some engineering question which are frequently asked in various intrviews

archdevil

Elite Member
Sep 21, 2017
267
397
India
#1
51) What does monolithic slab mean?
Monolithic slabs are foundation systems constructed as one single concrete pour that consists of a concrete slab with thickened portions of the slab under load bearing walls and all perimeter edges that take the place of footers.
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52) What is the meaning of slab on grade?
A slab-on-grade means no basement, no basement walls, just one slab of concrete on which you build your house. They aren't suitable for all building sites, which we will get into later, but for now let's assume you can build on one.
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53) What is a slab of concrete?
A concrete slab is common structural element of modern buildings. Horizontalslabs of steel reinforced concrete, typically between 4 and 20 inches (10 and 50 centimeters) thick, are most often used to construct floors and ceilings, while thinnerslabs are also used for exterior paving.
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54) What is the meaning of suspended slab?
Suspended slabs are above-ground level slabs which are not directly in contact with the earth. They are commonly used to create floors for the upper storeys of houses, but can also be sat on top of pre-constructed walls to form a ground floor.
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55) What is span in civil engineering?
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.
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56) What is the meaning of suspended slab?
Suspended slabs are slabs that are not in direct contact with the ground. They form roofs or floors above ground level. Suspended slabs are grouped into two types: one way slabs which are supported on two sides. two way slabs which are supported on all four sides.
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57) What is a beam and column?
If you keep it horizontally it is called a Beam which carries the loads by bending, simply called flexure. If you keep it vertically forms a Column which carries load by undergoing compression. If you keep it in an inclined fashion it is called a Strut which carries horizontal and vertical components of forces.
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58) How thick does a concrete slab need to be for a garage?
The form should have a slight slope (a couple of inches per 20 ft) so that water runs away from the area instead of pooling on your garage floor. The slope should be steeper if you have a sink or water heater in the garage. Step 5: Pour and level the concrete. A standard garage floor is typically 4 inches thick.
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59) Can you put concrete on concrete?
Yes, you can pour new concrete over top of the old, but here are some things to keep in mind. If your new slab will be larger than the old building, you need to be careful about cracks mirroring through around the perimeter of the old building. I would recommend using some extra rebar in these areas.
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60) How thick does a concrete floor need to be?
A concrete floor should be about 4 inches thick if it is in a residential home or building. For a building supporting heavy loads, 5 to 6 inches is the recommended thickness. A good quality concrete floor will have even thickness throughout.
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61) What is the raft foundation?
Raft foundations (sometimes known as Mat Foundations) are a large concrete slab which can support a number of columns and walls. The slab is spread out under the entire building or at least a large part of it which lowers the contact pressure compared to the traditionally used strip or trench footings.
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62) How deep does a footing need to be for a block wall?
The first step in building a block wall is pouring a concrete footing for the blocks to rest on. The footing has to be below frost line and as level as you can make it. For a foundation wall with 7 courses (rows) of block, the footing was 30 inches below grade, 24 inches wide and 12 inches deep.
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63) What is a frost wall?
A frost wall is a type of wall that adds no structural integrity to the building, but acts as an insulator. It is typical to see frost walls placed in basements since most basements are made of nothing more than cement and brick, which does not provide much insulation.
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64) What is a floating foundation?
FLOATING FOUNDATION-: A floating foundation is the foundation of a building that does not use footings,The foundation actually does float on the earth and moves as the temperatures compact and expand the soil. It is also known as a slab foundation.
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65) What is floating in concrete?
A concrete float is a tool used to finish a concrete surface by making it smooth. Afloat is used after the surface has been made level using a screed. In addition to removing surface imperfections, floating will compact the concrete as preparation for further steps.
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66) What is a suspended floor construction?
Suspended Timber Ground Floors consist of the finished timber floorboards being attached to floor joists, which are suspended above the subfloor of the foundation. These floor joists are raised above the subfloor on small supporting walls called tassel walls (or sleeper walls).
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67) What is a footing in construction?
Footings are an important part of foundation construction. They are typically made of concrete with rebar reinforcement that has been poured into an excavated trench. The purpose of footings is to support the foundation and prevent settling. Footingsare especially important in areas with troublesome soils.
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68) What is a pile mat?
A pile cap is a thick concrete mat that rests on concrete or timber piles that have been driven into soft or unstable ground to provide a suitable stable foundation. It usually forms part of the foundation of a building, typically a multi-story building, structure or support base for heavy equipment.
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69) What is Coffering used for?
A coffer (or coffering) in architecture, is a series of sunken panels. in the shape of a square, rectangle, or octagon in a ceiling, soffit or vault.
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70) What is a waffle slab?
Resembling the food after which they are named, concrete waffle slabs are reinforced concrete floors and roofs that use a square grid of deep sides. This form of construction is used in airports, parking garages, commercial and industrial buildings, bridges, residences and other structures requiring extra stability.
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71) What is a concrete strip footing?
A wall footing or strip footing is a continuous strip of concrete that serves to spread the weight of a load-bearing wall across an area of soil. It is the component of a shallow foundation.
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72) What is a continuous footing?
A strip footing is a type of shallow foundation which is provided for the load bearing wall and for economy purpose, in row of columns which are so closely spaced that their spread footing overlap or nearly touch each other. Strip footing is also know as continuous footing.
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73) What is a strip foundation used for?
Deep Strip foundations are the least expensive and are used. when ground conditions are good. A concrete strip, sometimes reinforced with steel mesh, supports the walls. The trench depth is variable but in most cases should be at least 1m with a width of 600mm. The concrete should have a minimum depth of 225mm.
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74) What is the foundation wall?
If typical continuous concrete footings are used, they usually support a foundation wall that acts either as a retaining wall to form a basement or as a frost wall with earth on both sides. Foundation walls can be built of reinforced concrete or masonry, particularly...
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75) How deep should the footing be?
The projection of the footing on either side of the wall is supposed to be no greater than the depth of the footing. The bottom of the footing should be at least 12" below the finished grade line (surface of the ground). It may need to be deeper. It must be below the frost line.
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76) What is punching shear in flat slabs?
Punching shear is a type of failure of reinforced concrete slabs subjected to high localized forces. In flat slab structures this occurs at column support points. The failure is due to shear.
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77) What is two way shear?
However two way shear is punching shear and its effect is two way. It's also called flat slab shear. You can press your Palm with pen to visualize two way shear. Pen tries to punch and hence two way shear is called punching shear.
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78) What is hollow core plank?
A hollow core slab, also known as a voided slab, hollow core plank or simply a concrete plank is a precast slab of prestressed concrete typically used in the construction of floors in multi-story apartment buildings.
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79) What is meant by prestressed concrete?
Prestressed concrete is a method for overcoming concrete's natural weakness in tension. It can be used to produce beams, floors or bridges with a longer span than is practical with ordinary reinforced concrete. It is often used in commercial and residential construction as a foundation slab.
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80) What is slip form construction?
Slip forming, continuous poured, continuously formed, or slipform construction is a construction method in which concrete is poured into a continuously movingform. Slip forming is used for tall structures (such as bridges, towers, buildings, and dams), as well as horizontal structures, such as roadways.
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81) What is a tilt up?
Tilt-up, tilt-slab or tilt-wall is a type of building and a construction technique using concrete. Though it is a cost-effective technique with a shorter completion time, poor performance in earthquakes has mandated significant seismic retrofit requirements in older buildings.
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82) What is post tensioning of concrete?
Post tensioning is a technique for reinforcing concrete. ... Prestressing simply means that the steel is stressed (pulled or tensioned) before the concrete has to support the service loads. Most precast, prestressed concrete is actually pre-tensioned-the steel is pulled before the concrete is poured.
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83) What is the function of a foundation?
Foundation is the lower portion of the building usually located below ground level, which transmits the loads of the super structure to the supporting soil. A foundationis therefore that part of the structure which is in direct contact with the ground to which loads are transmitted.
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84) What is the combined footing?
It is used when the two column are so close to each other that their individualfootings would overlap. A combined footing is also provided when the property line is so close to one column that a spread footing would be eccentrically loaded when kept entirely within the property line.
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85) What is a ribbed slab?
They provide a very good form of construction where slab vibration is an issue, such as laboratories and hospitals. Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction. Normally the ribs and the beams are the same depth.
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86) What is a flat slab?
A flat slab is a two-way reinforced concrete slab that usually does not have beams and girders, and the loads are transferred directly to the supporting concrete columns.
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87) What is a spread footing?
role in building foundations. in soil mechanics. ... Spread foundations may be either of the spread footing (made with wide bases placed directly beneath the load-bearing beams or walls), mat (consisting of slabs, usually of reinforced concrete, which underlie the entire area of a building),
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88) What is a deep foundation?
A deep foundation is a type of foundation which transfers building loads to the earth farther down from the surface than a shallow foundation does, to a subsurface layer or a range of depths. A pile is a vertical structural element of adeep foundation, driven or drilled deep into the ground at the building site.
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89) What is a concrete strip footing?
A wall footing or strip footing is a continuous strip of concrete that serves to spread the weight of a load-bearing wall across an area of soil. It is the component of a shallow foundation.
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90) What is a frost wall?
A frost wall is a type of wall that adds no structural integrity to the building, but acts as an insulator. It is typical to see frost walls placed in basements since most basements are made of nothing more than cement and brick, which does not provide much insulation.
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91) What is a suspended floor?
A suspended concrete floor is a floor slab where its perimeter is, or at least two of its opposite edges are, supported on walls, beams or columns that carry its self weight and imposed loading. The floor spans between supports and will normally deflect under load to a dimension that is limited by the design used.
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92) What is the single span bridge?
A 'span' in engineering parlance means 'the gap between two supports' This bridgeis single span: A single span slab is a slab that is supported at either end.
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93) What is the slump in concrete?
The concrete slump test measures the consistency of fresh concrete before it sets. It is performed to check the workability of freshly made concrete, and therefore the ease with which concrete flows. It can also be used as an indicator of an improperly mixed batch.
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94) What is a caisson pile?
A pile machine in Amsterdam, the Netherlands. Also called caissons, drilled shafts, drilled piers, Cast-in-drilled-hole piles (CIDH piles) or Cast-in-Situ piles, a borehole is drilled into the ground, then concrete (and often some sort of reinforcing) is placed into the borehole to form the pile.
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95) What is a suspended floor?
A suspended Floor is a specialist construction made of a solid concrete Floor, a system of sleeper walls and timber joists, upon which sits a supported timber floor.
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96) What is a ribbed slab?
They provide a very good form of construction where slab vibration is an issue, such as laboratories and hospitals. Ribbed slabs are made up of wide band beams running between columns with narrow ribs spanning the orthogonal direction. Normally the ribs and the beams are the same depth.
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97) What is a strip foundation?
Strip foundations are used where the soil is of good bearing capacity. The key sizes of a strip foundation for concrete cavity wall construction and timber frame cavity wall construction are similar. ... The depth of a strip foundation must be equal to or greater than the overall width of the wall.
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98) What is meant by punching shear?
Punching shear is a type of failure of reinforced concrete slabs subjected to high localized forces. In flat slab structures this occurs at column support points. The failure is due to shear.
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99) What is a hollow core slab?
Diagram of a concrete slab of hollow core construction. Photograph of a concrete plank roof. A hollow core slab, also known as a voided slab, hollow core plank or simply a concrete plank is a precast slab of prestressed concrete typically used in the construction of floors in multi-story apartment buildings.
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100) What is Slipform paver?
Slipform paving is defined as a process used to consolidate, form into geometric shape and surface finish a PCC mass by pulling the forms continuously through and surrounding the plastic concrete mass.
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101) What is meant by shallow foundation?
A shallow foundation is a type of foundation which transfers building loads to the earth very near the surface, rather than to a subsurface layer or a range of depths as does a deep foundation.
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102) What is a pier in construction?
Pier, in building construction, vertical loadbearing member such as an intermediate support for adjacent ends of two bridge spans. In foundations for large buildings,piers are usually cylindrical concrete shafts, cast in prepared holes, while in bridges they take the form of caissons, which are sunk into position.
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103) What is the slump test?
The slump test is a means of assessing the consistency of fresh concrete. It is used, indirectly, as a means of checking that the correct amount of water has been added to the mix. The test is carried out in accordance with BS EN 12350-2,Testing fresh concrete.
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104) What is the slump value of concrete?
Very dry mixes; having slump 0 – 25 mm are used in road making, low workability mixes; having slump 10 – 40 mm are used for foundations with light reinforcement, medium workability mixes; 50 - 90 for normal reinforced concrete placed with vibration, high workability concrete; > 100 mm.