Azevedo, A.G.S.; Molano, J.C.A.; Parente, I.; Freitas, T.O.G.; Camões, A.; Faria, P.; Savastano, H., Jr. Effect of the Rehydration Method on the Physical–Mechanical Properties of CO2-Cured Magnesium-Based Fiber Cement Boards. CivilEng2024, 5, 247-264.
Azevedo, A.G.S.; Molano, J.C.A.; Parente, I.; Freitas, T.O.G.; Camões, A.; Faria, P.; Savastano, H., Jr. Effect of the Rehydration Method on the Physical–Mechanical Properties of CO2-Cured Magnesium-Based Fiber Cement Boards. CivilEng 2024, 5, 247-264.
Azevedo, A.G.S.; Molano, J.C.A.; Parente, I.; Freitas, T.O.G.; Camões, A.; Faria, P.; Savastano, H., Jr. Effect of the Rehydration Method on the Physical–Mechanical Properties of CO2-Cured Magnesium-Based Fiber Cement Boards. CivilEng2024, 5, 247-264.
Azevedo, A.G.S.; Molano, J.C.A.; Parente, I.; Freitas, T.O.G.; Camões, A.; Faria, P.; Savastano, H., Jr. Effect of the Rehydration Method on the Physical–Mechanical Properties of CO2-Cured Magnesium-Based Fiber Cement Boards. CivilEng 2024, 5, 247-264.
Abstract
During carbonation process, the presence of water is an important parameter to accelerate this phenomenon. The carbon dioxide (CO2) has been used as curing process production of fiber cement boards keeping the dimensional stability of cellulose fibers in cementitious matrix and promoting the CO2 capture of environment. In addition, magnesium oxysulfate (MOS) cement has been used as another alternative binder to reduce the amount of CO2 in the nature. The aim of this scientific paper is analysis the effect of rehydration method on the physical-mechanical properties of CO2-cured magnesium-based fiber cement boards. These boards were produced by Hatschek process simulation. The physical-mechanical performance and microstructural characteristics of MOS boards before and after carbonation were investigated by: water absorption (WA), apparent porosity (AP), and bulk density (BD); four-point bending test; X-ray diffraction (XRD); thermogravimetric analysis (TGA) and scanning electron microscopy (SEM). According to the results, it was possible observe which the accelerated carbonation process resulted in improvements in the mechanical properties of the boards. The boards carbonated after 48 hours showed higher Modulus of Rupture values. The rehydration process of the composites before carbonation led to enhancements in the boards pre-cured for 48 and 72 hours, demonstrating that carbonation occurred more effectively after the supply of water through rehydration. The improvements in mechanical properties were associated with the formation of hydration products, which preferentially formed in the pores and voids of the fiber-cement. The presence of these carbonation products altered the physical properties of the materials, increasing the density of the boards and reducing the void volume. The decomposition of the formed carbonates was confirmed by thermogravimetric analysis, which indicated that the rehydration process favored the carbonation of the materials
Keywords
MOS cement; rehydration method; carbonation; fiber cement boards; civil construction
Subject
Engineering, Civil Engineering
Copyright:
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