Production of bamboo leaf ash by auto-combustion for pozzolanic and sustainable use in cementitious matrices

[EN] In the context of world concern with the environment, this study aims to characterize an auto combustion produced bamboo leaf ash (BLA) by its pozzolanic behaviour, reactivity and its influence in the total porosity, pore size distribution, tortuosity and mechanical behaviour of cementitious matrices. The chemical and physical characterization of the BLA was carried using X-ray fluorescence, determination of amorphous silica content, X-ray diffraction, Fourier Transform Infrared Spectrophotometry (FTIR), laser granulometry and field emission scanning electron microscopy (FESEM). The assessed BLA is a siliceous material (74.23%) with an amorphous nature due to the amorphous silica content, which represents 92.33% of the total silica. The BLA was classified as highly reactive by assessing its pH and conductivity in a saturated calcium hydroxide (CH) medium for different proportions and temperatures. Frattini analysis, the study of CH:BLA pastes (Thermogravimetric analysis and FTIR) and Portland cement (OPC)/pozzolan pastes (Thermogravimetric analysis and FESEM) are in agreement with this classification. The replacement of OPC by BLA improved the mechanical behaviour of the cementitious matrices, as well their durability. All the mortars containing BLA presented very similar compressive strength to a control mortar (100% OPC) after only 3 days of curing and at the following tested curing ages: 7, 28 and 90 days. In the mercury intrusion porosimetry analysis, the pastes with 20 and 30% BLA content presented higher tortuosity or fewer connected pores than the control paste. Thus, the auto-combustion method proved to be successful and BLA is a suitable alternative for sustainable high-performance matrices. (C) 2019 Elsevier Ltd. All rights reserved.The authors would like to thank São Paulo Research Foundation (FAPESP), grant #2016/16403-5 and #2017/21563-4.Moraes, M.; Moraes, J.; Tashima, M.; Akasaki, J.; Soriano Martinez, L.; Borrachero Rosado, MV.; Paya Bernabeu, JJ. (2019). Production of bamboo leaf ash by auto-combustion for pozzolanic and sustainable use in cementitious matrices. Construction and Building Materials. 208:369-380. https://doi.org/10.1016/j.conbuildmat.2019.03.007S36938020

Compressive strength and microstructure of alkali-activated blast furnace slag/sewage sludge ash (GGBS/SSA) blends cured at room temperature

In the present work, ground granulated blast furnace slag (GGBS) and sewage sludge ash (SSA) blends were assessed for the production of alkali-activated pastes and mortars. Percentages of SSA to substitute GGBS ranged from 0–30 wt.% and sodium concentrations of 6–10 mol.kg-1 were used for the activating solutions. Pastes and mortars were cured at 20 ºC for up to 90 days. Raw materials were characterised by granulometric analysis, XRF, XRD, FTIR and SEM techniques. The replacement percentage of GGBS by SSA and the sodium hydroxide concentration of the alkaline activator were optimised to produce mortar with compressive strengths close to 30 MPa after 28 curing days at room temperature. Best results were obtained in samples blended with 20 wt.% SSA activated with 6 mol.kg-1 NaOH solutions which, according to the XRD, FTIR and microscopic results, contained higher amounts of (N,C)-A-S-H gel. The potential use of SSA for the development of alternative cementitious materials at room temperature has been demonstrated

A 100% waste-based alkali-activated material by using olive-stone biomass ash (OBA) and blast furnace slag (BFS)

[EN] This study presents the use of olive-stone biomass ash (OBA) as an alkali source in alkali-activated materials (AAM) based on blast furnace slag (BFS). The OBA was physically and chemically characterized. It presented high K2O and CaO contents, and yielded high alkalinity in water medium. The newly designed OBA + BFS mixes (a 100% waste-based AAM) reached a compressive strength of 30 MPa after 7 days of curing at 65 ºC, which was higher than for BFS activated with KOH solution. Thermogravimetric studies showed the formation of C-S-H/(C,K)-A-S-H gels and hydrotalcite. The OBA presented excellent performance as a component in AAM and a good valorisation was achievedFont-Pérez, A.; Soriano Martínez, L.; Moraes, J.; Tashima, M.; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Paya Bernabeu, JJ. (2017). A 100% waste-based alkali-activated material by using olive-stone biomass ash (OBA) and blast furnace slag (BFS). Materials Letters. 203:46-49. https://doi.org/10.1016/j.matlet.2017.05.129S464920

Effect of sugar cane straw ash (SCSA) as solid precursor and the alkaline activator composition on alkali-activated binders based on blast furnace slag (BFS)

[EN] Alkali-activated materials (AAM) comprise one of the solutions to diminish the use of Portland cement in building construction and, consequently, a reduction in the environmental problems related to CO2 emissions and energy consumption may be achieved. These kinds of binders are obtained when a mineral precursor (calcium silicate or aluminosilicate material) is mixed with an alkaline solution. In this study, the blast furnace slag (BFS) combined with a new waste from the sugar cane industry, sugar cane straw ash (SCSA), is utilised. This new residue was studied replacing partially the blast furnace slag in BFS/SCSA proportions of 100/0, 85/15, 75/25, 67/33 and 50/50. The alkaline solution concentration plays an important role in obtaining AAM with good mechanical properties. Therefore, this paper intends to assess the influence of the activating solution (composed of sodium hydroxide and sodium silicate) through different H2O/Na2O (called g) and SiO2/Na2O (called e) molar ratios. For BFS/SCSA proportions of 100/0 and 75/25, the g values assessed were 22, 28 and 37, whereas the e values selected were 0 and 0.75. In order to study the effects of SCSA in the mixture, other BFS/SCSA proportions (0¿50% replacement) were assessed by only g and e ratios of 28 and 0¿0.75, respectively. To reach these objectives, mortars and pastes were manufactured in order to study their behaviour in the following tests: compressive strength (3, 7, 28 and 90 days of curing at 25 C), Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), X-ray diffraction (XRD), mercury intrusion porosimetry (MIP) and field emission scanning electron microscopy (FESEM). The results showed that the alkaline solution influenced the compressive strength development, and specimens reached more than 60 MPa after 90 days of curingThe authors would like to thanks to CNPq processo no 401724/2013-1 and the "Ministerio de Educacion, Cultura y Deporte" of Spain ("Cooperacion Interuniversitaria" program with Brazil PHB-2011-0016-PC). Thanks are also given to the Electron Microscopy Service of the Universitat Politecnica de Valencia.Moraes, J.; Mitsuuchi Tashima, M.; Akasaki, JL.; J.L.P.Melges; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Soriano Martínez, L.... (2017). Effect of sugar cane straw ash (SCSA) as solid precursor and the alkaline activator composition on alkali-activated binders based on blast furnace slag (BFS). Construction and Building Materials. 144:214-224. https://doi.org/10.1016/j.conbuildmat.2017.03.166S21422414

Optimum use of sugar cane straw ash (SCSA) in alkali-activated binders based on blast furnace slag (BFS)

[EN] Alkali-activated binders (AABs) are a material obtained from the combination of a solid precursor and an alkaline activating solution. In this study, one solid precursor used was blast-furnace slag (BFS) and the other was an agro waste: sugar cane straw ash (SCSA). Sodium hydroxide was used for preparing activating solutions. In order to reach the potential reactivity of the SCSA, a study varying the BFS/SCSA mass ratio and H2O=Na2O molar ratio was carried out. The BFS/SCSA ratio varied from 100=0 to 70=30, and H2O=Na2O was studied in the range of 11.1¿18.5. To fulfill this objective, specimens were assessed by their compressive strength of mortars and microstructural studies of pastes [X-ray diffraction (XRD); thermogravimetric analysis (TGA); Fourier transform infrared spectroscopy (FTIR); and field emission scanning electron microscopy (FESEM)] in the curing time range of 3¿90 days at 25°C. Results from these tests showed that the best BFS/SCSA and H2O=Na2O ratios were 70=30 and 18.5, respectively. This study revealed an interesting valorization of the SCSA as a complementary precursor in BFS-based AABs because of the improvement of mechanical properties and the reduction in the consumption of BFS in AABThe authors would like to thank CNPq processo n° 401724/2013-1, CNPq processo n° 140779/2015-0, and the Ministerio de Educación, Cultura y Deporte of Spain ( Cooperación Interuniversitaria program with Brazil PHB-2011-0016-PC). Thanks are also given to the Electron Microscopy Service of the Universitat Politècnica de València.Moraes, J.; Tashima, M.; Melges, J.; Akasaki, J.; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Soriano Martinez, L.... (2018). Optimum use of sugar cane straw ash (SCSA) in alkali-activated binders based on blast furnace slag (BFS). Journal of Materials in Civil Engineering. 30(6):1-12. https://doi.org/10.1061/(ASCE)MT.1943-5533.0002261S11230

New use of sugar cane straw ash in alkali-activated materials: a silica source for the prparation of alkaline activator

[EN] Alkali silicates, expensive and highly pollutant chemical reagents, are required to produce the alkaline activator for high-performance alkali-activated materials. This study presents a new silica source for producing the alkaline activator, sugar cane straw ash (SCSA). An activating suspension was prepared with SCSA and NaOH by means of a thermal bottle. The ash reacting time inside the thermal bottle (s) was assessed from 0 to 48 h, and the SCSA amount in suspension, represented by the SiO2/Na2O ratio (e), was analysed from 0 to 1.82. Compressive strengths were obtained from blast-furnace slag-based mortars that were cured for three days at 65 C, with the optimal mortars produced when s = 24 h and e = 1.46. Comparison of these new SCSA systems with two common silica sources, sodium silicate chemical reagent and rice husk ash, revealed that SCSA yielded lower results than the former and similar results to the latter silica source.The authors would like to thank CNPq processo no 401724/2013-1 and CNPq processo no 140779/2015-0. The authors would also like to thank the Electron Microscopy Service of the Universitat Politecnica de Valencia.Moraes, J.; Font-Pérez, A.; Soriano Martinez, L.; Akasaki, J.; Tashima, M.; Monzó Balbuena, JM.; Borrachero Rosado, MV.... (2018). New use of sugar cane straw ash in alkali-activated materials: a silica source for the prparation of alkaline activator. Construction and Building Materials. 171:611-621. https://doi.org/10.1016/j.conbuildmat.2018.03.230S61162117

Pozzolanic reactivity studies on a miomass-derived waste from sugar cane production: sugar cane straw ash (SCSA)

"This document is the Accepted Manuscript version of a Published Work that appeared in final form in ACS Sustainable Chemistry & Engineering, copyright © American Chemical Society after peer review and technical editing by the publisher. To access the final edited and published work see http://pubs.acs.org/doi/abs/10.1021%2Facssuschemeng.6b00770.”Biomass has gained in importance as an energy source in recent years. One of the crops that presents interesting opportunities with regard to biomass is sugar cane. In Brazil, sugar cane production is increasing for alcohol and sugar manufacture. Some by-products, such as sugar cane straw, also are obtained during harvesting. Due the calorific value of the sugar cane straw, its use as biomass is increasing. After the straw is burned to produce energy, an ash is obtained: sugar cane straw ash (SCSA). This waste needs an appropriate destination and, since the recent publication of successful studies using biomass derived-ashes as pozzolanic material, the present study aimed to assess the pozzolanic reactivity of sugar cane straw ash. The pozzolanic activity was assessed using a new and simple recently proposed method: evaluation of the electrical conductivity of calcium hydroxide (CH) and pozzolan suspensions, in which solid CH is initially present. These results were compared to those of two other well-established techniques: Fourier transformed infrared spectroscopy and thermogravimetric analysis. The evaluation by all three techniques is similar and shows that sugar cane straw ash is a good pozzolanic material: high lime fixation values for CH:SCSA mixes were determined by thermogravimetric analysis and unsaturation respect to CH in 3.5:6.5 CH:SCSA suspension was achieved at 60ºC. According to this behaviour, a bright future for SCSA as a replacement for Portland cement is expected.We thank CNPq (processo no. 401724/2013-1) and the "Ministerio de Education, Cultura y Deporte" of Spain ("Cooperacion Interuniversitaria" program with Brazil PHB-2011-0016-PC). Thanks are also due to the Electron Microscopy Service of the Universitat Politecnica de ValenciaMoraes, J.; Melges, JLP.; Akasaki, JL.; Tashima, MM.; Soriano Martínez, L.; Monzó Balbuena, JM.; Borrachero Rosado, MV.... (2016). Pozzolanic reactivity studies on a miomass-derived waste from sugar cane production: sugar cane straw ash (SCSA). ACS Sustainable Chemistry and Engineering. 4(8):4273-4279. https://doi.org/10.1021/acssuschemeng.6b00770S427342794

Utilisation of sugar cane straw ash (SCSA) as pozzolan in partially replacement of Portland cement

[ES] La producción de caña de azúcar en Brasil ha aumentado considerablemente en los últimos 10 años. Después del proceso de cosecha mecanizada, se genera un residuo llamado paja de caña de azúcar. Esta paja tiene un buen poder calorífico y puede ser utilizada para generar energía como una biomasa. Sin embargo, después de este proceso de generación de energía se obtiene otro residuo, el cual no tiene un destino adecuado, llamado ceniza de la paja de caña de azúcar (CPC). Una destinación para este residuo es su valorización como un material puzolánico. Para ello, la CPC ha sido caracterizada físicamente y químicamente. La ceniza ha presentado cantidad de sílice amorfa que puede ser utilizada como una puzolana sustituyendo parcialmente el cemento Portland. La reactividad de la ceniza ha sido evaluada por el ensayo de termogravimetría (TGA) en pastas de cal y puzolana. También fueron estudiadas cinco sustituciones del cemento Portland por CPC en morteros: 0 (control), 15, 20, 25 y 30%. En este estudio se prepararon probetas para romper a ensayos de resistencia a compresión en las edades de 3, 7, 28 y 90 días después de un curado a 25 ºC en atmósfera húmeda. Los datos mostraron que la CPC reacciona con la cal y presenta una importante contribución para la resistencia mecánica. Todos los morteros presentaron resistencias a compresión similares después de 90 días de aproximadamente 45 MPa. La conclusión de este trabajo es que esta ceniza CPC puede ser utilizada sustituyendo parcialmente el cemento Portland.[EN] Sugarcane production in Brazil considerably increased in the last 10 years. After the mechanized harvesting, it is generated a waste called by sugar cane straw. This straw presents good calorific value and it can be utilised in energy production as a biomass. However, after the energy generation, it is obtained another waste, which does not have a suitable destination, known as the sugar cane straw ash (SCSA). A destination to this material can be as pozzolanic material. Therefore, the SCSA was physically and chemically characterised. The ash presented amorphous silica that can be used in partial replacement of the Port land cement. The ash reactivity was assessed by thermogravimetric analysis (TGA) of lime/pozzolan pastes. Also five replacement percentages of the Portland cement by SCSA in mortars were evaluated: 0 (control), 15, 20, 25 and 30%. Specimens were moulded in order to be assessed by compressive strength after 3, 7, 28 and 90 days of curing at 25 ºC. All mortars presented similar compressive strength after 90 days of curing of approximately 45 MPa. It can be concluded that the SCSA can be used in partial replac ement of the Portland cement.Los autores desean agradecer al CNPq Brasil por la beca del primer autor, J.C.B. Moraes (proceso 153164/2016-6), y al proceso 401724/2013-1. También al Ministerio de Educación, Cultura y Deporte de España (Cooperación Interuniversitaria con Brasil, proyecto PHB-2011-0016-PC).Moraes, J.; Akasaki, J.; Tashima, M.; Soriano Martinez, L.; Borrachero Rosado, MV.; Paya Bernabeu, JJ. (2018). Utillizacion de la ceniza de paja de caña de azúcar (CPC) como puzolana en sustituciones parciales del cemento portland. Materiales compuestos. 2(1):6-9. http://hdl.handle.net/10251/147925S692

Salt slag recycled by-products in high insulation geopolymer cellular concrete manufacturing

[EN] This investigation presents an important contribution to the understanding of the ¿zero discharge in the aluminium cycle¿ goal. The salt slag recycled by-product was reused as alternative aerating agent in the manufacture of cellular concretes: fluid catalytic cracking catalyst (FCC) ¿ based geopolymer (GCC) and blast furnace (BFS) ¿ based alkali-activated (AACC). The hydrogen emission test was used to evaluate the gas releasing properties because of the presence of metallic aluminium in the salt slag. Density (kg/cm3), compressive strength (MPa) and thermal conductivity (W/mK) for GCC were 75, 6.9 and 0.31 and for AACC were 602, 7.5 and 0.16.The authors give special grateful to Befesa Aluminio S.L (Valladolid, Spain) for the granulated paval supply. The authors would also thanks to Cementval and BPOil for precursors supplying. Thanks are given to the Electron Microscopy Service of the Universitat Politècnica de València (Spain).Font-Pérez, A.; Soriano Martinez, L.; Monzó Balbuena, JM.; Moraes, J.; Borrachero Rosado, MV.; Paya Bernabeu, JJ. (2020). Salt slag recycled by-products in high insulation geopolymer cellular concrete manufacturing. Construction and Building Materials. 231:1-13. https://doi.org/10.1016/j.conbuildmat.2019.117114S113231Meyer, C. (2009). The greening of the concrete industry. Cement and Concrete Composites, 31(8), 601-605. doi:10.1016/j.cemconcomp.2008.12.010Petek Gursel, A., Masanet, E., Horvath, A., & Stadel, A. (2014). Life-cycle inventory analysis of concrete production: A critical review. Cement and Concrete Composites, 51, 38-48. doi:10.1016/j.cemconcomp.2014.03.005Panesar, D. K. (2013). Cellular concrete properties and the effect of synthetic and protein foaming agents. Construction and Building Materials, 44, 575-584. doi:10.1016/j.conbuildmat.2013.03.024B. Dolton, C. Hannah, Cellular Concrete : Engineering and Technological Advancement for Construction in Cold Climates, (2006) 1–11.Narayanan, N., & Ramamurthy, K. (2000). Structure and properties of aerated concrete: a review. Cement and Concrete Composites, 22(5), 321-329. doi:10.1016/s0958-9465(00)00016-0Holt, E., & Raivio, P. (2005). Use of gasification residues in aerated autoclaved concrete. Cement and Concrete Research, 35(4), 796-802. doi:10.1016/j.cemconres.2004.05.005Mo, K. H., Alengaram, U. J., Jumaat, M. Z., Yap, S. P., & Lee, S. C. (2016). Green concrete partially comprised of farming waste residues: a review. Journal of Cleaner Production, 117, 122-138. doi:10.1016/j.jclepro.2016.01.022Luukkonen, T., Abdollahnejad, Z., Yliniemi, J., Kinnunen, P., & Illikainen, M. (2018). One-part alkali-activated materials: A review. Cement and Concrete Research, 103, 21-34. doi:10.1016/j.cemconres.2017.10.001Duxson, P., Provis, J. L., Lukey, G. C., & van Deventer, J. S. J. (2007). The role of inorganic polymer technology in the development of ‘green concrete’. Cement and Concrete Research, 37(12), 1590-1597. doi:10.1016/j.cemconres.2007.08.018Ducman, V., & Korat, L. (2016). Characterization of geopolymer fly-ash based foams obtained with the addition of Al powder or H2O2 as foaming agents. Materials Characterization, 113, 207-213. doi:10.1016/j.matchar.2016.01.019Esmaily, H., & Nuranian, H. (2012). Non-autoclaved high strength cellular concrete from alkali activated slag. Construction and Building Materials, 26(1), 200-206. doi:10.1016/j.conbuildmat.2011.06.010Font, A., Borrachero, M. V., Soriano, L., Monzó, J., & Payá, J. (2017). Geopolymer eco-cellular concrete (GECC) based on fluid catalytic cracking catalyst residue (FCC) with addition of recycled aluminium foil powder. Journal of Cleaner Production, 168, 1120-1131. doi:10.1016/j.jclepro.2017.09.110Font, A., Borrachero, M. V., Soriano, L., Monzó, J., Mellado, A., & Payá, J. (2018). New eco-cellular concretes: sustainable and energy-efficient materials. Green Chemistry, 20(20), 4684-4694. doi:10.1039/c8gc02066cArellano Aguilar, R., Burciaga Díaz, O., & Escalante García, J. I. (2010). Lightweight concretes of activated metakaolin-fly ash binders, with blast furnace slag aggregates. Construction and Building Materials, 24(7), 1166-1175. doi:10.1016/j.conbuildmat.2009.12.024RLG International cementreview, (n.d.).World Aluminium, Environmental Metrics Report Year 2010 Data Final, (2014) 21.Hong, S.-H., Lee, D.-W., & Kim, B.-K. (2000). Manufacturing of aluminum flake powder from foil scrap by dry ball milling process. Journal of Materials Processing Technology, 100(1-3), 105-109. doi:10.1016/s0924-0136(99)00469-0A. Al Ashraf, Energy Consumption and the CO2 footprint in aluminium production, (2014).Befesa :: Press :: News archive :: 2013, (n.d.). http://www.befesa.es/web/en/prensa/historico_de_noticias/2013/bma_20130307.html (accessed April 15, 2018).Araújo, E. G. de, & Tenório, J. A. S. (2005). Cellular Concrete with Addition of Aluminum Recycled Foil Powders. Materials Science Forum, 498-499, 198-204. doi:10.4028/www.scientific.net/msf.498-499.198Song, Y., Li, B., Yang, E.-H., Liu, Y., & Ding, T. (2015). Feasibility study on utilization of municipal solid waste incineration bottom ash as aerating agent for the production of autoclaved aerated concrete. Cement and Concrete Composites, 56, 51-58. doi:10.1016/j.cemconcomp.2014.11.006Moraes, J. C. B., Tashima, M. M., Akasaki, J. L., Melges, J. L. P., Monzó, J., Borrachero, M. V., … Payá, J. (2016). Increasing the sustainability of alkali-activated binders: The use of sugar cane straw ash (SCSA). Construction and Building Materials, 124, 148-154. doi:10.1016/j.conbuildmat.2016.07.090N.E. En, N. Une-en, española, (2005).F. Babbitt, R.E. Barnett, M.L. Cornelius, B.T. Dye, D.L. Liotti, S.B. Schmidt, J.E. Tanner, S.C. Valentini, ACI 523.3R-14 Guide for Cellular Concretes above 50 lb/ft3 (800 kg/m3), 2014.ASTM International, ASTM D5334 – 14 Standard Test Method for Determination of Thermal Conductivity of Soil and Soft Rock by Thermal Needle Probe Procedure, (n.d.).IEEE 442-1981 – IEEE Guide for Soil Thermal Resistivity Measurements, (n.d.).D.R. van Boggelen, Safe aluminium dosing in AAC plants, 5th Int. Conf. Autoclaved Aerated Concr. (2011) 45–50.Porciúncula, C. B., Marcilio, N. R., Tessaro, I. C., & Gerchmann, M. (2012). Production of hydrogen in the reaction between aluminum and water in the presence of NaOH and KOH. Brazilian Journal of Chemical Engineering, 29(2), 337-348. doi:10.1590/s0104-66322012000200014Aleksandrov, Y. A., Tsyganova, E. I., & Pisarev, A. L. (2003). Russian Journal of General Chemistry, 73(5), 689-694. doi:10.1023/a:1026114331597Yang, K.-H., Lee, K.-H., Song, J.-K., & Gong, M.-H. (2014). Properties and sustainability of alkali-activated slag foamed concrete. Journal of Cleaner Production, 68, 226-233. doi:10.1016/j.jclepro.2013.12.068Sanjayan, J. G., Nazari, A., Chen, L., & Nguyen, G. H. (2015). Physical and mechanical properties of lightweight aerated geopolymer. Construction and Building Materials, 79, 236-244. doi:10.1016/j.conbuildmat.2015.01.043Nambiar, E. K. K., & Ramamurthy, K. (2007). Air‐void characterisation of foam concrete. Cement and Concrete Research, 37(2), 221-230. doi:10.1016/j.cemconres.2006.10.009Narayanan, N., & Ramamurthy, K. (2000). Microstructural investigations on aerated concrete. Cement and Concrete Research, 30(3), 457-464. doi:10.1016/s0008-8846(00)00199-xAlexanderson, J. (1979). Relations between structure and mechanical properties of autoclaved aerated concrete. Cement and Concrete Research, 9(4), 507-514. doi:10.1016/0008-8846(79)90049-

Behavior of metakaolin-based geopolymers incorporating sewage sludge ash (SSA)

[EN] In recent years, geopolymers have become a widely researched binding material. There are technological and environmental advantages tousing this type of binder instead of Portland cement. In this study, binary systems of geopolymers were produced by using mixtures of metakaolin (MK) ,a well-known aluminosilicate raw material, and a residue from sewage sludge incineration: sewage sludge ash (SSA). This ash was used to partially replace the metakaolin in proportions of 0 20%. The mixtures were activated with alkaline solutions and they were cured by using two different conditions: at room temperature (25 °C) and in a thermal bath (65 °C). The samples were assessed by X-ray diffraction, scanning electron microscopy (pastes) and compressive strength (mortars). The results from these studies showed zeolite formation (faujasite) in geopolymers cured in the thermal bath, which caused a decrease in the compressive strength of the alkali-activated mortars.Replacement of MK with SSA caused a lower reduction in the compressive strength of mortars cured at 65 °C. However, at room temperature, similar mechanical strength was observed for the MK and MK-SSA systems. These results demonstrated that SSA is a suitable mineral precursor for partial replacement of MK in geopolymer production.The authors acknowledge Santander Universidades for the grant to Lucia Reig (program: Becas lberoamerica Jovenes Profesores Investigadores Espana 2014), CAPES (CAPES/DGU no 266/12), CNPq (no. 14/2013 processo 478057/2013-0) Scanning electron microscopy service of FEIS/UNESP and CNPq (processo 309015/2015-4).Istuque, D.; Reig Cerdá, L.; Moraes, J.; Akasaki, JL.; Borrachero Rosado, MV.; Soriano Martínez, L.; Paya Bernabeu, JJ.... (2016). Behavior of metakaolin-based geopolymers incorporating sewage sludge ash (SSA). Materials Letters. 180:192-195. https://doi.org/10.1016/j.matlet.2016.05.137S19219518