Water



WATER

Water used for concrete mixes, washing of aggregates and equipment, wetting of surfaces or ponding during curing or for wetting formwork and washing reinforcement shall conform to the following.

Requirements

  1. Water used for mixing and curing shall be clean and free from injurious amounts of oils, acids, alkalis, salts, sugar, organic materials or other substances that may be deleterious to concrete or steel.
  2. Potable water is best suitable for use in concrete. Water from different sources such as underground water, natural surface water etc., shall be tested to prove that its quality shall conform to water quality requirements of BIS and chemical limitations listed in Table 1 of IS: 456.
  3. In case of doubt regarding development of strength, the suitability of water for producing concrete shall be ascertained by the compressive strength and initial setting time tests.
  4. The pH value of water used in concrete works shall not be less than 6.
  5. Temperature of water for concrete shall not be less than 5°C and not more than 40°C.
  6. Water may be cooled to not less than 5°C by the gradual addition of chilled water or ice as follows:
  1.    No ice particles shall be present in the mix.
  2. Alternatively, flaked ice may be used.
  1. Every effort should be made to protect water pipes and tanks from the sun by burying, shading, insulation or painting white.
  2. Mixing or curing of concrete with sea water is not recommended because of the presence of harmful salts in sea water.

Sampling and testing

  1. The Contractor shall take samples of the water being used or which it is proposed to use for mixing concrete and test them for quality as directed by the Engineer.
  2. The sample of water taken for testing shall represent the water proposed to be used for concreting. The sample shall not receive any treatment before testing other than that envisaged in the regular supply of water proposed for use in concrete. The sample shall be stored in a clean container previously rinsed out with similar water.
  3. Average 28 days compressive strength of at least three 150 mm concrete cubes prepared with water proposed to be used shall not be less than 90 percent of the average of strength of three similar concrete cubes prepared with distilled water. The cubes shall be prepared, cured and tested in accordance with the requirements of IS: 516.
  4. The initial setting time of test block made with the appropriate cement and the water proposed to be used shall not be less than 30 minutes and shall not differ by 30 minutes from the initial setting time of control test block prepared with the same cement and distilled water. The test blocks shall be prepared and tested in accordance with the requirements of IS: 4031 (Part 5).
  5. No source of water shall be approved until the required tests have demonstrated its suitability for use in concrete.
  6. The use of water from a municipal or government supply does not preclude the requirement for testing.
  7. Water shall be tested as indicated in table.

Quality Control tests for water for use in concrete

Sl. No.

Test

Code

Permissible value

Minimum frequency of sampling

 

1

 

Suspended matter

 

IS: 3025 (Part 17)

 

2000 mg/litre

Water from each source

before commencement of

work and thereafter every

three months till completion

of work.

2

Organiccontents

IS: 3025(Part 16)

200 mg/litre

- do -

3

Inorganiccontents

IS: 3025(Part 19)

3000 mg/litre

- do -

4

Sulphates(as SO2)

IS: 3025(Part 24)

400 mg/litre

- do -

5

Chlorides(as Cl)

IS: 3025(Part 32)

2000 mg/litre (PCC)

500 mg/litre (RCC)

- do -

6

pH value

 

Not less than 6

- do -

Tolerance and Classification

As per ISI-IS: 2296-1982, the tolerance limits of parameters are specified as per classified use of water (Table 1,2,3,4,5 below) depending on various uses of water. The following classifications have been adopted in India.

Class of Water

Classification

Type of use

Class A

Drinking water source without conventional treatment but after disinfection

Class B

Outdoor bathing

Class C

Drinking water source with conventional treatment followed by disinfection.

Class D

Fish culture and wild life propagation

Class E

Irrigation, industrial cooling or controlled waste disposal

TOLERANCE   LIMITS

TOLERANCE LIMITS FOR INLAND SURFACE WATERS, CLASS – A

S.No.

Characteristic

Tolerance

(1)

(2)

(3)

(i)

pH

6.5 to 8.5

(ii)

Dissolved Oxygen, mg/l,

6.0

(iii)

Bio-chemical Oxygen Demand

2.0

(iv)

Total Coliform Organisms, MPN/100 ml, Max

50

(v)

Colour, Hazen units, Max

10

(vi)

Odour

unobjectionable

(vii)

Taste

Agreeable taste

(viii)

Total Dissolved Solids, mg/l, Max

500

(ix)

Total Hardness (as CaCO3), mg/l ,Max

300

(x)

Calcium Hardness (as CaCO3), mg/l, Max

200

(xi)

Magnesium (as CaCO3), mg/1,Max

100

(xii)

Copper (as Cu), mg/l, Max

1.5

(xiii)

Iron (as Fe), mg/l,Max

0.3

(xiv)

Manganese (as Mn), mg/1,Max

0.5

(xv)

Chlorides (as Cl), mg/l,Max

250

(xvi)

Sulphate (as SO4), mg/l ,Max

400

(xvii)

Nitrates (as NO2), mg/1,Max

20

(xviii)

Fluorides (as F,) mg/l,Max

1.5

(xix)

Phenolic compounds(as C6H5OH), mg/l,Max

0.002

(xx)

Mercury (as Hg), mg/l ,Max

0.001

(xxi)

Cadmium (as Cd), mg/1,Max

0.01

(xxii)

Selenium (as Se), mg/l ,Max

0.01

(xxiii)

Arsenic (as As), mg/1,Max

0.05

(xxiv)

Cyanides (as CN), mg/l, Max

0.05

(xxv)

Lead (as Pb), mg/l, Max

0.1

(xxvi)

Zinc (as Zn), mg/l, Max

15

(xxvii)

Chromium (asCr6+ ), mg/l,Max

0.05

(xxviii)

Anionic detergents, (as MBAS), mg/l ,Max .

0.2

(xxix)

Poly-nuclear aromatic hydrocarbons (PAH),

0.2

(xxx)

Mineral oil, mg/l ,Max

0.01

(xxxi)

Barium (as Ba), mg/l ,Max

1.0

(xxxii)

Silver (as Ag), mg/l Max

0.05

(xxxiii)

Pesticides

Absent

(xxxiv)

Alpha emitters, µc/ml, Max

10-9

(xxxv)

Beta emitters, µc/ml, Max

10-8

TOLERANCE LIMITS FOR INLAND SURFACE WATERS, CLASS – B

S.No

Characteristic

Tolerance Limit

(1)

(2)

(3)

(i)

pH Value

6.5 to 8.5

(ii)

Dissolved Oxygen, mg/1,Max

5.0

(iii)

Biochemical Oxygen Demand (5 days at 20 °C),

3.0

(iv)

Total Coliform Organisms, MPN/100 ml, Max

500

(v)

Fluorides (as F)

1.5

(vi)

Colour, Hazen units, Max

300

(vii)

Cyanides (as CN), mg/l, Max

0.05

(viii)

Arsenic (as As), mg/l, Max

0.2

(ix)

Phenolic Compounds (as C6H5OH) mg/l, Max

0.005

(x)

Chromium (as Cr6+), mg/l, Max

1.0

(xi)

Anionic detergents (as MBAS), mg/l, Max

1.0

(xii)

Alpha emitters, µc/ml, Max

10-8

TOLERANCE LIMITS FOR INLAND SURFACE WATERS, CLASS – C

S.No.

Characteristic

Tolerance Limit

(1)

(2)

(3)

(i)

pH Value

6.5 to 8.5

(ii)

Dissolved Oxygen, mg/l Minimum

4.0

(iii)

Biochemical Oxygen Demand

3.0

(iv)

Total coliform organisms, MPN/100 ml, Max

5000

(v)

Colour, Hazen units, Max

300

(vi)

Fluorides (as F), mg/l ,Max

1.5

(vii)

Cadmium (as Cd), mg/l, Max

0.01

(viii)

Chlorides (as Cl), mg/l, Max

600

(ix)

Chromium (as Cr6+), mg/l, Max

0.05

(x)

Cyanides (as CN), mg/l, Max

0.05

(xi)

Total Dissolved Solids, mg/l, Max

1500

(xii)

Selenium (as Se), mg/l, Max

0.05

(xiii)

Sulphates (as SO4), mg/l, Max

400

(xiv)

Lead (as Pb), mg/l, Max

0.1

(xv)

Copper (as Cu),mg/l,Max

1.5

(xvi)

Arsenic (as As), mg/l, Max

0.2

(xvii)

Iron (as Fe), mg/l, Max

50

(xviii)

Phenolic compounds (as C6H5OH), mg/l,

0.005

(xix)

Zinc (as Zn), mg/l, Max

15

(xx)

Insecticides, mg/l, Max

Absent

(xxi)

Anionic detergents (as MBAS), mg/l, Max

1.0

(xxii)

Oils and grease, mg/l, Max

0.1

(xxiii)

Nitrates (as NO3), mg/1,Max

50

(xxiv)

Alpha emititers, µc/mg, Max

10-9

(xxv)

Beta emitters, µc/ml, Max

10-8

*****