| dc.description.abstract | The demand for Portland cement in the civil construction market makes it the most consumed
industrialized material in the world, with an annual global production of around 4.0 billion t,
projecting an increase of 4.5% per year. Among the production processes of the cement
industry, the high levels of pollution consist of limestone extraction, transport of particulate
material and in the clinkerization furnace where a large volume of gases is generated. In this
scenario, the objective of this work is to investigate the use of low-cost, easily obtainable,
unconventional materials, using innovative technologies in the manufacture of concrete, with
the proposal of improving performance, durability, reduction of environmental impact and the
possibility of preserving the natural resources. Therefore, in the search for sustainability and
for alternative materials to be used in the production of concrete, the use of petroleum catalyst
residue as a partial substitute for cement was investigated. The petroleum catalyst residue
(FCC) used in the study is a thin, mesoporous material, light gray in color, with high specific
surface area and high pore volume, consisting essentially of sílica (SiO2) and alumina (Al2O3),
and presents satisfactory properties as a pozzolanic material of high reactivity and source of
aluminosílicate, which show a high potential of use in the production of concrete. The addition
of polyethylene glycol (PEG 400) was also studied, since its properties contribute to greater
water retention, favoring the curing of the concrete. Specimens were produced with different
dosages, the first with conventional concrete and the others with PEG 400 (1.5%) and
substitutions of 2%, 5%, 10% and 20% of catalyst residue, in relation to the total mass of the
cement. The specimens were immersed in an aqueous solution of calcium hydroxide and
hydrochloric acid (HCl). The effects of polymer additions and residue were investigated in
terms of physical, mechanical, durability and morphological properties of the developed
concrete. Experiments were carried out to determine the water absorption by capillarity and by
immersion, the void and specific masses, the pozzolanicity index of the residue, as well as
mechanical characterization tests. The results indicate that the sample with PEG 400 showed a
greater consistency in the fresh state (130 mm) than the others (120 mm) and the higher the
percentage of FCC, the higher the water absorption rates and the void index and the lower the
capillary absorption. The mechanical strength of the sample containing 2% RC and 1.5% PEG
400 obtained a higher average compressive strength (15.67 MPa) than the conventional sample
(12.80 MPa). In samples immersed in HCl solution, the higher the FCC content, the greater the
decrease in mechanical strength; images obtained through SEM, found that samples containing
2% of FCC addition are less porous than the conventional sample. The development of concrete
with innovative materials can help to reduce the negative environmental impacts of the cement
industry and also improve product properties. | |
