Additius de formigó lleuger | Agents espumants d'alt rendiment per al formigó cel·lular
The role of proteïna concreta
A protein capable of repairing cracks in concrete structures has been identified in a marine organism. Aquesta proteïna és capaç de mineralitzar la calcita, and thus reduces the need for cement. This protein is found in the barnacle Tetraclita japonica formosana.
The bioremediase protein consists of amino acids (L-alanine, glycine, serine, and phosphoserine) and peptide bonds. It is also hydrolyzed by the enzyme urea hydrolysis, which results in a metabolic reaction that leads to a self-repair process. This metabolic process is known as microbially induced concrete repair (MICP).
Compressive strength augmentation of pozzolana cement modified with bacterial bioremediase protein was determined using a manual pressure bench. Més que 30% compressive strength was achieved after a period of curing (Fig. 3A and B).
Enhanced interfacial adhesion was also observed in the samples containing bioremediase protein. This enhanced interfacial adhesion was accompanied by increased densified microstructure, and improved tensile strength of the samples.
Pore size and total porosity of the cellular concrete were reduced in the bioremediase protein amended samples. The decrease in pore size was observed because the cement contained higher calcite content.
A més, the pore sizes of the bioremediase protein incorporated cellular concrete were less sensitive to air change in a given proportion of air as compared to synthetic foam. This was reflected in the sorptivity coefficient of the bioremediase protein based cellular concrete.
The results show that the microbially induced self-healing property of proteïna concreta can be beneficial in the construction sector, as it significantly reduces CO 2 emission. A més, the bioremediase protein is a promising alternative to conventional Portland cement.