Description : How long will it take for the concrete to achieve 100% of its strength? (A) 7 days (B) 14 days (C) 21 days (D) 28 day
Last Answer : Answer: Option D
Description : In favourable circumstances a 15 cm concrete cube after 28 days, attains a maximum crushing strength (A) 100 kg/cm2 (B) 200 kg/cm2 (C) 300 kg/cm2 (D) 400 kg/cm
Description : The 28 days cube strength of mass concrete using aggregates of maximum size 5 cm for gravity dams should be (A) Between 150 to 300 kg/cm2 (B) Between 350 to 600 kg/cm2 (C) Between 150 to 500 kg/cm2 (D) Below 200 kg/cm2
Description : According to IS specifications, the compressive strength of ordinary Portland cement after three days should not be less than (A) 7 MPa (B) 11.5 MPa (C) 16 MPa (D) 21 MPa
Last Answer : Answer: Option C
Description : Newly constructed pavement with ordinary Portland cement attains its working strength after (A) 7 days (B) 14 days (C) 21 days (D) 28 days
Description : For performing the compressive strength test of cement, the size of cube mould should be (a) 7.06cm (b)75mm (c)80mm (d)All the above
Last Answer : (a) 7.06cm
Description : Minimum compressive strength of cement required at the age of 3 days for ordinary Portland cement of grade 33 is [ A ] 1.15 N/mm2 [ B ] 11.5 N/mm2 [ C ] 2.10 N/mm2 [ D ] 21 N/mm2
Last Answer : [ B ] 11.5 N/mm2
Description : Minimum number of 50 kg cement bags per cubic metre of concrete for a mix corresponding to crushing strength 280 kg/cm2 at 28 days, are (A) 5.0 (B) 6.5 (C) 7.0 (D) 7.5
Last Answer : Answer: Option B
Description : For lime concrete, (A) Slump is 50 to 75 mm (B) Flexural strength at 90 days is 0.2 N/mm2 (C) Compressive strength at 90 days is 1.5 N/mm2 (D) All the above
Description : The compressive strength of 100 mm cube as compared to 150 mm cube is always (A) Less (B) More (C) Equal (D) None of the above
Description : Pick up the incorrect statement from the following. For performing compressive strength test of cement (A) Cement and standard sand mortar are used in the ratio of 1 : 3 (B) Water is added at the ... cm 10 cm is used (D) The prepared moulds are kept in a atmosphere of 50% relative humidity
Last Answer : Answer: Option A
Description : For testing compressive strength of cement, the size of cube used is (A) 50 mm (B) 70.6 mm (C) 100 mm (D) 150 mm
Last Answer : B
Description : The strength of concrete after one year as compared to 28 days strength is about (A) 10 to 15% more (B) 15 to 20% more (C) 20 to 25% more (D) 25 to 50% more
Description : At 28 days of curing concrete attains a strength of [ A ] 20 to 25% [ B ] 60 to 70% [ C ] 65 to 80% [ D ] 90 to 95%
Last Answer : [ D ] 90 to 95%
Description : A rolling contact bearing is specified as X307. Calculate the bearing diameter. (a) 35 mm (b) 28 mm (c) 21 mm (d) 7 mm
Last Answer : (a) 35 mm
Description : The compressive strength an ordinary Portland cement (1:3) after 7 days test should not be less than. (a) 11N/mm2 (b) 17.5 N/mm2 (c) 22 N/mm2 (d) 27.5N/m2
Last Answer : (b) 17.5 N/mm2
Description : The modular ratio m of a concrete whose permissible compressive stress is C, may be obtained from the equation. (A) m = 700/3C (B) m = 1400/3C (C) m = 2800/3C (D) m = 3500/3C
Description : Slump test of concrete is a measure of its (A) Consistency (B) Compressive strength (C) Tensile strength (D) Impact value
Last Answer : (A) Consistency
Description : Permissible compressive strength of M 200 concrete grade is (A) 100 kg/cm2 (B) 150 kg/cm2 (C) 200 kg/cm2 (D) 250 kg/cm2
Last Answer : (C) 200 kg/cm2
Description : Permissible compressive strength of M 300 concrete grade is (A) 100 kg/cm2 (B) 150 kg/cm2 (C) 200 kg/cm2 (D) 300 kg/cm2
Last Answer : (D) 300 kg/cm2
Description : A higher modular ratio shows (A) Higher compressive strength of concrete (B) Lower compressive strength of concrete (C) Higher tensile strength of steel (D) Lower tensile strength of steel
Description : Modulus of rupture of concrete is a measure of (A) Flexural tensile strength (B) Direct tensile strength (C) Compressive strength (D) Split tensile strength
Description : According to IS: 4561978, the flexural strength of concrete is (A) Directly proportional to compressive strength (B) Inversely proportional to compressive strength (C) Directly proportional to square root of compressive strength (D) Inversely proportional to square root of compressive strength
Description : Permissible compressive strength of M 150 concrete grade is (A) 100 kg/cm2 (B) 150 kg/cm2 (C) 200 kg/cm2 (D) 250 kg/cm2
Description : Allowable shear strength of concrete, depends upon (A) Shear strength (B) Tensile strength (C) Compressive strength (D) None of these
Description : In limit state design of concrete for flexure, the area of stress block is taken as (a) 0.530 fck. Xu (b) 0.446 fck . Xu ( c) 0.420 fck .Xu (d) 0.360 fck . Xu Where fck is characteristic compressive strength of concrete and Xu is the depth of neutral axis from top.
Last Answer : (d) 0.360 fck . Xu
Description : Normally, the tensile strength of concrete is about____________of its compressive strength (a) 10 to 15% (b) 15 to 20% (c) 20 to 25% (d) 25 to 30%
Last Answer : (a) 10 to 15%
Description : The tensile strength of concrete is about ________ of its compressive strength [ A ] 10% to 15% [ B ] 30% to 40% [ C ] 50% [ D ] 60% to 75%
Last Answer : [ A ] 10% to 15%
Description : Slump test of concrete is a measure of its [ A ] Consistency [ B ] Compressive strength [ C ] Tensile strength [ D ] Impact value
Last Answer : [ A ] Consistency
Description : The minimum cube strength of concrete used for a pre-stressed member, is (A) 50 kg/cm2 (B) 150 kg/cm2 (C) 250 kg/cm2 (D) 350 kg/cm
Description : Cube strength of controlled concrete to be used for pre-tensioned and post-tensioned work respectively should not be less than (A) 35 MPa and 42 MPa (B) 42 MPa and 35 MPa (C) 42 MPa and 53 MPa (D) 53 MPa and 42 MPa
Description : Generally the strength of concrete is represented by the crushing stress of concrete cube of size [ A ] 50 mm [ B ] 100 mm [ C ] 150 mm [ D ] 250 mm
Last Answer : [ C ] 150 mm
Description : The approximate ratio between the strength of cement concrete at seven days and 28 days is a) 3/ 4 b) 2/3* c) 1/2 d) 1/3
Last Answer : b) 2/3*
Description : Which of the following cements is expected to have the highest compressive strength after 3 days (a) Ordinary Portland cement (b) Rapid hardening cement (c) High alumina cement (d) Sulphate resisting cement.
Last Answer : (c) High alumina cement
Description : As per IS: 456, permissible direct compressive stress M20 grade concrete in working stress method of designer [ A ] 5.0 N/mm2 [ B ] 7.0 N/mm2 [ C ] 10.0 N/mm2 [ D ] 20.0 N/mm2
Last Answer : [ A ] 5.0 N/mm2
Description : In working stress method of design, permissible compressive bending stress for M20 grade concrete is given by [ A ] 5.0 N/mm2 [ B ] 7.0 N/mm2 [ C ] 10.0 N/mm2 [ D ] 20 N/mm2
Last Answer : [ B ] 7.0 N/mm2
Description : Steel rods are used in reinforced concrete to increase its __________ strength. (A) Shear (B) Tensile (C) Compressive (D) None of these
Last Answer : (B) Tensile
Description : Steel rods are normally used for concrete reinforcement because concrete and steel have almost equal (A) Tensile strength (B) Compressive strength (C) Young's modulus (D) Thermal co-efficient of expansion
Last Answer : (D) Thermal co-efficient of expansion
Description : Explain the rebound hammer test procedure and show the relationship between compressive strength and rebound number with hammer horizontal and vertical on dry and wet surface of concrete.
Last Answer : Rebound Hammer Test: i. Initially the plunger of rebound hammer is Kept touching to the target concrete surface ii. Then the tubular casing of hammer is pushed towards concrete, so that the spring gets ... of concrete will be less, But if it is more, then concrete possess sufficient strength.
Description : Explain the laboratory procedure to determine the compressive strength of concrete cubes as per IS-516-1959 with reference to following points: i. Preparation of test specimen ii. Procedure of testing iii. Interpretation of results
Last Answer : Preparation of test specimen: i. Take three cubes of 15 cm sides and apply oil to its inner surface. ii. Prepare the concrete mixture of required grade and fill it in each mould in 3 layers. ... say 23N/mm 2) than the specified grade M20, then that concrete is safe and good for construction.
Description : Illustrate the effect of properties of coarse aggregates on compressive strength of concrete.
Last Answer : Effect of properties of coarse aggregates on compressive strength of concrete. i. Size of aggregate: If coarse aggregate particles are of large size (say 20 mm) in concrete mixture , then ... of strength. But if water absorption is less concrete becomes as per proportion giving required strength.
Description : Explain the procedure to determine compressive strength of concrete in lab.
Last Answer : Procedure to determine compressive strength of concrete in lab: The following steps are essential to determine the compressive strength of concrete in the laboratory. 1. Take three cube moulds of 15 cm side and ... in mm2 . 8. Calculate average compressive strength of three test cubes in N/mm2 .
Description : The development of first 28 days strength is on account of the hydration of (a) Tricalcium silicate (b) Dicalcium silicate (c) Tricalcium aluminate (d) Tetra calcium alumina ferrite
Last Answer : (a) Tricalcium silicate
Description : For an ordinary Portland cement (A) Residual does not exceed 10% when sieved through IS Sieve No. 9 (B) Soundness varies from 5 to 10 mm (C) Initial setting time is not less than 30 minutes (D) Compressive stress after 7 days, is not less than 175 kg/cm2
Last Answer : (C) Initial setting time is not less than 30 minutes
Description : The compressive strength of cement should not be less than about 110Kg/cm2 after three days & not less than 170Kg/cm2 after seven days. The fineness of an ordinary cement as determined by turbidimetric method should be about __________ cm2 /gm. (A) 800 (B) 1600 (C) 4000 (D) 8500
Last Answer : (B) 1600
Description : The form Work including the props can be removed from beams, only after (A) 3 day (B) 7 days (C) 14 days (D) 21 days
Description : Steel beam theory is used for (A) Design of simple steel beams (B) Steel beams encased in concrete (C) Doubly reinforced beams ignoring compressive stress in concrete (D) Beams if shear exceeds 4 times allowable shear stress
Description : A short column 20 cm 20 cm in section is reinforced with 4 bars whose area of cross section is 20 sq. cm. If permissible compressive stresses in concrete and steel are 40 kg/cm2 and 300 kg/cm2 , the Safe load on ... should not exceed (A) 4120 kg (B) 41,200 kg (C) 412,000 kg (D) None of these