Explain the importance of water/cement ratio in the concrete mix.

Explain the importance of water/cement ratio in the concrete mix.
by

1 Answer

Answer :

Importance of water/cement ratio in the concrete mix : i. The W/C ratio plays very vital role in concrete mixture. The improper or random selection of W/C ratio leads in various defects in fresh and hardened concrete. ii. If W/C ratio is less (say w/c= 1/4 = 0.25), then concrete will become harsh and results in honeycombing or porous nature due to poor workability. iii. If w/c ratio is more (say w/c = 3/4 = 0.75), then concrete undergoes segregation and bleeding. Thus finally concrete shows defects in it. iv. Therefore w/c ratio should be optimum, which depends on grade of concrete and exposure conditions hence w/c ratio should be selected from IS: 456:2000. v. If w/c ratio is opted out properly as mentioned above, then concrete possess good workability, compressive strength and durability ultimately.
by

Related questions

According to Water-Cement Ratio Law, the strength of workable plastic concrete (A) Depends upon the amount of water used in the mix (B) Does not depend upon the quality of cement mixed with aggregates (C) Does not depend upon the quantity of cement mixed with aggregates (D) All the above

Description : According to Water-Cement Ratio Law, the strength of workable plastic concrete (A) Depends upon the amount of water used in the mix (B) Does not depend upon the quality of cement mixed with aggregates (C) Does not depend upon the quantity of cement mixed with aggregates (D) All the above

Last Answer : Answer: Option D

If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is (A) 8 kg (B) 10 kg (C) 12 kg (D) 14 kg

Description : If 50 kg of fine aggregates and 100 kg of coarse aggregates are mixed in a concrete whose water cement ratio is 0.6, the weight of water required for harsh mix, is (A) 8 kg (B) 10 kg (C) 12 kg (D) 14 kg

Last Answer : Answer: Option C

Workability of concrete is inversely proportional to (A) Time of transit (B) water-cement ratio (C) The air in the mix (D) Size of aggregate

Description : Workability of concrete is inversely proportional to (A) Time of transit (B) water-cement ratio (C) The air in the mix (D) Size of aggregate

Last Answer : Answer: Option A

Shrinkage in concrete can be reduced by using (A) Low water cement ratio (B) Less cement in the concrete (C) Proper concrete mix (D) All the above

Description : Shrinkage in concrete can be reduced by using (A) Low water cement ratio (B) Less cement in the concrete (C) Proper concrete mix (D) All the above

Last Answer : Answer: Option D

For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is (A) 10 kg (B) 12 kg (C) 14 kg (D) 16 k

Description : For a concrete mix 1:3:6 and water cement ratio 0.6 both by weight, the quantity of water required per bag, is (A) 10 kg (B) 12 kg (C) 14 kg (D) 16 kg

Last Answer : Answer: Option C

Workability of concrete mix with low water cement ratio is determined by (A) Tensile strength test (B) Slump test (C) Compaction factor test (D) Flexural strength test

Description : Workability of concrete mix with low water cement ratio is determined by (A) Tensile strength test (B) Slump test (C) Compaction factor test (D) Flexural strength test

Last Answer : Answer: Option C

The factors which effects the design of concrete mix is (a) Fineness modulus (b) Water cement ratio (c) Slump (d) All of these

Description : The factors which effects the design of concrete mix is (a) Fineness modulus (b) Water cement ratio (c) Slump (d) All of these

Last Answer : (d) All of these

According to the rule of water cement ratio, the strength of concrete wholly depends upon. (a) The quality of cement. (b) The quality of cement mixed with aggregate. (c) The amount of water used in preparation of concrete mix. (d) All of the above

Description : According to the rule of water cement ratio, the strength of concrete wholly depends upon. (a) The quality of cement. (b) The quality of cement mixed with aggregate. (c) The amount of water used in preparation of concrete mix. (d) All of the above

Last Answer : (c) The amount of water used in preparation of concrete mix.

Workability of concrete mix with low water cement ratio is determined by [ A ] Tensile strength test [ B ] Slump cone test [ C ] Compaction factor test [ D ] Flexural strength test

Description : Workability of concrete mix with low water cement ratio is determined by [ A ] Tensile strength test [ B ] Slump cone test [ C ] Compaction factor test [ D ] Flexural strength test

Last Answer : [ C ] Compaction factor test

The ratio of differenct ingredients (cement, sand and aggregate) in concrete mix of grade M20 is. (a) 1:1:2 (b) 1:1.5:2 (c) 1:2:4 (d) 1:3:6

Description : The ratio of differenct ingredients (cement, sand and aggregate) in concrete mix of grade M20 is. (a) 1:1:2 (b) 1:1.5:2 (c) 1:2:4 (d) 1:3:6

Last Answer : (b) 1:1.5:2

The shrinkage of concrete (A) Is proportional to water content is the mix (B) Is proportional to cement concrete (C) Increases with age of concrete (D) All the above

Description : The shrinkage of concrete (A) Is proportional to water content is the mix (B) Is proportional to cement concrete (C) Increases with age of concrete (D) All the above

Last Answer : (D) All the above

Pick up the correct statement from the following: (A) The weight of ingredients of concrete mix, is taken in kilograms (B) Water and aggregates are measured in litres (C) 20 bags of cement make one tonne (D) All the above

Description : Pick up the correct statement from the following: (A) The weight of ingredients of concrete mix, is taken in kilograms (B) Water and aggregates are measured in litres (C) 20 bags of cement make one tonne (D) All the above

Last Answer : Answer: Option D

Inert material of a cement concrete mix, is (A) Water (B) Cement (C) Aggregate (D) None of these

Description : Inert material of a cement concrete mix, is (A) Water (B) Cement (C) Aggregate (D) None of these

Last Answer : Answer: Option C

Pick up the incorrect statement from the following. While performing preliminary test on concrete (A) Proportions of the material and water should be the same as to be used at the work site (B) Cement should be mixed by hand in order to maintain uniformity (C) Concrete mix should be stored in air-tight containers (D) Concrete ingredients should be kept at a temperature of 37° ± 2°C

Description : Pick up the incorrect statement from the following. While performing preliminary test on concrete (A) Proportions of the material and water should be the same as to be used at the work site (B) ... in air-tight containers (D) Concrete ingredients should be kept at a temperature of 37° 2°C

Last Answer : Answer: Option D

Pick up the correct statement from the following: (A) An increase in water content must be accompanied by an increase in cement content (B) Angular and rough aggregates reduce the workability of the concrete (C) The slump of the concrete mix decreases due to an increase in temperature (D) All the above

Description : Pick up the correct statement from the following: (A) An increase in water content must be accompanied by an increase in cement content (B) Angular and rough aggregates reduce the workability of the ... The slump of the concrete mix decreases due to an increase in temperature (D) All the above

Last Answer : Answer: Option D

The basic purpose of a retarder in concrete is (A) To increase the initial setting time of cement paste in concrete (B) To decrease the initial setting time of cement paste in concrete (C) To render the concrete more water tight (D) To improve the workability of concrete mix

Description : The basic purpose of a retarder in concrete is (A) To increase the initial setting time of cement paste in concrete (B) To decrease the initial setting time of cement paste in concrete (C) To render the concrete more water tight (D) To improve the workability of concrete mix

Last Answer : Answer: Option A

Inert material of a cement concrete mix, is [ A ] Water [ B ] Aggregate [ C ] Cement [ D ] None of these

Description : Inert material of a cement concrete mix, is [ A ] Water [ B ] Aggregate [ C ] Cement [ D ] None of these

Last Answer : [ B ] Aggregate

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

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

After casting, an ordinary cement concrete on drying (A) Expands (B) Mix (C) Shrinks (D) None of these

Description : After casting, an ordinary cement concrete on drying (A) Expands (B) Mix (C) Shrinks (D) None of these

Last Answer : (C) Shrinks

For batching 1:3:6 concrete mix by volume, the ingredients required per bag of 50 kg cement, are: (A) 70 litres of sand and 120 litres of aggregates (B) 70 kg of sand and 140 litres of aggregates (C) 105 litres of sand and 140 litres of aggregates (D) 105 litres of sand and 210 litres of aggregates

Description : For batching 1:3:6 concrete mix by volume, the ingredients required per bag of 50 kg cement, are: (A) 70 litres of sand and 120 litres of aggregates (B) 70 kg of sand and 140 litres of ... C) 105 litres of sand and 140 litres of aggregates (D) 105 litres of sand and 210 litres of aggregates

Last Answer : Answer: Option D

Modulus of elasticity of concrete is primarily influenced by [ A ] Elastic properties of aggregate [ B ] Curing of concrete [ C ] Age of concrete [ D ] Mix proportion and type of cement

Description : Modulus of elasticity of concrete is primarily influenced by [ A ] Elastic properties of aggregate [ B ] Curing of concrete [ C ] Age of concrete [ D ] Mix proportion and type of cement

Last Answer : [ A ] Elastic properties of aggregate

Pick up the incorrect statement from the following. If water cement ratio is (A) Increased, strength of concrete increases (B) Decreased, strength of concrete increases(D) None of these (C) Increased, strength of concrete is not affected

Description : Pick up the incorrect statement from the following. If water cement ratio is (A) Increased, strength of concrete increases (B) Decreased, strength of concrete increases (C) Increased, strength of concrete is not affected (D) None of these

Last Answer : Answer: Option C

Strength of concrete increases with (A) Increase in water-cement ratio (B) Increase in fineness of cement (C) Decrease in curing time (D) Decrease in size of aggregate

Description : Strength of concrete increases with (A) Increase in water-cement ratio (B) Increase in fineness of cement (C) Decrease in curing time (D) Decrease in size of aggregate

Last Answer : (B) Increase in fineness of cement

While designing an air entrained concrete (A) Water cement ratio is reduced (B) Proportion of aggregates is reduced (C) An allowance for the entrained air is made (D) All the above

Description : While designing an air entrained concrete (A) Water cement ratio is reduced (B) Proportion of aggregates is reduced (C) An allowance for the entrained air is made (D) All the above

Last Answer : (D) All the above

The condition not applicable to water cement ratio law, is (A) Internal moisture conditions on hydration continue till complete strength is gained (B) Concrete specimens may be tested at any temperature (C) Concrete specimens need be of same age (D) Concrete specimens need be of same size

Description : The condition not applicable to water cement ratio law, is (A) Internal moisture conditions on hydration continue till complete strength is gained (B) Concrete specimens may be tested at any temperature (C) Concrete specimens need be of same age (D) Concrete specimens need be of same size

Last Answer : Answer: Option B

Water cement ratio is (A) Volume of water to that of cement (B) Weight of water to that of cement (C) Weight of concrete to that of water (D) Both (a) and (b) of the above

Description : Water cement ratio is (A) Volume of water to that of cement (B) Weight of water to that of cement (C) Weight of concrete to that of water (D) Both (a) and (b) of the above

Last Answer : Answer: Option D

C.R.R.I. charts are used to obtain a relationship between strength of concrete and (A) Water cement ratio (B) Workability (C) Grading of aggregate (D) Fineness modulus

Description : C.R.R.I. charts are used to obtain a relationship between strength of concrete and (A) Water cement ratio (B) Workability (C) Grading of aggregate (D) Fineness modulus

Last Answer : Answer: Option A

The lower water cement ratio in concrete, introduces (A) Smaller creep and shrinkage (B) Greater density and smaller permeability (C) Improved frost resistance (D) All the above

Description : The lower water cement ratio in concrete, introduces (A) Smaller creep and shrinkage (B) Greater density and smaller permeability (C) Improved frost resistance (D) All the above

Last Answer : Answer: Option D

Minimum required water cement ratio for a workable concrete, is (A) 0.30 (B) 0.40 (C) 0.50 (D) 0.60

Description : Minimum required water cement ratio for a workable concrete, is (A) 0.30 (B) 0.40 (C) 0.50 (D) 0.60

Last Answer : Answer: Option B

Pick up the correct statement from the following: (A) For thin structures subjected to wetting and drying, the water cement ratio should be 0.45 (B) For mass concrete structures subjected to wetting and drying, the water ratio should be 0.55 (C) For thin structures which remain continuously under water, the water-cement ratio by weight should be 0.55 (D) All the above

Description : Pick up the correct statement from the following: (A) For thin structures subjected to wetting and drying, the water cement ratio should be 0.45 (B) For mass concrete structures subjected to wetting and ... under water, the water-cement ratio by weight should be 0.55 (D) All the above

Last Answer : Answer: Option D

Which one of the following statements is not correct with respect to PSC beams? (a) Loss due to shrinkage is proportional to water-cement ratio used in concrete (b) Loss due to creep is proportional to the age of the member at the time of loading. (c) Loss due to elastic deformation is directly proportionally to the modulus of elasticity of concrete (d) Loss due to friction occurs in post tensioned concrete members

Description : Which one of the following statements is not correct with respect to PSC beams? (a) Loss due to shrinkage is proportional to water-cement ratio used in concrete (b) Loss due to creep is ... to the modulus of elasticity of concrete (d) Loss due to friction occurs in post tensioned concrete members

Last Answer : (c) Loss due to elastic deformation is directly proportionally to the modulus of elasticity of concrete

For different concrete specimens, each hydrated tot he same degree, the permeability is (a) Higher with lower water cement ratio and higher cement content (b) Lower with lower water cement ratio and higher cement content (c) Lower with higher water cement ratio and lower cement content (d) Lower with higher water cement ratio and higher cement content

Description : For different concrete specimens, each hydrated tot he same degree, the permeability is (a) Higher with lower water cement ratio and higher cement content (b) Lower with lower water cement ratio ... ratio and lower cement content (d) Lower with higher water cement ratio and higher cement content

Last Answer : (b) Lower with lower water cement ratio and higher cement content

The workability of concrete is expressed by (a) Water-cement ratio (b) Slump value (c) Compaction factor (d) Both (a) and (b)

Description : The workability of concrete is expressed by (a) Water-cement ratio (b) Slump value (c) Compaction factor (d) Both (a) and (b)

Last Answer : (d) Both (a) and (b)

The strength of cement concrete increases with (a) The increase of water cement ratio. (b) The decrease of water cement ratio. (c) The increase of cement ratio (d) None of these

Description : The strength of cement concrete increases with (a) The increase of water cement ratio. (b) The decrease of water cement ratio. (c) The increase of cement ratio (d) None of these

Last Answer : (a) The increase of water cement ratio.

Water cement ratio is (a) Weight of water to that of cement. (b) Weight of concrete to that of water. (c) Volume of concrete to that of water. (d) All the above.

Description : Water cement ratio is (a) Weight of water to that of cement. (b) Weight of concrete to that of water. (c) Volume of concrete to that of water. (d) All the above.

Last Answer : (a) Weight of water to that of cement.

The main factors affecting the permeability of concrete are (i)Grade of concrete (ii)Minimum cement content (iii)Maximum water cement ratio [ A ] i [ B ] i and ii [ C ] ii and iii [ D ] i, ii and iii

Description : The main factors affecting the permeability of concrete are (i)Grade of concrete (ii)Minimum cement content (iii)Maximum water cement ratio [ A ] i [ B ] i and ii [ C ] ii and iii [ D ] i, ii and iii

Last Answer : [ C ] ii and iii

The main factors affecting the permeability of concrete are (i)Grade of concrete (ii)Minimum cement content (iii)Maximum water cement ratio [ A ] i [ B ] i and ii [ C ] ii and iii [ D ] i, ii and iii

Description : The main factors affecting the permeability of concrete are (i)Grade of concrete (ii)Minimum cement content (iii)Maximum water cement ratio [ A ] i [ B ] i and ii [ C ] ii and iii [ D ] i, ii and iii

Last Answer : [ C ] ii and iii

The workability of concrete is mostly influenced by its [ A ] Water cement ratio [ B ] Aggregate cement ratio [ C ] Cement content [ D ] Water content

Description : The workability of concrete is mostly influenced by its [ A ] Water cement ratio [ B ] Aggregate cement ratio [ C ] Cement content [ D ] Water content

Last Answer : [ A ] Water cement ratio

High strength of concrete requires a water cement ratio of [ A ] 0.10 to 0.15 [ B ] 0.25 to 0.30 [ C ] 0.45 to 0.60 [ D ] 0.75 to 0.90

Description : High strength of concrete requires a water cement ratio of [ A ] 0.10 to 0.15 [ B ] 0.25 to 0.30 [ C ] 0.45 to 0.60 [ D ] 0.75 to 0.90

Last Answer : [ B ] 0.25 to 0.30

Shrinkage in concrete can be reduced by using (i) Low water cement ratio (ii) More amount of cement in the concrete (iii) Presaturated aggregates [ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iii

Description : Shrinkage in concrete can be reduced by using (i) Low water cement ratio (ii) More amount of cement in the concrete (iii) Presaturated aggregates [ A ] i [ B ] i and ii [ C ] i and iii [ D ] i, ii and iii

Last Answer : [ C ] i and iii

How does the ratio sand to cement effect the strength of concrete?

Description : How does the ratio sand to cement effect the strength of concrete?

Last Answer : Need answer

The ratio of various ingredients (cement, sand, aggregates) in concrete of grade M 200, is (A) 1 : 2 : 4 (B) 1 : 3 : 6 (C) 1 : 1½ : 3 (D) 1 : 1 : 2

Description : The ratio of various ingredients (cement, sand, aggregates) in concrete of grade M 200, is (A) 1 : 2 : 4 (B) 1 : 3 : 6 (C) 1 : 1½ : 3 (D) 1 : 1 : 2

Last Answer : (C) 1 : 1½ : 3

If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is (A) M 100 (B) M 150 (C) M 200 (D) M 250

Description : If the various concrete ingredients i.e. cement, sand and aggregates are in the ratio of 1:3:6, the grade of concrete, is (A) M 100 (B) M 150 (C) M 200 (D) M 250

Last Answer : Answer: Option A

Workability of concrete is directly proportional to (A) Aggregate cement ratio (B) Time of transit (C) Grading of the aggregate (D) All of above

Description : Workability of concrete is directly proportional to (A) Aggregate cement ratio (B) Time of transit (C) Grading of the aggregate (D) All of above

Last Answer : Answer: Option C

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

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*

Explain the method of concrete mix design procedure by I.S. method as IS-10262.

Description : Explain the method of concrete mix design procedure by I.S. method as IS-10262.

Last Answer : Procedure of IS method of concrete mix design: The concrete mix design is done by IS 10262-2009 using following steps  1. Calculation of target mean strength: The concrete mix design is ... volume of all ingredients of concrete the mix proportion is calculated for said mix design of concrete.

How much water do you mix with cement mix?

Description : How much water do you mix with cement mix?

Last Answer : A basic mixture for general use (paths, etc) is: 1 cement : 2 sand : 3 gravel by volume. Mix ingredients dry and add water until the concrete is workable. If too sloppy it may be weak, if too dry it may be difficult to work with.A basic mortar mix (brick laying, etc) is: 1 water : 2 cement : 3 sand.

The fluid generally used for grouting is (A) Cement and water mix (B) Clay suspension (C) Sodium silicate (D) All the above

Description : The fluid generally used for grouting is (A) Cement and water mix (B) Clay suspension (C) Sodium silicate (D) All the above

Last Answer : (D) All the above

For preparing a test-specimen, it is necessary (A) To mix cement and fine aggregate by dry hand (B) To mix coarse aggregates (C) To mix water to the cement, fine aggregates and coarse aggregates (D) All the above

Description : For preparing a test-specimen, it is necessary (A) To mix cement and fine aggregate by dry hand (B) To mix coarse aggregates (C) To mix water to the cement, fine aggregates and coarse aggregates (D) All the above

Last Answer : Answer: Option D

In order to prepare a test specimen, it is necessary to (a) Mix the cement and fine aggregate (sand ) dry hand (b) Mix the coarse aggregate (c) Mix water to the cement, fine aggregate and coarse aggregate (d) All of the above

Description : In order to prepare a test specimen, it is necessary to (a) Mix the cement and fine aggregate (sand ) dry hand (b) Mix the coarse aggregate (c) Mix water to the cement, fine aggregate and coarse aggregate (d) All of the above

Last Answer : (d) All of the above