This document summarizes an experimental study on the durability properties of ultra-high strength steel fiber reinforced concrete. Four mix designs were tested with different combinations of cement, supplementary cementitious materials, sand, copper slag and superplasticizer. Compressive strength tests were conducted on 100mm cubes at 1, 3, 7 days of curing. Further tests planned include rapid chloride permeability testing, sorptivity testing and compressive strength testing at 28 and 90 days, along with evaluating an optimized mix by replacing cement with nano-silica and adding crimped steel fibers. The experimental results will help in understanding the durability performance of ultra-high strength fiber reinforced concrete.

1. DURABILITY PROPERTIES OF ULTRA HIGH STEEL FIBER
REINFORED PERFORMECE CONCRETE
UNDER THE GUIDENCE OF
Mr. B. KRISHNA CHAITANYA
BATCH – A2 A - SECTION
D.MOUNIK KALYAN L20CE183
CH.NAVADEEP NEERAJ L20CE181
A.DEERAJ KRISHNA Y19CE007
C.PAVAN KUMAR Y19CE018

2. INTRODUCTION
 Conventional concrete is strong in compression and weak in tension, and fails when brittle
without any deformation . Ultra-high-performance concrete (UHPC) may be able to resolve
these problems. The strength of UHPC is greater than 150 MPa compressive strength and
greater than 5 Mpa tensile strength.
 To achieve highly flowable, high mechanical, and excellent durability, ultra-high-
performance concrete (UHPC) should be produced using the optimum combination of
cement and supplementary cementitious materials, adequate sand gradation, low water-to-
binder ratio and high-range water reducer (HRWR) . UHPC offers better durability than
conventional concrete because of its discontinuous pore structure .

3. MATERIALS AND MIX PROPORTIONS
 Cement
Ordinary Portland Cement (OPC) of 53 grade is used. Specific gravity of cement =3.15 as per IS:269 -
2015.
 Fine aggregate
Locally available sand is collected having specific gravity 2.6 .
 Silica Fume
The material is an ultrafine non-crystalline silica by-product of the production of silicon metals and
ferrosilicon alloys that is a highly- reactive pozzolan. It is a supplementary cementatious material.

4. MATERIALS AND MIX PROPORTIONS
 Ground Granulated Blast-Furnace Slag
Another type of supplementary cementitious material is GGBFS, which is a by-product of the steel
manufacturing process .
 Copper Slag (CS)
It is a by-product material produced from the process of manufacturing copper. Adding CS also develops
improvement in the workability of concrete and increasing the dosage of slag may lead to reducing the dosage
of super plasticizer.
 Super plasticizers
Superplasticizers are high-range water reducers made up of organic polymers. It improves the flowability of
concrete.

5. Cement Fine aggregate SilicaFume
GGBS Copper Slag(CS)

7. MATERIALS AND MIX PROPORTIONS
MIX -1
ITEMS PROPOTATIONS
CEMENT 1
GGBS 0.42857143
SILICA FUME 0.35714286
SAND 0.71428571
WCS(20%) 0.14285714
HRWR 0.05714286
WATER 0.338928571
MIX -2
ITEMS PROPOTATIONS
CEMENT 1
GGBS 0.35714286
SILICA FUME 0.42857143
SAND 0.71428571
WCS(20%) 0.14285714
HRWR 0.05714286
WATER 0.338928571
MIX -3
ITEMS PROPOTATIONS
CEMENT 1
GGBS 0.42857143
SILICA FUME 0.35714286
SAND 0.71428571
WCS(20%) 0.14285714
HRWR 0.05714286
WATER 0.39285714
MIX -4
ITEMS PROPOTATIONS
CEMENT 1
GGBS 0.35714286
SILICA FUME 0.42857143
SAND 0.71428571
WCS(20%) 0.14285714
HRWR 0.05714286
WATER 0.39285714

8. EXPERMENTAL PROGRAMME
 COMPRESSIVE STRENGTH
 Compressive strength is the ability of material or structure to carry the loads on its surface without any
crack or deflection. These specimens are tested by compression testing machine after 1,3,7,28 and 90 days
curing. Cubes of size 100x100x100 mm are tested .
 Load should be applied gradually at the rate of 140 kg/cm2 per minute till the Specimens fails. Load at
the failure divided by area of specimen gives the compressive strength of concrete.
 Compressive Strength = Load / Cross-sectional Area
`

9. EXPERMENTAL PROGRAMME
 Sorptivity test
 This test was carried out with adherence to ASTM C 1585-04, which is used to determine the rate of absorption
(sorptivity) of water by concrete, by measuring the increase in the mass of a specimen. In general, the rate of
absorption of concrete at the surface differs from that of a sample taken from the interior, since the exterior
surface is often subjected to less than the intended time of curing and is exposed to the most potentially adverse
conditions. This test method is used to measure the water absorption rate of both the surface and interior of the
concrete. The standard test specimen is a 100 mm diameter disc, with a length of 50 mm.

10. EXPERMENTAL PROGRAMME
 BOND STRENGTH TEST
 Bond strength tests were conducted respectively in accordance with the RILEM
recommendations The specimens prepared for the pull out tests were 100 ×100
mm in cross section. The ribbed bars used were 12 mm diameter.The pull out
specimens were tested by applying the load to the bar at a rate of 0.1 kN/s (0.02248 kip/s).
The slip of the free end of the reinforcement was recorded using a digital transducer with
an accuracy of 0.001 mm.The ultimate pull out load using Eq.
τu=Fuπ⋅ϕ⋅L
where τu is the ultimate bond stress (MPa), ϕ is the rebar diameter (mm), L is the bond
length (mm), and Fu is the ultimate pullout load (N).

11. EXPERMENTAL PROGRAMME
 Rapid chloride permeability test (RCPT)
 The durability of concrete is determined by its resistance to chloride ion penetration, which is related
directly to low permeability, which dominates the process of deterioration. This study was conducted as
per ASTM C 1202-19. RCPT apparatus is shown in Fig. In the test, chloride ions from the NaCl solution
cell are driven towards the NaOH solution cell, through the pore network present in the concrete placed
in between the cells. An ammeter in the test setup measures the intensity of the electric current, which is
proportional to the movement of chloride ions.Test conducted on specimens of 50 mm in height and 100
mm in diameter for each CFRHPC mix after 28 days and 90 days of curing.

12. WORK COMPLETED TILL DATE
We have done compressive strength test of the UHSFRPC after 1,3,7 days of curing
respectively for cubes of cross sections [100mm*100mm*100mm] for the four mix proportions
mentioned above. Details of which are mentioned in the Table below.
1 DAY
Weight [
kg]
Cube
number
Compressive
strength[KN]
MIX 1 2.35 2 340
MIX 2 2.345 1 300
MIX 3 2.33 1 320
MIX 4 2.37 3 315
3 DAYS Weight [ kg]
Cube
number
Compressive
strength[KN]
MIX 1 2.37 6 500
MIX 2 2.27 6 357
MIX 3 2.35 6 375
MIX 4 2.26 6 535
7 DAYS Weight [ kg]
Cube
number
Compressive
strength [KN]
MIX 1 2.4 7 550
MIX 2 2.335 7 645
MIX 3 2.435 3 670
MIX 4 2.33 4 625

13. Work needed to be done further
 rcpt test for discs for 28 and 90 days respectively for all the four mixes.
 Sorptivity test test for discs for 28 and 90 days respectively for all the four mixes.
 Compressive strength test for cubes for 28 and 90 days respectively for all the four mixes.
 Based on the results obtained from the above mentioned destructive and non destructive
tests results of respective mixes. In the best mix cement is replaced with Nano Silica (NS)
about 1.5%, 2.5% and 3.5% .From the above best NS blender mix crimpled steel fibers are
added about 1%,2%,3% of the volume of the concrete and then properties are assesed.

14. THANK YOU