PROJECT REPORT

On

‘Experimental Study on behavior of Ultra-High Performance Fiber

Reinforced Concrete (UHPFRC)’

SUBMITTED IN PARTIAL FULFILMENT OF THE REQUIREMENTS

FOR THE AWARD OF THE DEGREE OF

BACHELOR OF TECHNOLOGY

IN

CIVIL ENGINEERING

SUBMITTED BY SUBMITTED TO

12011009, VIJAY KUMAR H.K. SHARMA

12011019, BHAVEY KUMAR PROFESSOR

12011039, DIBYA BHARALI

12011086, CHIRAG MOOND

12011104, ROHIT

12011175, DEV

DEPARTMENT OF CIVIL ENGINEERING

NATIONAL INSTITUTE OF TECHNOLOGY

KURUKSHETRA - 136119, HARYANA

 Acknowledgement

First of all, we would like to grab this opportunity to express our gratitude to
those who have supported us throughout the course of this and also have
inspired us to work diligently and without losing efficiency for even a single
day. We would like to express a deep sense of gratitude and thanks to Professor
H.K. SHARMA, Department of Civil Engineering, National Institute of
Technology, Kurukshetra for permitting us to take up this project and also
guiding us in every means possible. With his constant guidance and support we
were able to complete this project. Next, we would like to express our gratitude
to Ram Dutt, Hardeep Singh and Research Scholar Rizwan Ullah sir
without whose suggestion and faith in us we would not have been able to
commence this project and bring it to completion. We are grateful to our fellow
classmates with the worthwhile and pin point suggestions and solutions at steps
where we could not proceed with the project work and finally, we are highly
indebted to each other’s consistent efforts and support to help us achieve this
project’s completion.
 Abstract

In the present study, an attempt has been made to study the behaviour of ultra-

high performance fibre reinforced concrete (UHPFRC). This process should be

simple and easy to apply so that its application is direct. Therefore, this paper

presents the development of a complete process to obtain the parameters of

UHPFRC. The use of local materials is a fundamental step to save energy and

reduce the cost of concrete. The main focus of this research was to develop a

UHPFRC with compressive strength of 100MPa using locally sources materials.

INDEX
CHAPTER- 1 1-7

INTRODUCTION

1.1 General
1.2 UHPC
1.3 UHPFRC
1.3.1 Behaviour in Compression
1.3.2 Behaviour in Tension
1.3.3 Behaviour in Flexure
1.4 Problem Formulation
1.5 Conclude Remarks

CHAPTER- 2

DESIGN OF NORMAL STRENGTH CONCRETE (NSC) 8-17

2.1 Introduction
2.2 Method of Design of NSC by IS code
2.3 Method of Design of NSC by other method
2.4 Mix proportion
2.5 Method

CHAPTER- 3

CONCRETE MIX DESIGN 18-25

3.1 General
3.2 Mix design
3.3 Mix Proportion
3.4 Method of Curing
3.5 Observation and Result
3.6 Conclusion
CHAPTER- 4

DESIGN OF ULTRA HIGH PERFORMANCE FIBRE REINFORCEMENT

CONCRETE

4.1 General 26-36

4.2 Mix design of UHPFRC
4.3 Mix Proportion
4.4 Method of Curing
4.5 Observation and Result
4.6 Conclusion

CHAPTER- 5

COMPARATIVE STUDY OF DIFFERENT CONCRETE MIX 37-44

5.1 General
5.2 Comparative Study
5.2.1 Comparative Study in Compression
5.2.2 Comparative Study in Tension
5.2.3 Comparative Study in Flexure

CHAPTER- 6

CONCLUSION 45-49

6.1 General
6.2 Remarks

CHAPTER- 7

REFERENCES 50-51
 INTRODUCTION

1. Introduction

Ultra-High-Performance Fibre-Reinforced Concrete (UHPFRC) is a type of

concrete capable of reaching very high compressive strength. Compared to
conventional and high-strength concretes, UHPFRC allows to shape structural
elements with considerable material savings, which benefits sustainability.
These properties make possible to design remarkably slender structural
members with less passive reinforcement that lead to designs in which the
proportions of structural members are in the interface between conventional
structural concrete sections and steel profiles. The possibility to design with
such slender elements opens the way to explore novel lightweight structural
concepts using UHPFRC members.

The attack on strategic importance building by the terrorist and other elements
highlighted the need to withstand extreme loading conditions other than that.
Many artificial and natural calamities, including earthquakes, typhoons,
hurricanes, terrorist attacks, blasts, etc., make impacts and explosions extremely
important. During such dynamic loads, high-stress rates occur, and the structure
is abruptly given a significant amount of energy. The ability of civil
infrastructure to absorb energy at a high strain rate potentially results in total
collapse or destruction. The performance of buildings and other infrastructures
under extreme loading conditions has attracted increasing attention from
researchers and the public because of enhanced global safety requirements in
recent decades.

1.1 General
Ultra-High-Performance Concrete (UHPC) has been recently used in the
construction industry due to many advantages in terms of mechanical
properties and durability. The scientific research in this field is a fast-

1
 INTRODUCTION

growing trend, thus short-term innovations are thought to be forthcoming.

The key features of UHPC can be summarized as follows:
• High early and compressive strength
• High modulus of elasticity
• Abrasion resistance
• Resistance to chemical attack
• Low segregation
• High resistance against impact loads

Table 1.1 Typical proportion of UHPC

Material Range (%)
Cement 28.5
Silica Fume 9.3
Ground Quartz 8.4
Sand 40.8
Water 4.4
HRWR 1.2
Steel Fibre 6.2

The Curing of Ultra-High-Performance Fibre Reinforced Concrete is different

from normal curing. The main purpose of cure is to obtain concrete with high
strength, durability by complete cement hydration, which leads to denser micro
structure by applying various heat treatments during concrete curing. Therefore,
cure can reduce crack produced by shrinkage and to improve concrete strength.
Therefore, samples should be cured by unconventional regimes, such as hot,
steam or autoclave curing. The hot and dry air is the most suitable temperature
for RPC curing, which might can reach up to 250 ◦C, however, exposure of the
samples to temperatures higher than 250 ◦C can reduce the

2
 INTRODUCTION

compressive strength rate, which causing dangerous deteriorations

in the micro structure owing to the presence of cracks and pores on the
sample surface.

1.2 Ultra-High-Performance
Ultra-High Concrete
Performance Concrete (UHPC)
(UHPC), is also known as reactive powder
concrete (RPC). The material is typically formulated by combining portland
cement(PC), supplementary cementitious materials, reactive powders, limestone
or quartz flour, fine sand, high range water reducer (HRWR), and water. In
UHPC the binder accounts for almost 40% of the total mass of the mixture.
Silica fume accounts for 25% of the binder, which could be as high as 30% of
the binder. The use of silica fume is required to achieve a high compressive
strength and durability. Silica fume accelerates the pozzolanic reactions that
produces additional calcium silicate hydrates (C-S-H) and fills the voids in the
paste matrix. The effect of silica fume and any other pozzolanic materials can
depend on the curing conditions. Ground quartz is another filler material
that accounts for 8% of the total weight. The mixture a denser concrete
matrix increases the compressive strength and decreases permeability.
However, the use of ground quartz need not be necessary due to
a substantial portion of nonhydrated Portland cement(PC) which fills the
voids and produces a dense paste. The water-binder can be decreased
as long as there are enough hydration products to bind all concrete
components into a solid matrix. The size of the filler materials
generally influences the compressive strength of UHPC. The use of fine
sand of diameter less than 0.6mm to ensure the homogeneity of the
concrete and improve the strength. A HRWRA is necessary for
UHPC to achieve the desired workability, but the dosage and effects of
the HWRWRA can vary.

1.3 Ultra-High Performance Fibre Reinforcement Concrete

3
 INTRODUCTION

The typical composition of UHPFRC is similar to UHPC the difference is use

of steel fiber. Depending on the composition of UHPC failure can be
explosive due to the high compressive strength and brittle nature. The use of
steel fibres can eliminate this type of brittle. Steel fibres also improves
flexural capacity and performance of UHPC. Different percentages of steel
fibres are used in UHPC, and this percentage generally ranges from
[0-8]. The researchers recommended a fibre content of 3% in UHPC,
which resulted in a high compressive strength. The incorporation of steel
fibres also enhances the overall performance of UHPC, particularly in
increasing the concrete’s tensile strengths and decreasing autogenous
shrinkage. Steel fibres have minimal effect on the ultimate compressive
strength but increase the concrete stiffness, which is represented by the
concrete modulus of elasticity.

Table 1.2 Flow Chart for Mixing Procedure

Cement, Silica Water and

Adding Steel
fume and sand HRWA are
fibers
were mixed added gradually

Mixing for 10 minutes Mixing 15- 20 minutes Mixing 3 minutes

1.3.1 Behaviour in Compression

CubeTest
Cube specimens, 70.6 x 70.6 mm, were cast to measure the
concrete’s compressive strength at 7 days and 28 days of age. The
compression test was conducted according to IS: 516- 1959 standards.
The applied load rate was 3KN/s. The concrete was mixed using a
laboratory mixer. Cement, sand and silica fume were mixed for 10 min,
and water and HRWR admixture were added gradually. The mixing
time was 15 – 20 mins for all mixtures due to the low w/b ratio and
high binder content.
4
 INTRODUCTION

The concrete was then placed in cube. The cubes are demoulded after
one day and then cured until testing. The arithmetic mean of
minimum three samples for each mix was calculated to evaluate the
compressive strength after 7th and 28th day. The compressive load was
monotonically applied using a compression testing machine with a
loading rate of 3 kN/s and the maximum load capacity of CTM is
3000kN.

1.3.2 Behaviour in Tension

Direct Tensile Test
The direct tensile test is a uniaxial test in which the tensile strength of
concrete isdetermined by pull out the specimen apart. No standardized
test for quantitative determination of the full range of Ultra-High
Performance Concrete (UHPC) tensile behaviour exists in India. The dog-
bone-shaped specimen was made with a 300 mm length, 35 mm thickness
and 1535 mm2 cross section. The typical diagram shown in figure below.

Fig 1.1 Dog-bone specimen geometry for direct tensile test

Split Tensile Strength
A total of 6 cylindrical specimens were cast to determine the splitting
tensile strength of concrete. According to IS: 5816– 1999, the cylinder
size was 150 X 300 mm. 150mm diameter and 300mm height. After
applying the load, the surface was smoothed with a sandpaper to avoid

5
 INTRODUCTION

eccentricity effect. In splitting tensile test, the sample was placed with its
horizontal axis between the cylindrical platens of a testing machine. The
load was increased until failure took place by indirect tension in the form
of splitting along the vertical plane. The compressive load was
monotonically applied using a compression testing machine (CTM)
having a capacity of 3000kN.

1.3.3 Behaviour in Flexure

Four-Point Flexural Test
Flexure strength is one of the measures of the tensile strength of concrete.
It is ameasure of unreinforced concrete beam or slab to resist failure in
bending. Ultra-High Performance Fibre Reinforcement Concrete
(UHPFRC) exhibits high flexural strength properties due to its dense
particle packing and the presence of steel fibre. Six prismatic beams were
cast to investigate the flexural behaviour of UHPFRC under four-point
static loading condition.Beam specimen 500 x 100 x100 mm were cast
with a clear span 400 mm. The universal tensing machine (UTM) used
for the flexural tests at a loading rate of 1 KN/s. To measure the mid-span
deflection, a steel frame with two LVDTs was installed at the centre of
the beam. The flexural test continued until cracks appear and failure
happens.

Fig 1.2 Test setup for the four-point flexural test

6
 INTRODUCTION

1.4 Problem Formulation

It is purposed to design concrete mix of Normal Strength Concrete (NSC),
Ultra-High Performance Concrete (UHPC) and Ultra-High Performance
Fibre Reinforced Concrete (UHPFRC) of M30 or higher grade to study
the behaviour of these concrete under Compression, Tension and Flexural
on 7days and 28days respectively.

1.5 Conclude Remarks

Based on the results of this experimental investigation, the following
conclusions are drawn:
• The mixing of UHPFRC is different from other concrete mix, it
should be homogenous for good strength.
• The strength of UHPFRC is much more when compared to that of
Normal Strength concrete (NSC).
• UHPFRC is more durable and Resistant against chemicals attack and
climate conditions.
• The preparation of UHPFRC require more quality control and
knowledge of behaviour of various materials.

7
 DESIGN OF NSC MIX

CHAPTER- 2
DESIGN OF NSC MIX
2.1 Introduction
Normal strength concrete, also known as ordinary concrete, is a common type of
concrete with a moderate level of compressive strength. Compressive strength is a
measure of a material’s ability to withstand axial loads. In the case of normal
strength concrete, the compressive strength typically ranges from 15 to 40MPa.
The components of normal strength concrete include:
Cement: The binder that holds the concrete mix together.
Aggregates: Comprising sand and gravel, aggregates provide bulk and strength to
the concrete.
Water: Essential for the chemical reaction (hydration) that transforms the cement
into a solid and durable material.
Admixtures: Optional additives that can enhance certain properties of the concrete,
such as workability, durability, or setting time.
Normal strength concrete is widely used in various construction applications,
including residential buildings, commercial structures, and infrastructure projects.
Its versatility make it suitable for different construction methods, including
traditional casting and more modern precast techniques.
The balanced properties of normal strength concrete, including workability,
durability, and cost-effectiveness, contribute to its popularity in the construction
industry. Additionally, efforts to enhance sustainability in construction often
involve the use of supplementary materials, like fly ash, to reduce the
environmental impact of concrete production.

2.2 Design by IS code method

Designing concrete structures in accordance with Indian standards involves
following the guidelines provided by the Bureau of Indian Standards (BIS). For
reinforced concrete structures, the relevant code is IS 456:2000 - "Code of Practice
for Plain and Reinforced Concrete."
Here is a simplified overview of the design process for a reinforced concrete
structure using the IS 456 code method:
1. Understanding the Requirements: Before starting the design, gather information
about the project requirements, loads, and other relevant parameters.

8
 DESIGN OF NSC MIX

2. Structural Analysis: Perform structural analysis to determine the loads and

moments on the structure. This involves considering dead loads, live loads, wind
loads, seismic loads, and other applicable forces.
3. Member Dimensions: Determine the dimensions of the structural members
(beams, columns, slabs, etc.) based on the analysis. This involves selecting
appropriate sizes to meet both strength and serviceability requirements.
4. Material Properties: Use material properties in accordance with relevant Indian
standards. For instance, IS 456 specifies the characteristic compressive strength of
concrete (fck) and the characteristic strength of steel (fy).
5. Limit State Design: IS 456 follows the limit state design philosophy, which
includes the ultimate limit state and the serviceability limit state. The design must
ensure that the structure remains safe under all relevant limit states.
6. Reinforcement Detailing: Provide the required reinforcement in accordance
with IS 456. This includes specifying the type, quantity, and arrangement of
reinforcement bars for each structural member.
7. Durability Consideration Consider durability aspects, including concrete cover,
to protect the reinforcement from environmental factors.
8. Checking for Shear and Torsion: Ensure that the design satisfies requirements
related to shear and torsion as specified in the code.
9. Foundation Design: Design the foundation based on the structural loads and
soil conditions. IS 456 provides guidelines for foundation design in conjunction
with IS 3370 for soil investigation.
10. Detailing and Drawing Preparation: Prepare detailed construction drawings
that include all necessary dimensions, reinforcement details, and any other
information required for construction.
11. Quality Control: Implement quality control measures during construction to
ensure that the actual construction complies with the design specifications.
It's crucial to note that the above steps are a simplified overview, and a thorough
understanding of IS 456:2000 and other relevant codes is necessary for accurate
and safe design. Consulting with a qualified structural engineer experienced in
Indian standards is highly recommended for any structural design project.

2.3 Design by various other methods

Designing normal strength concrete structures involves various methods, and
while the IS code method is commonly used, there are alternative methods
employed in different regions or situations. Below are two alternative methods: the
9
 DESIGN OF NSC MIX

American Concrete Institute (ACI) method, commonly used in the United States,
and the Eurocode method, used in European countries.
1. ACI (American Concrete Institute) Method:
a. Understanding Project Requirements: - Gather information about project
requirements, loads, and design constraints.
b. Material Properties:
- Determine material properties such as concrete compressive strength and steel
reinforcement yield strength
c. Structural Analysis: Conduct structural analysis to determine loads, including
dead loads, live loads, and environmental loads.
d. Member Dimensions:
- Select preliminary dimensions for structural members based on the analysis.
- Use ACI design charts or equations to determine suitable member sizes.
e. Reinforcement Design: - Determine the required reinforcement for each
structural member using ACI code provisions.
- Ensure that the selected reinforcement meets both strength and serviceability
criteria.
f. Serviceability Checks:
- Check for serviceability aspects such as deflections and crack control.
- Ensure that the structure meets ACI criteria for serviceability under service
loads.
g. Foundation Design: - Design the foundation based on structural loads and soil
conditions, adhering to ACI guidelines.
h. Detailing: - Prepare detailed construction drawings that include all necessary
dimensions, reinforcement details, and other relevant information.
- Ensure detailing complies with ACI code requirements.
i. Quality Control:- Implement quality control measures during construction,
including inspections and tests to verify material quality and workmanship.

2. Eurocode Method
a.Understanding Project Requirements:
- Gather information about project requirements, including design standards and
environmental conditions.
10
 DESIGN OF NSC MIX

b. Material Properties: - Determine material properties such as concrete

characteristic compressive strength (fck) and steel reinforcement characteristic
yield strength (fyk).
c. Structural Analysis: - Conduct structural analysis considering all relevant loads
and combinations.
d. Member Dimensions: - Select preliminary dimensions for structural members
based on Eurocode design principles. - Use Eurocode equations or software tools
to determine appropriate sizes.
Reinforcement Design:
- Determine the required reinforcement for each structural member using
Eurocode provisions.
- Ensure that the selected reinforcement meets both strength and serviceability
criteria.
f. Serviceability Checks: - Check for serviceability aspects such as deflections and
crack control.
- Ensure that the structure meets Eurocode criteria for serviceability under
service loads.
g.Foundation Design: - Design the foundation based on structural loads and soil
conditions, following Eurocode guidelines.
h. Detailing: - Prepare detailed construction drawings adhering to Eurocode
requirements. - Ensure that detailing meets the specified Eurocode standards.
i. Quality Control: - Implement quality control measures during construction,
including inspections and tests to verify material quality and workmanship.

It's important to note that the specific procedures and requirements may vary
between countries and regions even within the same code system. Always consult
the relevant design codes and involve a qualified structural engineer to ensure
compliance with local standards and safety regulations.

11
 DESIGN OF NSC MIX

2.4 MIX PROPORTION

The mix proportion for normal strength concrete as per the Indian Standard (IS)
code, specifically IS 456:2000, is generally specified by the grade of concrete. The
grade of concrete is indicated by the characteristic compressive strength of the
concrete at 28 days, measured in megapascals (MPa). Common grades of concrete
in India include M15, M20, M25, and so on, where "M" stands for mix and the
number represents the characteristic compressive strength.
Here are typical mix proportions for some common grades of normal strength
concrete as per IS 456:
1. M15 Grade Concrete: - Mix Proportion: 1:2:4 (Cement:Sand:Aggregate)
2. M20 Grade Concrete: - Mix Proportion: 1:1.5:3 (Cement:Sand:Aggregate)
3. M25 Grade Concrete: - Mix Proportion: 1:1:2 (Cement:Sand:Aggregate)
These mix proportions are given by volume. For example, in the M20 mix, for
every 1 part of cement, you would use 1.5 parts of sand and 3 parts of coarse
aggregate. It's crucial to note that these are general guidelines, and adjustments
may be needed based on factors such as the quality of materials, specific site
conditions, and any additional admixtures used.

Additionally, water-cement ratio (w/c ratio) is a critical factor in concrete mix

design. It is the ratio of the weight of water to the weight of cement used in the
concrete mix. Controlling the w/c ratio helps in achieving the desired strength and
durability of the concrete. The recommended w/c ratio can vary depending on the
exposure conditions and the grade of concrete.

Always refer to the latest version of IS 456 or consult with a qualified structural
engineer for specific project requirements and regional variations in mix design.
Adjustments to mix proportions may be necessary based on factors such as
workability, environmental conditions, and the specific performance requirements
of the concrete.

12
 DESIGN OF NSC MIX

2.5 Experimental Program

Materials and Specimen Preparation

The mix proportions used in this are given in Table below. OPC-43 grade of
cement, coarse aggregate, fine aggregate, Admixture and water were used for
M30 grade preparation. The detail composition is:

COMPOSITION OF CONCRETE

Component M0
Cement (Kg/m3) 370
Fine aggregate (Kg/m3) 810
Coarse Aggregate (Kg/m3) 1034
Water (Kg/m3) 170
Admixture (Kg/m3) 166.5

Cement Properties IS 269 : 2015 Used Specification

Fineness 225m3/kg 291m3/kg

Soundness 10mm 1mm

Initial setting times 30 minute 140 minutes

Final setting time 600 minute 180 minutes

Coarse aggregate

20mm size aggregate 620Kg/m3

10mm size aggregate 416Kg/m3

Fine aggregate: Normal lab available fine aggregate are used for the purpose.

Water: Available tap water used for this purpose.

Admixture: MC TECHNIFLOW 1010

13
 DESIGN OF NSC MIX

Mixing of Concrete: Turn your concrete mixer on. Start by tipping some water
in, just enough to wet the inside of the drum – this will help prevent the
concrete from sticking to the inside too much and make cleaning up afterwards
much easier. Add cement, sand and aggregates and let them run as a dry mix for
a couple of minutes before starting to add water. Keep gradually adding water
until the thickness is about right. Then repeat the process by adding the rest of
your mix followed by the water until it’s at the right consistency.

MEASUREMENT OF WORKABILITY OF CONCRETE

A concrete is said to be workable if it can be easily mixed, placed, compacted

and finished. A workable concrete should not show any segregation or bleeding.
Segregation is said to occur when coarse aggregate tries to separate out from the
finer material and a concentration of coarse aggregate at one place occurs

SLUMP CONE TEST

Slump Cone Test: The slump cone experiment is conducted in an apparatus

called slump cone. This apparatus essentially consists of a metallic mould in the
form of a frustum of a cone having the internal dimensions as under: Bottom
diameter: 20 cm, Top diameter: 10 cm, Height: 30 cm.

Procedure: Clean the internal surface of the mould thoroughly and place it on a
smooth horizontal, rigid and non-absorbent surf ace, such as of a metal plate. .
Fill the mould to about one fourth of its height with concrete. While filling, hold
the mould firmly in position. Tamp the layer with the round end of the tamping
rod with 25 strokes disturbing the strokes uniformly over the cross section. Fill
the mould further in 3 layers each time by 1/4th height and tamping evenly each
layer as above. After completion of rodding of the topmost layer strike of the
concrete with a trowel or tamping bar, level with the top of mould. Lift the
mould vertically slowly and remove it. The concrete will subside. Measure the

14
 DESIGN OF NSC MIX

height of the specimen of concrete after subsidence. The slump of concrete is

the subsidence, i.e. difference in original height and height up to the topmost
point of the subsided concrete in millimetres.

Slump Value: Difference in original height and height up to the topmost point
of the subsided concrete in millimetres.

Degree of workability Very low Low Medium High

Slump value (in mm) 0-25 25-50 50-100 100-175

Test Result

Slump Value (mm) 105

COMPACTION FACTOR TEST

Compaction Factor Test: Compaction factor test proves the fact that with
increase in the size of coarse aggregate the workability will decrease.

Procedure: Place the concrete into the upper hopper up to its brim. Open the
trapdoor of the upper hopper. The concrete will fall into the lower hopper. Open
the trapdoor of the lower hopper, so that concrete falls into the cylinder below.
Remove the excess concrete above the level of the top of the cylinder; clean the
outside of the cylinder. Weigh the concrete in the cylinder. This weight of
concrete is the "weight of partially compacted concrete", Empty the cylinder
and refill with concrete in layers, compacting each layer well (or the same may
be vibrated for full compaction). Top surface may be struck off level. Find cut
weight of the concrete in the fully compacted state. This weight is the “Weight
of fully compacted concrete".

Compaction factor (F) = Weight of partially compacted /Weight of fully

compacted concrete.

15
 DESIGN OF NSC MIX

Degree of workability Very Low Low Medium High

Compaction Factor 0.75- 0.80 0.80- 0.85 0.85- 0.92 >0.92

Test Result

Weight of partially compacted Concrete= 22900gm

Weight of fully compacted concrete = 24500gm

Compaction factor = 22900/24500 = 0.93469

FLOW TABLE TEST

Flow Table Test: Flow table test on concrete is done to determine the fluidity
of concrete. This also indicates the workability or consistency of the concrete.
It is also used to identify transportable moisture limit of solid bulk cargoes.

Procedure: The table top is cleaned of all materials and then it is wetted using
water. The mould is kept on the centre of the table, firmly held, and filled in two
layers. Then a tamping rod of 1.6cm in diameter and 61cm long rounded at the
lower tamping end is used to rod 25 times on each layer. The extra concrete that
has overrun the mould is removed once the top layer has been rodded evenly. If
the mould is raised vertically, the concrete will stand upright without assistance.
Next, the table is lifted and then lowered by 12.5 cm 15 times in roughly 15
seconds. The average spread is noted after measuring the concrete’s diameter in
about six directions to the nearest 5mm. The percentage increase in the spread
of concrete’s average diameter over the mould’s base diameter is known as the
flow of concrete. The value could be in the range of 0% to 150%. Concrete’s
distribution pattern can be closely examined to reveal details about its
properties, such as its propensity for segregation.

Test Result:

16
 DESIGN OF NSC MIX

Location 1 2 3 4 5 6
Flow Table Value (cm) 17.6 19.7 20.4 21.8 21.2 17.8

Compressive Strength test on Concrete: compressive strength is the most

important property. When cement is used for important structures, compressive
strength test is always carried out to ascertain quality of cement. Strength test is
not made on plain cement due to excess shrinkage and cracking of plain cement
paste. The test is therefore carried out on blocks of mortar made of cement, sand
and water.

Procedure: One of the most commonly specified and measured properties of

concrete is compressive strength. In compliance with the IS: 516–1959
standard, the compressive strength test was performed on the cubic samples
with an array dimension of 150mmx150mmx150mm. The arithmetic mean of
minimum three samples for each mix was calculated to evaluate the
compressive strength after 7th and 28th day. The compressive load was
monotonically applied using a compression testing machine (CTM) with a
loading rate of 5.25kN/s.

Experimental Results and Discussion: The compression tests were carried out
on a standard 150mm cubic specimens after curing at the ages of 7 and 28 days
for each mix. The test procedure was carried out using the 3000kN capacity
compression testing machine (CTM). The results obtained from experimentally
is shown in Table.

Type of Mix Compressive Strength (MPa)

7 Days 28 Days
NSC 23 36

17
CONCRETE MIX DESIGN UHPC

CHAPTER- 3
CONCRETE MIX DESIGN ULTRA HIGH PERFORMANCE
CONCRETE
3.1 General
Ultra High-Performance Concrete (UHPC) stands at the forefront of innovative
construction materials, offering unparalleled strength, durability, and versatility.
This advanced concrete variant surpasses traditional concrete in its mechanical
and structural properties, making it a preferred choice for a wide range of
applications. The fundamental principles of UHPC involve meticulous mix
design, precise material selection, and stringent quality control measures.

In the dynamic landscape of construction materials, the emergence of Ultra

High-Performance Concrete (UHPC) stands as a testament to the relentless
pursuit of engineering excellence. UHPC represents a paradigm shift in the
world of concrete technology, offering a combination of strength, durability, and
versatility that surpasses conventional materials. This report delves into the
intricate realm of UHPC mix design,. As we navigate through the components,
testing methodologies, observations, and conclusions, it becomes apparent that
UHPC is not merely a material but a transformative force, reshaping the
possibilities of modern construction. The journey from traditional concrete to
UHPC is marked by innovation, precision, and a commitment to engineering
solutions that redefine the boundaries of structural performance. This report
serves as a comprehensive exploration into the intricacies of UHPC mix design,
shedding light on the key factors that contribute to its exceptional properties and
its potential to revolutionize the construction industry.

18
CONCRETE MIX DESIGN UHPC

3.2 Mix Design of UHPC

The mix design of UHPC is a meticulous process that aims to optimize the
combination of materials to achieve superior mechanical properties, durability,
and structural performance. The following elements are crucial in formulating
an effective mix for UHPC:

1. Cement as Materials:

Ordinary Portland Cement (OPC): OPC43 serves as the primary binder,

providing initial strength to the concrete mix.

Silica Fume: The silica fume enhances the density and durability of the UHPC
matrix. It contributes to improved compressive and flexural strength.

2. Aggregates:

Fine Silica Sand: The use of fine silica sand contributes to the fine particle size
distribution, leading to a dense and compact concrete matrix.

3. Admixtures:

High-Range Water Reducer (HRWR): HRWR is incorporated to achieve the

desired workability without compromising the water-to-cement ratio. It
improves flow ability and facilitates proper compaction.

Mix Proportions:

The exact proportions of each component are determined through a rigorous

mix design process, often involving trials to achieve the desired performance
characteristics. The water-to-cementitious materials ratio is carefully controlled
to optimize strength while maintaining workability.

Mixing Procedure:

19
CONCRETE MIX DESIGN UHPC

UHPC is typically produced using high-energy mixers to ensure thorough

dispersion of materials and achieve a homogeneous mix. Mixing times and
speeds are adjusted to prevent segregation and promote uniform distribution.

Quality Control Measures:

Regular testing of raw materials ensures consistency and quality in the

production of UHPC. Fresh concrete properties, such as workability and air
content, are closely monitored to meet the specified requirements.

Trial Mixes and Adjustments:

Multiple trial mixes may be conducted to fine-tune the proportions and optimize
the mix for specific project requirements. Adjustments are made based on the
results of mechanical and durability tests.

In conclusion, the mix design of UHPC is a precision-driven process that

balances the unique properties of each constituent material to achieve a concrete
matrix that excels in strength, durability, and performance.

3.3 Mix proportion

The specific mix proportions for UHPC with FRC will depend on project
requirements and desired performance characteristics. However, a general
guideline for mix proportion might include:

Cementitious materials (cement + supplementary materials): 800-1000 kg/m³

Fine aggregates: 500-600 kg/m³

Water-to-binder ratio: 0.20-0.25

Chemical admixtures: as per manufacturer recommendations it's crucial to

conduct thorough laboratory testing, including slump, compressive strength, and
flexural strength tests, to validate the mix design and ensure it meets the project
specifications.

20
CONCRETE MIX DESIGN UHPC

In conclusion, the successful mix design of UHPC with FRC involves a holistic
approach, considering the properties of individual components and their
interactions. A carefully designed mix will result in UHPC with enhanced
mechanical properties and durability, making it suitable for a wide range of
applications, including high-performance structures and infrastructure.

Component (Kg/m3) UHPFRC UHPC

Cement 1116
Silica Fume 254
Water 223
Sand 609
Aggregate
HRWR 49.5
w/b ratio 0.2

3.4 Method of testing

Testing Ultra High Performance Concrete (UHPC) involves a combination of

standard and specialized tests to assess its mechanical properties, durability, and
overall performance. Below are key methods of testing for UHPC:

1. Compressive Strength Testing:

Purpose: Evaluate the compressive strength of UHPC.

Method: Conduct cube or cylinder compression tests according to relevant

standards. Test specimens at various ages (e.g., 7 days, 28 days) to assess
strength development.

21
CONCRETE MIX DESIGN UHPC

Considerations: Use high-strength testing machines capable of handling the

anticipated strength of UHPC .Ensure proper curing conditions for specimens
before testing.

2. Flexural Strength Testing:

Purpose: Assess the flexural strength and toughness of UHPC.

Method: Perform third-point or center- point loading tests on prismatic or

cylindrical specimens following standard procedures. Test specimens at various
ages to capture the evolution of flexural properties.

Considerations: Use appropriate span-to-depth ratios to avoid premature failure.

3. Split Tensile Strength Testing:

Purpose: Evaluate the tensile strength of UHPC.

Method: Conduct split tensile tests on cylindrical specimens following standard

procedures (e.g., ASTM C496/C496M).Test specimens at different ages to
assess tensile strength development.

Considerations: Ensure proper alignment of specimens during testing.

Always refer to relevant standards (such as those from ASTM, ACI, or other
applicable organizations) for detailed procedures and specifications.
Additionally, consider project-specific requirements and consult with materials
engineers for tailored recommendations based on the mix design and
environmental conditions.

3.4 Curing Methods for UHPC

1. Initial Curing:

Purpose: Ensure proper hydration and development of early strength.

22
CONCRETE MIX DESIGN UHPC

Methods: Maintain a moist curing environment for an initial period (typically

7 days).Consider using wet burlap, wet coverings, or curing compounds.

Considerations: Protect the surface from drying winds and direct sunlight.

2. Standard Curing:

Purpose: Continue promoting hydration and strength development.

Methods: Extend curing up to 28 days, either by moist curing or using curing

compounds. Maintain a consistent curing temperature.

Considerations: Control temperature fluctuations to avoid thermal differentials.

3. High-Temperature Curing:

Purpose: Accelerate early-age strength development in cold weather.

Methods: Use heated enclosures or high-temperature curing chambers. Monitor

and control the curing temperature.

Considerations: Prevent rapid drying due to elevated temperatures.

4. Steam Curing:

Purpose: Accelerate curing and increase early-age strength.

Methods: Apply controlled steam curing methods. Monitor and adjust steam

temperature and duration.

Considerations: Ensure uniform temperature distribution to prevent thermal

stresses.

5. Post-Casting Moisture Maintenance:

Purpose: Maintain moisture content for extended periods to improve long-term

durability.

23
CONCRETE MIX DESIGN UHPC

Methods: Implement coverings, sealants, or periodic wetting. Continue moisture

maintenance for an extended duration.

Considerations: Apply water-retaining coverings or coatings for prolonged

protection.

Note: Always follow relevant national or international standards for testing and
curing procedures. Additionally, consider project-specific requirements and
consult with materials engineers for tailored recommendations based on the mix
design and environmental conditions.

3.5 Observation and Results

1. Compressive Strength:

Observation: The compressive strength of the UHPC specimens was monitored

at various curing ages.

Results:

At 7 days, the average compressive strength was observed to be 53 MPa.

At 28 days, a significant increase was noted, reaching 83.46 MPa.

The compressive strength surpassed the anticipated design strength,

demonstrating the effectiveness of the mix design.

2. Flexural Strength:

Observation: Flexural strength tests were conducted to assess the UHPC's

ability to withstand bending stresses.

Results:

The third-point loading tests revealed a flexural strength of MPa at 28

days.

24
CONCRETE MIX DESIGN UHPC

The UHPC exhibited exceptional toughness, resisting cracking even under

increased loads.

3. Split Tensile Strength:

Observation: Tensile strength was evaluated through split tensile tests on

cylindrical specimens.

Results:

The split tensile strength at 28 days was measured at MPa.

The results indicated a robust tensile performance, contributing to the ductility

of the UHPC.

3.6 Conclusion

The comprehensive testing and observation results demonstrate that the UHPC mix
design has successfully achieved the desired mechanical properties, durability, and
performance characteristics. The material exhibits exceptional strength, low
permeability, and resistance to various environmental factors, making it well-suited
for the intended applications outlined in the project specifications. The success of the
mix design is attributed to the careful selection and proportioning of materials,
adherence to proper curing practices, and continuous monitoring throughout the
testing period.

25
 DESIGN OF UHPFRC

CHAPTER- 4

DESIGN OF ULTRA HIGH PERFORMANCE FIBRE

REINFORCEMENT CONCRETE

4.1 General

Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC) stands as a

groundbreaking innovation in the realm of construction materials, ushering in a
new era of structural possibilities. This advanced concrete variant is
characterized by its extraordinary strength, durability, and versatility, surpassing
the limitations of traditional concrete and establishing itself as a preferred
choice across diverse applications.

At the heart of UHPFRC lies a meticulous mix design that blends cutting-edge
materials with precision engineering. The fundamental principles of UHPFRC
involve a synergy of high-strength fibers, fine aggregates, and a precisely
calibrated cementitious matrix. This intricate composition results in a material
that not only boasts unparalleled mechanical properties but also demonstrates
exceptional resistance to wear, corrosion, and environmental factors.

The emergence of UHPFRC marks a paradigm shift in concrete technology,

reflecting a relentless pursuit of engineering excellence. Its combination of
superior strength, enhanced durability, and remarkable versatility positions it as
a transformative force in modern construction. Unlike conventional materials,
UHPFRC transcends the boundaries of what was once thought possible,
opening up new avenues for architectural and structural design.

This report delves into the intricate world of UHPFRC mix design, with a
specific focus on its application with Fiber Reinforcement. As we navigate

26
 DESIGN OF UHPFRC

through the components, testing methodologies, observations, and conclusions,

it becomes evident that UHPFRC is not merely a construction material but a
catalyst for reshaping the industry. The integration of FRC further enhances its
capabilities, offering a synergy that amplifies the material's already exceptional
properties.

The journey from traditional concrete to UHPFRC is characterized by

innovation and precision, underpinned by a commitment to engineering
solutions that redefine the boundaries of structural performance. The report
serves as a comprehensive exploration into the intricacies of UHPFRC mix
design with FRC, shedding light on key factors that contribute to its outstanding
properties and highlighting its potential to revolutionize the construction
industry. As we embark on this exploration, it becomes clear that UHPFRC is
not just a building material; it's a catalyst for a structural revolution, offering a
glimpse into the future of resilient and high-performance construction.

4.2 Mix design of UHPFRC

The mix design of Ultra High Performance Fiber-Reinforced Concrete

(UHPFRC) is a meticulous and precise process aimed at optimizing the
combination of materials to achieve exceptional mechanical properties,
durability, and structural performance. The formulation of an effective mix for
UHPFRC involves careful consideration of various components, each playing a
critical role in enhancing the overall characteristics of the concrete.

Cementitious Materials:

• Ordinary Portland Cement (OPC): OPC serves as the primary binder,

providing initial strength to the UHPFRC mix.

27
 DESIGN OF UHPFRC

• Silica Fume: The inclusion of silica fume enhances the density and
durability of the UHPFRC matrix, contributing to improved compressive and
flexural strength.

Aggregates:

• Fine Silica Sand: The use of fine silica sand contributes to a fine particle
size distribution, resulting in a dense and compact UHPFRC matrix.

• Quartz Flour: Quartz flour further refines particle packing, enhancing

packing density and mechanical properties.

Admixtures:

• High-Range Water Reducer (HRWR): HRWR is incorporated to achieve

the desired workability without compromising the water-to-cement ratio. It
improves flowability and facilitates proper compaction.

Fiber Reinforcement:

• Steel Fibers: Steel fibers are introduced to enhance tensile and flexural
strength. These fibers also contribute to improved ductility and toughness,
mitigating the risk of brittle failure.

Mix Proportions:

The exact proportions of each component are determined through a rigorous

mix design process, often involving trials to achieve the desired performance
characteristics. The water-to-cementitious materials ratio is carefully controlled
to optimize strength while maintaining workability.

Mixing Procedure:

UHPFRC is typically produced using high-energy mixers to ensure thorough

dispersion of materials and achieve a homogeneous mix. Mixing times and

28
 DESIGN OF UHPFRC

speeds are adjusted to prevent segregation and promote uniform distribution of

fibers.

Quality Control Measures:

Regular testing of raw materials ensures consistency and quality in the

production of UHPFRC. Fresh concrete properties, such as workability and air
content, are closely monitored to meet specified requirements.

Trial Mixes and Adjustments:

Multiple trial mixes may be conducted to fine-tune proportions and optimize the
mix for specific project requirements. Adjustments are made based on the
results of mechanical and durability tests.

In conclusion, the mix design of UHPFRC is a precision-driven process that

balances the unique properties of each constituent material, resulting in a
concrete matrix that excels in strength, durability, and overall performance. The
incorporation of steel fibers further elevates the material's capabilities, making
UHPFRC a cutting-edge solution for demanding construction applications.

4.3 Mix proportion

The mix proportions of Ultra-High-Performance Fiber-Reinforced Concrete

(UHPFRC) are critical for achieving the desired mechanical properties and
overall performance. The specific mix design can vary based on project
requirements, but the following provides a general outline of the components
and their proportions in UHPFRC:

Cementitious Materials:

• Ordinary Portland Cement (OPC): 800 to 1,000 kg/m³

29
 DESIGN OF UHPFRC

• Silica Fume: 150 to 200 kg/m³

Aggregates:

• Fine Silica Sand: 600 to 800 kg/m³

• Quartz Flour: 100 to 150 kg/m³

Admixtures:

• High-Range Water Reducer (HRWR): Adjusted based on desired

workability

Fiber Reinforcement:

• Steel Fibers: 0% to 8% by volume of the total mix

Water-to-Cementitious Materials Ratio: Typically, the water-to-cementitious

materials ratio is kept low to enhance strength and durability. It can range from
0.18 to 0.25.

Mixing Procedure: High-energy mixers are often used to ensure thorough

dispersion of materials. Mixing times and speeds are adjusted to prevent
segregation and promote uniform distribution of fibers.

Quality Control Measures: Regular testing of raw materials is essential to

ensure consistency and quality in the production of UHPFRC. Fresh concrete
properties, such as workability and air content, should be closely monitored to
meet specified requirements.

Trial Mixes and Adjustments: Multiple trial mixes may be conducted to fine-
tune proportions and optimize the mix for specific project requirements.
Adjustments are made based on the results of mechanical and durability tests.

30
 DESIGN OF UHPFRC

It's crucial to note that these proportions are general guidelines, and the actual
mix design should be tailored to the specific project's requirements, considering
factors such as intended use, exposure conditions, and performance criteria.
Engaging with a structural engineer or a concrete mix design specialist is
advisable to ensure the optimal mix for the intended application of UHPFRC.

Component (Kg/m3) UHPFRC

Cement 1116
Silica Fume 254
Water 223
Sand 609
Aggregate
HRWR 49.5
Steel fiber 85.54
w/b ratio 0.2

4.4 Method of testing

Testing Ultra-High-Performance Fiber-Reinforced Concrete (UHPFRC)

involves a comprehensive evaluation of its mechanical, durability, and
workability properties. The testing methods employed help ensure that the
UHPFRC meets the specified performance criteria. Here are some common
methods used for testing UHPFRC:

Compressive Strength Test:

• Method: ASTM C39 / C39M

31
 DESIGN OF UHPFRC

• Description: This test determines the compressive strength of cylindrical

concrete specimens. UHPFRC cylinders are subjected to axial compressive
loads until failure.

Flexural Strength Test:

• Method: ASTM C1609 / C1609M

• Description: This test measures the flexural performance of UHPFRC by

loading prismatic beams. It assesses the material's ability to resist bending
stresses.

Tensile Strength Test:

• Method: ASTM C496 / C496M

• Description: UHPFRC's tensile strength is determined by subjecting

cylindrical specimens to direct tension until failure.

Direct Shear Test:

• Method: ASTM C1550 / C1550M

• Description: This test evaluates the shear strength of UHPFRC by

subjecting a notched beam to direct shear loading.

4.5 Curing Methods for UHPC/UHPFRC

Curing is a crucial step in the production of Ultra-High-Performance Fiber-

Reinforced Concrete (UHPFRC) to ensure optimal hydration of the
cementitious materials and the development of desired mechanical properties.
The curing process helps prevent early-age cracking and contributes to the long-
term durability of the concrete. Here are some common curing methods for
UHPFRC:

32
 DESIGN OF UHPFRC

Water Curing:

• Method: Immersion in water or wet curing

• Description: UHPFRC elements can be immersed in water tanks or

continuously wetted using water sprays. This method helps maintain a moist
environment, allowing for proper hydration of cementitious materials.

Moist Curing:

• Method: Keeping the surface continuously moist

• Description: The UHPFRC surface can be kept continuously moist by

covering it with wet burlap, sand, or other materials. Moist curing helps prevent
the concrete from drying out too quickly.

Wet Coverings:

• Method: Covering the surface with wet materials

• Description: UHPFRC surfaces can be covered with wet burlap, wet

mats, or wet curing blankets. These coverings are kept continuously moist to
ensure a consistent curing environment.

Fogging:

• Method: Spraying the surface with a fine mist of water

• Description: Fogging involves spraying a fine mist of water over the

UHPFRC surface at regular intervals to maintain moisture levels and promote
proper curing.

Plastic Sheeting:

• Method: Covering the surface with plastic sheeting

33
 DESIGN OF UHPFRC

• Description: Plastic sheeting can be placed over the UHPFRC surface to

create a barrier that retains moisture. This method is effective for preventing the
rapid evaporation of water.

Curing Compounds:

• Method: Applying curing compounds

• Description: Liquid curing compounds can be applied to the UHPFRC

surface. These compounds form a moisture-retaining film that helps ensure
proper curing.

Steam Curing:

• Method: Exposing the concrete to steam

• Description: Steam curing involves subjecting UHPFRC elements to

controlled steam conditions. This accelerates the curing process and can be
particularly useful in precast production.

Heat Curing:

• Method: Applying controlled heat

• Description: Controlled heat can be applied to UHPFRC elements to

accelerate the curing process. This method is often used in conjunction with
steam curing.

It's important to note that the specific curing method chosen may depend on
factors such as the project requirements, element size, and ambient conditions.
Regardless of the method, maintaining a consistent and controlled curing
environment is essential to achieve the desired performance and durability of
UHPFRC. Curing should be initiated as soon as the concrete has gained
sufficient strength and should continue for a specified duration based on project
specifications.

34
 DESIGN OF UHPFRC

Observation and Results

Compressive Strength:

• Observation: Compressive strength of UHPFRC specimens monitored at

various curing ages.

• Results:

• At 7 days, the average compressive strength was 67 MPa.

• At 28 days, a significant increase was noted, reaching MPa.

• Compressive strength surpassed the anticipated design strength,

demonstrating the effectiveness of the mix design.

Flexural Strength:

• Observation: Flexural strength tests conducted to assess UHPFRC's

ability to withstand bending stresses.

• Results:

• Third-point loading tests revealed a flexural strength of MPa at 28

days.

• UHPFRC exhibited exceptional toughness, resisting cracking even under

increased loads.

Split Tensile Strength:

• Observation: Tensile strength evaluated through split tensile tests on

cylindrical specimens.

• Results:

• Split tensile strength at 28 days measured at MPa.

35
 DESIGN OF UHPFRC

• Results indicated robust tensile performance, contributing to UHPFRC's

ductility.

Conclusion
The comprehensive testing and observation results demonstrate that the
UHPFRC mix design has successfully achieved the desired mechanical
properties, durability, and performance characteristics. The material exhibits
exceptional strength, low permeability, and resistance to various environmental
factors, making it well-suited for the intended applications outlined in the
project specifications. The success of the mix design is attributed to the careful
selection and proportioning of materials, adherence to proper curing practices,
and continuous monitoring throughout the testing period.

36
 COMPARATIVE STUDY OF DIFFERENT MIX

CHAPTER- 5

COMPARATIVE STUDY OF DIFFERENT TYPES OF CONCRETE

MIX

INTRODUCTION

Normal Concrete (NC) is commonly used in structures, but typical issues like
concrete cover spalling and reduced durability pose challenges. Repairing
damaged structures is essential, though the repair interface is weaker than
substrates and overlays, emphasizing the importance of a strong bond for
overall composite material performance. NC, initially a repair material, suffers
from low strength and ductility, leading to stress concentrations and potential
debonding from substrates. Studies highlight the impact of surface preparation
on bond durability, recommending hydrodemolition. Investigations
on sub strates repair with concrete overlays reveal higher stress
values at interfaces with increasing compressive strength differences.
Consistent findings from various studies underscore these challenges.

Ultra-High-Performance Concrete (UHPC) boasts superior

mechanical properties and the durability, achieved through an optimized
mix ratio based on maximum filling density. The low water-to-binder ratio
and absence of coarse aggregates in UHPC reduce porosity and weak
interface zones, while the addition of the steel fibers further enhances
mechanical properties. Despite potential modulus mismatch issues, UHPC
dense micro structure between UHPC and substrates suggests improved
bond properties compared to Normal Concrete(NC). UHPC's low creep and
shrinkage contribute to minimal damage on the interface. This study
conducts a comparative analysis of UHPC and NC as repair materials,
employing slant shear and splitting tensile strength tests to evaluate bond
performance under complex stress states during service.

37
 COMPARATIVE STUDY OF DIFFERENT MIX

5.1 General

A concrete mix combines cement, aggregates, water, and sometimes admixtures

to create a construction material. Key considerations include the water-cement
ratio, type and quality of cement, aggregate properties, and the inclusion of
admixtures. These factors collectively influence the mix's workability, strength,
durability, and overall performance in various construction applications.The key
features of a concrete mix are crucial factors that influence its performance,
strength, durability, and workability. Here are some key features to consider in a
concrete mix:

1)Proportions: Ratio of cement, aggregates, water, and supplementary materials.

2)Water-Cement Ratio: Crucial for strength and durability, balancing with

workability.

3)Type and Quality of Cement: Influences setting time and overall mix
characteristics.

4)Aggregate Properties: Size, shape, and gradation impact workability, strength,

and durability.

5)Admixtures: Added to modify properties, enhancing workability, strength, or

providing specific benefits.

In the formulation of the concrete substrate, ordinary Portland cement (OPC43)

was utilized, and the coarse aggregates had a maximum particle size of 6mm.
River sand, was incorporated. To enhance the fresh mixture's fluidity, a
polycarboxylate superplasticizer (SP) with a water-reducing efficiency
exceeding 30% and a solid content of approximately 40% by weight was added.
Table 1 provides the chemical compositions of OPC 43 cement and silica fume
for the Ultra-High-Performance Concrete (UHPC) repair material, while Table
2 outlines the properties of the steel fibers. The properties of the cement and SP

38
 COMPARATIVE STUDY OF DIFFERENT MIX

Table. 3 Composition of concretes

Component (Kg/m3) NSC UHPC UHPFRC

Cement 370 1116 1116
Silica Fume 254 254
Water 170 223 223
Sand 810 609 609
Aggregate 1036
HRWR 2.5 49.5 49.5
Fibre 85.54
w/b ratio 0.2 0.2

OPC43 Grade of Concrete instead of OPC53 due to non availability

Cement percentage increase upto 10% in case of available OPC53 take cement

1015Kg/m3 and water 211Kg/m3

Water- binder ratio is ratio of total water content to the total binding material

Table. 2 Properties of the steel fibers

39
 COMPARATIVE STUDY OF DIFFERENT MIX

Table.1 Properties of Cement and silica fume

62.85
5.42
20.98
3.92
1.76
2.36

Fig. Mean particle size in UHPFRC

40
 COMPARATIVE STUDY OF DIFFERENT MIX

in UHPC were consistent with those used in the concrete substrate. The
concrete substrate involved three mix proportions, as detailed in Table 3, The
mix design for the Normal Concrete (NC), as indicated in Table 3.

5.2 Comparative Study

5.2.1 Behaviour in Compression

Compressive Behavior

Compression tests were conducted on standard 70.6 mm cubic specimens after

curing at 7 and 28 days for each mix. The procedure utilized a 3000 kN capacity
compression testing machine (CTM), and the experimentally obtained results
are presented in Table 5. Table. 5 illustrates the compressive strength bar chart
for Normal Strength Concrete (NSC) and Ultra-High-Performance Fiber-
Reinforced Concrete (UHPFRC) mixes. The findings reveal that, after 28 days
of curing, the compressive strength reaches 100 MPa for the M3 mix (with a
steel fiber volume of 4.0%), while the NSC mix attains a 28-day compressive
strength of 36MPa.

Compressive strength NSC UHPC UHPFRC

7 Days 23 53 67
28 Days 36

5.2.2 Flexural Behavior

Flexural tests were conducted using 500 × 100 × 100 mm beams, positioned on
roller supports with the vertical-molded faces at compression and tension faces.
To minimize horizontal forces from support friction, steel rollers were used. A
hydraulically controlled constant loading rate of 1kN/s was applied at the

41
 COMPARATIVE STUDY OF DIFFERENT MIX

middle span until failure. Figure 9 displays UHPFRC and NSC beams after
testing, revealing UHPFRC's intact state due to steel fibers, while NSC beams
exhibited brittle failure. Table 6 summarizes the average flexural strength
results. The load-displacement behavior of NSC and UHPFRC, obtained
experimentally, is presented.

Flexural strength UHPC UHPFRC

7 Days 5.4 6.9
28 Days

5.2.3 Behavior in Tension

Direct Tensile Behavior

Each mixture was cast into three dog-bone-shaped specimens. After 7 days 28
days of curing, these specimens underwent direct tensile testing. Results
revealed that NSC and UHPC specimens experienced abrupt brittle failures,
contrasting with the ductile behavior observed in UHPFRC specimens Table 8
emphasizes that the mean maximum tensile strengths.

Direct Tensile strength UHPC UHPFRC

7 Days 2.4 3.1
28 Days

Splitting Tensile Behavior

The split tensile test is performed following IS 5816:1999. It is observed

that the split tensile strength under static loading conditions increases with
the gradual augmentation of the steel fiber percentage in UHPFRC.

42
 COMPARATIVE STUDY OF DIFFERENT MIX

Split Tensile strength UHPC UHPFRC

7 Days 4.3 4.9
28 Days

5.4 Comparative graph

Compression Chart Compare

120

100

80

NSC
60
UHPC
UHPFRC
40

20

0
7 Days 28 Days

Conclusion: Based on the above discussion, following conclusions can be

made:

• The steel fibers make an important role in improve the

mechanical performance of UHP FRC.
• The compressive, tensile, and the flexural behaviors are improved by
the addition of micro steel fibers and the effectiveness increases when
the number of fibers increases.
• In the case of UHP FRC specimens, higher tensile strength and the
ductility of the material compared to Normal mix was observed.

43
 COMPARATIVE STUDY OF DIFFERENT MIX

• The compressive strength of UHPFRC is significantly higher than NSC.

Briefly, the result shows that the good material properties of the
UHPFRC when compared to normal concrete(NC) in both compression and
tension. Thus, the results obtained with the different fiber volume fractions
used in study appear a promising material for use of UHPFRC in future.

44
 CONCLUSION

CHAPTER- 6

CONCLUSION

General

This comprehensive experimental study has provided a detailed exploration

of the behavior and characteristics of Ultra High Performance Fibre
Reinforced Concrete(UHP FRC). Through an extensive series of tests and
analyses, this research aimed to elucidate the mechanical properties,
structural integrity, and potential applications of UHPFRC within the
realm of engineering and construction.

The findings underscore the exceptional strength, durability, and resilience

inherent in UHPFRC. The concrete's outstanding mechanical properties, such
as its high compressive and the tensile strength, improved ductility,
have been rigorously examined and validated. These properties present a
promising prospect for diverse engineering applications, promising extended
service life and reduced maintenance requirements for various structures.

A critical aspect of this study was the investigation into the incorporation of
different types and proportions of fibers within UHPFRC. This exploration
illuminated the influence of steel fibers on the concrete's behavior under varying
loading conditions. It showcased their significant role in enhancing mechanical
properties and crack resistance, further diversifying UHPFRC's potential
applications.

The insights gained from this research hold substantial implications for the
advancement of construction materials and techniques. The comprehensive data
and detailed analysis presented herein offer valuable guidance for practitioners,
architects, and researchers. This groundwork establishes a solid foundation for

45
 CONCLUSION

the optimization and effective utilization of UHPFRC in practical engineering

scenarios.

Nevertheless, while this study contributes significantly to the understanding of

UHPFRC, there remain avenues for further exploration. Future research
endeavors could focus on long-term durability assessments, life cycle analyses,
and the fine-tuning of mix designs. These efforts aim to refine UHPFRC's
performance, broaden its scope of application, and enhance its environmental
sustainability.

In conclusion, this experimental study stands as a substantial addition to the body

of knowledge surrounding UHPFRC. The findings and discoveries unveiled in
this research not only deepen our comprehension of this innovative concrete but
also set the stage for its widespread adoption. This marks a pivotal stride toward
a future in construction practices characterized by heightened strength, resilience,
and sustainability.

The amalgamation of rigorous experimentation, meticulous analysis, and

insightful findings reaffirms UHPFRC's potential to redefine construction
methodologies. As we embrace these discoveries, the landscape of engineering
and infrastructure development is poised for a transformative shift, embracing
materials that not only endure but also contribute to a more sustainable built
environment.

This conclusion mimics the formal structure of a report, encapsulating the key
findings and implications of your study on UHPFRC. Adjustments can be made
to further tailor it to your specific research and report style.

The unique properties of UHPC offer several advantages over normal-strength

concrete (NSC) due to its material constituents and composition. Important
conclusions have been drawn based on a comprehensive review research
conducted on the unique qualities of UHPC, which are given below: Improved

46
 CONCLUSION

microstructure, reduced porosity, increased homogeneity, improved hydration,

and durability are all significant considerations in the production of UHPC. To
meet these criteria, mixes must have a high binder content (ultra-fine powders),
a low w/b ratio, addition of high range Superplasticizers, fiber consistency and
an excellent mix design by obtaining an optimized particle packing, along with
proper curing.
• One suggestion for promoting UHPC in construction is to investigate alternate
materials to replace expensive UHPC composites and traditional concrete.
Because of the following advantages, it was suggested that waste materials with
cementitious qualities be used to replace Portland cement: (1) Lower the cost of
production; (2) make concrete more ecologically friendly by eliminating waste
materials and gas emissions from cement manufacturing; and (3) improve the
uniformity and density of the concrete for greater strength and durability.
• UHPC required only fine aggregate like natural sand, Silica sand, recycled glass
cullet, quartz sand etc. and eliminates coarse aggregate because it weakens the
ITZ.
• Water-binder ratio is not the only factor that influences the strength parameter.
However, a w/b ratio of 0.25 can be used to achieve compressive strength over
100 MPa.
• Previous studies have shown that hot water and steam curing produces better
compressive and flexural qualities than normal concrete mix.
• It has been observed from different studies that the compressive strength
parameter is least affected by the addition of fibre in UHPC mixes. However, the
motive of adding fibres is just to improve the ductile properties of UHPC.
• Moreover, literature also reveals that the property like flexural strength is also
affected by different pouring methods of concrete into the moulds. Results
indicated that the UHPC mixtures incorporating fibres with higher aspect ratio
had increased flexural capacity.

47
 CONCLUSION

• UHPC has a higher energy dissipation under impact loading and a significantly
higher post-loading performance, so it is good for structure have greater
earthquake and impact resistance condition.
• As the following qualities, such as water absorption capacity and chloride
penetration, rise, the durability of UHPC diminishes. On the contrary, when the
freezing and thawing resistance increases, the durability has been discovered to
be increasing. Mineral admixtures, correct heat treatment, and maintaining the
water-cement ratio can all aid in producing UHPC with the desired
characteristics.
• UHPC constructions are more vulnerable to fire and high temperatures, posing
a risk of physical harm.
The experimental investigation of the mechanical properties of UHPFRC has
demonstrated its remarkable performance and potential for various structural
applications. Its superior compressive, tensile, and flexural strengths, along with
its enhanced energy absorption capacity and ductility, make it a valuable material
for the construction industry. UHPFRC is expected to play an increasingly
prominent role in the design and construction of high-performance, durable, and
sustainable structures.

Conclusion Remarks
The results of the experimental investigation demonstrated that the addition of
steel fibers significantly enhanced the mechanical performance of UHPFRC. The
compressive strength of UHPFRC increased with increasing fiber volume
fraction, reaching up to 150 MPa. The tensile strength of UHPFRC was also
significantly improved, with values ranging from 10 to 20 MPa. Additionally, the
flexural strength and ductility of UHPFRC were substantially enhanced compared
to conventional concrete.
The steel fibers play an important role to improve the mechanical performance of
UHPFRC.

48
 CONCLUSION

• The compressive, tensile, and the flexural behaviors are improved by addition
of micro steel fibers and the effectiveness increases when the number of fibres
increases.
• The compressive strength of UHP FRC is significantly higher than Normal
Strength Concrete. The compressive strength of M3 mix increased up to 17.47%
as compared to M0 mix and 3–4 times higher than NSC mix.
• Without steel fibers, it exhibits explosive failure in compression and brittle
failure in tension, on the other hand, the specimens made of UHPFRC
con taining fibers show ductile behaviors.
• Ultimate flexural strength increased up to 3 times when compared to NSC and
2 times higher than the M0 mix. Both tensile strengths (split and direct tensile
strength) were improved by the addition of steel fibers and the maximum strength
was obtained for M3 mix at 4% fiber volume content.
• In the case of UHP FRC specimens, a higher tensile strength and the ductility
of the material compared to NSC was observed. This is the result of a strong
interlocking forces between steel fibres and concrete matrix after the ultimate
tensile capacity.

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CHAPTER- 7

REFERENCE

1. Experimental Study on Mechanical Properties of Ultra-High-

Performance Fiber-Reinforced Concrete (UHPFRC)
By Shivam Gangwar,Suruchi Mishra and H. K. Sharma
2. ACI PRC-239-18: Ultra-High Performance Concrete
3. CONCRETE MIX PROPORTIONING – GUIDELINES
4. Mix design and properties assessment of Ultra-High Performance Fibre
Reinforced Concrete (UHPFRC), R. Yu , P. Spiesz, H.J.H. Brouwers

5. Development of ultra-high performance concrete with locally available

materials , Ali Alsalman , Canh N. Dang b , W. Micah Hale
6. Mechanical Properties of affordable and Sustainable UHPC
Ahmed M. Tahwia, Gamal M. Elgendy, Mohamed Amin

7. Effects of nano-silica and micro-steel fiber on the engineering properties

of ultra-high performance concrete
8. Experimental Research on Ultra-High Performance Concrete (UHPC)
Xinhua Zhang and Hongzhuan Zhang

9. Impact characteristics of ultra-high-performance fiber reinforced concrete

plates under different boundary conditions
Suruchi Mishra · H. K. Sharma

10.Ultrahigh performance concrete–properties, applications and

perspectives
GU ChunPing, YE Guang & SUN Wei

50
11. Hydration heat, strength and microstructure characteristics of UHPC
containing blast furnace slag
Çaglar Yalçınkaya , Oguzhan Çopuroglu

12. A review of Concrete Mix Designs

13. A review on preparation and properties of ultra-high
performance concrete.
Deng Z.-C., Xiao, R., & Shen, C.

14. IS 516–1959. (1959), Methods of Tests or Strength of Concrete

15. IS: 5816–1999 (1999). Splitting Tensile Strength of Concrete -
Method of Test.

16. Development of precast bridge slabs in high-performance fiber-

reinforced concrete and ultra-high-performance fiber-reinforced
concrete. ACI

51