Floor slab

In many industrial halls, conduction inro the ground is a major factor for heat loss. Therefore, an adequate modeling of the floor slab and the underlying, thermally active, soil is very crucial for reliable simulation resuirs. In this case, the soil model in the TRNSYS model was established using results from an additionally performed finite-element program analysis. 

The relationships between air exchange rate and temperature difference were determined using COMB (Fig. 11.51) and then integrated as the ventilation model in the thermal model. The rhermai behavior is modeled with the TRNSYS multizone type, considering the hall and the room below the thick concrete test floor slab. For the hall, a room model with two air temperature nodes (one for the occupied zone and one for the rest of the hall) and geometrically detailed radiation exchange is used. 

In many instances, adequate existing civil/stmctural or services installation information may not be available. Guessing the likely bearing capacity of floor slabs, foundations, structural steel or sub-slab ground, etc. can prove disastrous. Equally, assuming likely operational conditions for new installations can lead to embarrassing (and quite possibly dangerous) under-performance. The cheapest or quickest installation is not always the best or... 

Two possible forms of membrane are hot applied mastic asphalt or bitumen/butyl rubber sheeting with welded or glued joints. The membrane under the floor slabs has to be lapped with that around the walls. It is essential that the membrane is protected during construction, and a typical arrangement is as shown in Figure 6.15. 

The ground floor of an industrial building is arguably the most important stmctural element. Failure of a floor slab or even a topping can lead to enormous expense and dismption due to repair or replacement. Considerations in the design of a ground slab may include ... 

Low-voltage electric resistance heater cables fixed to the structural floor slab and then protected within a 50 mm thickness of cement and sand to give a suitable surface on which the floor vapour barrier can be laid. The heating is thermostatically controlled, and it is usual to include a distance reading or recording thermometer to give visual indication of the temperature of the floor at several locations below the insulation. 

The theory of operation for the SSD system is that by penetrating the concrete floor slab with an exhaust pipe one gains access to the area beneath the slab. The area, often a gravel bed, serves as a... 

The following is a list of recommendations that builders can use to utilize the foundation as a mechanical barrier to radon entry. Foundation walls and floor slabs are often constructed of poured concrete. Plastic shrinkage, and therefore cracking, is a natural function of the drying process of concrete. Many factors, such as the water/cement/aggregate ratio, humidity, and temperature, influence the amount of cracking that occurs in a poured concrete foundation. Cracking may be minimized by... 

Coatings are applied to the outside or inside of the foundation, creating a radon-resistant barrier between the source and the inside of the home. They come in a wide variety of materials including paint-like products that can be brushed on the interior of the foundation, tar-like materials that are applied to the outside, and cementitious materials that can be brushed or troweled on. They cannot be applied to the underside of the concrete floor slab for obvious reasons, so they must be applied to the inside surface of the slab. The effective life of an interior coating can be greatly diminished by damage therefore, care must be taken to provide protection to the material used. 

Membrane banners are applied to the exterior of the foundation and also beneath the floor slab during construction. Materials used for the membrane barriers range from coextruded poly olefin to polyvinyl chloride to foil sheets with many other materials in between. All membrane barriers must have the edges sealed to prevent radon from migrating around the edges and back into the building. 

Due to difficulties often encountered in sealing subfloors and insulating pipes in crawlspace houses, which rarely have a poured floor slab, another radon-resistant alternative that can be applied after construction should be considered. This mitigation technique is a variation of the successful SSD methods used in basements. Polyethylene sheeting is often used as a moisture barrier applied directly over the soil in crawlspaces. The polyethylene sheeting can be used as a gastight barrier that forms a small-volume plenum above the soil where radon collects. A fan can be installed to pull the collected soil gas from under the sheeting and exhaust it outside the house. 

The perimeter crack is located between the edge of the floor slab and the foundation wall. This applies to slabs in basements, crawlspaces, and slab-on-grade foundations. As a cold joint, this perimeter crack is always a potential radon entry point. Contractors building radon-resistant houses... 

The floor slab itself was fully effective against radon ingress. 

Figure 1 indicates a typical nitroglycerin facility "inside out" wood frame construction at a concrete floor slab. Note that the exterior cant strip, the lead conductive floor cant and the wood cap are all sloped to discourage product build-up and facilitate cleaning. This assembly also indicates spray-on foam insulation as an optional construction item. At Radford AAP this is a safety approved insulation system. The insulation at Radford AAP received a chlorinated rubber paint coating for weathering. 

The walls are 12 ft (366 cm) from floor slab to roof. The shorter walls are 66.67 ft (2,032 cm) long, a 5.6 to 1 height to width ratio. Therefore all walls will be analyzed as one way beams pinned at the base by a crossed reinforcing configuration at the slab level (similar to Figure 8.10), and pinned at the top due to a thinner roof slab (Figure 8,11), The wall is assumed to be unrestrained (for axial forces) at the top end and will not respond in tensile membrane action. 

The side shear wall is a cantilever which transfers roof diaphragm reactions to the floor slab and foundation. The 17 foot (518 cm) height is a bit conservative because... 

The floor slab will be designed to act as a diaphragm to evenly spread lateral forces to all piles battered in the direction of loading. For load distribution purposes, the foundation is presumed infinitely stiff in comparison to the stiffness of piles in soil. 

Other applications include the construction of floor slabs where manipulation of the level of the admixture in the concrete will result in the production of bleed water should it be required to enhance finishing. The use of VEAs in grouting and underwater concrete applications is discussed below. 

The Sulphur Innovations Ltd. material, Sulfurcrete, has been sold commercially as pre-cast products (pipeline weights, median barriers, parking curbs, etc.) and poured in place as road patches, floor slabs, retaining walls, etc. (20). 

Foundation Open Sheltered Structure Structure Elev. Slabs 10 inch Floor Slabs 6 inch Tie Beams... 

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