Cimento álcali ativado com cinza do bagaço da cana-de-açúcar

Abstract

The aim is to make the use of raw materials around the world more rational day by day. At the same time, the environmental damage caused by the Portland Cement industry has motivated the search for environmentally less aggressive alternatives, such as Alkali-Activated Cements (AAC). This work, in this context, sought to investigate, through a systematic literature review, which are the variables of interest for the study of an alkali-activated cement (AAC) with Sugarcane Bagasse Ash (SCBA), as well as to develop an AAC from this residue, with carbide lime (CL) as a source of calcium and sodium hydroxide as an activator, using as variables the curing time, molarity of the activator, ash/lime ratio and comparing the one-part and two-part systems, with molded specimens and subjected to Unconfined Compressive Strength (UCS) test, leaching test, Scanning Electron Microscopy (SEM), X-ray Diffraction (XRD) and Fourier Transform Infrared Spectroscopy (FTIR). In the systematic literature review (first part of the work), it was observed that the most commonly used activator for AAC studies with SCBA has been sodium hydroxide and that the most important variables for determining the behavior of AAC with SCBA are the presence or absence of calcium and the type of activator. The most commonly used curing times are 7 and 28 days, at room temperature. Most of the AAC studies with SCBA used activators with high molarities, causing greater environmental impact. In the second part of the work, for AAC with SCBA, CL and sodium hydroxide, the highest UCS value was 2,0 moles, in 28 days of curing, with an ash/lime ratio of 2,33 and the Two Part mixing method, reaching 1,60 MPa. It was found that the curing time was the most significant variable and there was no significant difference between the mixing methods. Furthermore, SEM, XRD and FTIR results confirmed the presence of cementing gels. Some possible applications may be stabilization of mining waste, soil stabilization, shallow foundation bases in small-scale works, etc.