PHOTOCATALYTIC
CEMENT
CONTENTS
Introduction.
Historical background.
Principal and mechanism.
Photocatalytic Cement For Sustainable Infrastructure
Construction
Photocatalytic Cement To Improve Indoor Air Quality
Applications
Advantages
Conclusions
References
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PHOTOCATALYTIC CEMENT
INTRODUCTION
PC is a rapidly emerging and innovative technology
It exhibit self cleaning and depolluting properties
Air pollution is major crisis in modernization and urbanization
PC material helps to mitigate air pollution
It uses energy from sunlight(or other UV light sources) to
convert harmful substances
They reduces products like NOx, SOx, tobacco, smoke,
bacteria etc. from atmosphere
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PHOTOCATALYTIC CEMENT
Titanium dioxide ( TiO2) is the catalyst used
They decompose organic materials and products of
reaction can easily be washed of by rain
Can be employed in all types of concrete, plaster and
mortar
Other photo catalysts like ZnO,WO3,Fe-TiO3 and
SrTiO3 can also be used
They are incorporated with concrete and hence
known as photocatalytic or self cleaning concrete
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PHOTOCATALYTIC CEMENT
HISTORICAL BACKGROUND
Photocatalysis of cement is a recent matter
It was applied to buildings to obtain self
cleaning
and antibacterial surfaces
Had its best movement in Japan in 1990s
First development made by Italcementi and
Mitsubishi
First application in “Dives in Miscericordia”,
a church
in Rome Fig 1:Church “Dives in Misericordia”
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PHOTOCATALYTIC CEMENT
PRINCIPLE AND MECHANISM
TiO2 is activate by UV light (<390mm)
It absorbs UV radiation and produces
electron(e-) and hole(h+) pairs
h+ of titanium dioxide breaks apart the
water molecule
to form hydrogen gas and hydroxyl radical
e- reacts with oxygen molecule to form
Fig2: Mechanism of photo catalysis
super oxide anion.
This cycle continues when light is available 6
PHOTOCATALYTIC CEMENT
UV radiation and other
pollutants
Concrete made from photo
catalytic material(TiO2)
Hydroxyl radicals Super oxide anions
Mix with pollutants
( NOx, COx, smoke, etc. )
Less harmful substances
( oxygen, water etc. )
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Fig3: Photocatalytic Process
PHOTOCATALYTIC CEMENT
PHOTOCATALYTIC CEMENT
FOR SUSTAINABLE
INFRASTRUCTURE
CONSTRUCTION
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PHOTOCATALYTIC CEMENT
1.PERVIOUS CONCRETE PAVEMENTS
example of photo catalytic pavement applications are represented by
paving blocks and slabs
Using these precast concrete elements, several parking lots, local roads,
sidewalks, shopping centres, pedestrian areas have been completed.
It possessing high water draining properties and sound-absorbing
properties
Sustainable engineering practice can be obtained with this no-fine
concrete
Aggregate grading allows adequate drainage of recyclable rainwater,
reducing maintenance cost and increasing durability
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PHOTOCATALYTIC CEMENT
Fig4:1 3D scan of pervious concrete pavement surface
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PHOTOCATALYTIC CEMENT
2.TWO-LIFT PAVING
The lower, base level layer is expected to be constructed with less expensive
materials (e.g., a low cementitious-material content base lift)
It is then overlaid with a thinner top wearing-course of concrete containing
photocatalytic cement.
Reconstruction of Route 141 in St. Louis
Represent one of the most technically advanced and environmentally-
friendly concrete pavement systems ever employed.
This experimental road was constructed in October 2011
Monitoring campaign lasted for one year at least, the. pervious shoulders
were constructed in May 2012. 12
PHOTOCATALYTIC CEMENT
Fig5:Two-lift technology for paving
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PHOTOCATALYTIC CEMENT
3.CONCRETE LINING AND COATINGS
FOR TUNNELS
Ability of photocatalytic cement to oxidize pollutants induced by
light radiation can be effectively exploited in tunnels illuminated by
artificial UV light
High pressure sodium vapour lamps mostly used in tunnels are
replaced by metal halide lamps, able to emit higher amounts of UV
rays
Smoothing cement-based coats, containing photoactive TiO2, can be
effectively applied as final sprayed coating The higher achieved
brilliance positively affects safety aspects as well as visual comfort 14
PHOTOCATALYTIC CEMENT
Reduce the maintenance as well as cleaning interventions
Exits of city tunnels are generally the most polluted spots in the city
Photo catalytic cleaning of this spots could, indeed, prove to be the cheaper way to
protect the health of citizens
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Fig6:Photocatalytic coating to the internal surface of tunnel
PHOTOCATALYTIC CEMENT
PHOTOCATALYTIC CEMENT TO
IMPROVE INDOOR AIR QUALITY
A clean indoor air is important for the well-being and health of
people
Most of people spend 90% of their time indoors especially the
young, the elderly and those who are chronically ill.
Air inside buildings can be more polluted than outdoor because there
are various sources of pollution in some big cities
Air cleaning agents such as Titanium dioxide (TiO2) can be used for
producing concrete composite panels, using local waste materials for
solving the problem of carbon dioxide (CO2) in indoor air buildings
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PHOTOCATALYTIC CEMENT
LABORATORY ANALYSIS
SAMPLE PROPORTIONS
o The samples were fabricated in steel moulds with internal
dimensions of 20 × 10 ×5 cm
o The wet mixed materials were weighed between 400 and 500 g for
each sample
o Moulds were filled by hand compaction
o After 1 day, the samples were removed from their moulds and tested
for CO2 photo degradation at 15, 30, and 60 days with GC gas
equipment
MIX PROPORTIONS
o Mixes were prepared with RA, TiO2, water and sand
o Study focuses on usefulness of recycled materials, so a series of
mixes were prepared to find out the effects of titanium dioxide and
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proportions on CO2 removal efficiency
PHOTOCATALYTIC CEMENT
o Cement to aggregate ratios ranging from 1:2, 1:2:5 and 1:3 was prepared
o Aggregate sizes vary from 300 to 2.36 mm
o The varying amount of TiO2 were studied by preparing samples with the TiO2
Anatase content ranging from 0.06 to 0.08%
Relative proportions (by weight (g))
Ratio Cement RA Sand Water TiO2
1:2 1.0 2.0 0.5 5.0 0.50
1:2:5 1.0 2.5 0.6 5.4 0.50
1:3 1.0 3.0 0.7 6.0 0.50
1:2 1.0 2.5 0.5 6.5 0.50
1:2:5 1.0 3.0 0.6 7.9 0.50
1:3 1.0 3.5 0.7 8.3 0.50
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PHOTOCATALYTIC CEMENT Fig7:Mixes prepared with different materials
EQUIPMENTS
• Central part is a gas reactor allowing a sample of size 10× 20 cm2 to be fixed
• Reactor is made from materials which are non-absorbing to the applied pollutant
and can hold up UV-A light of high irradiance
• Tightly closed with a glass plate made from borosilicate glass allowing the UV-A
radiation to pass through
• Surface of the specimen is fixed parallel to the covering glass inside the reactor,
leaving a slot of 0.3 cm for the gas to pass through it
• Sample gas only passes the reactor through the slot between the sample surface
and the glass cover in longitudinal direction
• Parts inside the box are to allow laminar flow of the gas along the sample surface
• 10 W UV-A fluorescent lamps with wavelengths 366 nm were used to supply
photo irradiation to activate the photo catalyst
• Two types of sensors were used, temperature and humidity sensor
• The tool that was used to analyse the result of CO2 removal efficiency by 19
computer is GC gas
fig8:Schematic diagram of experimental setup
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PHOTOCATALYTIC CEMENT
RESULTS
1. Influence of porosity of the panel surface layer on carbon dioxide removal
•Samples showed the highest microporosity, 10.02 and 10.55 m2g-1
•Higher framework microporosity leads to higher interaction adsorbents between the
TiO2 and CO2 molecules
•Results show that porosity of the surface layer is important, which increased the area
available to reacts with the pollutants
•Porosity of the surface layer was affected by the type of materials with which they
were prepared
•Materials with a lower density led to a higher porosity of the panels
•Particle size distributions of the materials used also affected the porosity of the
panels.
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2. Influence of TiO2 and local material on carbon dioxide photo-degradation
under UV light
•RA mixes achieved a much higher CO2 removal compared to the sand mixes
•This is due to the porous nature of RA compared to that of sand
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3. Effect of particle size of aggregates on carbon dioxide photo-degradation
•Different aggregate sizes was believed to affect their ability to remove CO2
•Varying the particle size distribution of aggregates would change the porosity of
the specimens
•Specimens were divided into two groups-one was prepared with all aggregate sizes
below 2.36 mm included and the other with aggregate sizes only between 300 μm
and 2.36 mm
•Specimens tested at 1 and 2 weeks with cement to aggregate ratio of 1:3
•The results indicated that the specimens prepared with aggregate sizes between 300
μm and 2.36 mm (the more absorbent specimens) achieved approximately 6%
higher CO2 removal during the 2 weeks from the test
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4. Effect of porosity on carbon dioxides photo degradation
• A clear preference can be realized that the CO2 removal increased with increase in
porosity.
• The influence of the relative porosity depends to a large extent on the type of
material used and the effect at the surface prevails over the oxidizing effect when
high values of relative humidity are applied
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Fig9:Influence of TiO2 and cement/aggregate ratio on CO2 photo degradation
under UV light after 2 weeks
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PHOTOCATALYTIC CEMENT
Fig 10:Influence of porosity on CO2 photo degradation under UV light after 4 weeks 26
and 5weeks
PHOTOCATALYTIC CEMENT
APPLICATIONS OF PHOTOCATALYTIC
CEMENT
Pavement (stones and slabs)
Roofing tiles
Noise and screen barriers
Facades (wall cladding)
Rendering (dry mortar/exterior cement plaster)
Road construction (e.g. white topping)
Precast and architectural concrete panels
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PHOTOCATALYTIC CEMENT
ADVANTAGES OF PHOTOCATALYTIC
CEMENT
Reduces NOx content in atmosphere.
Keeps the concrete young
Depollute other pollutants
Eco friendly
Reduces depletion of ozone layer
Reduces corrosion and patch formation in the
concrete
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CONCLUSION
Photo catalytic cement is a rapidly emerging and innovative technology in
material science that exhibit self-cleaning and depolluting properties owing
to the presence of titanium dioxide
Recent materials science approaches have demonstrated that photo catalytic
activity may be conferred to broadly used construction materials such as
glass and cement based materials like concrete and mortar.
As research continues to improve these materials, the use of the technology
will continue to spread.
The capability of photo catalysis to reduce the levels of urban pollutants has
been confirmed both in the laboratory and in the field.
It is a promising way to minimize contaminants and improve the aesthetic
quality of our urban environments.
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PHOTOCATALYTIC CEMENT
REFERENCE
[1] Ranjit K. Odedra, K.A.Parmar,Dr.N.K.Arora,“Photocatalytic
Self- cleaning Concrete”, IJSRD - International Journal for
Scientific Research & Development| Vol. 1, Issue 11, 2014
[2] Andrea Folli,w,z Isabelle Pochard,y Andre Nonat,y Ulla H.
Jakobsen,z Ashley M. Shepherd,z and Donald E.
Macphee,Department of Chemistry, University of Aberdeen,
Aberdeen AB24 3UE, Scotland, U.K., ”Engineering
Photocatalytic Cements: Understanding TiO2 Surface
Chemistry to Control and Modulate Photocatalytic
Performances” 2010 The American Ceramic Society
[3] KO Kotresh K.M, Dr.B. Sairam Pattnaik, Mahaboob Patel,”
Study on Photocatalytic Cement as Solution for Pollution
Control”, Volume: 4, Issue: 3, Mar 2014
[4] Jatinder Kumar1, Anurag Srivastava, Ajay Bansal,”
Production of self-cleaning cement using modified titanium
dioxide”, International Journal of Innovative Research in
Science, Engineering and Technology, Vol. 2, Issue 7, July 2013 30
THANK YOU
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