Civil Engineering Drawing Multiple Choice Questions on “Earthwork, Concrete and R.C.C. work”.
1. _______________ are engineering works created through the processing of parts of the earth’s surface involving quantities of soil or unformed rock.
a) Surfacework
b) Landwork
c) Earthworks
d) Hosework
Answer: c
Clarification: Typical earthworks include roads, railway beds, causeways, dams, levees, canals, and berms. Other common earthworks are land grading to reconfigure the topography of a site, or to stabilize slopes.
2. An ___________________ beam is one in which the tension capacity of the tensile reinforcement is smaller than the combined compression capacity of the concrete and the compression steel (under-reinforced at tensile face).
a) extra-reinforced
b) less-reinforced
c) under-reinforced
d) over-reinforced
Answer: c
Clarification: When the reinforced concrete element is subject to increasing bending moment, the tension steel yields while the concrete does not reach its ultimate failure condition. As the tension steel yields and stretches, an “under-reinforced” concrete also yields in a ductile manner, exhibiting a large deformation and warning before its ultimate failure. In this case the yield stress of the steel governs the design.
3. When aggregate is mixed together with dry Portland cement and water, the mixture forms a fluid _________ that is easily poured and moulded into shape.
a) curry
b) furry
c) slurry
d) gel
Answer: c
Clarification: A slurry is a thin sloppy mud or cement or, in extended use, any fluid mixture of a pulverized solid with a liquid (usually water), often used as a convenient way of handling solids in bulk. Slurries behave in some ways like thick fluids, flowing under gravity and are also capable of being pumped if not too thick.
4. Excavation may be classified by type of material- Earth excavation ________ excavation, rock excavation, muck excavation, unclassified excavation.
a) bottom soil
b) sub-soil
c) topsoil
d) surface soil
Answer: c
Clarification: Topsoil is the upper, outermost layer of soil, usually the top 2 inches (5.1 cm) to 8 inches (20 cm). It has the highest concentration of organic matter and microorganisms and is where most of the Earth’s biological soil activity occurs. Four elements constitute the composition of soil. Those elements are mineral particles, organic matter, water, and air. The volume of top soil consists of 50 to 80% of these particles which form the skeletal structure of most soils.
5. Heavy construction equipment is usually used due to the amounts of material to be moved – up to millions of cubic metres.
a) True
b) False
Answer: a
Clarification: Earthwork construction was revolutionized by the development of the (Fresno) scraper and other earth-moving machines such as the loader, the dump truck, the grader, the bulldozer, the backhoe, and the dragline excavator.
6. In the past, earthwork excavating calculations were done by hand using a slide rule and with methods such as Simpson’s rule.
a) True
b) False
Answer: a
Clarification: In numerical analysis, Simpson’s rule is a method for numerical integration, the numerical approximation of definite integrals. The slide rule, also known colloquially in the United States as a slipstick, is a mechanical analog computer. The slide rule is used primarily for multiplication and division, and also for functions such as exponents, roots, logarithms and trigonometry, but typically not for addition or subtraction.
7. A mixture of bentonite and water used to make slurry walls.
a) True
b) False
Answer: a
Clarification: Bentonite is an absorbent aluminium phyllosilicate clay consisting mostly of montmorillonite. It was named by Wilbur C. Knight in 1898 after the Cretaceous Benton Shale near Rock River, Wyoming.
8. Manure slurry, a mixture of animal waste, organic matter, and sometimes water often known simply as “slurry” in agricultural use, used as fertilizer after ageing in a slurry pit.
a) True
b) False
Answer: a
Clarification: A slurry pit, also known as a farm slurry pit, slurry tank, slurry lagoon or slurry store, is a hole, dam, or circular concrete structure where farmers gather all their animal waste together with other unusable organic matter, such as hay and water run off from washing down dairies, stables, and barns, in order to convert it, over a lengthy period of time, into fertilizer that can eventually be reused on their lands to fertilize crops.
9. Chemical admixture may accelerate or slow down the rate at which the concrete hardens.
a) True
b) False
Answer: a
Clarification: Chemical admixtures are added to achieve varied properties. These ingredients may accelerate or slow down the rate at which the concrete hardens, and impart many other useful properties including increased tensile strength, entrainment of air and water resistance.
10. Concrete can be formulated with high tensile strength, but always has lower compressive strength.
a) True
b) False
Answer: b
Clarification: Reinforcement is often included in concrete. Concrete can be formulated with high compressive strength, but always has lower tensile strength. For this reason it is usually reinforced with materials that are strong in tension, typically steel rebar.
11. Reinforced concrete (RC) is a composite material in which concrete’s relatively low tensile strength and ductility are counteracted by the inclusion of reinforcement having higher tensile strength or ductility.
a) True
b) False
Answer: a
Clarification: The reinforcement is usually, though not necessarily, steel reinforcing bars (rebar) and is usually embedded passively in the concrete before the concrete sets. Reinforcing schemes are generally designed to resist tensile stresses in particular regions of the concrete that might cause unacceptable cracking and/or structural failure. Modern reinforced concrete can contain varied reinforcing materials made of steel, polymers or alternate composite material in conjunction with rebar or not.
12. Reinforced concrete can be classified as precast or postcast concrete.
a) True
b) False
Answer: b
Clarification: Reinforced concrete can be classified as precast or cast-in-place concrete. Designing and implementing the most efficient floor system is key to creating optimal building structures. Small changes in the design of a floor system can have significant impact on material costs, construction schedule, ultimate strength, operating costs, occupancy levels and end use of a building.
13. The coefficient of thermal expansion of concrete is very small to that of steel, eliminating large internal stresses due to differences in thermal expansion or contraction.
a) True
b) False
Answer: b
Clarification: The coefficient of thermal expansion of concrete is similar to that of steel, eliminating large internal stresses due to differences in thermal expansion or contraction.
14. The reinforcement in an RC structure, such as a steel bar, has to undergo the same strain or deformation as the surrounding concrete in order to prevent discontinuity, slip or separation of the two materials under load.
a) True
b) False
Answer: a
Clarification: Maintaining composite action requires transfer of load between the concrete and steel. The direct stress is transferred from the concrete to the bar interface so as to change the tensile stress in the reinforcing bar along its length, this load transfer is achieved by means of bond (anchorage) and is idealized as a continuous stress field that develops in the vicinity of the steel-concrete interface.
15. Prestressing concrete is a technique that decreases the load-bearing strength of concrete beams.
a) True
b) False
Answer: b
Clarification: Prestressing concrete is a technique that greatly increases the load-bearing strength of concrete beams.