SRM CIVIL WORKS PVT LTD

1. An over all view of Ready mix concrete scenario in
Tamil Nadu : Sustainability construction
Arivusudar NagarajanArivusudar Nagarajan

2. Ready mix concrete plant layout
2

3. RMC Means
• Organizing.
• Planning .
• Scheduling.
• implementing .
3

4. Type of Batching plants
• Model name CP 18 – 16cum/hr .
• Model name CP 30 – 30cum/hr .
• Model name M1 - 56cum/hr .
• Model name M3 - 64cum/hr
As per BIS 4926-2003
4

5. Departments in RMC
• Quality control.
• Sales & Marketing.
• Plant & machinery .
• Transport & maintenances.
• Accounts .
5

6. 6
PLANT LAYOUTPLANT LAYOUT

7. 7
CONVEYOR BELT

8. 8
Type of Mixer 1) Non-tilting reversible drum concrete mixer, 2) Double conical
tilting mixer, 3) Pan mixer, 4) Turbo pan mixer, and 5) Single shaft compulsory
mixer/pug mill.
Ready Mixed Concrete Plants Ready mixed concrete (RMC) plants shall be
equipped with computer (containing minimum 15 recipes), monitor and printer.
Delivery slips of RMC plants shall contain the following information
1.Name of RMC plant supplier with logo and address
2. Delivery note No.
3. Name of receiving party
4.Ordered quantity in m ,
5. Recipe number,
6.Number of batches,
7.Batch size in m3,

9. 9
8.Date,
9.Starting time,
10.Moisture percentage of each material at the time of batching,
11. Weighing chart for each type of component with total for each
component independently,
12.Total quantity delivered in m3,
13. Remarks column,
14.Transit mixer number and capacity,
15.Transit mixer driver’s name,
16. Representative of RMC plant (signature column), and
Representative of customer (signature column).

10. 10
DOUBLE SHAFT MIXER

11. 11
BATCHING PLANTBATCHING PLANT

12. 12

13. CONCRETE PUMPS
13

14. Transit Miller with 6cum capacity
14

15. TRUCK MOUNTED BOOM PUMPS
15

16. RMC PLACEMENT THROUGH BOOM PUMPS
16

17. Planning
17

18. Problems in RMC
1. Traffic obstructions public , festival , Government ,
natural calamities .
2. Concrete delivery timing with 2hours maximum.
3. Skilled persons required for all the departments .
4. Raw materials scarcity in metro’s
5. Demand of customers .
6. Outstanding of customers
7. Transit Miller – inside blade functioning .
8. RPM in Transit miller .
9. Temperature problems .
18

19. 10. On time delivery as per code suggested .
11. Dosage of concrete as per code suggested .
12. Raining time batching will gets very slow.
13.Batching timing per vehicles 30Min.
14. Vehicles' arrangements .
15. Tracking using GPS modeling .
16. Cold joint problems .
17.Ball pass issues .
18.Delay in concrete – debited amount .
19. No of vehicles .
20 Quality Accept – Slump min 80mm +/-10mm , Avg
Compressive strength 3 days – 45% , 7 days -65 % ,
28 days – 100% .
21. If any case in failure in cube – Customer will go the illegal or
NDT Testing .
19

20. 22. Air voids in concrete .
23. Usage of cement materials.
24. Mix design or any problems .
Etc ………………………….
20

21. RMC pricing for Dec15
21

22. Global Market
• The Ready Mix Concrete (RMC) industry is growing due to the
superior technical properties over normal concrete, but the
potential is still huge.
• The Ready Mix Concrete (RMC) industry in India is in its early
stages with cement consumption of just 2-3 per cent of total
production.
• The cement companies are able to leverage the RMC market
in a better way since cement is one of the essential
ingredients in the manufacture of RMC. Of course, acquiring
and operating suitable aggregate quarries in India is a difficult
task, but since cement companies possess sufficient
experience in limestone quarrying will have technical
competency of running such captive operations too.
22

23. The industry
• The construction has industry benefited from Ready mix
Concrete right from its inception during the late 40’s. This
technology has since grown in a big way in Europe and USA,
consuming more than 60% of the cement produced.
• Ready mix Concrete industry in India is likely to consume
more than 5% of the cement produced from the current
levels of around 3%.
• The plant is capable of programming 99 different types of
mixes for producing different grades of concrete both
automatically and manually.
23

24. RMC & GGBS POTENTIAL IN TAMIL
NADU
24

25. Advantages of Ready mix Vs Site mix,
• Several quality and time required is among the most
prominent.
• Besides, labour and space requirements on site for the latter
add to the cost.
• A typical 1500 sq ft of area will take around 6-8 hours for
concreting if site mix is used which if compared to Ready mix,
will take only 2-3 hours.
• Ready mix is also environment friendly and any grade of
concrete is available at a given point of time.
• A wide range of computer-controlled concrete batching plants,
transit mixers for transporting the RMC to the construction
sites, pumps and concrete placing are manufactured in India.
25

26. Cont…
• The use of RMC is growing due to its superior technical
properties than normal concrete. The difference between
normal concrete and RMC lies in the technology used for
production.
• In the case of RMC, all the ingredients are proportioned in
accordance with the standard codes of practice to get the
targeted strength and durability.
• The quality of concrete depends on the way it is mixed,
placed, compacted, finished, cured and protected. RMC used
in construction makes it possible to achieve speed with
quality.
26

27. Green concrete –slag

29. Development of GGBS Production in
India:
• India has witnessed a rapid growing rate in slag
grinding and the production of quality GGBS has been
seen literally across the country since the mid-2007s.
• Central government for the steel industry and the
increased awareness and recognition of the benefits
on the use of quality GGBS not only by cement
manufacturers and ready-mixed concrete players, but
also by real estate developers, architects and designers
and the public. With the establishment of the national
standard IS 455-1989, market demand for quality
GGBS has been given a big boost.
29

30. • The number of slag grinding plants set up in India over recent
years 12 projected between 2010 to 2015, VRM and press
mill. Major players in Manufacturing GGBS are JSW & Tata
Cement the number of operating slag grinding plants has
increased from one to a projected.
• Cement the number of operating slag grinding plants has
increased from one to a projected 12. Out of the 12 GGBS
plants, about 5 plants were set up over the 5-year period.
From 2013 to 2015.
• The total GGBS production has gone from a zero position to
an amazing projected 31.2Mt per year by end of 2007.
30

31. Green market by-products potential in India
• The fine particles of fly ash by virtue of their
lightness can become air borne, if not managed well.
• At present nearly 65,000 acres of land is occupied by
ash ponds. The fly ash generated in India is likely to
reach 145 million tons mark by 2008 and 200 Million
tons mark by 2015.
• About 70% of hot slag is granulated and
incorporated in to cement. Hot slag production is
projected to rise to more than 10 million tons in the
next few years.
31

32. • Granulated slag (ggbs) is the glassy grannular material that is
formed in the process of producing iron in a blast furnace and
is formed by rapidly chilling the molten material and
subsequently grinding it in to a fine powder.
• India is also a prime rice producing country in the world.
Nearly 100 million tons of paddy produces 20 million tons of
rice husks which in turn can produce about 4 million tons of
rice husk ash.
• Good quality rice husk ash can become a substitute for silica
fume.
32

33. Working with Ground Granulated Blast
furnace Slag (GGBS) Concrete
Water Demand - GGBS allows for water reduction
of 3 to 5% in concrete without any loss in
workability.
Water should not be added to GGBS concrete after
dispatch from the concrete plant as it reduces
strength and durability of the concrete.

34. Engineering Benefits:
• Concrete made with GGBS continues to gain strength
over time, and has been shown to double its 28-day
strength over periods of 10 to 12 years.
• GGBS cement prevents the occurrence of
efflorescence, the staining of concrete surfaces by
calcium carbonate deposits. Due to its much lower
lime content and lower permeability, GGBS is
effective in preventing efflorescence when used at
replacement levels of 50% to 60%.
34

35. Durable concrete requires high percentage mixture of GGBS:
• Lower temperature rise in concrete, reducing the risk of
thermal cracking in massive concrete structures.
• Elimination of the risk of damage caused by alkali-silica
reaction (ASR).
• High resistance to chloride ingress, reducing the risk of
reinforcement corrosions .
• High resistance to attacks by sulphate and other chemicals
35

36. Setting Times
• Concrete with up to 30% GGBS will exhibit similar initial
setting as concrete with Portland cement only.
• At replacement levels of 40 to 50% the initial set is likely to be
extended by one to two hours and for concrete containing
more than 50% GGBS setting time maybe extended past three
hours.
• Longer setting times can have the advantage of allowing
concrete to be worked for longer periods meaning time
delays, including delays in transport, between mixing and
using concrete are less critical.
• They also reduce the risk of cold joints in larger concrete
pours.

37. Strength development
 GGBS concrete has slightly slower strength development at
early ages, but will have equal if not greater strength at 28
days compared to non GGBS concrete.
 At 7 days GGBS concretes will have 50 to 60% of its
characteristic strength compared to 70 to 80% for Portland
cement only concrete at the same time.
 At 28 days GGBS concrete will have fully developed its
characteristic strength and will continue to develop strength
past 90 days.
 It is good practice to make 56 day cubes when using GGBS
concrete at 50% and above should there be any concern over
later strength development.

39. Bleeding
• Concrete with up to 40% GGBS replacement does not
exhibit different bleeding characteristics from that of
concrete made with Portland cement.
• For higher percentages of GGBS there is a longer
period of bleeding due to the increase in setting
times of these mixes. Concrete should be allowed to
bleed fully before finishing.

40. Strength results: GGBS Vs Fly Ash Mix
40

41. Mix Cost comparison – Grade wise

42. Mix Cost comparison – Grade wise

43. Grade M50
OPC + PFA mix OPC + GGBS mix
Material Qty Cost Material Qty Cost
OPC 440 2259.84OPC 230 1181.28
Flyash 30 33GGBS 230 598
Cementecious cost 2292.8 Cementecious cost 1779.28
Mix Type
Mix
cost 7 DAYS %
28
DAYS %
OPC + PFA
mix 3780 44.45 Mpa 88 49.15 99.67
OPC + GGBS
mix 3266 31.85 Mpa 64 43.89 87.76
SAVING = 514/Cum

44. 44
Grade M25
OPC + PFA mix
(MAHA)
OPC + PFA mix
(Bharathi) OPC + GGBS mix (MAHA)
OPC + GGBS mix
(Bharathi) Triple blend (MAHA) Triple blend (bharathi)
Material Qty Cost
Materi
al Qty Cost Material Qty Cost
Materi
al Qty Cost Material Qty Cost Material Qty Cost
OPC 290 1489.44OPC 350 1855OPC 238 1222.368OPC 238 1261.4OPC 175 899OPC 175 928
Flyash 70 77Flyash 0 0GGBS 102 265.2GGBS 102 265.2Flyash 52 57Flyash 52 57
GGBS 123 320GGBS 123 320
Cementecious
cost 1566.44
Cementecious
cost 1855
Cementecious
cost 1487.568
Cementecious
cost 1526.6Cementecious cost 1276
Cementecious
cost 1305

45. 45
Mix Type Mix cost 7 DAYS % 28 DAYS %
OPC + PFA mix (MAHA) 305318.37 MPA 73
OPC + PFA mix (Bharathi)) 334220.59 MPA 82
OPC + GGBS mix (MAHA) 2975
OPC + GGBS mix (Bharathi) 3014
Triple blend (MAHA) 2763
Triple blend (Bharathi) 2792

46. 46
ALCOFINE MIX & COST DETAILS
Grade M25
OPC + PFA mix (MAHA)
OPC + PFA mix
(HEMADRI)
OPC + PFA mix
(BHAVYA)
OPC + PFA + A.F mix
(MAHA)
OPC + PFA + A.F mix
(HEMADRI)
OPC + PFA + A.F mix
(BHAVYA)
Material Qty Cost
Materi
al Qty Cost Material Qty Cost Material Qty Cost Material Qty Cost Material Qty Cost
OPC 290 1489.44OPC 350 1855OPC 280 1484OPC 266 1366.6OPC 266 1410OPC 266 1410
Flyash 70 77Flyash 0 0
FLY
ASH 60 1.38
FLY
ASH 60 66
FLY
ASH 60 66
FLY
ASH 60 66
ALCOF
INE 14 0.322
ALCOFI
NE 14 0
ALCOF
INE 14 0
Cementecious cost 1566.44
Cementecious
cost 1855
Cementecious
cost 1485.38
Cementecious
cost 1432.498
Cementecious
cost 1476
Cementecious
cost 1476

47. 47
Mix Type Mix cost 7 DAYS %
OPC + PFA mix (MAHA) 3053 18.37 MPA 73
OPC + PFA mix Bharathi 3342 20.59 MPA 82
OPC + PFA mix (BHAVY) 2972 16.15 MPA 65
OPC + PFA+A.F mix (MAHA) 2919 19.25 MPA 77
OPC + PFA+A.F mix bharathi 2963 18.07 MPA 72
OPC + PFA+A.F mix (BHAVYA) 2963 23.40 MPA 93

48. 48
CEMENT REPLACEMENT
MATERIALS
FLY ASH
 It is finely divided residue resulting from the combustion
of powdered coal and transported by the flue gases and
collected by electrostatic precipitator ( Thermal Power
plants)
 Mostly used pozzolonic material
 Reference IS-3812.
 Replacement up to 35 percentage .
Contd…

49. 49
 Savings in cement
 Reducing heat of hydration
 Reducing water demand
 Spherical shape and smooth surface of flyash helps to
reduce the inter-particle friction and thus facilitates
mobility.
 Reduce Bleeding and drying shrinkage.
 Fly ash particles plasticize cement paste and improves
flowability and rheology of the mix.
 Contributes to strength
Contd…
ADVANTAGES OF FLY ASH

50. 50
CEMENT
+ C-S-H
Gel + Ca(OH)2
WATER FLYASH C-S-H Gel
SECONDARY HYDRATION OF FLY
ASH

51. 51
PETROGRAPHIC VIEW OF FLY ASH

52. 52

53. 53
FLYASH-PARTICLE PACKING
EFFECT
FLYASH

54. 54
Cement Flyash
BALL BEARING EFFECT

55. 55
Trapped Water
DISPERSION OF CEMENT
PARTICLES WITH FLY ASH

56. 56
 Fly ash is called as coal ash materials.
 Ready mix concrete using waste materials as cost
saving .
 Customers preferred to site mix .
 % of replacement involved in concrete mix.
Contd…
Customer Awareness

57. 57
 Condensed Silica Fume is a by product of ferro-Silicon
alloy industry and it is the dust which is collected from
furnace exhaust system
 Fineness of silica fume is @ 15000 m2
/kg as against 280 to
290 m2
/kg of Cement
 Contributes significantly to compressive strength due to
micro-filler effect and excellent pozzolanic properties
 Leads to increase in density and reduction of permeability
in concrete
 It’s use is must for manufacturing of concrete above M50
Contd…
SILICA FUME (Micro Silica)

58. 58
 Condensed Alco Fume is a by product of ferro-Silicon alloy
industry and it is the dust which is collected from furnace
exhaust system
 Contributes significantly to compressive strength due to
micro-filler effect and excellent pozzolanic properties
 Leads to increase in density and reduction of permeability
in concrete
 It’s use is must for manufacturing of concrete above M45
Contd…
Alco fine

59. 59
SILICA FUME

60. 60
Admixtures are materials mostly chemicals that are added in small
quantities during the preparation of concrete to impart certain specific
properties to it.
The requirements may be
 Improving the workability of concrete during placing
 Retarding or accelerating setting
 Improving the impermeability and water tightness of the cast
concrete.
 Imparting corrosion inhibition etc
 Entraining air in concrete
Chemical Admixtures

61. 61
Compatibility test by
Marsh Cone Apparatus

62. 62
DEFLOCCULATION OF CEMENT
PARTICLES

63. 63
DISPERSION OF MECHANISM

64. 64
EFFECT OF SUPER PLASTICISER
ON WORKABILITY

65. 65
SLUMP : Collapse

66. 66
EFFECT OF SUPER PLASTICISER
ON WORKABILITY

67. 67
PUMPABLE CONCRETE

68. 1. Air entrainers :
TYPES OF ADMIXTURES
They entrain air in the form of micro air bubbles which
helps in improving the durability of concrete in freezing
environment, sulphate and alkali attack.
2. Water reducers
To reduce the water-cement ratio and yet retain
workability. It is possible to reduce water upto 12%.
The only precaution is that it should be mixed thoroughly

69. 3. Accelerating admixtures :
To accelerate setting of cement in
cold environment or where early setting is desired.
It assists in early removal of form work
4. Retarding admixtures :
To delay the setting time of concrete, for RMC supplied
to far off sites.
Prolongs setting time, giving higher strength at later
stages, also results in reduction in micro cracks.

70. 5. Super plasticisers :
To make flowing concrete for concreting in
heavily reinforced sections, tremie concrete, for
pumping concrete.
(when added to normal concrete with 75mm slump
upto 250mm can be achieved)
6. High range water reducers :
PC based admixtures
Water reduction capacity of about 25-40%
High performance
Early strength and early setting

71. 7. Bonding agents :
To increase bond strength,
old and new concrete(in repair and rehabilitation works),
they are usually modified latex or polymer compounds
8. Corrosion inhibitors :
To inhibit corrosion

72. • Aggregate is the word used to describe any inert material .
• Usually rock derivative generally between 50mm down to 75 micron used
to produce concrete .
• It is divided into coarse aggregate and fine aggregate
• Those which are 4.75mm to 50mm are classified as coarse aggregates
• Those below 4.75mm to 75 micron as fine aggregates
• Except for mass concrete in dams etc. which may contain upto 150mm
size aggregate, the maximum size of aggregate is normally 20mm in most
cases
• But it may be 40mm for plain concrete or massive works.
72
AGGREGATES

73. 73
 Specific gravity: it should have good crushing strength
and density
 Surface texture: it should be smooth,slightly rough but
not honeycombed
 Particle shape : it should not be flaky or elongated.
 Porosity : it should have very low water absorption
 Should not be Reactive
PROPERTIES OF COARSE
AGGREGATES

74.  Water demand,
 Workability
 Cohesion of concrete in plastic state
 Strength,
 Density,
 Durability
 Porosity of hardened concrete
 Stability : it should be chemically inert.
 Impurities: it should be free from impurities (like silt,
clay)
 Compactness: it should be graded, as then only the
voids can be less.
74
PROPERTIES OF AGGREGATE
EFFECT

75. • Specific gravity implies the absolute weight per unit volume
of aggregates
• A low specific gravity may indicate
 high porosity
 poor durability
 low strength.
• Specific gravity of aggregates is used in arriving at mix design
• Generally the specific gravity of good aggregates is greater
than 2.5 g/cm3
75
SPECIFIC GRAVITY

76. • Surface texture reveals how grainy or smooth the surface
of the aggregate is.
• It indicates bonding strength and porosity.
• Higher the smoothness of the particle, lesser is the
bonding between aggregate and cement matrix.
• rough textured aggregates develop higher bond strength
than smooth textured aggregates,
• This property is especially considered while producing
high strength concretes.
76
SURFACE TEXTURE

77. Particle shapes are classified as
 Irregular
 Rounded
 Flaky
 Angular
 Aggregates should be as much cubical as possible in shape
77
PARTICLE SHAPE

78. • Grading of aggregates means particle size
distribution of the aggregates.
• Principle of grading is that smaller size
particles fill up the voids left in larger size
particles.
78
GRADING

79. IS sieve
Designatio
n
Percentage passing for single size aggregate of nominal size by
weight
63 mm 40mm 20 mm 16 mm 12.5 mm 10 mm Remarks
80 mm 100 - - -
63 mm 85-100 100 - -
40 mm 0-30 85-100 100 -
20 mm 0-5 0-20 85-100 100
16 mm - - 85-100 100
12.5 mm - - - 85-100 100
10 mm 0-5 0-5 0-20 0-30 0-45 85-100
4.75 mm 0-5 0-5 0-10 0-20
2.26 mm - - - 0-5
79
GRADING OF COARSE
AGGREGATE

80. • Indian standards divides the sand into four
zones
• zone-I to zone-IV based on the sieve analysis
• Sand falling in zone-I is coarse and that falling in
zone-IV is fine.
• Sand falling in zone IV shall not be used for
reinforced concrete work.
• Fineness modulus for sand : ranges from 2.2 to
3.2, higher value indicates coarser grading
80
SAND

81. 81
IS sieve
designation
Percentage passing
Zone-I Zone-II Zone-III Zone-IV
10 mm 100 100 100 100
4.75 mm 90-100 90-100 90-100 90-100
2.36 mm 60-95 75-100 85-100 95-100
1.18 mm 36-70 55-90 75-100 90-100
600 microns 15-34 35-59 60-79 80-100
300 microns 5-20 8-30 12-40 15-50
150 microns 0-10 0-10 0-10 0-15
Remarks Very coarse Coarse Medium Fine
REQUIREMENT OF FINE
AGGREGATES

82. • Water helps in dispersing the cement evenly
• Quality of water for making concrete and
for curing
• Water should be free from salts, oils, acids,
alkalis, sugar and organic materials
• pH value shall not be less than 6
• Sea water is not suitable for making
concrete
82
WATER

83. SL.
No.
Description Tested as per Permissible limit (max) mg/l
1 Organic IS-3025(part-18) 200
2 Inorganic IS-3025(part-18) 3000
3 Sulphates (as SO3)
Sulphates (as SO4)
IS-3025(part-24)
IS-3025(part-24)
400
500
4 Chlorides (as Cl) IS-3025(part-32) 2000 mg/l for concrete not
containing embedded steel
1000 mg/l for RCC work
5 Suspended matter IS-3025(part-17) 2000
83
PERMISSIBLE LIMITS FOR SOLIDS IN
WATER

84. FRESH CONCRETE
 Fresh concrete is a freshly mixed material which
can be moulded into any shape.
 Workability: is the ease with which fresh
concrete can be mixed, transported, placed and
compacted in the moulds or forms
 Apart from water-cement ratio the concrete has
to be compacted well to get the required
strength
84
UNDERSTANDING CONCRETE

85. TESTS ON FRESH CONCRETE
 WORKABILITY
1. Slump Test
2. Compaction Factor Test
3. Flow Test.
 Yield Test

86. 86
• It is the science of the deformation and flow
of materials and is concerned with
relationships between stress, strain, rate of
strain and time.
• The term Rheology deals with the materials
whose flow properties are more
complicated than those of fluids (liquids or
gases)
RHEOLOGY OF CONCRETE

87. Factors affecting workability:
• Water content
• Mix proportions
• Size of aggregates
• Shape of aggregates
• Surface texture of aggregate
• Grading of aggregate
• Use of admixture
87

88. Segregation:
 Segregation can be defined as the separation of the
constituent materials of concrete.
Bleeding:
 Sometimes referred as water gain
 It’s a particular form of segregation due to
highly wet mix
 If water cement ratio is more than 0.7
 Badly proportioned and insufficiently mixed
concrete
88

89. BLEEDING
89
 While traversing from bottom to top
 Bleeding channels responsible for permeability
 It may be interrupted by aggregates (flaky)
 It may be interrupted by reinforcement
 Reduces bond between reinforcement,
aggregate and paste
 Remedy— re-vibration, delayed finishing

90. Cement – 3.15
Coarse aggregate – 2.70
Sand – 2.60
Water – 1.00
Fly ash – 2.15
Silica Fume - 2.20
90
SPECIFIC GRAVITY

91.  Compaction of concrete is the process
adopted for expelling the entrapped air
from the concrete.
 The entrapped air in the form of voids
reduces the strength of concrete.
 For every 1% of entrapped air, the strength
of concrete falls about 5% to 6%.
91
COMPACTION

92.  Hand compaction
 Tamping
 Ramming : generally permitted for
unreinforced foundation concrete
 RCC should never be rammed
 Compaction by vibration: common needle
vibrator dia is 25mm to 40mm
 External vibrators
 Surface vibrators
92
METHODS OF COMPACTION
Contd…

93.  When inserting a needle vibrator, allow it to
penetrate the bottom of the layer as quickly as
possible.
 If it is done slowly, the upper part of the
concrete will get compacted and prevent the air
in the bottom layer from escaping.
 The vibrator should be left in the concrete for
about 10 sec. and then withdrawn slowly. If it is
withdrawn fast, a hole will be left in the
concrete.
93
PRECAUTIONS
Contd…

94.  The vibrator should be inserted again at a
distance of not more than 50 cm from its
last position.
 The vibrator should not be allowed to touch
the face of the form work or the
reinforcement to prevent the reinforcement
from losing bond with concrete
 Do not stop the vibrator when the needle is
in the concrete.
 Do not over vibrate or under vibrate
94

95. 95
• The rate of levelling should not be less than
the rate placing of concrete
FINISHING OF CONCRETE

96. 96
 Effect of Water-Cement ratio
 Effect of maximum size of aggregate on
strength
 Grades of concrete:
 Concrete in construction is specified by
grade like M20,M25 etc. Usually increments
of five.
 M20 means the specified crushing strength
is 20 N/mm2
STRENGTH OF CONCRETE

97. 97
CURING
 Why Curing ?
 To prevent loss of moisture from the Concrete
due to combined effect of hot sun and drying
wind
 Creation of conditions for promotion of
uninterrupted and progressive hydration of
cement during the period immediately after
placing
 Curing does not mean only application of
water
HARDENED CONCRETE

98. 98
1. WATER CURING
2. MEMBRANE CURING
3. APPLICATION OF HEAT (Steam Curing)
4. ACCELERATED CURING
CURING METHODS

99. 99
• Sampling Criteria
• Cube Testing
• Acceptance Criteria
• Non Destructive Testing of Concrete
1. Rebound Hammer Test
2. Ultra sonic pulse velocity testing
• Core Test
COMPRESSIVE STRENGTH

100. 100
OTHER CONCRETES :
• High strength concrete
• High performance concrete
• Mass Concrete
• Light-weight concrete
• High-density concrete
• No-fines concrete
• Roller compacted concrete
• Ferrocement
• Self compacting concrete.

101. 101
HIGH STRENGTH CONCRETE
 CONCRETE GRADE FROM M60 ONWARDS
REGARDED AS HIGH STRENGTH CONCRETE
 FOR HIGH STRENGTH CONCRETE DESIGN
STANDARDS GIVEN IN THE CODE IS-456-2000
MAY NOT BE APPLICABLE
 THEY HAVE TO BE OBTAINED FROM SPECIFIED
LITERATURES OR BY EXPERIMENTAL RESULTS
SPECIAL CONCRETES

102. 102
POSSESSING
1. HIGH WORKABILITY
2. HIGH STRENGTH
3. HIGH DENSITY
4. HIGH DIMENSIONAL STABILITY
5. LOW PERMEABILITY
6. RESISTANCE TO CHEMICAL ATTACK
HIGH PERFORMANCE CONCRETE

103. 103
NORMAL CONCRETE
 HEAVY SELF WEIGHT
(DENSITY 2200 to 2600 KG/M3
)
LIGHT WEIGHT CONCRETE
 DENSITY (300 to 1850 KG/M3
)
 LOW THERMAL CONDUCTIVITY
LIGHT WEIGHT CONCRETE

104. 104
 DENSITY 3360 TO 3840 KG/M3
EVEN 5280
KG/M3
USING IRON AS BOTH F.A. AND C.A
 DENSITY 50% HIGHER THAN THE
CONVENTIONAL CONCRETE
 USED AS A SHIELDING MATERIAL FOR
PROTECTION FROM RADIATION
HIGH DENSITY CONCRETE

105. 105
• It is made by introducing air or gas into the
slurry composed of cement and finely
crushed sand by alluminium powder.
• Uniformly cellular structure is formed.
• Also called as gas concrete, foam concrete,
cellular concrete
AERATED CONCRETE

106. 106
 By Omitting fine aggregate fraction
 Made by cement, water and single sized coarse
aggregates
 Having large voids and hence light in weight
 Applications
 Temporary structures
 In external walls for Thermal insulation
 Rough texture gives good base for plastering
 Free from dampness because of low capillary action
on account of large voids
NO-FINES CONCRETE

107. ROLLER COMPACTING CONCRETE
• Recent development particularly in the field of
Dam construction.
• Lean mix
• No slump concrete
• High volume fly ash to the extent of 60 to 65%
• Compacted by Rollers.
• Compressive strength of about 7 Mpa to 30
Mpa

108. FERRO CEMENT
 It is a relatively new material consisting of
wire meshes and cement morar.
 Thickness of elements is 2 to 3 cm
 Water –cement ratio 0.4 to 0.45
 Cement -sand ratio 1:2
 External cover to reinforcement is 2 to 3mm

109. APPLICATIONS OF FERROCEMNT
 FOR CASTING DOMESTIC OVER-HEAD WATER
TANKS
 FOR TANKS USED AS GRAIN SILOS IN VILLAGES
 FOR CONTAINER USED AS GAS HOLDER UNIT
IN “GOBBAR GAS” PLANTS.
 IDEAL MATERIAL FOR BOAT BUILDING
 FOR MANHOLE COVER

110. SELF COMPACTING CONCRETE
• Self levelling concrete
• With Super plasticizer (Glenium )
• Fines
• Should not be vibrated
• Applications
Precast units.

111. MASS CONCRETE
• It’s is a concrete having considerable
dimensions that may get affected by thermal
behavior of Concrete. Ex-Concrete Dam
• Members with minimum cross sectional
dimension of a solid concrete member
approaches or exceeds 2 to 3 ft
• Cement contents above 364 kg/m3

112. • It is a latest development in the construction
industry
• Concrete is batched and mixed in a
centralised Plant and transported to the
sites far-away from the plant through
Transit-Mixers and placed through pumps to
the required height and distances.
112
RMC (READY MIX CONCRETE)

113. ANY QUESTIONS ?
113

114. THANK YOU
114