Quick Answer: How Far Can Concrete Span Without Support?

Which is better one way slab or two way slab

In one way slab the slabs are supported by the beams on the two opposite sides.

In two way slab the slabs are supported on all the four sides .

…

In one way slab the ratio of Longer span to shorter span is equal or greater than 2.

(i.e l/b ≥ 2)..

What is the maximum length of a beam

Most recent answer In any way the length of RC beam is limited, as an example in the bridge like what I have said above, we can use a beam up to 25m, after that it’s more economical to work with pre-stressed concrete up to 40m, and then it’s better to use steel beam.

How thick is a residential slab

4 inchesStandard concrete floor slab thickness in residential construction is 4 inches. Five to six inches is recommended if the concrete will receive occasional heavy loads, such as motor homes or garbage trucks. To prepare the base, cut the ground level to the proper depth to allow for the slab thickness.

What is the strongest concrete mix ratio

Concrete is made from cement, sand, gravel and water. In making concrete strong, these ingredients should usually be mixed in a ratio of 1:2:3:0.5 to achieve maximum strength. That is 1 part cement, 2 parts sand, 3 parts gravel, and 0.5 part water.

What is the maximum span between columns

Span (distance) between two columns One can use beams of size 9″ X 12″ (225 MM x 300MM) with a slab thickness of 5″ (125 MM) cast in M20 concrete for spans up to 5m. There are other considerations like secondary and tertiary spans, point loads and wall loads which have to be considered.

What is the span of a slab

The distance between the centers of support, or the clear distance between supports plus the effective depth of the beam or slab, the lesser value being taken.

Where is one way slab used

One way & Two way Slabs Floor System. One way and two way slabs as floor systems are the most conventional forms of structural floor systems. Reinforced thin plate elements are supported over beams, masonry walls or directly over columns. Beam and slab arrangement can be the best example for one way and two way slabs.

How thick is a suspended concrete slab

around 200mmA suspended slab is raised off the ground and has an accessible sub-floor area. In a residential situation, the slab is around 200mm thick and is supported by external sub-floor walls of brick or concrete block etc. The slab is also supported by free-standing brick or concrete piers.

What is reinforce concrete slab

A reinforced concrete slab is a crucial structural element and is used to provide flat surfaces(floors and ceilings) in buildings. On the basis of reinforcement provided, beam support, and the ratio of the spans, slabs are generally classified into one-way slab and two-way slab.

How far can you cantilever a concrete slab

Cantilevers are usually limited to a span of about 25 to 35% of the back span and should be supported by a stiff support such as a beam or column. They should not be supported off another cantilever at right angles. The deflection of a cantilever is sensitive to the rotation at the support.

What is the span of a beam

Span is the distance between two intermediate supports for a structure, e.g. a beam or a bridge. A span can be closed by a solid beam or by a rope. The first kind is used for bridges, the second one for power lines, overhead telecommunication lines, some type of antennas or for aerial tramways.

Can I pour concrete directly on dirt

Long story short, yes you can pour concrete over dirt.

Do you need gravel under concrete

Whether you pour concrete for a walkway or patio, a strong gravel base is required to prevent the concrete from cracking and shifting. Gravel is especially important in clay soil because it doesn’t drain well, which results in water pooling under the concrete slab and slowly eroding the soil as it finally drains.

Can I pour a 2 inch concrete slab

If done properly, new concrete can often be poured right over an existing slab. For this to be feasible, the contractor needs to pour at least 2 inches thick, use smaller aggregate, and incorporate reinforcement such as welded wire mesh or fiber mixed into the concrete.

What is the maximum span of a beam

When supporting joists that span 12 feet with no overhang beyond the beam, a double ply beam can span in feet a value equal to its depth in inches. A double 2×12 beam can span 12 feet; a (2) 2×10 can span 10 feet and so on.

What is column span

Definition and Usage. The column-span property specifies how many columns an element should span across.

What is the main reason for edge beams on a slab

A dropped edge beam is where the edge of a concrete slab turns down to retain fill underneath the home. This alleviates the need of building a retaining wall on the boundary which can cause issues down the track with neighbours and your local council.

What is the maximum span of a slab

The answer to question is simple, the limit to span is about 6–15m depending upon how much you spend because as the length increases depth of slab increases since bending moment is increasing and the structure will become more and more uneconomical.

What is the minimum thickness you can pour concrete

25 to 50 mmThe minimum recommended thickness is 1 to 2 in. (25 to 50 mm) for a fully bonded concrete overlay placed on a base slab that is practically free of cracks and in which the concrete is sound, clean, and of good quality. The use of welded wire fabric reinforcement is usually not warranted under these conditions.

How long can a concrete slab span

Reinforced concrete allows a wide range of structural options and provides cost-effective solutions for a multitude of situations—from residential buildings with moderate live loads and spans of about 25 ft, to commercial buildings with heavier live loads and spans ranging from 40 ft to 50 ft and beyond.