Italcementi
Italcementi Group
TX Active
The Photocatalytic Active Principle
®
TECHNICAL
REPORT
TX Active
The Photocatalytic Active Principle
®
TECHNICAL REPORT
TABLE OF CONTENTS
PREFACE ......................................................................................................
3
AIR POLLUTION
..........................................................................................
4
REGULATIONS
............................................................................................
7
THE PHOTOCATALYSIS
..............................................................................
TX ACTIVE® THE PHOTOCATALYTIC ACTIVE PRINCIPLE
11
..........................
12
...............................................................................
13
THE TX ACTIVE® RANGE .............................................................................
16
CUSTOMER TOOLS .....................................................................................
17
CASE HISTORIES WITH MONITORING RESULTS .......................................
TX Aria® ........................................................................................................
TX Arca® .......................................................................................................
19
19
24
WORLDWIDE REFERENCES .........................................................................
27
FAQs ............................................................................................................
29
SELECTED BIBLIOGRAPHY ..........................................................................
32
MEASURING BENEFITS
TX Active® by Italcementi - TECHNICAL REPORT
2
PREFACE
TX Active® by Italcementi - TECHNICAL REPORT
PREFACE
Photochemistry plays a role of primary importance in both biological processes and
environmental control. For this reason, the use of light for environmental purposes could be
a valid answer to the demand for a cleaner environment and a better quality of life.
Accordingly, the photochemical technology applied to building materials can be a winning
solution, and the intense researches in this field has laid the foundation for extensive
applications in various industrial sectors.
The solar energy that reaches the Earth’s surface is equivalent to approximately 10,000 times
the annual energy consumption worldwide and the pursuit of an efficient conversion of all of
this energy into useful forms (i.e. thermal conditioning, transportation, industrial production,
etc.) is one of the most important opportunities for technology developments.
In particular, a new promising field is represented by the environmental depollution, and
within this challenge Italcementi developed a new photocatalytic cement able to answer the
environmental concerns by triggering its TX Active® principle contained in the final products.
The results of the tests performed in our laboratories and on site allow us to state that
photocatalytic cementitious materials, when irradiated by appropriate light, increase the
effectiveness of abating noxious organic and inorganic substances they come into contact
with, such as NOX, SOX, NH3, CO, volatile organic compounds (VOCs), chlorinated organic
compounds, aldehydes and polycondensed aromatic compounds that are responsible for air
pollution.
In addition, experimental evidences show that photocatalytic cement based products are able
to maintain their aesthetic appearance unaltered for a long time as well.
In view of the above, we believe the use of photocatalysts applied to building materials could
improvement of the living conditions of our urban environments.
Enrico Borgarello
R&D Central Manager
3
AIR POLLUTION
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AIR POLLUTION
Clean air is considered to be a basic requirement for human health and well-being. However,
air pollution continues to pose a significant threat to health worldwide.
Air pollution is a set of noxious effects altering the biosphere with repercussions on human
beings. Such harmful effects depend on the action of agents that, once released into the air
mainly as by-products from human activities, modify the existing equilibrium.
Accordingly, in the atmosphere there is a presence of substances that in the air natural
composition do not occur, or if they do occur, they have a lower concentration level and, just
because of such presence, they have a noxious effect on human beings, animals, vegetation
and materials.
As a matter of fact, numerous researches affirm that exposure to high levels of air pollution
is associated with cardiovascular and respiratory diseases and according to the World Health
Organization (WHO), more than 2 million premature deaths each year can be attributed to
the effects of urban outdoor and indoor air pollution.
The WHO estimates that reducing levels of one particular type of pollutants (known as
PM10) could reduce deaths in polluted cities by as much as 15% every year. On the subject,
the Istituto Nazionale dei Tumori (The National Institute research against cancers), Milan Italy, estimates that a 50% decrease in air pollution, just in the city of Milan, would prevent
1,200 deaths and 10,000 cases of respiratory diseases per year, as well as an additional 1.5
year life expectancy per citizen.
Polluting Sources
Sand storm on the
Canary Island
4
In the 1990 Clean Air Act Amendments, the Environmental Protection Agency (EPA) lists 188
“toxic air pollutants” of both organic and inorganic origin. Although pollutants may be natural
or man-made and may take the form of solid particles, liquid droplets or gases, the polluting
substances released into the biosphere are mostly generated by anthropogenic activities.
The main actors responsible for air pollution are represented by the internal combustion
engine vehicles, factories, refineries and power plants, fuels for residential heating, and the
waste incinerators, particularly if not equipped with dust abating and fume purification
systems. Polluting agents may also derive from the use of pesticides in rural areas, and from
the dust generated by mining and agricultural operations.
Interestingly enough, air pollution may also have natural origins; for example, it may derive
from dusts produced by strong winds blowing in the deserts, by sand, ash and dust coming
from volcanic explosions, and by salty sea water nuclei brought on shore by strong winds.
In addition, the pollution coming from natural gases may be caused by
volcanic explosions, fumaroles, marshes or decomposing matter. Once the
polluting substances get airborne by winds and updrafts, the coarse
particles return rapidly to the earth’s surface by gravity (fallout), while the
fine ones are removed from the atmosphere by rain precipitation (washout).
The main pollutants are: sulfur dioxide (SO2), nitrogen oxides (NOX),
carbon monoxide (CO), ozone, benzene, polycyclic aromatic hydrocarbons
(PAHs), PM10 (Particulate Matter < 10 micrometers in size), and lead.
At local level, the problem involves urban pollution caused by vehicular
traffic, building heating systems, industrial and power plants. Cities are
indeed the places where the unbalancing sources get mainly concentrated
with direct effects also on human health.
As an example, according to EPA, in USA there are ten metro areas, (i.e. Los Angeles,
Chicago, New York, etc.) home to 57 million people, considered to be severely polluted,
meaning that the pollution levels are 50% higher than what EPA deems harmful to human
health and the environment, plus an additional fourteen metro areas rate as seriously
polluted (Atlanta, Dallas, San Diego etc.).
TX Active® by Italcementi - TECHNICAL REPORT
AIR POLLUTION
However, air pollution is not limited to metropolitan
areas, but is “migratory” in nature. From the Envisat
high-resolution global atmospheric map of nitrogen
dioxide pollution, it is possible to see how human
activities impact air quality worldwide: “high vertical
column distributions of nitrogen dioxide are associated
with major cities across North America, Europe and
north-east China, along with other sites such as Mexico
City in Central America and South African coal-fired
power plants located close together in the eastern
Highveld plateau of that country. Also across South East
Asia and much of Africa can be seen nitrogen dioxide
produced by biomass burning and ship tracks are visible
in some locations (i.e. the Red Sea and the Indian Ocean
between the southern tip of India and Indonesia).
The image shows the
Nitrogen Dioxide (NO2)
Vertical Column Density
(VCD) in the troposphere
between January 2003
and June 2004.
SCIAMACHY
Instrumentation
Equipment on the ESA’s
Envisat.
The scale is in 1015
molecules/cm2.
Primary and secondary pollution and photochemical smog
Primary pollutants are defined as those pollutants that are emitted directly from
their own sources.
The main primary pollutants are released by combustion processes of any kind, i.e. unburned
hydrocarbons, carbon monoxide, nitrogen oxides (mainly as monoxide) and particulate
matter. In case of sulfur containing fuels, sulfur dioxide release might occur too.
Once emitted into the atmosphere, primary pollutants undergo diffusion, transport and
deposition processes as well as chemical & physical transformations which may lead to the
formation of new polluting species, sometimes more toxic and with a wider-range action
than the original pollutants.
The dispersion of polluting substances into the atmosphere, caused by phenomena of
turbulent diffusion and air mass transport, as well as their removal through deposition
processes, are strictly dependent on the dynamic behavior of the lower layers of the
atmosphere. It follows that, in order to study the primary pollutants behavior, it is necessary
both to understand the qualitative, quantitative and time-dependent profile of the emissions
and to gather information regarding the meteorological processes that regulate the dynamic
behavior of the lower troposphere (stability classes, wind direction and intensity).
Secondary pollutants are defined as the polluting species resulting from the
physical-chemical transformation of primary pollutants, i.e. of the chemical species
released into the atmosphere directly from their own sources.
Among the secondary pollutants formation processes, of great importance is the series of
reactions between nitrogen oxides and hydrocarbons in the presence of sunlight. This chain
of reactions leads to the oxidation of nitric monoxide (NO) into nitrogen dioxide (NO2), to the
production of ozone (O3) and the oxidation of hydrocarbons, with the formation of
peroxyacetylnitrate (PAN), formaldehyde, nitric acid, nitrates and nitro-derivatives particles,
and hundreds of other minor chemical species.
The whole set of these reactions products is defined as “photochemical smog”,
which represents one of the most harmful forms of pollution for the ecosystem.
5
AIR POLLUTION
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The use of the term “smog” derives from the strong visibility reduction occurring during the
photochemical pollution events, caused by the formation of a great number of particles of
considerable size.
To trigger a photochemical pollution process, it is necessary the presence of sunlight,
nitrogen oxides and VOCs; in addition, the process is enhanced by the high atmospheric
temperatures. Since nitrogen oxides and VOCs are among the emissions main constituents in
urban areas, the cities located in geographical areas with intense solar radiation and high
temperatures (e.g. in the Mediterranean areas), represent the best candidates to develop
episodes of intense photochemical smog.
In the lower atmosphere, the ozone is produced from the reaction of atmospheric oxygen
with atomic oxygen coming from of nitrogen dioxide photolysis, and in turn the ozone is
removed by the nitrogen monoxide to form new NO2.
In unpolluted atmospheres, where there is no appreciable concentration of other chemical
species, this series of reactions represents a cycle (the ozone photo stationary cycle), and for
this reason there is no chance of photochemical pollution. The basic principle, whereby the
atmosphere may get enriched in ozone and other photo-oxidizing species (i.e. that are chemical
oxidizing species resulting from chemical reactions occurring only in the presence of light),
relies in the NO2 formation through alternative ways, that do not entail any ozone removal.
Therefore, the identification of NO2 formation paths is the clue to understand the
photochemical oxidizing processes.
The main alternative to form NO2 is represented by the oxidation of NO by peroxide radicals
(RO2). These free radicals come from the degradation of volatile hydrocarbon (RH) molecules
and their subsequent reaction with atmospheric oxygen. The attack to volatile hydrocarbons is
due to the presence of other types of free radicals in the atmosphere, the hydroxyl radicals (OH).
Therefore, the processes generating the hydroxyl radicals, are fundamental in triggering the
photochemical pollution.
Basically, also the production of OH radicals is a photochemical type reaction, which main
precursors are nitrous acid, formaldehyde and ozone itself. Therefore, the ozone is not only
the most important product in the photochemical pollution processes from a quantitative
point of view, but also part of the “fuel” that triggers the process itself. The same is valid, to
a certain point, for nitrous acid and formaldehyde, which are the OH radicals precursors but
they undergo through a secondary formation path from species involved in the
photochemical processes (nitrogen dioxide for nitrous acid, and hydrocarbons and radicals or
ozone for formaldehyde).
These remarks allow us to understand the reason why acute photochemical smog events
often persist, with increasing intensities, for many consecutive days.
Finally, the origin of a photochemical smog event is composed of various phases that can be
summarized as follows:
1. an atmosphere rich in primary pollutants, such as nitrogen oxides and volatile
hydrocarbons, as well as OH radicals precursors, like nitrous acid, formaldehyde and
ozone, is hit by UV solar radiation.
2. the UV radiation causes the photolysis of nitrous acid, formaldehyde and ozone (as per
each own increasing level of UV energy required), with production of OH radicals.
3. the OH radicals attack several species of reactive volatile hydrocarbons, triggering a series
of chain reactions that lead to the degradation of the hydrocarbon molecules and the
formation of peroxide radicals (RO2).
4. the RO2 radicals oxidize nitrogen monoxide, producing NO2; each radical takes part in
many NO to NO2 conversion cycles, before extinguishing.
5. the NO2 through photolysis produces ozone, re-generating an NO molecule that becomes
available for a new oxidation process.
6. Alternatively, NO2 reacts either with OH radicals, producing nitric acid, or with
peroxyacetyl radicals, forming peroxyacetylnitrate (the final products that complete the
reactions series) and in this case, NO2 is removed from the photochemical cycle.
(Source: RSA 2001 - Report on the Status of the Environment in Italy)
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TX Active® by Italcementi - TECHNICAL REPORT
REGULATIONS
REGULATIONS
European regulation
At European level, an official CEN (European Commettee for Standardization) working group has
been set up to define common guidelines and regulations, but it has not still started its activity.
Over the last few years, the regulations related to air quality assessment and management have
been modified according to the directives issued by the European Commission, which work is
based on the development of a control strategy through the definition of long-term objectives.
In 1996, the European Union adopted a framework directive on air quality assessment and
management (Directive No. 96/62/CE), followed in 1999 by an application directive (1999/
30/EC) that identifies the limit values for pollutants such as nitrogen oxides and dioxide,
sulfur dioxide, lead and PM 10. However as of to date, the Commission emphasizes the
Countries are in considerable default towards these Community duties.
An international ISO working group (ISO-TC 206/WG 37, “Test method for photocatalytic
materials”) has recently published the ISO22197-1 standard with the following title: “Fine
ceramics (advanced ceramics, advanced technical ceramics) — Test method for airpurification performance of semiconducting photocatalytic materials. Part 1: Removal of
nitric oxide”. This standard has been derived from the 2004 Japanese one (JIS R 1701-1), not
specifically developed for cement-based materials. Finally, other ISO drafts are under
discussion and once they become final standards, they will be a reference to assess the
products’ performance as well as a useful tool to both public and private building contractors
that might want to include them in their tenders.
Italy: UNI standards
Within UNI (the Italian organization for standardization), for over three years an official
“Photocatalysis” group has been working to define and publish testing standards for building
materials with photocatalytic activity. In particular, as of today, three standards have been
published about cement-based materials:
- UNI 11238-1. Determination of the catalytic degradation of organic micropollutants in air.
Part 1: Photocatalytic cementitious materials.
- UNI 11247. Determination of the catalytic degradation of nitrous dioxides by photocatalytic
inorganic materials.
- UNI 11259. Determination of the photocatalytic activity of hydraulic binders. Rhodamine
test method.
UNI 11238-1
In this standard, a method to measure the degradation of volatile organic compounds (i.e.
BTEX, that is Benzene, Toluene, Ethylbenzene and Xylene) by photocatalytic cementitious
materials is described.
The method, called Gas Chromatography Method, was initially developed as part of the
PICADA Project and measures the photodegradation of ppb level air organic compounds in a
continuous flow system of a gaseous stream passing over a surface.
Thanks to a specially designed stirred-flow reactor, effective mixing and uniform reactants
concentration at high conversion factor are achieved, allowing to measure the surface
photocatalytic activity.
The photocatalytic activity is defined as specific degradation rate, normalized for an
irradiating UV-light of 1,000 µW/cm², and expressed in (µg/m²·h) / (µg/m³), that is m/h, for
the BTEX standard mixture.
The pollutant concentrations in the gaseous stream and the irradiation levels are comparable
to those found under real ambient conditions.
In addition, it is possible to study the effects of variations in pollutants concentration,
irradiation levels and titanium dioxide percentages in the cementitious materials.
7
REGULATIONS
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UNI 11247
It refers to one of the methods commonly used to assess the photocatalytic activity of
inorganic materials with respect to NOX abatement. Generally, these tests are carried out
with a fixed NOX concentration (equal to 0.55 ppm, of which 0.15 ppm of NO2 and 0.4 ppm
of NO) in N2, corresponding to a possible atmospheric pollution. The results can be expressed
as a percentage of NOX decomposition by a photocatalytic sample under UV radiation. Also,
it is possible to calculate the intrinsic photocatalytic activity of the inorganic material.
In the standardized method, that is a “dynamic” method, the NOX content of a continuous
gaseous stream, representing a polluted air stream, is monitored after being in contact with
the surface of a photocatalytic sample. The test set-up is represented in the following figure.
A schematic view
of the “dynamic”
method
The simulated polluted air is controlled and injected into the reaction chamber containing the
sample.
System description and test conditions are as follows:
• An artificial atmosphere generator system with a NOX source, to provide a continuous flow
with a constant NOX concentration;
• A reaction chamber containing the sample with a UV lamp (irradiance between 300 and
400 nm, 300 Watt power at 365 nm) providing an accurate light intensity (20 W/m²) on
the sample surface. The size of the chamber (3 liters) is sized in order to test samples with
a defined exposed surface area (65 cm²).
• The NOX concentration at the outlet of the reaction chamber is measured with a
chemiluminescence NOX meter.
The measurement procedure is as follows:
1. Stabilization. The sample is placed inside the reaction chamber with the polluted air flow
(3 l/min) and the UV Lamp switched off. This phase lasts about 1 hour and is necessary to
equalize the adsorption processes and assure a constant NOX concentration (i.e. gas flow
stabilization) in the air supply flow. This initial value is noted as Co.
2. Irradiation. The UV Lamp is switched on and the system is allowed to equalize for a certain
time (normally about 1 hour). The irradiated equilibrium concentration is noted as Ceq.
3. Return. The UV Lamp is switched off and the NOX concentration is checked to its initial
value. An example of the measured curve is shown here below.
Data obtained
with the
dynamic test
method
8
REGULATIONS
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The result is given as NOX reduction percentage Q = (1-Ceq/C0)·100. For the example of the
graph before, Q = 33%.
The photocatalytic activity (P.A.) of nitrogen oxide reduction (as units of m/h) for different
reaction times can be calculated from the formula:
P.A. =
(C B − C L ) F
× × I m × h-1
CB
S
where CB and CL are the NOX, NO2, NO concentrations measured at equilibrium respectively
in dark and under light conditions; S is the geometrical surface area of the specimen under
investigation, in m2; F is the gas flow, in m3/h; I is the adimensional intensity of the luminous
flow that is obtained by comparing the experimentally measured intensity I’ (in W/m2) and
1,000 W/m2, which corresponds to about 100,000 Lux (that is the average value that the
solar light reaches at noon on an average July day).
Among the other types of tests, there is a “static” or “gas recirculation” method, where a
certain volume of polluted air is put into a closed circuit with no air exchange during the
experiment. The sample to be tested for photocatalytic activity is put into a glass reaction
chamber with a UV Lamp on top. See figure here below.
Gas sampling is carried out over time to monitor NOX concentration variations, that are
measured with the chemiluminescence NOX meter.
Test parameters are similar to those ones of the “dynamic” method:
A schematic view
of the “static”
method
With reference to the above figure, tests are carried out as follows:
• Mixing and reaction chambers are first filled with air. Then a certain amount of NOX is
added in the mixing chamber, until a constant concentration at equilibrium is attained.
• Consequently, the NOX is pumped into the closed circuit (i.e. the mixing chamber and the
reaction chamber) and the analyzer records the NOX concentration at time zero, called C0.
The above procedure is repeated twice: firstly with the photocatalytic sample inside the
reaction chamber and the UV Lamp turned off (or when it is possible with an equivalent nonphotocatalytic sample with the UV Lamp turned on); secondly with the sample inside the
reaction chamber and the UV Lamp turned on.
The NOX concentration is recorded at time zero (C0) and after certain fixed times (Ct) (e.g. 30
and 60 min.).
The adsorption on the sample surface is evaluated by assimilating the adsorption part of the
abatement of the gas concentration in the dark.
The test results can be given in terms of NOX reduction percentage (either before and after
switching on the Lamp if a single photocatalytic sample is used, or by comparing the results
of a sample with photocatalytic surface and a reference sample with no photocatalytic
surface).
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REGULATIONS
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UNI 11259
This standard is known also as the Rhodamine test, published in February 2008. This method
permits to monitor the colorimetric variations over time (to a maximum of 26 hours), equal
to the discoloration of cement-based samples previously surface-treated with an organic
pigment, and under a continuous exposition to UV-A radiations (i.e. a UV- Lamp) at a
distance from the sample equal to 1m.
The Rhodamine B is used as pigment, that is a red organic
dye applied in solution on the surface of the specimens.
Application of
rhodamine solution on
the sample surface
Measurement of the
colorimetric
parameters
The photocatalytic activity is observed and measured with
reference to the Rhodamine fading. For the colorimetric
measurement, a CIE L*a*b* colorimeter is used, by
monitoring “a*” (the reference parameter for the red
colour).
The sample is a standard paste (containing cement, standard sand and water) prismatic
specimen prepared according to the UNI EN 196-1 standard.
First, just before the exposition to the UV-A Lamp, a* is measured at t0, namely a* (0h).
Then, once the Lamp is switched on and UV-A irradiation starts, two more measures are
performed: after 4 hours, that is a* (4h), and after 26 hours, a* (26h).
Then R4 and R26 are calculated as follows:
R4 =
a* (0h) − a* (4h)
×100
a * (0h)
R26 =
a * (0h) − a * (26h)
×100
a * (0h)
The hydraulic binder is considered as photocatalytic, if the following conditions are fulfilled:
R4 > 20%
R26 > 50%
Trend of a discoloration
test
This method cannot be generically used for the
photocatalytic evaluation of cement-based finished
products or concretes, because of the possible interaction
with other organic admixtures contained in the products.
These UNI test methods represent a common reference
enabling comparable measurements on different
photocatalytic products.
France: AFNOR standards
Also in France, the AFNOR Group has recently set up a technical committee on
“Photocatalysis” and its work is in progress to establish some standards similar to those ones
already published or in phase of final approval in Italy.
10
THE PHOTOCATALYSIS
TX Active® by Italcementi - TECHNICAL REPORT
THE PHOTOCATALYSIS
Photocatalysis is the natural phenomenon similar to photosynthesis, whereby a substance
called photocatalyst through the action of natural or artificial light triggers a strong oxidation
process converting noxious organic and inorganic substances into absolutely harmless
compounds.
Photocatalysis is therefore an accelerator of oxidation processes already existing in
nature. It promotes a faster decomposition of pollutants, preventing them from
accumulating.
In the last decade, there have been many studies, experimentations and testings carried out
by CTG, the Technical Center of Italcementi Group, in collaboration with Universities and
Regional Research Centers of different Countries (such as the CNR – National Research
Center Air pollution institute in Italy, the Regional Laboratories of western Paris etc.).
Oxygen
Carbon Dioxide
Light
Water
The photocatalytic
process presents
many similarities to
what happens in
nature through the
photosynthesis
Energy
Sugar
In each occasion, the effectiveness of the photocatalytic cementitious materials was evident,
proving they have a real eco - sustainable value.
Laboratory tests showed how just a 3-minute radiation is sufficient to obtain a polluting agents
reduction of up to 75%; large-scale experiments confirmed even greater abatement values.
This is how the photocatalytic city works
Light
Organic Pollutants
Inorganic Pollutants
(1)
(2)
(1) CO, VOCs (benzene, toluene), Methyl Mercaptan (gas), Organic chlorinated compounds,
policondensed aromatic compounds, Acetaldehyde Formaldehyde.
(2) NOX SOX, NH3 (gas).
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TX ACTIVE BY ITALCEMENTI
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TX ACTIVE® BY ITALCEMENTI:
THE PHOTOCATALYTIC ACTIVE PRINCIPLE
The TX Active® photocatalytic principle is the basis of the photoactive cements and binders,
designed and patented by Italcementi. It is used for manufacturing a wide range of
cementitious products - from paints to mortars and precast elements - with which pavements,
plasters and any type of horizontal or vertical structure and coating can be made.
TX Active® does not get consume during the reaction, so that its effects are not limited in time.
For a good photocatalytic effectiveness, the following conditions must be satisfied:
1. De-polluting applications:
• Presence of relatively high concentrations of NOX;
• Daylight, or, as an alternative, an acceptable amount of UV light (for indoor applications);
• Regular rinsing either with rain or cleaning water to wash away the nitrates.
and ideal places for this product are:
• Busy streets, and high traffic lanes;
• Parking lots, intersections and squares;
• Gas stations and toll roads.
The photocatalysis
mechanism applied to
cementitious materials
2. Self-cleaning applications
• Green environment
• Dry or standard condition of humidity
• Daylight
Richard Meier’s Dives
in Misericordia Church,
Rome, TX Active® first
application
The first opportunity to use photocatalytic cementitious materials occurred in 1996, thanks to
the role of technical sponsor Italcementi played in the realization of Richard Meier’s Dives in
Misericordia Church, in Rome. The project, winner of the international contest “50 Churches
for Rome 2000” promoted by the Vicariate of Rome, was characterized by three imposing,
white sails that were supposed to be made of precast concrete elements. A structure of such
a highly architectural prestige and symbolic significance demanded the use of an extraordinary
concrete, not only capable of high performances in mechanical strength and durability, but
also characterized by a white color with unparallel brilliance and the ability to maintain its
aesthetic appearance unaltered over time thanks to its surface self-cleaning properties.
For the first time the TX Active® principle had been applied.
The photocatalytic cements find effective use also in the field of prestigious architecture.
After the Church in Rome, many other projects have made use of their self-cleaning and
brilliance properties to keep their aesthetic value unaltered over time.
Italcementi’s know-how
Since 1996, Italcementi has filed 12 patents on photocatalysis applied to cementitious materials:
- On binders: “Hydraulic binder and cementitious composition containing phocatalyst particles”
- On applications: interlocking paving stones, cladding elements in general, plasters,
renderings, finishing coats and paints based on lime and cement, concrete or other types
of cement-based pavements.
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TX Active® by Italcementi - TECHNICAL REPORT
BENEFIT MEASUREMENT
MEASURING BENEFITS
TX Aria® - abating pollution
Effectiveness against NOX
The testing on the nitrogen oxides (NOX) abatement effectiveness is performed in a chamber
of a known volume where NOX is blown and diluted with air to achieve a preset pollutant
concentration.
As already explained, this type of test has already been standardized in Italy (UNI) and at
international level (ISO – by using different testing conditions).
The reactor used to measure the NO2 abatement and the graph illustrating how immediate the
abatement is once the light is turned on and after a 60’ chamber stabilization (recirculation test).
The effectiveness against NOX gases has also been demonstrated in occasion of the PICADA
Project, with tests performed at the Ispra (Italy) European laboratory inside an Indoortron
chamber (that is a walk-in environmental chamber featuring controlled temperature, relative
humidity, air quality, and air exchange rate, to study the sources of indoor pollution by
VOCs), and with in-situ monitoring campaigns, where a similar approach to that used one in
the laboratory was adopted.
Effectiveness against PM
The effectiveness of the photocatalytic cementitious materials in abating the organic
compounds contained in the Total Suspended Particles (TSP) was demonstrated in two
different studies: one carried out by the Chemistry Department of the University of Florence
and the latter by the University “La Sapienza” in Rome.
In Florence, a gascromatography flame ionization analyzer (GC-FD) was used to analyse the
TSP treated by mean of a UV light irradiating some photocatalytic cement-based tiles.
In Rome, a more complex approach based on a respirometric test has quantified the
degradation rate of organic PM10 particles in contact with photocatalytic cement-based
paints.
Substances that can be abated by photocatalysis:
Inorganic compounds: NOX; SOx; CO; NH3; CH3S; H2S
Chlorinated organic compounds: CH2Cl2; CHCl3; CCl4; 1,1-C2H4Cl2; 1,2-C2H4Cl2;
1,1,1-C2H3Cl3; 1,1,2-C2H3Cl3; 1,1,1,2-C2H2Cl4; 1,1,2,2-C2H2Cl4; 1,2-C2H2Cl2;
C2HCl3; C2Cl4; dioxins; chlorobenzene; chlorophenol.
Organic compounds: CH3OH; C2H5OH; CH3COOH; CH4;C2H6,C3H8; C2H4; C3H6;
C6H6; phenol; toluene; ethylbenzene; o-xylene; m-xylene; phenanthroquinone
Pesticides: Tradimefon; Pirimicarb; Asulam; Diazinon; MPMC; atrazine
Other compounds: bacteria; viruses; carcinogenic cells; PM.
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BENEFIT MEASUREMENT
TX Active® by Italcementi - TECHNICAL REPORT
TX Arca® - preserving aesthetics
The surfaces exposed to the atmosphere get stained by the deposition of organic pigmented
compounds – i.e. exhaust gases from motor vehicles, organic pollutants from both industrial
and everyday home activities, mold, mildew etc. In addition, high humidity and surfaces
roughness conditions promote their growth.
The photocatalysis not only operates by eliminating these organic molecules, but also indirectly
allows to reduce the negative effect of the dirt represented by common dust particles. These
latter ones, in fact, use organic molecules to grip onto the surfaces; by not having these
molecules, their grip is minimal and their removal becomes easier. Finally, in order to optimize
the cleaning action, it is useful to have smooth surfaces and with minimum porosity.
The laboratory tests showing the cleaning action have been based on field experiments: tiles
have been stained by using colored pollutants (Rhodamine and Bromocresol) and then
exposed to a light source for a period of 100 hours.
Right from the first few hours, the results from the photocatalytic action are considerable,
and after 1 day, the surface index turns out to be practically equal to the one of the
reference sample. After 4 days all the organic stain has been destroyed.
Under the same UV light conditions, the TX Arca® cleaning action is a function of the following
parameters:
• Environment: that represents the probability of the building surface of being stained and
dirtied.
- Green: corresponding to a building close to forests, parks or in the country, etc. In this case,
the stains and dirt are mainly of biological origin and can be removed by photocatalysis.
- Industrial: corresponding to a building close to industrial areas, chemical or power plants,
factories, etc. In this case the stains and dirt are mainly of inorganic origin (i.e. mineral
dusts, fumes, combustion residue, etc.) and can not be removed by photocatalysis. On the
other hand, these compounds, as mentioned earlier, use the organic molecules to grip to
the surfaces. Therefore, by removing these latter ones the grip may become minimal.
- Mixed: corresponding to a building close to cities or roads. In this case, it is possible to
have both organic and inorganic staining compounds.
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BENEFIT MEASUREMENT
TX Active® by Italcementi - TECHNICAL REPORT
• Exposure Conditions: that represents the Relative Humidity (R.H.), as a function of the
proliferation kinetics of staining compounds of biological origin.
- Dry Conditions: corresponding to a R.H. lower than 65%. In this case the concrete
surface is not exposed to proliferation of biological staining organisms.
- Humid Conditions: corresponding to a R.H. greater than 95%. In this case the concrete
surface is constantly in contact with rain or water, enhancing high proliferation of
biological staining organisms.
- Standard Conditions: corresponding to a R.H. between 65% and 95%. In this case the
concrete surface is in contact with rain and bad weather, with medium probability of
biological staining organisms.
• Surface Characteristics: that has a direct influence on the accumulation of both organic
and inorganic dirt, as well as on the surface humidity.
- Smooth: for this type of surface the grip is weak. In addition, the absence of roughness
makes the surface dry fast, with non proliferation of biological staining organisms.
- Rough: for this type of surface the grip is moderate. Accordingly this light roughness
enables the concrete surface to stay humid, promoting slight proliferation of biological
staining organisms.
- Very Rough: for this type of surface the grip is very strong. The presence of a very rough
surface enhances the presence of humidity and therefore the proliferation of staining
biological organisms. Moreover, the amount of photoactive paste is limited, therefore
this type of surface is not recommended.
The aforementioned parameters are summarized in the following Recommendation Guide:
N.A.
N.A.
N.A.
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THE TX ACTIVE® RANGE
TX Active® by Italcementi - TECHNICAL REPORT
THE TX ACTIVE® RANGE
The range of photocatalytic cements and binders is comprised of two families
differing in the type of benefits offered, namely, de-polluting benefits (i.e. cleaner
air) and aesthetic benefits (i.e. cleaner buildings). These products can be white, grey
or colored with inorganic pigments in order to obtain a distinctive appearance.
TX ARIA® - the Environmental Line: abating pollution
TX Aria® is the specific binder for paints, mortars and renderings, plasters, concrete
for photoactive building elements, capable of abating the noxious substances
produced by human activities, factories, cars and residential heating systems.
TX Aria® can be applied in horizontal structures, such as
• Concrete floors,
• Interlocking paving stones pavements,
• Cement-based pavements and road surfacing,
• Cementitious roofing tiles,
• Paints for roadway signs,
• Concrete roof tiles.
in vertical structures
• Renderings and plasters,
• Cement-based paints,
• Precast panels,
• Noise and safety concrete barriers for roads and highways.
and in tunnels, to improve ambient air quality and enhance safety
• Cementitious paints
• Concrete panels
• Concrete roads
TX Aria® is the first active way to fight the accumulation of smog responsible
substances.
TX ARCA® - the Architectural Line: preserving aesthetics
In Europe, TX Arca® is the cement complying with the EN standard 197-1
requirements specific for the realization of prestigious architectural works.
The aesthetic characteristics of concrete, either precast or on site, are enhanced
and preserved over time.
The decomposition of the micro-organisms responsible for staining the building
façades, which growth is promoted by the accumulation of grease, dust and rain,
allows to keep the surfaces always clean and to maintain the distinguishing
brilliance, typical of the TX Active® cements range, unaltered.
TX Arca® cement was developed in 1996 to meet the strict specifications set by
Richard Meier for the construction of the Dives in Misericordia Church in Rome:
white purity, brilliance and preservation of the aesthetic qualities over time.
Since then, TX Arca® cement has been representing the main cement for
prestigious architectural works; for which both the material quality and the style are
equally important and meaningful. The white concretes produced with TX Arca®
possess the same physico-mechanical performance as the traditional concretes.
In addition, they offer an extraordinary brilliance and the ability of preserving their
color, ensuring their original beauty over time.
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CUSTOMER TOOLS
TX Active® by Italcementi - TECHNICAL REPORT
CUSTOMER TOOLS
The quantification of the effectiveness of the TX Active® depolluting action is a fundamental
element for designers.
Differently from a laboratory, where every condition is controlled, in an “open” site, like a
city, many factors count on the capability of TX Active® to reduce pollutants: i.e. type and
extension of the treated surfaces (road and/or walls), air humidity, wind speed and direction,
buildings location, traffic quality and intensity, etc.
On the grounds of the PICADA Project experimental research and, in particular, of the
mathematical model used to evaluate the depolluting effectiveness, Italcementi Group has
developed EXP’AIR , a software application that is able to measure and simulate the benefits
of TX Active® in terms of reduction of pollutants such as NOX within the treatment of vertical
and horizontal structures of an urban context.
Picada project: the street canyon
The “Street Canyon” pilot site has been built in France in an area next to the Group Technical
Center’s labs (CTG) in Guerville, France. The experiment is the result of a European research
project, namely the PICADA Project (Photocatalytic Innovative Coverings Applications for Depollution Assessment), to which European research institutions and private companies consortia
- among which Italcementi has been active since some time with studies, patents and
applications - have been collaborating.
The methodology consists in testing the effectiveness of photocatalytic properties on a model
(scale 1:5) reproducing the environmental conditions of a street located between two buildings
in a generic urban context. Two lanes have been reproduced, each lane being about 18-m
long, 2.5-m wide and 5-m high. Both lanes had their walls plastered: one with TX Aria®
cement-based plaster and the other one with a traditional cementitious binder-based plaster.
Site Description: to simulate the polluting conditions generated by urban traffic, a
perforated pipe, from which exhaust gases were being discharged, was laid along the
entire length of the sidewalls. The exhaust gases were being produced by an engine
connected to the pipe and left on for 7 hours.
Monitoring: weather sensors were placed at different heights (3 and 5 m) and at
regular intervals along the entire length of the canyon to measure humidity,
temperature, and solar radiation. Anemometers were also installed to measure wind
speed and direction.
In addition, NOX and VOC analyzers were installed at both upper and side ends. Exhaust
gases have been monitored too, by measuring their speed, temperature and composition.
Micro-meteorological
readings
Pollution distribution
as a result of the joint
wind/traffic action
VOC reading
NOX reading
Characterization
of the source
of pollution, flow
and composition
of the gas
VOC sampler
Perforated pipe
Pollution generator
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CUSTOMER TOOLS
TX Active® by Italcementi - TECHNICAL REPORT
The mathematical model: a three-dimensional calculation model was used to reproduce air
and particulate matter flows under different conditions hypothesis. Through a numeric
simulation the polluting agents dispersion was reproduced analytically, by taking into account
both the surfaces inclination with respect to the air flows and the effect of solar radiation.
The results: the results were very interesting. The
depolluting action of the walls plastered with TX is
related to many variables depending on the pollutant
concentration, meteorological parameters (temperature,
relative humidity) quantification and solar radiation.
The NOX concentration varies noticeably between the
two canyons. It was possible to calculate the
photocatalytic effect depending on the wind direction
on the surfaces.
The pollution abatement depends on wind direction and
can reach 80%.
EXP’AIR
Easy to use, by selecting from the type of Configuration of the project: i.e road type (canyon
type, tunnel, etc.), wind direction, traffic conditions (200 vehicles per hour, etc.) and surfaces
to be designed with TX ARIA® (walls, façades, boardwalks, roads, etc.), it is possible to
visualize the environmental situation before and after the action of TX ARIA® and therefore
to measure the respective pollution reduction.
In addition to the environmental modeling and in order to ensure the right dosage for the
maximum benefits from the TX ARIA® application, the software is supported by Italcementi
highly qualified technical assistance, and periodically implemented with new data, obtained
with in-situ monitoring campaigns.
Model of atmospheric depollution in urban situation with TX ARIA®
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CASE HISTORIES
TX Active® by Italcementi - TECHNICAL REPORT
CASE HISTORIES WITH MONITORING RESULTS
The first use of a photocatalytic cement dates back to the second half of the nineties when
the roman church Dives in Misericordia was built to celebrate the Millennium Jubilee. At that
time, the focus was to achieve of a perfect white surface that could remain clean in time,
but the success of that impressive opera boosted the research of new applications and, in
particular, of the de-polluting field.
A milestone of TX Active® history is the Segrate Road Full Scale Test, in 2003: a heavy traffic
road was treated with a thin coating just to have the possibility to measure the effectiveness
of TX Active® in real on-site conditions. An astonishing NOX fall of about 50% was the final
proof that the era of testing was over and that the product was ready to be marketed.
From then on, many significant projects have been realized; herewith you can find some of
those ones where NOX measurements have been taken before and after treatment.
Borgo Palazzo street – Bergamo, Italy
The project involved the requalification of about 500 m of Borgo Palazzo street in Bergamo,
accounting for an active surface area of about 7,000 m2 with grey paving stones for the road
and red ones for the sidewalks.
Monitoring Campaigns
Two environmental monitoring campaigns, lasting two weeks each, the first one during
November 2006 and the second one during January 2007, have been carried out to monitor
the pollution level and compared to the asphalt reference along the same street. Test results
showed a pollution decrease between 30% and 40%. If we consider 500 mt. long street,
with a traffic of 400 cars/hour, with TX ARIA® products along both sides, the benefits from
the pollution decrease are comparable to a traffic reduction of 150 cars/hour. In other words,
the smog produced by one car out of three gets neutralized by the depolluting action of TX
ARIA®.
In the following table you can see the NOX average concentration value recorded for 5 days
along the road with a photocatalytic pavement. These values are compared to the ones
recorded along the same road but with an asphalt pavement.
Height from concentration in the
concentration in the
the ground photocatalytic pavement asphalt pavement
(reference)
% difference between
the two monitoring point
NOX
NO
NOX
NO
NOX
NO
30 cm
250 ppb
194 ppb
336 ppb
270 ppb
30 %
33 %
180 cm
260 ppb
201 ppb
316 ppb
248 ppb
20 %
20 %
An interesting test has been recently carried out to assess the medium-term performances of
installed paving blocks, in Borgo Palazzo Street.
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CASE HISTORIES
TX Active® by Italcementi - TECHNICAL REPORT
Some blocks were removed from the street and from the
walkways, to test them using a non-destructing
methodology derived from the standardized NOX
method, already described.
The aware that this test numerical results cannot be
compared to the ones from the standard methods in
terms of the polluting effectiveness.
The blocks were firstly tested "as is" (dusty block,
installed) then after a cycle of washing, cleaning and
drying where finally compared with similar blocks
available in the warehouse.
The graph here below shows that the clocks after
washing, cleaning and drying regained their original
depolluting characteristics.
The presence of dirt (like greasy substances etc.) might
slightly reduce the active surface of the blocks, That is
why it is strongly recommended a regular program for
road cleaning in order to maintain good depolluting
effectiveness for this type of applications.
Depolluting
effectiveness for road
paving blocks, in
different cleanliness
conditions
Umberto I Tunnel – Rome, Italy
Located in the centre of Rome, the Umberto I Tunnel is one of the most brilliant conceived
projects to ease Roman road traffic. It has been built at the beginning of XX century to
connect Tritone street to Nazionale avenue under the Quirinale Palace (that is the official
residence of the President of the Italian Republic), creating a direct route between Piazza di
Spagna and Nazionale avenue. By doing so, traffic circulation between the Flaminio district
and the Esquilino one has been greatly improved, resulting in a smoother traffic flow from
Termini Railway Station to Rome historic center.
Entrance from
Nazionale Avenue
Quirinale Gardens
Quirinale Palace
Entrance from Tritone
Street
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CASE HISTORIES
TX Active® by Italcementi - TECHNICAL REPORT
The Tunnel, of about 348 m length, 17 m width and 9 m height, was in bad conditions as far
safety standards in terms of both illumination and electrical systems and vaults maintenance,
as shown by the following picture taken before the requalification works.
Tunnel before
renovation
Accordingly, during August 2007, the Tunnel went under a one month restoration, during
which its 9,000 m2 vault has been covered with a TX ARIA® based cementitious paint, and a
specific lighting system has been installed to enhance the TX Aria® depolluting benefits and
increase road safety.
Combined lamp (UV + visible light)
Tunnel after renovation
Monitoring Campaigns
Before and after the Tunnel renovation, there have been monitoring campaign to measure
the pollution level in both conditions.
In particular, two monitoring campaigns were carried out before and after the renovation
work of the tunnel for a significant period of time (three weeks for each period), in order to
collect an adequate quantity of data collected for the numerical and statistical evaluation.
The following data were collected:
- NOX values (NO, NO2 and NOX);
- Weather conditions (Temperature, Relative Humidity, Atmospheric Pressure and Wind Speed)
and sometimes, light conditions inside and outside the Tunnel (UVA, UVB, RAD, Lux);
- Traffic situation, vehicles/hour.
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CASE HISTORIES
TX Active® by Italcementi - TECHNICAL REPORT
In addition, in order to make a comparison among different calculated mean values of NOX
in different positions of the Tunnel, the official data from ARPA Lazio (that is the Official
Environmental Protection Agency in Rome) of the area around the Tunnel, were also processed.
NOX values in the centre
of the tunnel, 1m
In the tunnel, the main parameters to be considered for the variation of polluting level are
traffic volumes and wind speed. Other weather conditions are to be considered less critical.
Besides, according to the adopted approach, light irradiation can be considered constant
along the two monitoring periods.
Considering the absolute values numerically calculated, a reduction of NOX over 20% was
determined. In particular, in the centre of the tunnel after the renovation works, it was
calculated:
- a 25% reduction of NO values;
- a 23% reduction of NOX values;
- a 19% reduction of NO2 values.
However, since the second campaign (September-October 2007) the pollution values registered
in the city of Rome are higher than the corresponding values in July 2007 (according to the
ARPA agency), we have calculated that the real depolluting effect induced by the system
(paint + lighting system) is higher than the above mentioned values (20-25%).
In this sense, according to the statistical approach applied to the data evaluation, the
reduction of pollution level in the centre of the tunnel results to be higher than 50%
(calculated abatements range from 51% until 64%).
Furthermore, another relevant effect derived from the
photocatalytic degradation of polluting gases is the
reduction of pollution peaks (individual values) observed
for all NOX gases (NO and NO2), also confirmed by the
statistical calculation of the variance for data population.
The photocatalytic treatment of the vault is really effective
and enables reduce the pollution level up to nearly
outdoor conditions, for the city of Rome.
During the two NOX monitoring periods some environmental
analysis were also carried out in the tunnel centre with
reference to the total particulate matter (PM total).
As to these analysis, an automatic sampling portable
equipment was used for a sampling of the total
particulate, by collecting on a filter the powders dispersed
in the tunnel, before and after the renovation work.
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TX Active® by Italcementi - TECHNICAL REPORT
CASE HISTORIES
The sampling analysis were carried out for about 10 hours per day. Collected powders were
analysed in order to quantify the presence of TiO2, as a percentage of the total amount of
powder.
The results demonstrated that there aren’t any relevant differences between the two periods,
in terms of TiO2 content. These percentages were also found in a similar sampling recently
carried out in another monitoring campaign in Via Borgo Palazzo, Bergamo (Italy).
Jean Bleuzen street – Vanves, France
Next to the Paris area highway, Jean Bleuzen
street has been included in the Road Network
Requalification Plan of Vanves.
Jean Bleuzen street is a “Canyon Street” in a
North-South position with a good exposure to
the sun and perpendicular to the main winds,
with more than 13,000 cars per day.
The requalification project consisted in 300
meter of TX ARIA® concrete overlay over a
traditional concrete substrate, with sidewalks
and curbs in paving stones made with TX ARIA®
as well, for a total of 6,000 m2 of depolluting
surface.
The immediate result was an improved aesthetic landscape and noise reduction, thanks to a
suitable concrete formulation and surface finishing (i.e. exposed aggregates), together with a
pollution decrease of at least 20%, that is going to be monitored for a year to assess the
contribution of photocatalytic cement on air and rainwater quality.
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CASE HISTORIES
TX Active® by Italcementi - TECHNICAL REPORT
Dives in Misericordia Church - Rome, Italy
The Dives in Misericordia Church has been consecrated in the Roman neighborhoods of Tor
Tre Teste, and realized by the American architect Richard Meier, winner of an international
competition promoted by the Vicariate of Rome.
In an area characterized by working-class buildings, lacking in focal points and areas
dedicated to the community social relations, the church stands out with its high sails (the
tallest one is 26m high) and its absolute white surfaces.
In order to avoid the use of a steel framework covered with white panels - a not durable
solution over time - the self-bearing sails have been subdivided into large, double curvature
precast ashlars (blocks), weighing 12 tons each.
To meet the aesthetic requirements (and not only) demanded by Richard Meier, it was used
TX Arca®, that ensures an unparalleled and time-enduring white color.
Color Monitoring
Currently, for the quantitative evaluation of the surface color,
a CIELAB colorimetric system is used, determining the following
chromatic components:
• a* - red/magenta and green component
• b* - blue and yellow component
• L* - black/white component (Luminance/Lightness )
For the three sails, measurements have been carried out on both external and internal
surfaces of the panels chosen (30 panels, corresponding to about 9% of the total).
Sail 3
Sail 2
Sail 1
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Northern
Wall
TX Active® by Italcementi - TECHNICAL REPORT
CASE HISTORIES
Measurements Mapping
• The maintenance of primary colour of white concrete elements is confirmed, after more
than 7 years of service life (see graph – Lightness).
• Last measurements referred to the northern wall (2007) shows the same values obtained in
occasion of the monitoring carried out during the panels production for the church
construction (2002).
• b* value variations are due to the presence of inorganic substances on the surface; indeed,
a chemical analysis confirmed that the most likely reason for this effect is due to possible
deposit of African sand carried by the sirocco wind (typical phenomenon in Roma area).
Indeed, if a water washing is applied to the surface of the panels, the original colour is
completely recovered, due to the sand removal.
• This phenomenon is not registered on the northern wall, which was built using the same
concrete since it is protected from the sirocco wind.
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CASE HISTORIES
TX Active® by Italcementi - TECHNICAL REPORT
La Cité de la Musique et des Beaux-Arts - Chambéry, France
Located in a residential area, it is composed of two buildings which structure is made of
precast elements with the function of load bearing exposed façade framework. It is the city
reference cultural center in Chambéry.
Color Monitoring
For this project 191 points, distributed among the four cardinal points and between the two
buildings as well as at different heights (i.e. ground floor and first floor) have been monitored
over time, by using the same CIELAB colorimetric system as in the previous project, Dives in
Misericordia church in Rome.
After approximately 5 years of monitoring, results in Chambery are excellent. The values
registered for the two buildings remain constant, even in different positions of the façades
(West/North/East/South) and the L* and b* values are typical, for light grey slag concrete.
Over the years, for both projects, the maintenance of primary color of concrete elements has
been confirmed by a very simple monitoring approach that at the same time has been very
effective in verifying the aesthetic benefits of the TX ARCA® products.
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TX Active® by Italcementi - TECHNICAL REPORT
WORLWIDE REFERENCES
WORLDWIDE REFERENCES
Air France Headquarters
Roissy Charles de Gaulle International Airport
Architects: Denis Vallode and Jean Pistre
Customer: Air France
Year: 2006
The building, located inside the Parisian Roissy-Charles de
Gaulle International Airport, hosts the prestigious
headquarters of Air France, the French flag carrier.
For this building, being in an area characterized by high
concentrations of hydrocarbons produced by the
continuous aircraft transit, a rough finishing was chosen
and treated with TX Active®. This was wanted to ensure the
homogeneity of the façades color over time.
Hotel de Police - Bordeaux, France
Architect: Claude Marty (Lacrouts
Massicaults SA Architects)
Customer: The French MInistry of Interior
Year: 2003
Located downtown, the building is
exposed to the action of the organic
pollutants typical of these urban areas.
Just to hinder these attacks to the
building aesthetic quality, architect
Claude Marty chose to use the TX
Active® cement to manufacture the
façades white, with smoothly finished
precast concrete cladding panels.
The double-layered panels containing white marble aggregates from Pirenei Mountains have
been polished to a glossy finishing to enhance further the typical luminosity of TX products.
In total, 750 panels, of which 700 are white in color, cover a surface area of 5,400 m2 of
architectural precast concrete.
The Commodore - Ostend, Belgium
Architect: Luc Declercq - E & L projects
Customer: Municipality of Ostend
Year: 2005
CCB, the Belgian subsidiary of Italcementi
Group, chose as first application of
photocatalytic cement in Belgium a
prestigious project: the Commodore, a
complex apartment building in Ostend
and designed by architect Luc Declercq in
collaboration with the E&L Projects firm.
The façades of the first six floors have
been made of white polished concrete.
The building, located by the sea, is highly exposed to organic pollutants that become
particularly aggressive in humid areas. In this case, too, the TX Active® action will ensure the
building aesthetic appearance will be maintained.
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WORLWIDE REFERENCES
TX Active® by Italcementi - TECHNICAL REPORT
Ciments du Maroc’s Headquarters - Casablanca, Morocco
Architect: Rachid Andaloussi
Customer: Ciments du Maroc*
Year: 2005
The building hosts the headquarters of
Ciments du Maroc, Italcementi Group
Moroccan Subsidiary. The round
structure of the building, that recalls
the Group’s spiral logo, has been made
with traditional concrete covered with
a TX Active® based white mineral
coating. Even more at these latitudes,
the sun represents the main ally in the
fight against organic pollution.
The Yoga Studio - Clarke County, Virginia, USA
Jim Burton, AIA
Carter + Burton Architecture
Berryville, Virginia
The clients’ and architect’s
commitment to sustainability through
the combined use of TX Active® and
other green technologies earned the
venture a LEED Gold certification when
it was completed in 2007. As part of
the LEED for Homes pilot program,
Southface Energy Institute was the
LEED provider for the project.
Towering oaks enhanced the property where Paul and Annie Mahon chose to build The
Yoga Studio. But seasonal bombardments of staining acorns and atmospheric compounds
from a busy grilling area threatened to mottle the pristine concrete surfaces of architect Jim
Burton’s vision for this haven of natural healing. The solution: the use of the TX Active®
photocatalytic cement. Burton specified TX Active® for the structure’s exterior concrete walls
and grill area (shown here). With self-cleaning capabilities activated by sunlight, the choice
proved to be a natural for building in woodsy environments. It also distinguished Burton as
the first architect to use photocatalytic cement on this side of the Atlantic.
(TX Active® has performed successfully in notable European architecture for over a decade.)
“Once winter came and the leaves fell
off the trees, sunlight was able to reach
the concrete and the acorn stains were
removed. This new technology keeps all
the concrete areas looking fresh.”
For more information on all completed projects, please contact us at the following e-mail:
[email protected]
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TX Active® by Italcementi - TECHNICAL REPORT
FAQs
FREQUENTLY ASKED QUESTIONS
1) What is TX Active®?
It is the active principle, with photocatalytic properties, developed by Italcementi. The products
containing TX Active® are able to break down air noxious organic and inorganic pollutants and
to preserve the aesthetic quality of the finished products over time. TX Active is an
environmental friendly certified product for mortars and plasters, paints, precast elements and
pavements.
TX Active®, with its self-cleaning and depolluting properties, is the seal of quality for
photoactive cementitious products.
2) What does Italcementi’s TX Active® product line consist of?
TX Aria® - Linea Ambiente (Environment Line), with its depolluting effect, is the specific binder
for paints, mortars and “rasanti” (leveling compounds), plasters & coatings, and concrete for
photoactive building elements. TX Aria® can effectively abate the airborne harmful pollutants
that are produced by human activities (industry, transport and residential heating units). TX
Aria® can be used for both horizontal and vertical structures as well as tunnels, where air
quality and safety conditions are eventually improved.
TX Arca® - Linea Architettura (Architectural Line), with its self-cleaning effect, is the cement
complying with the requirements set forth in European Standard EN 197/1 and is specifically
designed for building prestigious architectural works.
The aesthetic qualities of the final concrete elements, regardless of whether they are
prefabricated or cast on site, are enhanced and preserved for years. TX Arca® cement is the
cement for striking, high-end architectural works, in which quality of the construction material
used and final appearance are equally important and significant. Concrete made with TX Arca®
cement has the same physical & mechanical properties as traditional concrete. On top of that,
it offers a self-cleaning benefit and extraordinary brilliance so that original beauty is retained
for years.
3) What have the main applications been so far?
Among the main applications of photocatalytic materials produced by TX Active® let us recall:
– The self-locking block pavement laid in Borgo Palazzo Street, Bergamo. Tests results showed
a pollution decrease between 30% and 40%.
– The self-locking block pavement laid in Settemetri Street, Rome;
– The self-locking block pavement laid at the Cardinal Lambruschini School in Rome;
– The self-locking block pavement laid at the Maharishi Sathyananda Yoga Academy in Brescia;
– The self-locking block pavement laid at the Montichiarello Sports Center in Montichiari (Brescia);
– Indoor painting of the gym facility at the Scuola Media Statale, Ribolle Street, in Forlì.
– Reconstruction of a concrete footbridge by Mazzano (Brescia)
– Renovation of Umberto I tunnel in Rome
– Renovation of Jean Bleuzen Street – Vanves
– Sound-Proof walls, Paris, porte des Lilas
4) What are the main architectural projects carried out with TX Arca®?
There are many outstanding architectural works, the beauty of which is preserved thanks to
the self-cleaning effect of TX Active®: the Dives in Misericordia church in Rome, the new
headquarters of Air France at Charles de Gaulle airport in Paris, the Cité de la Musique et des
Beaux-Arts in Chambéry, the Hôtel de Police in Bordeaux, the Saint John’s Court Montecarlo
Bay residence in the Principality of Monaco. Centre d’art dramatique de Montreuil, multimedia
library de Saint Ouen (France).
5) Where are TX Active® products marketed?
The TX Active® range of products is already being marketed in Italy, France, Belgium, Spain,
United States and Canada. In the next months, it will be officially presented Morocco and
subsequently in Greece.
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FAQs
TX Active® by Italcementi - TECHNICAL REPORT
6) Where are Italcementi TX Active® cements produced?
The first cement from the TX range was manufactured in Italy at the Rezzato cement plant
(province of Brescia). Currently, there are two plants: once in the subsidiary Soclì in Izaourt, France,
in the High Pyrenees region, and the recent one in Calusco, Italy between Bergamo and Milan.
7) What is the current production of Italcementi TX Active® cement?
TX Active®, due to its innovative characteristics, requires more time to be established,
particularly considering a conservative sector such as the building industry. Since the product
launch, in Italy more than 400.000 m2 of photocatalytic surfaces have been produced,
equivalent to 56 football fields.
8) How much does it cost to use TX Active®?
Talking about the cost of producing structural elements made of photocatalytic cement means
little since what reaches the market is the finished product: the paint, the plaster, or the
manufactured block. Given that the part which interacts with the atmosphere is only the
surface, the photocatalytic principle is not used in structural applications, but only where it is
possible to maintain limited thicknesses, say from centimeters to a few millimeters. If,
therefore, the cost of Italcementi cement containing TX Active® is around 1 Euro/kg, the most
significant figure is the cost per square meter of the photocatalytic surface. And so the cost
incidence is remarkably low as can be seen from a few examples. To transform the façade of a
5-storey building into a photocatalytic surface, it is enough to add around 100 Euro to the cost
of a traditional paint or plaster. Paving in photocatalytic blocks costs on average between 10 20% more than traditional paving.
9) What has Italcementi discovered?
The application of the TX Active® principle to cementitious products enables the use of light
energy to decompose, through oxidization, the organic and inorganic substances present in
the atmosphere. Therefore, the use of Italcementi cements in the TX range, which contain the
TX Active® principle, actively contributes to mitigating air pollution in cities and to keeping the
surface of built elements clean.
10) What is photocatalysis?
It is a natural phenomenon whereby a substance, called a photocatalyst, alters the speed of a
chemical reaction through the action of light. By exploiting the energy of light, photocatalysts
induce the formation of strongly oxidizing reagents which can decompose some organic and
inorganic substances present in the atmosphere. Photocatalysis is, therefore, an accelerator for
oxidization processes that already exist in nature. Indeed, it promotes faster decomposition of
pollutants and prevents them from accumulating on the surfaces. The worsening of the level of
pollution in urban areas has recently driven research towards the application of the capability
of removing harmful substances present in the atmosphere. Photocatalysis, therefore, makes
an effective contribution to improving air quality.
11) Why does TX Active® need a cement-based support?
Cement makes a significant contribution to the TX Active® principle. It enhances its qualities
for the very reason that cement has excellent pollutant absorption capacities. Cement is also
the most commonly used material in the construction industry.
12) What is the contribution of photocatalytic cements to fighting pollution?
Structures made or covered with materials containing the TX Active® principle enable the
reduction of various pollutants in the atmosphere. Among these are particulate matter,
polycondensed aromatic hydrocarbons, nitrogen oxides, carbon monoxide and sulfur monoxide
which in urban settings are mainly emitted from cars and air heating units.
13) What patents are there for TX Active®?
Since 1996 Italcementi has filed 12 patents on photocatalysis applied to cementitious
materials. The patents concern a photocatalytic hydraulic binder and a series of specific
applications in construction (self-locking blocks, cladding elements in general, plasters &
renders, leveling compounds, lime & cement-based paints, concrete pavements).
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TX Active® by Italcementi - TECHNICAL REPORT
FAQs
14) Investments
About 5 million Euro have been pledged to the TX Active® research project. Another 5 million
Euro came from the EU within the framework of on-going research and innovation programs.
Every year we invest some 25 million Euro in Research, Development and Innovation; indeed, a
huge financial commitment for a sector like ours that, however distinguishes, us from our
competitors.
15) What were the main stages in the research?
Throughout the research period, various applications for TX Active® were completed, such as
high-strength photocatalytic white and grey concretes. During the test stage, the ability to
reduce pollutants present in the atmosphere was confirmed by the laboratories of Italcementi
and of universities and by various research bodies. It was subsequently proven that the
degradation of the organic and inorganic material on the surface of the cement-based element
enables preservation of the appearance of constructions even after prolonged exposure to the
external environment, thus preserving the initial conditions in terms of brightness.
16) Does photocatalysis always work: what about indoor spaces? Or when it rains?
Photocatalysis is also possible for indoor structures treated with photocatalytic TX Active®
cementitious materials, provided that diffuse solar radiation or artificial light is present. Also
when it rains a TX Active® product maintains its photocatalytic effect.
17) Can the principle be used up?
The mechanical durability of TX Active® cement-based applications is the same as that for
similar applications with standard cements. The photocatalytic principle is not subject to
consumption and therefore cannot be used up.
18) What were the most important experimental applications undertaken?
In 2002, a first test on a photocatalytic TX Active® mortar was used to cover the asphalt
surface of a section of Via Morandi in Segrate (province of Milan); a road which is 230m long
and 10m wide, and which everyday sees traffic flow of around 1,000 vehicles/hour. Monitoring
proved a reduction in nitrogen oxides on this urban road of around 60%.
In 2003, TX Active® self-locking blocks were laid over 8,000 m2 on an industrial site in the
province of Bergamo. The test showed that in the area covered by the TX Active® blocks the
concentration of nitrogen oxides measured was clearly lower than in a comparable area. The
reduction calculated on the basis of the average values recorded is around 45%.
19) What is the Italcementi Group?
The Italcementi Group is one of the largest cement producers in the world and the biggest in
the Mediterranean area. With 2006 annual sales amounting to about 5,854 million Euro,
Italcementi Group’s companies combine the expertise, know-how and cultures of 19 countries.
With a staff of over 22,850, the Group boasts a production capacity of around 70 million tons
of cement.
During 2005, within the expansion program in the Mediterranean rim, the Group has furthered
established its presence in Egypt, becoming the Country market leader.
In 2006, in India the total control of its Subsidiary has been acquired and in Kazakhastan an
agreement for new important developments has been signed. In June 2007, the Group has
entered the Chinese market.
20) What is the CTG?
The CTG - Centro Tecnico di Gruppo (Italcementi Group Technical Center) - is one of the most
important cement research centers in Europe. The CTG is located in Bergamo (Italy) and has a
secondary base in Guerville, France, and numbers 400 employees, of whom 60 are researchers.
21) Where can I find more information?
On the Italcementi website – www.italcementigroup.com – there is a section entirely dedicated
to TX Active®, the range of TX products, the main tests, the most recent applications and our
commercial partners who are authorized to make products bearing the TX Active® brand.
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BIBLIOGRAPHY
TX Active® by Italcementi - TECHNICAL REPORT
SELECTED BIBLIOGRAPHY
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TX-Eng.ww-Jun.09
Note: The indications and information about our products characteristics, even if they reflects the latest product tests and technological knowledge, cannot be
considered as warranty on the final result of the works using the products themselves. Therefore, it is up to the user to verify, by taking the consequent exclusive
responsibility, the compatibility of the ordered products with their foreseen usage, their correct placing and curing in order not to affect negatively their performance.
Italcementi
Via Camozzi, 124
24121 Bergamo, Italia
www.italcementigroup.com