Cementos able to repair their own cracks

The cement and its derivatives are one of the most commonly used in the construction materials, due to its good performance and low price. In recent years, a part of the scientific and technological research is heading to provide these materials of additional functionality. Specifically, the doctor Idurre Kaltzakorta has studied the possibility of adding cement capabilities such as the auto-reparación of cracks and latent heat energy storage. His doctoral thesis, carried out in the unit of construction of Tecnalia, was presented at the University of the Basque country (upv/ehu) under the title 'synthesis of silica microcapsules encapsulating different organic compounds for addition in the cement paste' (synthesis of microcapsules of silica with different organic compounds for cement paste).

As reflected in the title of his research, Kaltzakorta has created microcapsules of silica (glass base) with organic material in its interior, in order to provide the cement of new features. It has opted for two types of organic materials in particular, for each of these two additional features mentioned above. On the one hand, he has filled microcapsules with various resins epoxide (used in the manufacture of adhesives), to provide cement capacity to auto-reparar cracks. On the other hand, it has been encapsulated phase change materials. It's materials that absorb or release a large amount of heat to change the material of (from solid to liquid) or from liquid phase to gas and vice versa, and enable the storage of the material cementicio latent heat energy.

Kaltzakorta has studied the synthesis of the package, opting to synthesize the microcapsules combining the chemical sol-gel with emulsion technology. This route allows the encapsulation of organic material - difficult to obtain with other routes - soft temperature and pressure conditions.

Once obtained the microcapsules, is discussed in the thesis the effect of adding these to the cementitious matrix, to test the feasibility of the proposal. For this purpose, Kaltzakorta has used several techniques, such as the tomography of x-ray X, the electron microscopy of scanning, the mechanical tests, or the differential scanning calorimetry, which you have been used to study the characteristics of the new material cementicio.

In conclusion, the thesis demonstrates the feasibility of developing a new generation of capable of auto - repair cements and store energy of latent heat, based on the application of microcapsules of silica with various organic materials. In fact, the research for the development of the new cement with a capacity of autosellado of cracks resulted in a patent. In addition, according to Kaltzakorta, the proposal presented in this thesis is a bet for sustainability. Ensure that the material cementicio can auto-reparar on the one hand, increase the service life of structures. On the other hand, use a material capable of regulating the temperature inside the buildings to improve energy efficiency.

About the author

Idurre Kaltzakorta Arantzamendi (Ondarroa, 1978) holds a PhD in chemistry. He has presented his thesis in the Department of Química-Física of the Faculty of science and technology of the BASQUE country and her has been carried out under the direction of Dr. Edurne Erkizia Jauregi in the Group of nanomaterials in construction (NANOC) of the unit of construction of Tecnalia. It has also had the help of Professor Luis León Isidro and his group of the Department of QUÍMICA-FÍSICA of the UPV/EHU. He has also collaborated with Hokkaido University, in Sapporo, Japan.