Luigi Cassar’s research while affiliated with Italcementi Group and other places


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Publications (6)


Applications of TiO 2 Photocatalysis for Air Purification
  • Article

April 2011

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91 Reads

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10 Citations

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Luigi Cassar

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Yoshihiko Murata

A system consisting of TiO2 and cement has recently been studied within the framework of a strategy for alleviating environmental pollution through the use of construction materials containing photocatalysts. This technology for the photocatalytic degradation of organic pollutants is aimed at maintaining the aesthetic characteristics of concrete structures, particularly those based on white cement. The main reason for the discoloration of cementitious materials is the accumulation of coloured organic compounds on their surfaces (see also Sect. 3.2). Suitable amounts of TiO2 have been introduced into cement mixes to render the surfaces of the resulting structures photocatalytically active. In order to verify the photocatalysis, experiments focusing on the oxidation of several kinds of aromatic organic compounds have been carried out. For instance, white cement disks have been impregnated with a phenanthroquinone solution (0.1 mg/cm2), yielding homogeneously yellow surfaces. Accelerated irradiation tests were then performed with a solar simulator (100 h of irradiation, corresponding to 1 year of sunlight). A rapid restoration of the clean surface was obtained.


Figure 4: A schematic view of the “static” method 
Figure 5: Typical data obtained with the “static test” method 
Figure 6: Photocatalytic activity rate for single organic compounds [17, 18] 
Photocatalysis of cementitious materials
  • Article
  • Full-text available

January 2007

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2,657 Reads

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88 Citations

A new and innovative approach to the material science has demonstrated that photocatalytic activity may be conferred to cementitious construction materials such as paints, mortars, concrete manufacts, pavements, etc. This has been confirmed by the results obtained in the generalised use of self-cleaning surfaces which allows buildings to maintain their aesthetic appearance unaltered over time. In parallel, the capability of photocatalysis in cementitious materials to reduce the levels of urban pollution has been demonstrated in laboratory, at pilot scale and, more recently, with some specific in-field monitoring programs carried in occasion of relevant realizations. In this paper, after a description of the most relevant aspects concerning the photocatalysis applied to the cement-based materials, some test methods for the evaluation of the photocatalytic activity will be described. Furthermore, some pilot projects will be cited and finally, some examples of relevant applications will be reported.

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Photocatalysis of Cementitious Materials: Clean Buildings and Clean Air

May 2004

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324 Reads

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227 Citations

MRS Bulletin

While the primary function of concrete is structural, its pervasiveness in our society lends it to other functions and creates the need for it to maintain its integrity and aesthetic quality. Therefore, concrete with added functionality–for example, self-cleaning characteristics and the ability to remove pollutants–is desirable. Heterogeneous photocatalysis (e.g., gas–solid or liquid–solid catalytic processes caused by light irradiation) by semiconductor particles or coatings has now reached a high level of development and is a promising technology for the reduction of global environmental pollutants. Among the various semiconductor materials, TiO2 in the form of anatase has attracted wide interest, due to its strong oxidizing power under near-UV radiation, its chemical stability when exposed to acidic and basic compounds, its chemical inertness in the absence of UV light, and the absence of toxicity. TiO2 has proved very effective in the reduction of pollutants such as NOx, aromatics, ammonia, and aldehydes. Surprisingly, the use of TiO2 in combination with cementitious materials has shown a favorable synergistic effect in the reduction of pollutants. These new materials have already found relevant applications in self-cleaning building walls and in the reduction of urban pollutants.


Table 2 . Compressive strength, MPa
Table 3 – Other mechanical properties 
White cement for architectural concrete, possessing photocatalytic properties

January 2003

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5,153 Reads

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79 Citations

Luigi Cassar

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Carmine Pepe

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Giampietro Tognon

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[...]

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Rossano Amadelli

White cement is a key ingredient in architectural and decorative concrete. By using it, in particular, the resulting concrete not only becomes an expressive material that having an infinite range of colour tones, intensifies one of its aesthetic qualities, but could also gain remarkable validity in terms of structural qualities due to its high mechanical strength. This paper is intended to provide technical information to both designers, architects and contractors, in order to obtain a high performance concrete, similar to the natural materials like marble, possessing relevant properties in terms of durability, performances and added environmental properties. Indeed, a new type of white cement is here proposed, containing TiO 2 , possessing photocatalytic properties which allow to maintain the aesthetic characteristics of concrete over time and contribute to eliminate dangerous pollutants from the urban environment. A remarkable application is also described, concerning the innovative construction of a church in Rome, named "Dives in Misericordia" whose sails were built using white High Performance Concrete, based on this new cement. Main physical and mechanical properties of this HPC are described.



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Citations (4)


... Dióxido de titanio: es un mineral muy abundante en la tierra: también es el noveno elemento químico más abundante en la corteza terrestre. Se puede utilizar en cosmética como filtro UV o como colorante blanco (Cassar et al., 2007). Operacionalmente, concreto permeable con efecto fotocatalizador: análisis de las propiedades del concreto, específicamente resistencia a la compresión, permeabilidad y efecto fotocatalizador, a partir de la adición de TiO2 en porcentajes de 1.5%, 3.5% y 5.5% en fase rutilo y fase anatasa. ...

Reference:

Influencia Del Dióxido De Titanio En El Concreto Permeable Con Efecto Fotocatalizador
Photocatalysis of cementitious materials

... The pavement surface, which includes sidewalks, midways, multi-story highways, and parking, accounts for roughly 30-60% of all urban development areas. Incorporating photocatalytic cement composites into these places may be converted into environmentally friendly with improved air quality (Cassar 2004;Levinson et al. 2010). Using photocatalytic concrete in horizontal surfaces such as roof covering and vertical applications such as walls are effective ways to purify the environment on a wide scale. ...

Photocatalysis of Cementitious Materials: Clean Buildings and Clean Air
  • Citing Article
  • May 2004

MRS Bulletin

... Se recubrió un área de 10,000 m 2 con bloques de pavimento fotocatalítico y se evaluó la correspondiente eficiencia hacia la fotohabilitación de NO x . A pesar de que se realizaron pruebas de laboratorio para demostrar la eficiencia fotocatalítica de estos bloques a lo largo del tiempo (mediante equipo de intemperismo acelerado), en el exterior sus resultados no fueron tan prometedores (Beeldens et al., 2011). Pero esto se debió a que, en el exterior, y a pesar de que se encontró una disminución en la concentración de NO x , no fue posible extraer conclusiones sólidas ya que las mediciones se realizaron solo durante un periodo relativamente pequeño. ...

Applications of TiO 2 Photocatalysis for Air Purification
  • Citing Article
  • April 2011

... It should be noted that, as reported by several research [217][218][219][220][221][222], a problem in producing these composites is the way of incorporation of NT, as this is relatively difficult to ensure a homogeneous dispersion, NT tending to agglomerate. Another controversy is in terms of self-cleaning capacity, with Guerrero et al. [220] indicating that 1 wt% NT is sufficient and Yang et al. [221] indicating an optimum requirement of 10 wt% NT. ...

White cement for architectural concrete, possessing photocatalytic properties