Artigos científicos, teses e dissertações
Publicados nas melhores instituições de ensino

This work reports on the behavior of carbonation in reinforced concrete beams under stress regime on full and small scales having the lowest possible frame. The beams were made with and without adding silica from rice husk and silica fume (Fe-Si). For each beam on a full scale (c...

This paper discusses the effects of carbonation on the microstructure of Portland cement concrete for long-term durability applications. A class C40 concrete (characteristic compression strength between 40 MPa and 44 MPa on the 28th day, according to Brazilian standard NBR 8953) ...

ABSTRACT Carbonation and chloride action are the two leading causes of degradation in reinforced concrete structures. Despite the combined action of these two mechanisms being a reality, there is little research on the effect of this combination in cementitious matrices. Furtherm...

This work starts presenting the theoretical concepts needed for a good understanding of it’s contents, including corrosion of steel in concrete, passivation, despassivation, service life and concepts of risk analysis and reliability theory. In chapter three it’s discussed the sev...

This research is part of a project that aimed to evaluate the technical viability of the use of unground (in natura) residual Rice Husk Ash (RHA), without grinding, for structural concrete. The present work investigated the evaluation of the depth and the determination of the car...

The present worked aimed to study the effect of the addition of lime hydrated on the carbonation of concretes with high amount of mineral additions of fly ash, rice husk ash and blast furnance slag, in binary and ternary mixtures. The amount substitution varied of 50% to 90% of c...

Carbonation is a natural phenomenon observed in carbon structures, and it is a result of the combined presence of CO2 in the environment and moisture. Carbonation may lower the pH of the concrete to such an extent that the passivation layer of the steel is depleted and the onset ...

Carbonation is a natural phenomenon observed in carbon structures, and it is a result of the combined presence of CO2 in the environment and moisture. Carbonation may lower the pH of the concrete to such an extent that the passivation layer of the steel is depleted and the onset ...

Abstract The reaction of calcium oxide with carbon dioxide is one of the most important methods for the capture and concentration of greenhouse gas from the flue gases of industrial plants. In this work, the carbonation reaction of CaO obtained from various sources with CO2 was i...

Degradation of mechanical properties and durability of reinforced concrete structures occur when they are subjected to fire situations, depending on the characteristics of the material, fire duration and the ways of fire extinguishing. Mechanical properties such as compressive st...

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The carbonation phenomenon, reaction between CO2 from the atmosphere in the presence of humidity with the Portland cement hydration products, induces pH reduction to levels that can cause the elimination of steels protective layer, enabling the corrosion mechanism of the steel st...

Cement is the construction building material with higher responsibility by carbon dioxide emission of all industrial human activities, besides be a considerably expensive material, more than the rice husk ash in nature. Environmental benefits are generated in its utilization, bec...

This present paper evaluates the depth of carbonation of concrete test samplers taken from existing buildings where it was possible to recover the registers of concreting such as: date of execution, concrete mixture proportions, compression resistance and design specifications al...

Abstract The reutilization of waste is a valuable alternative for the preservation of natural resources and the environment. In this sense, Basic Oxygen Furnace (BOF) steel slag is one of the most residues generated in steel the industry. It is estimated that for each ton of stee...

The aim of this work was to investigate the carbonation kinetics of lithium orthosilicate (Li4SiO4) by thermogravimetry and via thermodynamic simulations, using CO2 concentrations of 15 vol.% (typical of combustion gases) and 100 vol.%. Tests were performed in a thermogravimetric...

The death kinetics of Aspergillus niger spores under high-pressure carbonation were investigated with respect to the concentration of dissolved CO2 (dCO2) and treatment temperature. All of the inactivation followed first-order death kinetics. The D value (decimal reduction time, ...

Abstract Researches on building performance have been developed over time. The Brazilian Performance Standard - NBR 15575 - deals with the issues of durability applied to residential buildings, establishing criteria and parameters to classify the systems into minimum, intermediat...

Improvement systems are being used with greater frequency in recent decades in order to increase market competitiveness. The intention to focus the study on a system -based improvements in performance assessment meets proposes a measurement of the action plans of this system. For...

Improvement systems are being used with greater frequency in recent decades in order to increase market competitiveness. The intention to focus the study on a system -based improvements in performance assessment meets proposes a measurement of the action plans of this system. For...