What is a drawback of heavy duty tower cranes?
They are more expensive.
What technology is used to enhance quality control in precast units?
RFID tags embedded in building products.
What financial advantage do developers gain from extra floor area?
Extra revenues cover additional costs and loss of flexibility.
What is a key difference in construction details between in-situ and precast construction?
Construction details are different for in-situ and precast construction.
What are Daido piles used for?
As foundations in public housing.
How do hollow cores in precast slabs affect their performance?
They decrease the overall weight while maintaining structural integrity.
What factors should be considered in different stages of precast construction?
Factors include site conditions, transportation logistics, and coordination between design and construction teams.
What is the purpose of the Green Building Certification Label?
To certify buildings that meet sustainable design standards.
Why is understanding design and connections important in precast construction?
It ensures structural integrity and proper load distribution among precast elements.
What is a disadvantage of wet trade construction?
It generates a lot of waste and is untidy (unsafe).
How does a dry joint perform?
Its performance is affected by workmanship and the durability of joint materials.
What are the two main types of dry joints?
Single-stage joint and multi-stage joint.
What does symmetrical mean in the context of shapes?
It refers to shapes that are balanced and proportionate on either side of a central line.
What are some benefits of using standard designs?
Improved quality control, faster project completion, and easier maintenance.
What is used to connect rebars in structural precast elements?
Splice sleeves.
What is a curing chamber?
A controlled environment used to maintain optimal conditions for curing concrete.
What is the purpose of fixing top reinforcement bars in construction?
To provide tensile strength and support to concrete structures.
What are some trades involved in constructing a toilet?
Plastering, painting, waterproofing, stonework, joiners, suspended ceiling, plumbing/drainage, electricity, and gas.
Why is ample storage space more feasible for public housing?
Because it requires a lot of space for precast units.
What is a monolithic joint?
A joint with a washed surface to expose aggregate.
What needs to be connected for prefabricated toilet cubicles to be ready for use?
Electricity, plumbing, and drainage.
What is the first stage in the factors to be considered in precast construction?
Design and Decision Stage.
What materials are typically used for gaskets in gasket joints?
Rubber, foam, or other flexible materials.
What must be clear for delivery during the movement and transportation stage?
Internal access roads.
Why are gasket joints important in precast concrete?
They help maintain structural integrity and prevent water ingress.
Why is it necessary to protect finished products in toilet cubicle construction?
Because the construction involves too many trades and workers, which increases the risk of damage.
What are the primary materials used in traditional block walls?
Concrete blocks or masonry units.
What should be avoided to ensure smooth transportation?
Disruption to traffic, particularly in terms of timing.
What is a drained joint in precast concrete construction?
A joint designed to allow water to escape, preventing water accumulation.
What is a filled joint in construction?
A joint that is filled with a material to prevent water infiltration and enhance structural integrity.
What materials can be compacted using a vibration table?
Concrete, asphalt, and other granular materials.
What is the primary purpose of a filled joint?
To prevent water infiltration and provide structural support.
Who needs to approve the precast production plans?
The architect, E&M consultant, and Buildings Department.
What materials are commonly used to fill joints?
Sealants, caulks, or other filler materials.
What is a Precast Partition Wall commonly referred to as?
Dry Wall.
What manufacturing process is used for precast piles?
Pre-tensioning in factory.
What are traditional walls made of?
Brick and block walls.
What is a semi-precast external wall?
A semi-finished concrete panel with its external face already tiled, which may eliminate scaffolding.
What does 'fixed lost form' refer to?
A type of formwork that is permanently left in place after the concrete has cured.
What is the purpose of a semi-precast external wall?
It is used as external face wall formwork (permanent formwork).
What needs to be confirmed at an early stage in construction?
Building services and finishes should be confirmed to freeze design.
What is the focus of the investigation regarding defective precast slabs?
Tracing the source and production batch.
How do hollow units affect the dead load in construction?
They reduce the dead load, leading to savings in structural components such as foundations and columns.
How can maximizing space utilization benefit construction projects?
It can lead to cost savings and improved functionality.
What is assessed after financial feasibility in the Design & Decision Stage?
Technical feasibility (structural/non-structural).
What impact does the use of machinery have on productivity?
It increases productivity, for example, using a vibration table for compaction.
What materials are commonly used for air sealing?
Foam, caulk, and weatherstripping.
What is Modular Integrated Construction (MiC)?
A construction method where free-standing integrated modules are manufactured in a prefabrication factory and then transported to site for installation.
What is a potential benefit of using wet joints?
Improved structural integrity and reduced risk of water infiltration.
What is the purpose of a vibration table in precast manufacturing?
To achieve better compaction of elements like slabs.
Why do toilet fixtures and finishes take a lot of time and labor?
Because they involve a lot of trades and works such as plumbing and drainage (P&D), gas supply, electricity, plastering, tiling, screeding, marble fixing, and painting.
What are filled joints vulnerable to?
Movement and weather attack.
What factors are considered in designing a tailor-made lifting beam?
Load capacity, dimensions, and specific project requirements.
What labor issue does precast construction help to avoid?
It helps avoid labor shortages affecting progress.
What is a traditional block wall?
A wall constructed using concrete blocks or masonry units.
Can prefabrication occur on-site or off-site?
Yes, it can occur both on-site and off-site.
What is one advantage of waterproofing toilet cubicles in a factory?
It results in better quality.
What is a benefit of non-structural prefabricated external walls in private development?
They could be exempted from Plot Ratio and Site Coverage calculation.
What is the minimum lead time a contractor needs to prepare for precast production?
Approximately 4 months.
What are the characteristics of rubber gaskets?
Compressible, high elastic recovery, good resistance to weather attack, impermeable to water and moisture.
What type of structure is a precast balcony?
A cantilever structure.
What is a precast refuse chute?
A system designed for the efficient disposal of waste in buildings.
What is a common issue with joints in precast units?
Cracks can easily develop at joints due to building movement.
What is the primary function of a precast refuse chute?
To facilitate the vertical transport of waste to a collection point.
What is a key difference in the usage of precast construction between public and private sectors?
Public projects often focus on large-scale infrastructure, while private projects may prioritize aesthetic and design flexibility.
How does a precast refuse chute benefit building design?
It optimizes space and improves waste management efficiency.
What are the advantages of using precast staircases?
They offer faster installation, consistent quality, and reduced on-site labor.
What material is typically used for precast refuse chutes?
Concrete.
What benefit does flexible layout design provide in semi-precast external walls?
It allows for variations in length and profile of the wall.
Why is casting precast facades horizontally beneficial?
It allows for better compaction and economy in formwork.
What are the benefits of using an On-Site Casting Yard?
Reduces transportation costs and allows for better coordination with the construction schedule.
When was the investigation into defective precast slabs conducted?
September 2016.
What is a gasket joint?
A type of joint used to create a seal between two surfaces, often in precast concrete construction.
What is a tailor-made lifting beam?
A customized lifting device designed to meet specific load requirements.
What angle is associated with the symmetrical shapes discussed?
45 degrees.
What is the first generation of infill panels?
Infill Panel.
Why are structural joints required in precast beams and columns?
To ensure continuity of rebars.
What is a key benefit of using lightweight concrete wall panels?
They reduce the overall weight of the structure.
Why are tailor-made lifting beams important?
They ensure safety and efficiency when handling precast elements.
What are some examples of prefabricated components?
Steel sections, door frames, curtain walls, plasterboard, drywall, cladding.
What are the joining methods mentioned for precast elements?
Dry joints (bolt & nut, dowel or weld) and monolithic concrete.
What is a drawback of traditional timber formwork staircases regarding durability?
They are easily damaged due to worker traffic.
In what type of market is design flexibility especially important?
In volatile markets.
What is the primary purpose of a vibration table?
To achieve compaction in concrete and other materials.
What is the significance of monolithic joints in construction?
They provide structural integrity and continuity in precast elements.
What is the significance of the number 84 in the context of conventional staircase formwork?
It may refer to a specific design or measurement standard.
What supports the Semi-Precast Slab?
Falseworks.
What type of joint is described as Z shaped?
Filled Joint.
What is a hollow precast floor slab?
A type of precast concrete element designed with hollow cores to reduce weight and material usage.
What is the purpose of offering different bedroom configurations?
To suit customers' needs.
What are the benefits of using hollow precast floor slabs?
They offer reduced weight, improved thermal insulation, and faster installation.
What type of seal is associated with the baffle?
Air seal.
How does factory production compare to site production in terms of material wastage?
Factory production reduces wastage on materials.
What is a significant consideration for site storage during the assembly stage?
Site storage occupies large areas and requires careful site layouts.
How does a filled joint contribute to the longevity of a structure?
By preventing water ingress and reducing the risk of corrosion and damage.
What is a monolithic joint?
A joint that bonds with insitu concrete, providing better structural integrity and lower risk of cracks.
What is a potential advantage of off-site production?
Cheaper labor costs in China.
What is crucial to do before the final fixing of precast units?
Align and plumb the units carefully.
What are the drawbacks of using precast piles?
Vibration and noise during installation.
What feature is included in the design of dry walls for electrical work?
Electrical conduits are already cast in and connected to protruded conduits from the slab.
In what type of construction is the Double Wall/Slab commonly used?
In Modular Integrated Construction (MiC) for residential and commercial buildings.
What is a key consideration when setting up an On-Site Casting Yard?
The availability of space and access to necessary materials and equipment.
Where is the Hong Kong Convention and Exhibition Centre located?
Hong Kong.
Why are vertical elements cast horizontally in precast construction?
It allows for better compaction.
What factors influence the speed of construction in the factory production stage?
Delivery schedule, production rate, number of moulds, size of workforce, and quantity of concrete.
Why is a curing chamber important in precast concrete manufacturing?
It ensures proper hydration and strength development of the concrete.
Why is proper installation of flashing important?
To prevent water damage and ensure the longevity of the building.
What significant policy introduced the idea of MiC?
The Chief Executive’s 2018 Policy Address.
How does weather impact precast construction progress?
Progress is not affected by weather.
What are monolithic joints?
Joints that are formed as a single continuous unit, typically on two sides and at the top.
How can filled joints be applied to avoid weathering?
Applied flush or set-back.
How does the placement of top reinforcement bars affect concrete performance?
It enhances the load-bearing capacity and durability of the structure.
Under what conditions do filled joints fail?
Under excessive compression or elongation.
Which PNAP sets out the requirements for MiC?
PNAP ADV-36 (2017).
What is the working mechanism of a gasket joint?
Pressure exerted on the gaskets to provide a weathertight seal.
Why is site storage important for mounting frames?
Proper site storage ensures that mounting frames are protected and organized for efficient use during construction.
What can happen if a window frame is not fixed properly before concreting?
It may lead to misalignment, structural issues, or difficulties in window installation.
What is a wet joint in precast construction?
A connection method where fresh concrete is applied to join precast elements.
What features are included in the GFA exemption?
Precast facade, utility platform, clubhouse facilities, etc.
How can the waterproof performance of a drained joint be enhanced?
By adding additional compressive joint material.
Why is early decision-making important for developers?
To address the differences in construction details and ensure smooth coordination.
What can result from an error in joint design or construction?
Water leakage, which can affect structural integrity and building stability.
Why is the contractor typically absent during the design stage?
The contractor cannot advise on buildability during this stage.
What is lost form construction?
A method where forms are not removed after the concrete sets, often using wet joints.
What is a key consideration when designing hollow precast floor slabs?
Ensuring adequate load-bearing capacity and structural stability.
What does RFID stand for?
Radio Frequency Identification.
What can replace timber formwork in construction?
Precast concrete elements can replace timber formwork.
How does a production line in precast construction ensure smooth operation?
It is not affected by weather or delays of a particular trade.
What must be guaranteed to maintain steady operation in precast construction?
A steady supply of precast components/elements.
What does the uniqueness of a project in private development refer to?
Different layout from flat to flat.
What materials are commonly used in prefabricated curtain wall panels?
Materials such as glass, aluminum, and concrete are commonly used.
What is one advantage of precast construction regarding formwork?
No need to erect and strike formwork on site.
What type of housing is mentioned as an example of repetitive design?
Public housing (Harmony block).
Where is prefabrication usually done?
In the factory.
How does precast construction affect the waiting time for concrete strength development?
There is no need to wait for the concrete to develop strength.
What type of join is associated with the first generation infill panel?
Weak Join.
What material is commonly used for top reinforcement bars?
Steel.
Why do developers need design flexibility in construction?
To adapt to changes in market demands, customer tastes, affordability, and government policy.
What is a key consideration when fixing top reinforcement bars?
Ensuring proper alignment and spacing.
What type of crane is associated with powerful hoisting plants?
Heavy duty tower crane.
What is a trial drive used for in the transportation stage?
To assess limitations on road width, height, corner turns, etc.
What is the primary use of a Semi-Precast Slab?
As permanent formwork.
What public concern led to the GFA exemption cap?
Concerns about 'inflated' floor area.
What document was issued in 2009 regarding building design?
"Building Design to Foster a Quality and Sustainable Built Environment."
What types of bedroom configurations are mentioned?
1, 2, and 3 Bedroom.
What is the significance of a Bottom Dry Joint in construction?
It helps in maintaining structural integrity and preventing water ingress.
What are the advantages of precast construction?
Precast construction offers benefits such as faster construction times, improved quality control, and reduced labor costs.
What is a key benefit of using a vibration table in construction?
Improved strength and durability of the final product.
What are some disadvantages of precast construction?
Disadvantages include higher transportation costs, limited design flexibility, and potential issues with site integration.
Why is sufficient time important in precast construction?
To ensure proper coordination and approval processes are completed.
What is a precast staircase?
A staircase that is manufactured off-site and then transported to the construction site.
What is a key benefit of repetitive design in hotel development?
Economy of scale.
How does the timeline for precast construction differ in public versus private projects?
Public projects may have longer timelines due to regulatory approvals, while private projects can often move more quickly.
What is the advantage of fixing aluminum window frames before concreting in precast facades?
It provides better waterproof performance.
What is a key advantage of a production line in precast construction?
Better continuity of operation.
What is a key consideration when transporting precast staircases?
Ensuring they are properly secured to prevent damage during transit.
Why is it called 'Lost Form'?
Because the precast unit is 'lost' after concrete is cast.
What is the construction sequence for a semi-precast external wall?
Fix precast Lost Form → install reinforcement/conduits → fix internal face wall formwork → concreting to wall.
What are the benefits of using prefabricated curtain wall panels?
They offer faster installation, improved quality control, and reduced construction waste.
Where is pre-tensioning typically carried out?
In the factory, as it is more difficult on site.
What is an example of a building that used prestressed concrete?
Cambridge House in Quarry Bay, which used U-shape semi-precast pre-tension beams.
What is the significance of tracing the production batch?
To identify the source of defects in precast slabs.
Why are structural precast elements not popular in Hong Kong?
Due to concerns about quality control and the lack of GFA exemption.
What type of labor is required for the installation of precast elements?
Semi-skilled labor.
What is Joint Practice Note No. 2 related to?
It is a second package of incentives to promote green and innovative buildings.
How can products be marked for quality control in precast manufacturing?
Products can be clearly marked or equipped with RFID for easy location if a defect is found.
What occurs during the Factory Production Stage?
The precast elements are manufactured.
What is a significant issue with the skilled labor force in Hong Kong?
The aging skilled labor force.
What is a key characteristic of timber formwork?
It is reusable and can be easily shaped.
How does a vibration table aid in compaction?
By using vibrations to eliminate air pockets and ensure uniform density.
What precast element is typically used as a base layer in flooring systems?
Sub-Slabs.
What is the typical frequency range for vibration tables used in compaction?
Usually between 50 to 60 Hz.
What is a common application for traditional block walls?
Used in residential and commercial buildings for load-bearing and non-load-bearing walls.
What should be considered when storing mounting frames on-site?
Considerations include space availability, protection from weather, and accessibility for installation.
What is a filled joint in construction?
A joint that is filled with a material to enhance structural integrity and prevent water infiltration.
What does the inner part of the drained joint serve as?
An air barrier to reduce wind pressure difference (pressure equalization).
What is the purpose of filling a joint?
To improve structural performance and seal against moisture and contaminants.
Why is it important to plan construction sequences?
To ensure efficiency and safety during the construction process.
What materials are commonly used to fill joints?
Sealants, grouts, or other compatible materials.
What is a key advantage of the monolithic joint in semi-precast external walls?
It lowers the risk of water leakage and cracks.
How is a monolithic joint formed in a precast balcony?
By pouring concrete with the slab.
How should precast elements be stored?
Stacked and stored according to the installation sequence.
What type of facades are commonly used in public housing?
Monolithic joints.
What is a risk associated with off-site production?
Possibility of interrupted supply.
What structural role can semi-precast external walls serve?
They can act as structural walls.
How does RFID contribute to product traceability?
By using radio waves to automatically identify and track tags attached to objects.
What is a key benefit of using RFID in product logistics?
Improved accuracy in tracking and managing inventory.
What is the role of a Guard House in a construction site?
To provide security and control access to the site.
What are the advantages of using precast concrete piles?
They offer high strength, durability, and can be installed quickly.
What is a dry joint in precast concrete construction?
A joint that uses mechanical connectors or fasteners to connect precast elements without additional concrete or grout.
What delivery method is suggested for urban sites regarding precast units?
Just-in-time delivery.
What may need to be applied for during transportation?
Traffic permits.
What are some of the trades involved in constructing toilet cubicles?
Plumbing and drainage (P&D), gas supply, electricity, plastering, tiling, screeding, marble fixing, and painting.
How does a curing chamber affect the quality of precast elements?
It helps achieve desired strength and durability by providing consistent curing conditions.
What is a key advantage of precast staircases?
They are immediately available for transportation once fixed.
Which precast concrete element is commonly used for vertical circulation in buildings?
Staircases.
What is a Bottom Dry Joint?
A type of joint in precast concrete construction that is designed to be dry and typically located at the bottom of precast elements.
What is one advantage of using traditional block walls?
They provide good structural integrity and durability.
What is a characteristic of semi-precast staircases?
They have permanent formwork with reinforcement already fixed.
What does 'just-in-time delivery' refer to?
A strategy to improve business return by reducing in-process inventory and its associated carrying costs.
What is the function of the outer part of the drained joint?
To stop water from passing through and drain it away with the aid of flashing.
How does accurate dimensional control affect gasket joints?
It affects the pressure exerted on the gaskets.
What can happen if a drained joint is not properly designed?
Water accumulation can lead to corrosion and structural failure.
Which precast element is often used as an outdoor extension of a building?
Balcony.
What is the purpose of wall reinforcement?
To provide structural support and stability to walls.
What type of precast element is used for interior partitioning?
Dry wall.
What are concealed conduits?
Pipes or channels embedded within walls to carry utilities without being visible.
What is a benefit of good quality in precast construction?
It leads to minimum defective works and lower demand for future repairs and maintenance.
What is a key factor in determining construction sequences?
The type of materials and methods used in the project.
How do precast piles compare in cost to bored piles?
Cheaper than bored piles.
What is the role of raking struts?
To provide temporary support to structures during construction.
What was the issue with the old joint design in facades?
It led to water leakage.
What curing methods improve the quality of precast facades?
Autoclaving and steam curing.
What is the benefit of applying external finishes before installation?
It eliminates the need for scaffolding, making it cheaper and safer.
What is the significance of the Tower Crane on a construction site?
To lift and move heavy materials and equipment vertically.
What factors influence the design of precast concrete piles?
Soil conditions, load requirements, and environmental factors.
Which regulations govern road traffic during transportation?
Road Traffic (Traffic Control) Regulations and Road Traffic (Construction and Maintenance of Vehicles) Regulations.
How does precast concrete contribute to construction efficiency?
By allowing for simultaneous site preparation and component fabrication.
Can you give an example of modular construction?
Precast toilet.
Where is the Bottom Dry Joint typically located?
At the bottom of precast elements.
What should be fixed on top of the sub-slab?
Concealed conduits and top layer reinforcement.
How do traditional block walls contribute to energy efficiency?
They have good thermal mass, helping to regulate indoor temperatures.
What is the purpose of construction sequences?
To outline the order of operations in a construction project.
What can cause a gasket joint to fail?
Minor deformation or unevenness leading to insufficient pressure.
What is a key consideration during the Movement & Transportation Stage?
Preventing damage during storage or transportation, especially protecting edges and corners.
How does a filled joint contribute to the longevity of a structure?
By preventing moisture damage and reducing the risk of corrosion.
Where should precast elements be hoisted from?
Only at the designated lifting inserts, using specially-designed hoisting frames or beams.
What is the precast element used for deep foundations?
Pile.
How are the joints in semi-precast external walls characterized?
They are invisible and fewer in number.
What safety measure is needed if the final balcony wall or railing is fixed in-situ?
A temporary railing is required for safety considerations.
How is a dry wall anchored?
By cartridge-fixed metal cleats to the ceiling and floor slab.
What equipment is important for lifting during the site assembly stage?
Tower crane lifting capacity.
What is a key feature of the new joint design?
It includes a monolithic joint and a dry joint.
How does a monolithic joint reduce water seepage risk?
It has joints on two sides and a top joint, creating a continuous structure.
What is the primary purpose of precast concrete piles?
To provide foundation support for buildings and other structures.
What is a wet joint in precast concrete construction?
A joint where concrete or grout is poured on-site to connect precast elements.
What mechanism does a filled joint in precast concrete rely on?
Adhesion of sealant.
What is the purpose of setting up a full-scale mock-up during the site assembly stage?
For demonstration and necessary tests, such as water tightness tests.
What is a key consideration when fixing a window frame before concreting?
Ensuring that the frame is level and securely anchored.
What is the purpose of using a wet joint?
To ensure a strong bond between precast elements.
What must the building design pass to entitle the GFA exemption?
Assessment by HK-BEAM for accreditation.
In which construction method is a wet joint commonly used?
In lost form construction.
In what types of construction are hollow precast floor slabs commonly used?
In residential, commercial, and industrial buildings.
What is a benefit of pre-tensioning in precast piles?
Stronger bending strength.
What procurement procedure is recommended for effective coordination?
Early award of window supplier/contractor.
How does the manufacturing process of precast staircases contribute to quality control?
Manufacturing in a controlled environment allows for better quality assurance and consistency.
What characterizes public housing design?
Standard and repetitive design.
How does the Double Wall/Slab design contribute to energy efficiency?
By providing better insulation, reducing energy consumption for heating and cooling.
In terms of funding, how do public and private precast projects typically differ?
Public projects are usually funded by government budgets, while private projects rely on private investment.
What is the purpose of a Waste Water Treatment Plant on a construction site?
To treat and manage wastewater generated during construction.
What is a Concrete Curing Facility used for?
To ensure proper curing of concrete elements to achieve desired strength and durability.
What design benefits does prestressed concrete provide?
Thinner slabs and no or shallow beam designs.
What are the four types of joints in precast concrete construction?
Filled Joint, Gasket Joint, Drained Joint, Monolithic Joint.
What is the construction method for a filled joint in precast concrete?
Dry joint.
What is a possible defect of a monolithic joint in precast concrete?
Poor workmanship.
Why is adequate temporary support and bracing necessary during the site assembly stage?
Because precast units are very heavy.
How does precast construction impact noise and air pollution?
It is conducted away from domestic areas, reducing noise and air pollution.
What is a common advantage of using precast in public projects?
Enhanced durability and reduced maintenance costs over time.
What is another name for a semi-precast external wall?
Lost Form.
What is a recycling benefit in precast construction?
Recycling materials such as reinforcement and formwork.
Why is accurate ordering of materials important in precast construction?
It helps avoid over-ordering, which can cause wastage.
What is the function of a Wheel Wash Machine?
To clean vehicle wheels before exiting the construction site to prevent soil and debris from being transported off-site.
What is the main advantage of prestressed concrete?
It fully utilizes the strength of materials (concrete and steel rebar).
What is the function of Steel Moulds Storage?
To store molds used for casting precast concrete elements.
How do expansion joints function in precast concrete construction?
Expansion joints allow for movement due to thermal expansion and contraction, preventing cracks and structural damage.
What must be considered regarding the load capacity of a facade lifting beam?
It should be designed to handle the weight of the facade elements safely.
What mechanisms do drained joints in precast concrete rely on?
Physical barrier (baffle) and cavity.
What mechanism does a monolithic joint in precast concrete rely on?
In-situ concrete bonding.
What is one advantage of using precast elements like refuse chutes?
They can be manufactured off-site, reducing on-site construction time.
What might be a priority for private sector precast construction?
Customization and unique architectural designs.
Why are semi-precast external walls considered lighter?
They require a smaller crane and allow for longer panel sizes.
What materials are used in dry walls to reduce dead load?
Hollow or lightweight concrete.
How do prefabricated curtain wall panels contribute to energy efficiency?
They can be designed with insulation and energy-efficient glazing to reduce energy consumption.
What is the primary purpose of joints in precast concrete construction?
To connect different precast elements and ensure structural integrity.
How does reducing building height affect structural loads?
It results in less wind load on the structure.
What is the purpose of RFID in logistics?
To trace the products and identify the source of defective products.
What design aspect is crucial for precast staircases?
They must be designed to fit precisely with other structural elements.
What installation advantage do semi-precast external walls offer regarding services?
Concealed service conduits can be installed in-situ, allowing for flexibility to change.
What is the purpose of non-shrinkage grout in the joint design?
To fill up the gap in liquid form.
What does 'S/C' stand for in the context of site offices?
Site Construction.
What is a consideration for transportation in off-site production?
Possibility of transportation by sea.
What is a benefit of using precast partition walls in terms of surface finish?
They provide a good surface finish with no or thinner coat of plastering.
What materials are used in the bottom dry joint?
Neoprene strip/joint filler and non-shrinkage grout.
What is a key challenge in the design of prefabricated curtain wall panels?
Ensuring proper integration with the building structure and other systems.
What are the two main types of joints used in precast concrete construction?
Wet joints and dry joints.
What role do sealants play in precast concrete joints?
Sealants are used to prevent water infiltration and ensure durability of the joints.
How does the design of a facade lifting beam affect construction efficiency?
A well-designed beam can streamline the lifting process and reduce time on site.
Which type of joint in precast concrete construction has the highest reliability?
Monolithic Joint.
What types of storage are mentioned for hazardous materials?
Chemical Waste Storage and Dangerous Goods Storage.
How are precast concrete piles typically installed?
They are driven into the ground using a pile driver or similar equipment.
What is a possible defect of a drained joint in precast concrete?
Workmanship issues in installing components like baffle, flashing, and air seal.
What is the purpose of the Kitchen and Toilet Setting Out?
To establish designated areas for food preparation and sanitation for workers.
Why are dry joints often preferred in precast concrete construction?
Because they allow for faster assembly and can be more easily disassembled if needed.
Why is the material choice important for facade lifting beams?
To ensure strength, durability, and resistance to environmental factors.
What is a possible defect of a gasket joint in precast concrete?
Movement, poor dimensional control, or deformation affecting pressure.
What is the significance of proper alignment in precast concrete joints?
Proper alignment ensures that the load is evenly distributed and the structural integrity is maintained.
What is the primary function of a facade lifting beam?
To support and lift facade elements during construction.
What safety measures should be implemented with facade lifting beams?
Proper rigging, load testing, and adherence to safety standards.
What is the construction method for a gasket joint in precast concrete?
Dry joint.
What is the construction method for a monolithic joint in precast concrete?
Wet joint.
What is a possible defect of a filled joint in precast concrete?
Adhesion failure due to unclean surface or excess movement.
Which type of joint in precast concrete construction is the fastest to construct?
Filled Joint and Gasket Joint.
What is the construction method for a drained joint in precast concrete?
Dry joint.
How does private development differ from public housing in terms of design?
Different layout design from project to project.
What is the goal of having different layouts in private development?
To suit customers’ needs and affordability.
What is a prefabricated curtain wall panel?
A building facade system that is manufactured off-site and then assembled on-site.
What are precast concrete piles?
Structural elements made of concrete that are cast in a controlled environment and then driven into the ground to support structures.
How does prestressed concrete contribute to cost savings?
It saves materials, reduces foundation costs, and decreases building height.
What mechanism does a gasket joint in precast concrete rely on?
Pressure exerted on gasket.
