International Research Journal of Engineering and Technology (IRJET)
e-ISSN: 2395-0056
Volume: 09 Issue: 05 | May 2022
p-ISSN: 2395-0072
www.irjet.net
Effect of Seawater on the Compressive Strength of Steel Fiber Reinforced Concrete. Chavala Krishna Priya1, Dr.P. Jyotsna Devi2, 1M.Tech,
Department Of Civil Engineering, Gayatri Vidya Parishad College for Degree and P.G Courses(A), Rushikonda, Visakhapatnam, A.P, India. 2Professor, Department Of Civil Engineering, Gayatri Vidya Parishad College for Degree and P.G Courses(A), Rushikonda, Visakhapatnam, A.P, India. ---------------------------------------------------------------------***---------------------------------------------------------------------
Abstract - This research aims to compare the compressive
swamps contains only about 0.3% of our freshwater.
strength of concrete using fresh water and seawater for
Most of the structures near the seashore deteriorate by
curing and compare the compressive strength of steel-
physical or chemical action due to seawater. This
reinforced concrete using fresh water and seawater for
research aims to increase the strength of concrete by
curing. A total of 24 cubes of specimens measuring
adding 1% of crimped steel fibres to the concrete. This
150×150×150mm using M30 grade concrete cubes were
is to overcome the strength loss in structures which are
cast. Twelve of them are cast by adding 1% crimped steel
exposed to seawater. Using M30 grade concrete casting
fibres and the remaining twelve are cast without steel fibres.
and curing of concrete specimen cubes in fresh water
Six of them are cast and cured with freshwater, six of them
and casting with fresh water and curing seawater, by
are cast with fresh water and cured in seawater. From the remaining twelve which are cast by adding 1% crimped steel
comparing the compressive strength between them.
fibres, six of them are cast and cured with fresh water and
The primary chemical constituents of seawater are the
six of them are cast with fresh and cured in seawater. These
ions of chloride, sodium, magnesium, calcium, and
cubes are tested for compression test at the curing ages of 7
potassium ions. In seawater containing up to 35,000
and 28 days. After the compression test is done a small piece
ppm of dissolved salts, sodium chloride (NaCl) is by far
of the cube from inside is extracted and sent to an analytical
the predominant salt. The pH value of seawater varies
laboratory to study the microstructure of the cube by using a
between 7.4 and 8.4. Corrosion of reinforcing steel
scanning microscope analysis.
occurs below a pH of 11. The chemical reactions in concrete are mainly due to the attack due to
Key Words: Compressive Strength, Steel fibres, Crimped
magnesium sulphate (MgSO4) presence. The mode of
Steel Fibre, Scanning Electron Microscope Analysis, SEM
attack is crystallisation. Potassium and magnesium
Analysis.
sulphates (K4SO4 and MgSO4) present in saltwater can
1. INTRODUCTION
cause sulphate attack on concrete because they can
About 70% of the earth's surface is covered
initially react with calcium hydroxide Ca(OH)2, which is
with water. Of that 97% is ocean water remaining 3%
present in the cement formed by the hydration of
is freshwater. Icecaps and glaciers contain over 68 % of
dicalcium silicate (C2S)and tricalcium silicate (C3S). The
the world's fresh water, while groundwater contains
attack of magnesium sulphate (MgSO4) is particularly
just over 30 %. The surface water of lakes, rivers, and
damaging,
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