Lateritic soil geopolymer composites for ceramics and engineering construction applications

Abstract

Characterization of an Amazonian, laterite‐doped, kaolinitic soil (LK) or “lateritic soil” and laterite‐doped metakaolin (LMK) calcined at two distinct rates, as well as granite‐marble (GM) particulate industrial wastes was performed by thermogravimetric analysis (TGA), scanning electron microscopy (SEM), X‐ray diffraction (XRD), energy dispersive X‐ray fluorescence (XRF) spectrometry, and particle size and distribution analysis. In addition, an LMK geopolymer (GP) and a lateritic metakaolin‐based GP reinforced with granite‐marble composite (LMKGP‐GM) were tested for water resistance and for mechanical strength. XRD and XRF were used to investigate the composition of the composite materials, while XRD confirmed the formation of GP. Just as in the case of highly reactive commercial metakaolin used in construction, according to this study, lateritic soil‐based metakaolin presented similar characteristics. Therefore, it could be used in the development of more sustainable ceramics and construction materials, including the use of GM waste as a reinforcing phase/aggregate.

Enhanced mechanical properties of porcelain ceramic tile/Kevlar fabric composite with bio‐inspired shell‐like structure

“…As stated above, both strength, fracture toughness, and fracture work of multilayered composites are significantly improved with respect to the bio‐inspired structure and the resin and fabric content, but the mechanical properties of the porcelain ceramic tiles are poor constrained by the lack of slip systems 24 . It is worth mentioning that the mechanical properties of the biologically inspired composites in this study are even better than those reported for advanced materials in engineering 25–27 . This unique combination of the main properties in this biologically inspired composite emphasizes the importance of complex hierarchical design for strengthening and toughening at multiple length scales, which has great significance in promoting the application levels of low‐performance ceramic materials in bio‐inspired high‐performance composites for actual ceramic manufacturers.…”

“…24 It is worth mentioning that the mechanical properties of the biologically inspired composites in this study are even better than those reported for advanced materials in engineering. [25][26][27] This unique combination of the main properties in this biologically inspired composite emphasizes the importance of complex hierarchical design for strengthening and toughening at multiple length scales, which has great significance in promoting the application levels of low-performance ceramic materials in bio-inspired high-performance composites for actual ceramic manufacturers.…”

Estudo do desempenho mecânico de geopolímero produzido com auto teor de ferro

“…Para Figura 6, ativada a uma concentração de NaOH 8 M, observa-se que com o passar dos dias de cura, há modos vibracionais semelhantes, ou seja, em ~3450 cm⁻ 1 tem-se bandas atribuídas às vibrações O-H [26,27].…”

“…Para Figura 7, porém, ativada a 10 M, observa-se que com o passar dos dias de cura, há modos em ~3450 cm⁻ 1 que são atribuídas às vibrações O-H. A banda menos intensa aos 28 Dias de cura, sugere a adsorção das moléculas de água do material [26,27]. Bandas entre 1650 cm⁻ 1 e 1630 cm⁻ 1 são atribuídas às interações fracas de moléculas de H 2 O que são adsorvidas na superfície ou estão presas nas regiões interlamelares da estrutura geopolimérica [28][29][30].…”

“…Recentemente alguns pesquisadores têm realizado estudos com solos lateríticos, geralmente compostos com 40% de óxido de ferro, para a síntese de geopolímeros [24][25][26]. Segundo os autores KAZE et al [27], em lateritas calcinadas, os minerais de ferro, quando ativados por solução alcalina ou ácida, participam da reação de geopolimerização formando géis de berlinita, silicato de ferro, poli(ferrosialato-siloxo) e poli(ferrosialato--disiloxo) e que a reatividade dos minerais de ferro depende do ativador utilizado e do seu estado disponível no precursor.…”