GROUTING OF CONCRETE, advantage ofGrouting,Characteristics of Grouting, GUNTING OF CONCRETE, Application of Guniting, Properties of Guniting, advantage and disadvantage of Guniting, UNDERWATER CONCRETING, Properties of underwater concrete, METHODS OF UNDERWATER CONCRETE, advantage and disadvantage of underwater concrete, HOT WEATHERING CONCRETE, precautions, COLD WEATHER CONCRETING, PUMPABLE CONCRETE, Requirements of Mix Design for Pumpable Concrete, Ready Mixed Concrete RMC, Types of Ready Mixed Concrete, advantage and disadvantage of ready mixed concrete, introduction in High performance concrete HPC, selection of materials, behaviour of fresh high performance concrete HPC , behaviour of Hardened High performance concrete HPC when to use High performance concrete HPC , application of HPC , Advantage of HPC , Limitations of HPC

1. MCT 6102 CONCRETE
TECHNOLOGY
ASSIGNMENT
MODULE – SPECIAL CONCRETE AND HIGH PERFORMANCE CONCRETE
COURSE CORDINATOR
SUBMITTED BY
DR HEMANT SOOD
ANKAJ KUMAR
ROLL NO- 202304
ME CTM ( REGULAR)

2. GROUTING OF CONCRETE
CEMENT GROUTING IS THE INJECTION OF PUMPABLE PORTLAND
CEMENT BASED GROUT INTO A SOIL OR ROCK FORMATION TO
CHANGE THE PHYSICAL CHARACTERISTICS OF THE FORMATION.
CEMENT GROUTING IS THE INJECTION UNDER PRESSURE OF
CEMENT OR GROUT TO FILL VOIDS OR FRACTURES IN THE SOIL,
ROCK UNIT OR CONCRETE STRUCTURE. CEMENT GROUTING IS A
PROCESS BY WHICH CEMENT IS INJECTED UNDER PRESSURE TO
FILL FRACTURES AND VOIDS IN CONCRETE STRUCTURES. CEMENT
GROUTING / INJECTION OF GROUT, UNDER PRESSURE, INTO
ROCK FRACTURES WILL IMPROVE THE STABILITY OF THE ROCK
FORMATION; PROVIDE PRE-CONSTRUCTION SITE IMPROVEMENT;
ARREST FOUNDATION SETTLEMENTS; STOP ROCKING SLABS IN
WAREHOUSES; REPAIR FRACTURES IN MACHINE BASES; RECTIFY
SINKHOLE PROBLEMS; LIFT AND LEVEL SLABS AND FOUNDATIONS;
CONTROL SOFT-GROUND SETTLEMENTS IN GRANULAR SOILS

3.  1 Advantages of Grouting Include:
 This can be done on almost any ground condition
 It does not induce vibration and can be controlled to avoid
structural damage
 Improvement in-ground structures can be measured
 Very useful for limited space and low headroom applications
 Used for slab jacking that lifts or levels the deformed foundation
 It can be installed adjacent to existing walls
 Can be used to control seepage, groundwater flow, and hazardous
waste materials Process and its types

4.  2Characteristics of Grouting
 Non-corrosive
 Not flammable, non-toxic
 Shrinkage compensated
 Process and its Specification
 Substrate preparation
 Able Adjustable Fixture
 Very good flow characteristics
 Excellent Bond to Concrete
 No segment or bleeding
 High final strengths
 Easy to use (ready to mix powder)
 Easy to mix, only add water
 Initial expansion by gas generation
 Impact and vibration resistant

5.  GUNTING OF CONCRETE
 Guniting is the most effective process of repairing concrete work
which has been damaged due to inferior work or other reasons. It is
also used for providing an impervious layer. The repairs are carried
out after completely chipping off the damaged concrete from the
surface and augmenting the reinforcement wherever necessary.
 A cement-sand mix, in the ratio 1:2 or 1:3 depending upon the
requirement, applied at high pressure over the surface with the help
of specialized equipment. They extensively used to rehabilitated
concrete bridges, dams, spillways buildings marine structures, etc..
This method is quite costly and can’t use in an isolated location

6.  Application of Guniting
 It widely used in different construction such as thin overhead vertical or
horizontal surface, particularly the curved or folded sections, canal,
reservoir, and tunnel lining.
 It also used in swimming pools, water retaining structures, and
prestressed tanks.
 It has successfully used in the stabilization of rock slopes and temporary
protection of freshly excavated rock surfaces.
 They are a utility for protection against long-term corrosion of pilling,
coal bunker, oil tanks, steel building frames, and other structures, as well
as in encasing structural steel for fireproofing.
 These are developed for high-temperature applications, such as the
refractory lining of kilns, chimneys, furnaces

7.  Properties of Guniting
 A small maximum size aggregate used and cement content is high.
 It should enhance durability in most cases.
 Whereas conventional concrete consolidates from vibration,
Guniting consolidated from the impact of a high-velocity jet
impinging on the surface. This process not only increases the
cement content due to rebound but also brings about different air-
void systems affecting the durability of Gunting.
 The application procedures have a greater effect on the in-place
properties of shotcrete than the mix proportions.

8. Advantages of Guniting
 The high compressive strength obtained.
 A Strenght of about 56 to 70 N/mm2 at 28 days generally obtained.
 The high impermeability achieved.
 It is the best choice in those work types were an unexpected
stoppage of work is possible.
 When the repairs carried out in any situation in a short time.
Disadvantages of Guniting
 In This Process Wastages a lot of concrete.
 They need skilled labor. Who takes a lot of charges to a complete
This process.
 This method quite costly and can’t use in an isolated location.

9.  UNDERWATER CONCRETING
 There are often situations such as basements, sewerage, ducts,
ports, bridges and marine works in which concrete is to be placed
under water.
 Special care must be taken whenever concrete is to be placed
under water, it should be plastic and cohesive but have good flow
capacity.
 Many difficulties in water formation, especially in places where the
depth is large, therefore proper mixing design, concrete production,
placement and quality control must be followed.

10.  Properties of underwater concrete:
 Adequate safety from corrosion can be achieved by using anti-
corrosion or protecting merchandise.
 Spalling of concrete can be avoided by expanding the concrete
carefully.
 Better maintenance process includes initial inspection, worsening
prediction, inspection, evaluation and remedial measures.
 During construction, social as well as economic aspects are
minimum along with engineering.

11. METHODS OF UNDERWATER CONCRETE:
 1) TREMIE METHOD:
 2) BUCKET PLACING METHOD
 3) PLACING IN BAGS METHOD
 4) PACKED CONCRETE METHOD

12. UNDERWATER CONCRETE CONSTRUCTION TECHNIQUES:
• CAISSONS
• COFFERDAM

13. ADVANTAGES OF UNDERWATER CONCRETE:
 It allows construction and excavation in a poor environment.
 It provides a harmless environment for working.
 Sheet piles are easy to install and remove.
 The material can usually be reused on other projects.
1.4.5 DISADVANTAGES OF UNDERWATER
CONCRETE:
 Rapidly rising water can eject the scour hole & it is one of
the main fundamental causes of bridge failure.
 Cracks, scaling, crazing and potting are very common in
concrete.
 Rebar is steel reinforcement bars that are passively located
within the concrete, they undergo corrosion.
 The concrete broke, flattened or piled up due to poor
installation and environmental factors.

14. HOT WEATHERING CONCRETE
The concrete placed at an atmospheric temperature above 40C is considered as hot weather
concreting.At this temperature certain special problems are usually encountered.
They are:
1. Rapid rate of hydration of cement, quick setting and early stiffening
2. Rapid evaporation of mixed water.
3. Greater plastic shrinkage.
4. Less time for finishing.
5. Reduced relative humidity.
6. Absorption of water from the concrete by the sub grade andformwork.
7. Difficulty in continuous and uninterrupted curing.
8. Difficulty in incorporation of Air entertainment.

15.  Precautions:
 Aggregate should be stack piled in shade frequent sprinkling of
water should be done to lower the temperature.
 Cold water may be used to lower the temperature and concrete or
use of ice can be done while mixing.
 Reinforcement formwork and subgrade should be wetted with cold
water prior to planning.
 It is better to do the concreting operations during the evening time
when temperature is low.
 Continuous wet curing is necessary

16.  6 COLD WEATHER CONCRETING
 Cold weather concreting is the process of placement, finishing,
curing, and protection of concrete during cold weather, as per ACI
306.1. The cold weather occurs when the average outdoor
temperature is below 4.4C (40F) for more than three successive
days. If the temperature of fresh concrete is 12.7C (55F) or greater,
and if the concrete is maintained at this temperature, then winter
concreting should be free from problems.
 Approximate set time for concrete at 21C (70F) is six hours. Set time
jumps to just over 14 hours if the concrete temperature drops to 4.4C
(40F). If it drops below this point and the concrete freezes early in
the process, loss of strength, up to 50 percent, increased
permeability and a lower resistance to weather may result.

17.  Preparations
 Concrete Pouring
 Concrete Protection
 Concrete Curing

18.  PUMPABLE CONCRETE
 Pumpable concrete is that type of concrete which can be pushed
through a pipeline for construction. It is made in such a manner that
its friction at the inner wall of the pipeline does not become very
high and that it does not wedge while flowing through the pipeline.
It is very important to have a clear understanding of what happens
to concrete when it is pumped through pipeline to any study of
concrete pumping. Pumpable concrete emerging from a pipeline
flows in the form of a plug which is separated from the pipe wall by
a thin lubricating layer consisting of cement paste. The water in the
paste is hydraulically linked with the inter particle water layer in the
plug.

19.  Requirements of Mix Design for Pumpable Concrete:
 The pumpable concrete should have:
 (a) It should have minimum fine particles smaller than 0.25 mm in size
(cement + fine aggregate), approximately 400 kg/m3 of concrete for
the max size of 32 mm of coarse aggregate. In case of very angular
and flaky aggregate, the quantity of fine aggregate may be increased
by 10%.
 (b) Amount of cement. This concrete must contain a minimum cement
content of 240 kg/m3 of concrete for max. size of 32 mm of coarse
aggregate. In case the max. size of coarse aggregate is 16 mm, then
quantity of cement should be increased by 10%.
 (c) Water/cement ratio. The water/cement ratio of pumpable concrete
may vary from 0.42 to 0.65.
 (d) Workability. The slump may be between 75 mm to 150 mm

20.  Ready Mixed Concrete
 Ready Mixed Concrete is a tailor – made concrete that is
manufactured in a factory or within a batching plant based on the
standard required specifications. The prepared concrete mix is then
taken to the work site within transit mixers mounted over a truck.
 This type of concrete guarantee higher durability and sustainability.
As the work is carried out by an expert supplier, the mixture formed is
precise and of higher quality. Special concrete mixtures too can be
made efficiently by this concrete manufacturing method

21.  Types of Ready Mixed Concrete
 There are three types of ready mix concrete (RMC) depending
upon the mixing of the various ingredients as given below:
 Transit mixed concrete
 Shrink mixed concrete
 Central mixed concrete

22. Advantages of Ready Mixed Concrete
 Quality concrete is obtained as a ready-mix concrete mix plant make use of
sophisticated equipment and consistent methods. There is strict control over the
testing of materials, process parameters and continuous monitoring of key practices
during the manufacture.Poor control on the input materials, batching and mixing
methods in the case of site mix concrete is solved in a ready-mix concrete method.
 Speed in the construction practices followed in ready mix concrete plant is followed
continuously by having mechanised operations. The output obtained from a site mix
concrete plant using a 8/12 mixer is 4 to 5 metric cubes per hour which is 30-60 metric
cubes per hour in a ready mix concrete plant.
 Better handling and proper mixing practice will help to reduce the consumption of
cement by 10 – 12%. Use of admixtures and other cementitious materials will help to
reduce the amount of cement.
 The concrete mixed is used with high versatility. It is placed by following best
concrete placing methods.
 Cement is saved and the dust caused is reduced as ready mix concrete make use of
bulk concrete instead of bags of cement.

23. Disadvantages of Ready Mixed Concrete
 The transit time from the time of preparation of concrete to the
delivery site, will result in loss of workability. This will demand for
additional water or admixtures to maintain the workability as per the
specification. At site, the QA/QC engineer are supposed to check
the workability through slump test before using it for construction.
 Traffic during the transit of concrete can result in setting of concrete.
This will hence require addition of admixtures to delay the setting
period. But unexpected traffic is a great problem.
 The formwork and placing arrangement must be prepared in
advance in large area as the concrete can be bought in larger
amounts