← Junior Engineer
Past Questions
A quick setting cement has an initial setting time of about -
A)
50 minutes
B)
40 minutes
C)
15 minutes
D)
5 minutes
In civil engineering and building materials, cements are categorized by their setting times to suit different construction needs.
1. **Ordinary Portland Cement (OPC):** The standard initial setting time is not less than 30 minutes (as per IS codes).
2. **Quick Setting Cement:** This is a specialized cement designed for applications where rapid hardening is required (such as underwater construction or urgent repairs). For quick setting cement, the initial setting time is significantly reduced, typically ranging from 5 to 15 minutes. Among the given options, 5 minutes is the characteristic value associated with 'quick setting' properties to distinguish it sharply from 'rapid hardening' or 'ordinary' cements.
3. **Rapid Hardening Cement:** This cement gains strength faster but its initial setting time is generally similar to or slightly shorter than OPC (around 30 minutes), though it reaches high strength quickly.
Comparing the options:
- 50 minutes and 40 minutes are typical or longer than standard OPC settings.
- 15 minutes is fast, but 'Quick Setting' specifically targets the shortest possible window, often cited as 5 minutes in technical textbooks for extreme rapid-set requirements.
Poisson’s ratio for a saturated clay is -
A)
0
B)
0.25
C)
0.5
D)
0.15
Poisson's ratio (μ) is the ratio of lateral strain to longitudinal strain. For a material to be considered 'incompressible' (meaning its volume remains constant during deformation), the Poisson's ratio must be exactly 0.5. Saturated clays are considered incompressible under undrained conditions because the water filling the voids cannot escape quickly, and water itself is virtually incompressible. Therefore, for saturated clay in an undrained state, the volume change is zero, leading to a Poisson's ratio of 0.5. Options a, b, and d represent values typical for unsaturated soils, rocks, or other elastic materials that allow for volume change during loading.
When HYSD bars are used in place of mild steel bars in a beam, the bond strength -
A)
Does not change
B)
Increases
C)
Decreases
D)
Becomes zero
Bond strength in reinforced concrete is the grip between the concrete and the reinforcing steel, which prevents the bar from slipping.
1. Mild Steel Bars: These are smooth, circular bars. The bond between mild steel and concrete is primarily based on chemical adhesion and friction. Because the surface is smooth, the bond strength is relatively low.
2. HYSD (High Yield Strength Deformed) Bars: These bars are manufactured with 'ribs' or 'lugs' (deformations) on their surface. These deformations provide a mechanical interlock between the steel and the surrounding concrete.
3. Comparison: The mechanical interlocking provided by the ribs of HYSD bars significantly increases the resistance to slippage compared to the simple adhesion of smooth mild steel bars. Therefore, when HYSD bars are used in place of mild steel bars, the bond strength increases.
- Option (a) is incorrect because the surface geometry changes significantly.
- Option (c) is incorrect because deformations are specifically designed to prevent slippage.
- Option (d) is incorrect because bond strength is essential for the composite action of RCC.
Gypsum is used as an admixture in cement grouts for -
A)
Accelerating the setting time
B)
Retarding the setting time
C)
Increasing the plasticity
D)
Reducing the grout shrinkage
Gypsum (Calcium Sulfate Dihydrate) is added to cement during the manufacturing process and can also be used as an admixture in grouts to control the hydration process. Specifically, gypsum reacts with the tricalcium aluminate (C3A) in cement to form ettringite, which creates a barrier around the C3A particles. This prevents the 'flash set' (rapid hardening) of the cement, thereby retarding the setting time. This is crucial in grouting operations to ensure the material remains fluid enough to fill voids and gaps completely before it hardens.
Analysis of other options:
- Option (a) is incorrect because accelerators (like Calcium Chloride) are used to speed up setting time, whereas gypsum slows it down.
- Option (c) is incorrect because plasticity is typically increased by plasticizers or superplasticizers, not gypsum.
- Option (d) is incorrect because shrinkage is reduced by using expansive agents or reducing the water-cement ratio, not by adding gypsum.
Air permeability method is used to determine -
A)
Soundness of cement
B)
Setting time
C)
Fineness of cement
D)
Resistance of cement
The air permeability method (also known as the Blaine air permeability test) is used to determine the fineness of cement. It works on the principle that the rate of air flow through a compacted bed of cement particles is proportional to the specific surface area of the particles. Finer cement has a higher specific surface area, which offers more resistance to the flow of air.
Why other options are incorrect:
- Soundness of cement (a) is typically measured using the Le Chatelier apparatus or the Autoclave test to detect delayed expansion.
- Setting time (b) is determined using the Vicat apparatus (Initial and Final setting times).
- Resistance of cement (d) is a general term, but strength/resistance is typically measured via compressive strength tests using mortar cubes.
Chemical reaction of the cement when it is mix with water is called as
A)
Setting time
B)
Hydration of cement
C)
Water cement ratio
D)
Final setting time
The chemical reaction that occurs when cement is mixed with water is known as 'Hydration'. During this process, the compounds in cement (primarily tricalcium silicate and dicalcium silicate) react chemically with water to form a hard, stone-like mass called Calcium Silicate Hydrate (C-S-H) gel, which binds the aggregates together and gives concrete its strength.
Why other options are incorrect:
- a. Setting time: This refers to the period of time it takes for the cement paste to lose its plasticity and harden; it is a result of hydration, not the reaction itself.
- c. Water cement ratio: This is the ratio of the weight of water to the weight of cement used in a mix, which affects the strength and workability of the concrete.
- d. Final setting time: This is the specific time elapsed from the moment water is added to the cement until the paste has completely lost its plasticity.
Well foundations are commonly used as foundation for the following structures -
A)
Water tanks
B)
Bridges
C)
Buildings
D)
Reciprocating machines
Well foundations (also known as caissons) are deep foundations used to transfer heavy structural loads to deeper, more stable soil or rock layers. They are specifically designed to be sunk through water or soft soil.
1. Why 'Bridges' is correct: Bridges, especially those crossing rivers, require foundations that can withstand scouring (the removal of soil around the pier by flowing water) and can be constructed in an aquatic environment. Well foundations provide the necessary stability and depth to reach hard strata beneath the riverbed.
2. Why other options are incorrect:
- Water tanks: These are typically supported by shallow foundations (like raft or isolated footings) because they are usually placed on stable ground and do not require deep penetration.
- Buildings: Most buildings use shallow foundations or pile foundations. While deep foundations are used for skyscrapers, 'well foundations' are specifically characteristic of bridge piers rather than general building construction.
- Reciprocating machines: These require heavy, vibration-damping foundations, typically achieved using massive reinforced concrete rafts or deep piles to minimize resonance and settlement, but not typically 'well foundations'.
The modulus of elasticity of timber is about -
A)
0.5 to 1.0 x 10⁴ N/mm²
B)
1.0 to 1.5 x 10⁴ N/mm²
C)
1.5 to 2.0 x 10⁴ N/mm²
D)
2.0 to 2.5 x 10⁴ N/mm²
The Modulus of Elasticity (E) of timber varies significantly depending on the species of wood, the moisture content, and the direction of the grain (parallel or perpendicular to the grain). For most structural timbers used in civil engineering, the modulus of elasticity parallel to the grain typically ranges from 5,000 N/mm² to 10,000 N/mm².
Converting this to scientific notation:
5,000 N/mm² = 0.5 x 10⁴ N/mm²
10,000 N/mm² = 1.0 x 10⁴ N/mm²
Therefore, the range is 0.5 to 1.0 x 10⁴ N/mm². Options b, c, and d provide values that are generally too high for standard structural timber, as those values would approach the stiffness of very dense hardwoods or composite materials, whereas the general range for common timber used in engineering calculations falls within option (a).
The ultimate bearing capacity of cohesionless soil depends upon -
A)
Width of footing
B)
Depth of footing
C)
Relative density
D)
All of these
The ultimate bearing capacity (q_u) of a soil is the maximum load per unit area that the soil can support before shear failure occurs. For cohesionless soils (where cohesion c = 0), the bearing capacity is typically calculated using Terzaghi's bearing capacity equation: q_u = q N_q + 0.5 γ B N_γ.
1. Width of footing (B): In the equation, the term '0.5 γ B N_γ' shows that the bearing capacity is directly proportional to the width of the footing. As B increases, the volume of the failure zone increases, increasing the bearing capacity.
2. Depth of footing (D_f): The term 'q N_q' (where q = γ D_f) represents the surcharge effect. As the depth of the footing increases, the overburden pressure increases, which provides more confinement to the soil beneath the footing, thereby increasing the ultimate bearing capacity.
3. Relative density (D_r): For cohesionless soils (sands), the angle of internal friction (φ) is heavily dependent on the relative density. The bearing capacity factors (N_q and N_γ) are functions of φ. A higher relative density leads to a higher angle of internal friction, which exponentially increases the values of N_q and N_γ, thus increasing the ultimate bearing capacity.
Since all three factors—width, depth, and relative density—directly influence the ultimate bearing capacity of cohesionless soil, the correct option is 'All of these'.
For chemical resistance, proportion of which one of the following compounds in cement clinker shall it be increased?
A)
Tricalcium Silicate
B)
Dicalcium Silicate
C)
Tetracalcium Aluminate
D)
Tetracalcium Aluminoferrite
To understand chemical resistance in cement, we must look at the Bogue's compounds in cement clinker:
1. Tricalcium Silicate (C3S): Responsible for early strength and high heat of hydration. It is more susceptible to chemical attack due to its rapid reaction.
2. Dicalcium Silicate (C2S): Responsible for ultimate (long-term) strength. It hydrates slowly and produces a denser, less permeable microstructure over time. Because it reacts slowly and contributes to a more stable matrix, increasing its proportion generally improves the chemical resistance (especially against sulfates and acids) compared to C3S.
3. Tricalcium Aluminate (C3A) / Tetracalcium Aluminate: This is the most chemically reactive component. It is highly susceptible to sulfate attack, which leads to expansion and cracking. To increase chemical resistance, C3A must be decreased, not increased.
4. Tetracalcium Aluminoferrite (C4AF): Acts primarily as a flux during manufacturing and contributes little to strength; it does not significantly enhance chemical resistance.
Therefore, to enhance the chemical resistance of cement, the proportion of Dicalcium Silicate (C2S) is increased while the proportion of Tricalcium Aluminate (C3A) is decreased.
A good brick, when immersed in water bath for 24 hours, should not absorb more than -
A)
20% ofits dry weight
B)
30% ofits saturated weight
C)
10% ofits dry weight
D)
20% ofits saturated weight
The water absorption test is a standard quality control test for bricks to determine their porosity and durability. According to Indian Standard (IS) codes and general engineering specifications for building materials:
1. **First Class Bricks:** Should not absorb more than 20% of their dry weight when immersed in water for 24 hours.
2. **Second Class Bricks:** Should not absorb more than 22% of their dry weight.
3. **Third Class Bricks:** May absorb up to 25% of their dry weight.
Calculation Method: Water absorption is calculated as:
(Weight of wet brick - Weight of dry brick) / (Weight of dry brick) × 100.
Therefore, for a 'good' (First Class) brick, the limit is 20% of its dry weight. Options b, c, and d are incorrect because the standard is measured against the dry weight, not the saturated weight, and 10% is too stringent for standard clay bricks, while 30% is too high for a quality brick.
In the following, identify the one which is different from the rest -
A)
Rain
B)
Drizzle
C)
Hail
D)
Fog
In the context of hydrology and meteorology, the options are categorized based on whether they represent forms of precipitation.
1. Rain: This is liquid precipitation occurring when water vapor condenses and falls as droplets.
2. Drizzle: This is a light form of liquid precipitation consisting of very small water droplets.
3. Hail: This is solid precipitation consisting of balls or lumps of ice.
4. Fog: This is a visible aerosol consisting of tiny water droplets or ice crystals suspended in the air at or near the Earth's surface. Unlike the other three, fog does not 'fall' from the atmosphere to the ground as precipitation; rather, it is a cloud that touches the ground.
Therefore, Rain, Drizzle, and Hail are all forms of precipitation, while Fog is a suspension of water droplets in the air (a weather phenomenon/cloud), making it the odd one out.
What is the range of fineness modulus of sand which is least suitable for making a good concrete?
A)
3.5 - 4.5
B)
2.9 - 3.2
C)
2.6-2.9
D)
2.2 - 2.6
Fineness Modulus (FM) is an empirical figure used to describe the average particle size of the aggregate. For fine aggregates (sand), the FM typically ranges from 2.0 to 3.5.
According to standard classifications of sand based on FM:
1. Fine Sand: FM = 2.2 to 2.6
2. Medium Sand: FM = 2.6 to 2.9
3. Coarse Sand: FM = 2.9 to 3.2
In concrete production, a well-graded aggregate is essential to minimize voids and reduce the amount of cement paste required. 'Fine sand' (FM 2.2 - 2.6) contains a higher proportion of very small particles. This increases the total surface area of the aggregate, which in turn increases the water demand for workability and the amount of cement needed to coat the particles. This often leads to higher shrinkage and a higher risk of cracking, making it the 'least suitable' among the given ranges for general structural concrete compared to medium or coarse sands. Therefore, the range 2.2 - 2.6 is the least suitable for making a good, economical, and durable concrete mix.
When an accumulated mass of snow melts, the resulting flow entering a stream is classified as -
A)
Direct runoff
B)
Base flow
C)
Subsurface flow
D)
Inter flow
In hydrology, runoff is generally divided into two main components: Direct Runoff and Base Flow.
1. **Direct Runoff**: This is the portion of precipitation (or snowmelt) that reaches the stream channel quickly. It consists of surface runoff (overland flow) and interflow. When an accumulated mass of snow melts, the water typically flows over the land surface or through the upper soil layers directly into the stream channel in a relatively short period. Therefore, snowmelt is categorized as a component of direct runoff.
2. **Base Flow**: This is the delayed flow that comes from groundwater aquifers. It sustains the stream during dry periods and is not the immediate result of a specific melting or precipitation event.
3. **Subsurface Flow**: While snowmelt can move through the soil, 'subsurface flow' is a general term. When it contributes to the immediate peak of a hydrograph following a melt event, it is part of the direct runoff (specifically interflow).
4. **Inter flow**: This is a specific type of subsurface flow that moves laterally through the soil above the water table. While snowmelt can contribute to interflow, the overall classification for the resulting flow entering the stream from a melt event is 'Direct Runoff'.
In coursed rubble masonry, the wall is built in courses varying from -
A)
300-450 mm
B)
350-450 mm
C)
400 - 500 mm
D)
450-500 mm
In masonry, rubble masonry is classified based on the dressing of stones and the method of laying. In 'Coursed Rubble Masonry', the stones are roughly squared and laid in courses. According to standard civil engineering practices and building material textbooks (such as those by S.K. Duggal or B.C. Punmia), the height of these courses typically varies between 300 mm to 450 mm. This ensures a balance between the structural stability of the wall and the efficiency of construction. Options b, c, and d provide ranges that are either too narrow or too high, exceeding the standard engineering specifications for typical coursed rubble work.
Darcy’s law of linear dependency between velocity of flow ‘v’ and hydraulic gradient ‘i’ is valid only for -
A)
Laminar flow
B)
Turbulent flow
C)
Fluid
D)
Both (a) & (b)
Darcy's Law is expressed as v = ki, where 'v' is the discharge velocity, 'k' is the coefficient of permeability, and 'i' is the hydraulic gradient. This law establishes a linear relationship between velocity and gradient. For this linear relationship to hold true, the flow of water through the porous medium must be laminar (where the Reynolds number is typically less than 1 to 10). In laminar flow, the viscous forces dominate, and the velocity is directly proportional to the pressure drop. If the flow becomes turbulent (high velocity or very coarse materials), the relationship becomes non-linear, and the velocity increases at a rate different from the hydraulic gradient, rendering Darcy's Law invalid. Therefore, option (a) is correct, and option (b) is incorrect.
Sedimentation analysis is based on -
A)
Atterberg’s limit
B)
Laboratory tests
C)
Stoke’s Law
D)
Hydrometer analysis
Sedimentation analysis is a method used to determine the grain size distribution of fine-grained soils (silts and clays) that are too small to be separated by mechanical sieving. This process is fundamentally based on Stoke's Law, which describes the settling velocity of a spherical particle falling through a viscous fluid. According to Stoke's Law, the velocity of a falling particle is proportional to the square of its diameter and the difference between the densities of the particle and the fluid.
Why other options are incorrect:
- a. Atterberg’s limits: These describe the consistency of fine-grained soils (Liquid Limit, Plastic Limit, etc.) and are not used for grain size analysis.
- b. Laboratory tests: While sedimentation analysis is performed as a laboratory test, this is a general category, not the scientific principle upon which the analysis is based.
- d. Hydrometer analysis: This is the name of the actual test/procedure used to perform sedimentation analysis, but the underlying physical law that makes the test possible is Stoke's Law.
The aggregate with rounded particles (river or seashore gravel) has minimum voids ranging from -
A)
42 - 43
B)
31 - 34
C)
30 - 33
D)
32 - 33
In building materials and concrete technology, the void ratio of aggregates depends heavily on the shape and grading of the particles.
1. **Rounded Aggregates**: Particles that are rounded (such as river gravel or seashore gravel) pack more efficiently and slide over each other more easily than angular particles. This results in a lower volume of voids. The typical range for voids in rounded aggregates is approximately 31% to 34%.
2. **Angular Aggregates**: Crushed stone or angular aggregates have a higher internal friction and do not pack as tightly, leading to a higher void ratio, typically ranging from 36% to 44%.
Comparing the options provided:
- Option (a) 42-43% corresponds to highly angular or poorly graded aggregates.
- Option (b) 31-34% aligns with the standard technical data for rounded river/sea gravels.
- Options (c) and (d) are slightly too low or too narrow to represent the standard range for these materials in civil engineering textbooks.
Timber can be made reasonably fire-resistant by -
A)
Soaking it in ammonium sulphate
B)
Coating with tar paint
C)
Pumping creosote oil into timber under high pressure
D)
Seasoning process
Timber is naturally combustible. To make it fire-resistant, it must be treated with fire-retardant chemicals. Ammonium sulphate is a well-known fire-retardant chemical; when timber is soaked in a solution of ammonium sulphate, the chemical penetrates the wood fibers. Upon exposure to heat/fire, it releases gases that help extinguish the flame or slow down the combustion process by forming a protective char layer.
Analysis of other options:
- Option b (Tar paint): Tar is a hydrocarbon-based material and is highly flammable, which would actually increase the fire risk.
- Option c (Creosote oil): Creosote is used primarily as a preservative to protect timber from fungi, insects, and moisture (decay), but it is not a fire retardant.
- Option d (Seasoning): Seasoning is the process of reducing the moisture content of timber to improve strength, stability, and durability, but it does not provide fire resistance.
The most important purpose of frog in a brick is to -
A)
Emboss manufacturer’s name
B)
Reduce the weight of brick
C)
Form keyed joint between brick and mortar
D)
Improve insulation by providing hollows
A 'frog' is the indentation or depression made on the top face of a brick. While it is often used to emboss the manufacturer's name or brand, its primary engineering purpose is to provide a mechanical key for the mortar. When mortar is placed into the frog, it creates a 'keyed joint' (interlocking bond) between the courses of bricks, significantly increasing the shear strength and stability of the masonry wall.
Analysis of other options:
- Option (a): Embossing the name is a secondary use, not the 'most important' engineering purpose.
- Option (b): While it slightly reduces the amount of clay used, reducing weight is not the primary design objective of a frog.
- Option (d): A frog is a shallow indentation, not a hollow cavity; therefore, it does not provide significant thermal insulation compared to hollow bricks.
The failure of a pile foundation is due to -
A)
General shear
B)
Local shear
C)
Mixed shear
D)
Punching shear
In soil mechanics and foundation engineering, the failure modes of shallow foundations (like spread footings) are typically categorized as General Shear, Local Shear, and Punching Shear based on the soil's compressibility and density. However, when considering the failure of a pile foundation—specifically in the context of the pile pushing into the bearing stratum or the soil failing beneath the pile tip—the failure is characterized by 'Punching Shear'.
1. General Shear Failure: Occurs in dense sands or stiff clays where a well-defined failure plane extends to the ground surface. This is typical of shallow foundations on dense soil.
2. Local Shear Failure: Occurs in medium-dense soils where failure planes do not reach the surface.
3. Punching Shear Failure: Occurs in loose sands or soft clays where the foundation (or pile tip) penetrates vertically into the soil with very little disturbance to the surrounding soil mass. Because piles are slender elements that transfer loads deep into the ground, their ultimate bearing capacity failure at the tip in soft/loose soils is a classic example of punching shear.
Therefore, among the given options, punching shear is the characteristic failure mode associated with the penetration of a pile into the soil.
Weep holes are provided in the retaining walls for the following reason -
A)
To avoid friction behind the wall
B)
To improve the appearance
C)
To avoid cracks due to shrinkage
D)
To provide drainage of backfill
Step-by-step reasoning:
1. **Function of Retaining Walls**: Retaining walls are designed to resist the lateral pressure of soil (backfill).
2. **The Role of Water**: When rain falls or groundwater accumulates behind a retaining wall, the water fills the voids in the soil. This creates 'hydrostatic pressure' in addition to the soil's lateral earth pressure.
3. **Risk of Failure**: If water is allowed to accumulate, the total pressure on the wall increases significantly, which can lead to the wall tilting, sliding, or complete structural failure.
4. **Purpose of Weep Holes**: Weep holes are small openings left in the wall to allow trapped water to drain out from the backfill into the front of the wall.
5. **Evaluating Options**:
- (a) Friction is actually desirable behind the wall to help with stability; weep holes do not aim to avoid it.
- (b) Weep holes are functional, not aesthetic; they often detract from a smooth appearance.
- (c) Shrinkage cracks are managed by joint design and material selection, not by drainage holes.
- (d) Providing drainage of backfill directly reduces hydrostatic pressure, ensuring the stability of the wall.
The instrument used to measure the wind velocity in the atmosphere is -
A)
Current meter
B)
Atmometer
C)
Pycnometer
D)
Anemometer
The correct instrument for measuring wind velocity is the Anemometer.
Step-by-step analysis of the options:
1. **Anemometer (Option d):** Derived from the Greek word 'anemos' (wind), this instrument is specifically designed to measure the speed (velocity) and pressure of the wind. Common types include cup anemometers and sonic anemometers.
2. **Current meter (Option a):** This is used to measure the velocity of flow in open channels or pipes (water current), not wind.
3. **Atmometer (Option b):** This is used to estimate the rate of evaporation from a free water surface into the atmosphere.
4. **Pycnometer (Option c):** This is a laboratory device used to measure the density or specific gravity of a liquid or solid substance.
Therefore, based on the definitions of these hydrological and meteorological instruments, the Anemometer is the only correct choice.
The toughness of aggregate is tested by -
A)
Impact test
B)
Crushing strength test
C)
Abrasion test
D)
Soundness test
In civil engineering and building materials, different tests are conducted on aggregates to determine their mechanical properties:
1. **Toughness (Impact Test):** Toughness is defined as the ability of an aggregate to resist failure under repeated impact or shock loading. The Aggregate Impact Value (AIV) test is specifically used to measure this property. It involves dropping a hammer of a specific weight from a fixed height onto the aggregate sample.
2. **Crushing Strength (Crushing Test):** This test measures the resistance of an aggregate to gradual compressive loading. It determines the 'Crushing Value', which indicates the strength of the aggregate.
3. **Hardness/Wear (Abrasion Test):** The Los Angeles Abrasion test is used to determine the hardness of aggregates, which is their resistance to surface wear and rubbing (abrasion).
4. **Soundness (Soundness Test):** This test evaluates the resistance of aggregates to weathering actions, such as freeze-thaw cycles or chemical reactions (using sodium or magnesium sulfate solutions).
Therefore, the test for toughness is the Impact test.
For shorter storey height, cheaper formwork and better lighting facilities, what is the recommended slab floor?
A)
T beam and slab
B)
Two way slab
C)
Flat slab
D)
Framed structure
A flat slab is a reinforced concrete slab supported directly by columns without the use of beams.
1. **Shorter Storey Height:** Because there are no beams protruding downwards from the ceiling, the overall depth of the floor system is reduced. This allows for a reduction in the total height of the building for the same number of storeys or allows for more headroom within a fixed height.
2. **Cheaper Formwork:** The formwork for a flat slab is simple and flat, unlike beam-and-slab systems which require complex shuttering for the beams. This significantly reduces labor costs and time during construction.
3. **Better Lighting and Ventilation:** The absence of beams provides a clear, unobstructed ceiling. This allows light and air to circulate more freely across the floor area and provides more flexibility for the installation of HVAC ducts and lighting fixtures.
Comparison with other options:
- **T-beam and slab / Framed structure:** These involve beams that increase the floor-to-floor height and require more complex formwork.
- **Two-way slab:** While a two-way slab distributes loads in two directions, it is typically supported by beams on all four edges in a standard framed structure, thus not offering the specific height and formwork advantages of a flat slab.