Test 14 - General Specifications for RCC Work

Question 1 ప్రశ్న 1

During inspection of cement delivered for an RCC overhead water tank, several bags contain hard lumps and the contractor cannot establish satisfactory storage conditions. Which action is most consistent with general RCC specifications?

A Use the cement after crushing the lumps because the specified cement grade remains unchanged. B Segregate the suspect cement and establish its conformity and suitability through the prescribed verification procedure before permitting its use. C Increase the mixing water to compensate for possible deterioration of the cement. D Use the deteriorated cement only near reinforcement where steel will compensate for any loss of concrete strength.

Question 2 ప్రశ్న 2

An RCC beam contains closely spaced reinforcement, and the contractor proposes using coarse aggregate with a nominal maximum size that may obstruct movement through the reinforcement cage. What should govern aggregate selection?

A The largest aggregate available at the quarry should always be selected irrespective of reinforcement congestion. B Coarse aggregate size has no relationship with reinforcement spacing or placing conditions. C Aggregate grading may be ignored when mechanical vibration is provided. D Select suitably graded aggregate with a nominal maximum size compatible with member dimensions, reinforcement spacing, cover and the approved concrete specification.

Question 3 ప్రశ్న 3

Water obtained from an untested surface-water source is proposed for mixing RCC. The water contains visible organic matter and its chemical quality is unknown. Which procedure is appropriate?

A Use the water without testing because cement neutralizes all impurities. B Accept the water whenever it appears transparent after standing for a few hours. C Verify that the water satisfies the applicable concrete-mixing water requirements and reject or treat unsuitable water before use. D Increase the cement content arbitrarily and use the water without further checks.

Question 4 ప్రశ్న 4

An approved RCC specification requires M25 concrete. Which interpretation of this grade designation is technically correct?

A The characteristic compressive strength of standard 150 mm concrete cubes at 28 days is 25 N/mm2. B The concrete must be prepared using a fixed volumetric ratio of 1:2:5. C The concrete must contain exactly 25 percent cement by volume. D Every individual concrete cube must develop exactly 25 N/mm2 at seven days.

Question 5 ప్రశ్న 5

A contract specifies approved design-mix M30 RCC for a water-retaining structure. The contractor proposes replacing it with a nominal volumetric mix considered approximately equivalent in strength. What is the correct specification-based decision?

A Permit the replacement automatically because the apparent richness of a nominal mix determines its concrete grade. B Maintain the specified approved design mix unless a formally approved alternative is supported by the required verification and contractual authorization. C Permit the contractor to select any mix provided the cement consumption is greater than the original estimate. D Replace the specified mix without testing because additional vibration guarantees the required characteristic strength.

Question 6 ప్రశ్న 6

Under IS 456, a batching system is set to measure 500 kg of cement and 200 kg of water for a concrete batch. Using the specified equipment-accuracy tolerances of ±2 percent for cement and ±3 percent for water, which pair of measuring ranges is correct?

A Cement: 485–515 kg; water: 196–204 kg. B Cement: 495–505 kg; water: 190–210 kg. C Cement: 490–510 kg; water: 194–206 kg. D Cement: 480–520 kg; water: 198–202 kg.

Question 7 ప్రశ్న 7

An approved RCC mix requires 400 kg of cement per batch with an effective water-cement ratio of 0.45. The aggregates contribute 24 litres of free surface water, and there are no other sources of mixing water. Assuming the density of water is 1 kg/L, how much additional water should be introduced?

A 180 litres. B 204 litres. C 144 litres. D 156 litres.

Question 8 ప్రశ్న 8

A contractor requests permission to use volume batching for RCC because the site's weighing equipment is temporarily unavailable. Which condition is consistent with IS 456?

A Volume batching may be allowed where weigh-batching is impracticable, provided accurate bulk densities are established and suitable bulking corrections and controls are applied. B Volume batching is automatically permissible for every RCC grade without establishing aggregate bulk density. C Volume batching eliminates the need to check aggregate moisture or sand bulking. D The same uncompensated gauge-box volume must always be used for wet and dry sand regardless of moisture condition.

Question 9 ప్రశ్న 9

During RCC production, a mechanical mixer discharges concrete with visibly nonuniform colour and pockets of incompletely mixed material. Which corrective action best satisfies general mixing specifications?

A Place the concrete immediately because compaction will necessarily complete the mixing process. B Add dry cement directly to the discharged material without controlling the resulting proportions. C Correct the mixing procedure and continue mechanical mixing until uniform distribution, colour and consistency are achieved, subject to the approved production controls. D Permit inconsistent batches whenever the nominal cement content is greater than the estimated requirement.

Question 10 ప్రశ్న 10

Ready-mixed concrete arrives for an RCC pump-house slab, but the delivery records do not clearly identify the supplied grade, batch details or relevant production information. What should the receiving engineer do before authorizing placement?

A Accept the concrete solely because the transit mixer belongs to an established supplier. B Verify the delivery documentation, approved mix identity and relevant workability and quality-control requirements before accepting the concrete for placement. C Determine the concrete grade only from its colour and apparent aggregate size. D Permit placement first and subsequently assign any convenient grade in the measurement book.

Question 11 ప్రశ్న 11

During placement of approved design-mix RCC, the site supervisor observes insufficient workability around congested reinforcement. Workers propose adding water directly to the concrete without further verification. Which response is technically appropriate?

A Add any quantity of water required because workability is unrelated to hardened concrete performance. B Increase the water-cement ratio without recording the change because only the cement quantity determines strength. C Add dry sand to the concrete after delivery without modifying other ingredients. D Stop unauthorized water addition and adopt an approved adjustment or workability-control procedure that preserves specified concrete performance.

Question 12 ప్రశ్న 12

Concrete is being deposited into a deep RCC column form using a method that allows the coarse aggregate to separate from the mortar during discharge. Which placement practice is most appropriate?

A Use a suitable placing arrangement, such as a properly positioned chute, pump delivery line or drop pipe, to minimize segregation and deposit concrete near its final position. B Allow uncontrolled discharge from any height because the reinforcement cage will automatically remix the concrete. C Deposit all the concrete at one side of the column and use the vibrator to drag it across the form. D Increase the water content until the separated coarse aggregate floats back into suspension.

Question 13 ప్రశ్న 13

A heavily reinforced RCC wall is being concreted in successive layers using an internal needle vibrator. Which compaction procedure is most appropriate?

A Use the vibrator primarily to move concrete horizontally over long distances within the formwork. B Continue vibration until coarse aggregates visibly collect at the bottom and mortar rises to the top. C Compact each layer systematically, allowing suitable penetration into the preceding still-plastic layer while avoiding excessive vibration and disturbance of reinforcement. D Compact only the exposed surface because internal voids are automatically eliminated by the self-weight of concrete.

Question 14 ప్రశ్న 14

After removal of formwork from an RCC column, significant honeycombing and exposed coarse aggregates are observed near a congested reinforcement zone. What is the most appropriate engineering response?

A Conceal the honeycombed area immediately with ordinary plaster without examining its extent. B Assess the extent and significance of the defect and implement an approved repair or other disposition based on the engineer's evaluation. C Ignore the defect because all honeycombing is purely cosmetic. D Remove the exposed aggregates and leave the resulting cavities empty to improve ventilation.

Question 15 ప్రశ్న 15

Before concreting an RCC beam, inspection reveals that the formwork joints are open and several supports are insufficiently braced. Which requirement should be enforced?

A Permit concreting because leakage of cement slurry assists in reducing excess water. B Remove lateral bracing to allow the shuttering to deform freely during vibration. C Fill the open joints with loose aggregate and proceed without inspecting the supports. D Ensure that formwork is sufficiently rigid, properly supported, dimensionally accurate and adequately tight against loss of cement slurry.

Question 16 ప్రశ్న 16

A contractor applies a form-release agent to shuttering for an RCC wall. During inspection, the agent is found coating several reinforcement bars. What correction is required?

A Clean contamination from the reinforcement and apply a suitable release agent as a thin uniform coating on the form-contact surfaces without coating the reinforcement. B Accept the coating because release agents increase the bond between steel and concrete. C Apply additional release agent directly to all reinforcement to reduce friction during concrete placement. D Omit reinforcement inspection because release-agent contamination affects only the appearance of formwork.

Question 17 ప్రశ్న 17

A reinforced concrete beam requires a specified nominal cover to the reinforcement. During inspection, the contractor measures this cover to the longitudinal bars while ignoring the stirrups positioned outside them. Which interpretation is correct?

A Nominal cover is always measured from the concrete surface to the centre of the longitudinal reinforcement. B Nominal cover may be reduced whenever transverse reinforcement is present. C Nominal cover should be maintained to the outermost reinforcement, including stirrups or links, using suitable spacers and supports. D Nominal cover is required only at the bottom face of an RCC beam.

Question 18 ప్రశ్న 18

Immediately before placing RCC in a water-retaining wall, the engineer discovers loose flaky rust and oil on some reinforcement, displaced spacers and an incorrectly positioned embedded sleeve. What is the appropriate pre-pour action?

A Proceed because fresh concrete will automatically correct the reinforcement and sleeve positions. B Clean the affected reinforcement, restore the specified cover and embedded-item positions, and obtain the required inspection clearance before concreting. C Increase the concrete slump so that the sleeve and reinforcement move into their correct positions. D Remove all spacers because reinforcement can be supported permanently by the fresh concrete.

Question 19 ప్రశ్న 19

A contractor proposes introducing several construction joints in an RCC reservoir wall solely for convenience, without obtaining approval for their locations. Which procedure is consistent with IS 456?

A Minimize construction joints and provide them at locations and in arrangements indicated or approved by the designer, following the specified joint-treatment procedure. B Place construction joints at any location provided the concrete surfaces are later painted. C Treat construction joints as interchangeable with expansion joints without considering the approved design. D Introduce an untreated horizontal joint at every change of concrete delivery vehicle.

Question 20 ప్రశ్న 20

Fresh RCC must be placed against a previously hardened concrete surface at an approved construction joint. The surface contains laitance and loose particles. Which preparation is technically appropriate?

A Place fresh concrete directly over the laitance because it acts as a natural bonding compound. B Apply a thick layer of dry cement powder without cleaning the hardened concrete. C Leave standing water on the hardened concrete surface to improve bonding automatically. D Remove laitance and unsound material, prepare a clean suitably roughened surface, bring it to the required saturated-surface-dry condition and compact fresh concrete properly at the interface.

Question 21 ప్రశ్న 21

While finishing a newly placed RCC floor slab, workers propose sprinkling dry cement powder and additional water over the surface to obtain a smooth finish. Which finishing practice is more appropriate?

A Add uncontrolled water during finishing because it always improves concrete surface strength. B Apply dry cement powder liberally to absorb bleed water and form a hard surface. C Use the specified screeding and finishing procedure at the appropriate stage without introducing uncontrolled water or dry cement, and commence suitable curing thereafter. D Complete all finishing before concrete placement so that no later surface treatment is necessary.

Question 22 ప్రశ్న 22

Under the moist-curing provisions of IS 456, which statement correctly identifies the minimum curing periods for ordinary Portland cement concrete and concrete containing blended cement or mineral admixtures under normal, non-hot-and-dry conditions?

A At least 7 days for ordinary Portland cement concrete and at least 10 days for concrete containing blended cement or mineral admixtures. B At least 3 days for ordinary Portland cement concrete and at least 5 days for concrete containing blended cement. C Exactly 7 days for both categories, regardless of the specified cementitious materials. D At least 14 days for ordinary Portland cement concrete and exactly 21 days for every blended-cement concrete.

Question 23 ప్రశ్న 23

An RCC roof slab made using ordinary Portland cement is exposed to dry and hot weather. The contractor proposes stopping moisture curing after seven days and using an unapproved curing compound for the remaining period. Which action is consistent with IS 456?

A Stop curing after seven days because the curing period never changes with weather conditions. B Maintain the required curing for at least ten days in dry and hot weather, or use a suitable approved alternative curing procedure with the engineer-in-charge's permission. C Replace curing entirely with an additional layer of dry cement spread over the slab. D Allow the slab to dry naturally after three days because high temperatures eliminate the need for continued hydration.

Question 24 ప్రశ్న 24

An RCC slab measures 7.00 m by 5.00 m with a uniform thickness of 0.15 m. It contains one full-depth rectangular opening measuring 1.20 m by 1.00 m. For measurement, deduct the full opening volume and assume there are no beams, projections or other adjustments. What is the net RCC concrete quantity?

A 5.250 m3. B 4.950 m3. C 5.100 m3. D 5.070 m3.

Question 25 ప్రశ్న 25

An isolated cast-in-situ rectangular RCC beam is 5.00 m long, 0.30 m wide and 0.50 m deep. The top is open during casting, while the soffit and both vertical sides require formwork. Assume no end shutters, junction adjustments, openings or other deductions. What is the total formwork contact area to be measured?

A 3.00 m2. B 5.00 m2. C 6.50 m2. D 7.50 m2.

Answer Key || సమాధానాల పట్టిక

Related Quizzes || సంబంధిత క్విజ్‌లు

Civil HMWSSB, Unit 9 - Estimation, Costing and Construction Management Quiz

TGPSC HMWSSB Quiz

Answer Key సమాధానాల పట్టిక

Related Quizzes సంబంధిత క్విజ్‌లు