Study of Magnesium Oxysulfate (MOS) Matrices Reinforced with Fiberglass and Limestone Filler for Applications in Civil Construction

This study evaluated Magnesium Oxysulfate (MOS)-based matrices reinforced with AR glass fibers and limestone addition for applications in civil construction. Examined how the use of fiberglass and limestone affected the mechanical and physical characteristics of MOS and the adhesion between matrix-fiberglass in this composite aiming for the Dimensional Stabilization of the composite, reducing its propensity to cracking, and reducing the final cost of the composite. Mechanical and Physical assays were performed and observations by SEM on samples cured at room temperature. The results showed that the addition of limestone content, above a certain quantity, improves the behavior of the MOS increasing its Flexural Strength, was beneficial for the Dimensional Stabilization of the composite, reducing its propensity to cracking, but high levels of limestone compromised the mechanical properties of the composite, due to the reduction of the Molar Ratio and the inert behavior of the limestone. Substitution levels between 10% and 20%, the pores formed acted to relieve internal tensions generated by the expansion of MgO, resulting in an improvement in Flexural Strength. The addition of fiberglass, proved to be effective in controlling shrinkage, preventing the formation of cracks and increasing tensile and Flexural Strength, like the behavior observed in Portland cements.