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M-80 Grade Pumpable Concrete

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By
Kaushal Kishore
Materials Engineer, Roorkee

A mix of M-80 Grade suitable for pumped concrete is to be designed with the following materials and detail.

1. OPC 53 Grade, 7-day strength 52.5 N/mm2, Spgr 3.15

2. Silica Fume Specific Gravity 2.20

3. Standard deviation for the mix 5.0 N/mm2

4. Grading and properties of river sand and 12.5 mm crushed aggregate are given in Table-1

5. Superplasticizer based on modified Polycarboxylate, specific gravity 1.06, liquid pH 6.0. With the given set of materials, it was found that at a dosages of 2.5 % bwc it gives a reduction of 30% of water for the required slump of 100 mm after one hour at the average day site temperature of 37 degree C.

6. As per grading of aggregates given in the Table-1, it is found that, if sand and aggregate are combined in the ratio of 45% and 55% they will give most suitable combined grading for pumped concrete.

7. Air in the mix assumed 1.5%.

DESIGN CALCULATIONS

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1. M-80 Grade of concrete design for a mean target strength of:
80 + 1.65 x 5 = 88.3 N/mm2 at 28 day age

2. With the given set of materials from various trials it was found that with OPC 450 Kg/m3, Silica Fume 45 Kg/m3 and W/C+SF ratio of 0.283 gives 28-day average cube compressive strength of 90.4 N/mm2.

3. Calculated density of the mix, worked out from reference 1.

M-80 Grade Pumpable Concrete

4. Aggregates = 2440 – 140 – 450 – 45 = 1805 kg/m3

5. Sand = 1805 x 0.45 = 810 kg/m3 (say)

6. 12.5 mm Aggregate = 1805 x 0.55 = 995 kg/m3 (say)

Thus for M-80 Grade of concrete, quantity of materials per cu.m of concrete on the basis of saturated and surface dry aggregates.

Water 140 kg/m3
OPC 53 Grade 450 kg/m3
Silica fume 45 kg/m3
River sand 810 kg/m3
12.5 mm crushed aggregate 995 kg/m3
Superplasticizer 11.250 kg/m3
W/(C+SF) Ratio 0.283
Slump mm 102
7-day cube strength N/mm2 67.3
28-day cube strength N/mm2 89.5

Table-1 Properties of Aggregates

I.S. Sieve size

Percentage passing by mass

River sand

45%

12.5 mm Crushed Agg

55%

Combined aggregates grading of the mix

20 mm

100

100

100

12.5 mm

100

95

x

10 mm

100

60

78

4.75 mm

95

5

46

2.36 mm

87

0

39

1.18 mm

72

32

600 Micron

40

18

300 Micron

22

10

150,Micron

5

2

Specific gravity

2.65

2.65

Water absorption %

0.8

0.5

Organic impurities %

Nil

Coal & lignite %

Nil

Nil

Clay lumps %

Nil

Nil

Materials finer than 75 micron I.S. Sieve %

0.2

Nil

Flakiness index

7.3

Crushing value %

10.5

REFERENCES
Kishore Kaushal  Mix design with water reduces, The Indian Concrete Journal, August 2011, Vol. 85, pp. 44-51.

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We at engineeringcivil.com are thankful to Er. Kaushal Kishore for submitting the paper on M-80 Grade Pumpable Concrete. This will be of great help to the ones who are looking for information regarding the pumpable concrete.

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Comments
  • Tanveer March 22, 2014 at 4:10 pm

    Use of psc cement in building construction

  • D. PANDA October 3, 2016 at 2:57 am

    sir,
    how to calculate the standard deviation according to new is code?

  • MURALINATHAN P August 19, 2017 at 9:08 am

    sir pls tell clearly in detail manner on how to calculate the mix design s per ACI code

  • Avinash Lall August 26, 2017 at 4:05 am

    which mfg. company is made foam and what is called

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