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A few Tasks: upper floor construction / Precast concrete upper floors


task 2... I have chosen my upper floor construction for a brief that i have been given. I have chosen Precast concrete upper floors but need to know how these floors provide adequate lateral restraint and how the floor should be constructed safely??

task 4... Explain how active and passive fire resistance measures, compartmentation and means of escape can be achieved??

task 5....Provide specification for both suspended ceilings and access floors 9to include material and fixing information??

I know this is quite alot to answer so any of it would be very helpful if not all!

By the way thanx so much for the information in previous questions that i have posted!!

Greetings, Graham!

I've found some information that might help. From the top:

task 2. Precast concrete hollowcore plank combined with metal-stud framing can cost up to 20% less than a steel frame with cast-in-place concrete floors. Precast is faster and lighter. Costs can be cut by using the undersides of the planks as ceilings & just applying paint. The upper surface floors can be finished using a grout mix to smooth the joints & smooth out irregularities between the slabs. No special topping is needed. Precast planking gets a two-hour fire rating and high Sound Transmission Coefficient ratings as well.
(I'm posting each answer separately because we're having heavy rain here and the electricity keeps going out, eating my hard work!)

task 3. Active measures include devices such as fire alarm and detection systems or sprinklers that require either human intervention or automatic activation. They help control fire spread. Passive fire protection measures are built into the structural system. The builder's choice of building materials, the dimensions of building components, compartmentation, and fire protection materials effect the fire spread. They need to provide sufficient fire resistance to prevent loss of structural stability within a prescribed time period based on the building's occupancy and fire safety objectives. NIST has come up with a best practice guideline.

Compartmentation calls for specially constructed fire doors that are to be kept closed at all times to prevent smoke and fire from spreading and to provide a protected escape route. Fire dampers, fire glass and fire- and smoke-resistant walls also help contain damage.

Conventional methods of fire escape are an open iron stairway on the building's exterior or an enclosed fire- and smoke-proof stairway. The iron stairway is the most common for multi-storied buildings when height allows it. Fire-resistant escape chutes could be used for occupants of upper floors, although they are primarily designed as a backup measure. Occupancy of the building and the time it would take to evacuate everyone are considerations when determining which type of escape method to provide.
task 5. It appears that each manufacturer has their own set of specifications for their ceilings. I did find this info from Armstrong: their suspended ceilings require a minimum of 3" of overhead clearance. If you are installing recessed lighting, measure the height of the light and add 2" of overhead clearance. Fiberglass suspended ceilings require a minimum clearance of 2-1/2".

This may not be the kind of specifications you need, so I recommend looking up individual manufacturers info.

Access, or raised, flooring is an elevated flooring system that can range in height from as low as 2" to as high as 72". It is comprised of 2'-0" square panels supported by various types of understructure systems. The panels vary in weight, strength and finish depending on the type of application. The understructure consists of pedestals that elevate the corners of each panel and also vary according to the type of application. They are designed to enhance performance in offices and equipment rooms and are non-combustible. The manufacturers also claim they are solid, quiet, lightweight, have excellent grounding and electrical continuity, are interchangeable with other panel strengths and have great rolling and ultimate load performances.

Hope this info is something like what you're looking for. Good luck!

Sarah, EssayForum.com


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