Estudio del comportamiento de diversos residuos de catalizadores de craqueo catalítico (FCC) en cemento Portland

The fluidized-bed catalytic cracking catalyst (FCC) it is a residue from the industry of the petroleum that shows a high pozzolanic reactivity and, in cementing matrix, it significantly improves their mechanical behaviour as well as durability. In this research a comparative study on residues of catalyst from different sources has been carried out, in order to know if these residues can be used jointly in an indiscriminate way or, on the contrary, it is necessary to classify them according to their characteristics. Thus, a study on five different FCC residues, supplied from different companies, has been carried out, and their physical-chemical characteristics, pozzolanic reactivity by means of thermogravimetric analysis and the evolution of the mechanical strength of mortars were studied. After analyzing all the aspects, it can be concluded that no significant differences among the different tested catalysts were found.El catalizador de craqueo catalítico (FCC) es un residuo de la industria del petróleo que posee una elevada reactividad puzolánica y en matrices cementicias mejora de manera importante los aspectos mecánicos así como de durabilidad. En este trabajo se realiza un estudio comparativo sobre residuos de catalizador de distintos orígenes, para poder conocer si se pueden utilizar conjuntamente de forma indiscriminada o por el contrario hay que catalogarlos según su origen. Para ello, se realizó un estudio sobre cinco residuos de catalizador de craqueo catalítico distintos, suministrados por diferentes empresas y se estudiaron sus características fisicoquímicas, reactividad puzolánica a través de estudios termogravimétricos y la evolución de las resistencias mecánicas en morteros. Tras analizar todos los aspectos se concluye que no existen diferencias significativas entre los distintos catalizadores empleados

Outstanding aspects on the use of spent FCC catalyst in binders

4 pages, 3 fiures, 7 tables.-- En: 1st Spanish National Conference on Advances in Materials Recycling and Eco – Energy Madrid, 12-13 November 2009.-- Editors: F. A. López, F. Puertas, F. J. Alguacil and A. Guerrero.FCC is a waste material from petrochemical plants which has interesting properties for preparing binders. FCC is lightly grey in color, and white FCC-portland cements with L*≥85 can be prepared. FCC reactivity is enhanced by grinding and it is attributed to pozzolanic reaction towards lime. Stratlingite is the main hydrated product from pozzolanic reaction, and CSH and CAH are also formed. Reactivity of FCC is high, and low curing temperature does not affect this contribution to strength in hardened mixtures. Additionally, high strength concrete can be easily prepared, and compressive strength greater 100MPa can be reached. Mixtures with low w/b ratio showed good behaviour in carbonation tests.Authors thank to Ministerio de Ciencia y Tecnología of Spain and FEDER the financial support of MAT 2001-2694 and BIA 2004-0052 projects.Peer reviewe

novel geopolymeric material cured at room temperature

[EN] Alkali activated binders are a new class of binding material with comparable or enhanced performance to Portland cement. These binding materials are obtained by a chemical reaction between an aluminosilicate material and a highly alkaline solution. In most cases, the setting hardening process of this binder is performed at high curing temperatures. In this paper, alkali activated mortars based on vitreous calcium aluminosilicate (VCAS) cured at room temperature are evaluated. Mechanical strength development and microstructural analysis (scanning electron microscopy, thermogravimetric analysis, X-ray diffraction and mercury intrusion porosimetry) of these materials are performed. Mortars yielded compressive strength ¡-89 MPa after 360 days. This is the first time that VCAS is used as aluminosilicate source material in the production of alkali activated mortars cured at room temperature.The authors acknowledge the Ministerio de Ciencia e Innovacio´ n of the Spanish Government (projecto. BIA2011-26947) and the Vitrominerals company for supplying VCAS samples.Mitsuuchi Tashima, M.; Soriano Martínez, L.; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Paya Bernabeu, JJ. (2013). novel geopolymeric material cured at room temperature. Advances in Applied Ceramics. 112:179-183. https://doi.org/10.1179/1743676112Y.0000000056S17918311

Las emociones en la enseñanza de las ciencias

En la primera part de l'article, s'incideix en la importància de l'estudi de les emocions des de la didàctica de les ciències, així com en la necessitat d'establir programes d'intervenció metacognitivos i metaemocionales, tant en l'aprenentatge com en la formació del professorat, perquè alumnes i professors puguin conèixer les seves emocions, controlar-les i autorregularlas. En la segona part, ens centrem en les emocions en el coneixement didàctic del contingut del professorat de ciències, incloent alguns resultats tant del diagnòstic emocional del professorat, segons diferents variables, com del programa d'intervenció de la Universitat d'Extremadura.The first part of this communication highlights the importance of studying emotions in the context of science teaching. It also examines the need for programs of meta-emotional and metacognitive intervention in learning and teacher education that are aimed at both the future teachers’and their pupils’ gaining awareness of, and then controlling and self-regulating, their emotions. The second part focuses on the role emotions play in science teachers’ pædagogical content knowledge, with the presentation of some results concerning the University of Extremadura’s intervention program and the emotional diagnosis of teachers.En la primera parte del artículo, se incide en la importancia del estudio de las emociones desde la didáctica de las ciencias, así como en la necesidad de establecer programas de intervención metacognitivos y metaemocionales, tanto en el aprendizaje como en la formación del profesorado, para que alumnos y profesores puedan conocer sus emociones, controlarlas y autorregularlas. En la segunda parte, nos centramos en las emociones en el conocimiento didáctico del contenido del profesorado de ciencias, incluyendo algunos resultados tanto del diagnóstico emocional del profesorado, según distintas variables, como del programa de intervención de la Universidad de Extremadura

New method to assess teh pozzolanic reactivity of mineral admixtures by measn of pH and electrical conductivity measurements in lime: pozzolan suspensions

A very simple method based on electrical conductivity and pH measurements was proposed for assessing reactivity of pozzolans. Calcium hydroxide:pozzolan water suspensions were monitored by means of measurements of electrical conductivity and pH values. In these suspensions, Ca(OH)2 in solid state was initially present, being them, thus, saturated in this reagent. Three testing temperatures were selected (40, 50 and 60 °C). In the experiments carried out, calcium hydroxide was suspended in deionized water for yielding a lime saturated suspension. The addition of siliceous pozzolan (two types of rice husk ash RHA and two types of densified silica fume DSF were tested) to the saturated lime suspension can produce the unsaturation of the system, depending on the testing time, testing temperature and reactivity of pozzolan. When unsaturation was reached, the loss of electrical conductivity was higher than 30% and the variation of pH was higher than 0.15 units. These threshold values were selected for characterizing the reactivity of pozzolans by means of a proposed template, classifying the pozzolan in three different reactivity levels.Mitsuuchi Tashima, M.; Soriano Martinez, L.; Monzó Balbuena, JM.; Borrachero Rosado, MV.; Akasaki, JL.; Paya Bernabeu, JJ. (2014). New method to assess teh pozzolanic reactivity of mineral admixtures by measn of pH and electrical conductivity measurements in lime: pozzolan suspensions. Materiales de Construcción. 64(316):32-44. doi:10.3989/mc.2014.00914S324464316Schneider, M., Romer, M., Tschudin, M., & Bolio, H. (2011). Sustainable cement production—present and future. Cement and Concrete Research, 41(7), 642-650. doi:10.1016/j.cemconres.2011.03.019Altmann, F., & Mechtcherine, V. (2013). Durability design strategies for new cementitious materials. Cement and Concrete Research, 54, 114-125. doi:10.1016/j.cemconres.2013.08.008Shi, C., Jiménez, A. F., & Palomo, A. (2011). New cements for the 21st century: The pursuit of an alternative to Portland cement. Cement and Concrete Research, 41(7), 750-763. doi:10.1016/j.cemconres.2011.03.0164. Payá, J. (2012) La "transmutación" sostenible de los residuos para nuevas materias primas en el ámbito del concreto. Dyna 79, 38–47.Donatello, S., Freeman-Pask, A., Tyrer, M., & Cheeseman, C. R. (2010). Effect of milling and acid washing on the pozzolanic activity of incinerator sewage sludge ash. Cement and Concrete Composites, 32(1), 54-61. doi:10.1016/j.cemconcomp.2009.09.002Soriano, L., Monzó, J., Bonilla, M., Tashima, M. M., Payá, J., & Borrachero, M. V. (2013). Effect of pozzolans on the hydration process of Portland cement cured at low temperatures. Cement and Concrete Composites, 42, 41-48. doi:10.1016/j.cemconcomp.2013.05.0077. Villar-Coci-a, E.; Frías, M.; Valencia-Morales, E.; Rojas, M.I.S. (2005) Validation of a kinetic-diffusive model to characterize pozzolanic reaction kinetics in sugar cane straw-clay ash/lime systems. Mater. Construcc. 55 [278], 29–40.8. Cruz, J.M.; Payá, J.; Lalinde, L.F.; Fita, I.C. (2011) Evaluation of electric properties of cement mortars containing pozzolans. Mater. Construcc. 61 [301], 7–26.Luxán, M. P., Madruga, F., & Saavedra, J. (1989). Rapid evaluation of pozzolanic activity of natural products by conductivity measurement. Cement and Concrete Research, 19(1), 63-68. doi:10.1016/0008-8846(89)90066-5Payá, J., Borrachero, M. ., Monzó, J., Peris-Mora, E., & Amahjour, F. (2001). Enhanced conductivity measurement techniques for evaluation of fly ash pozzolanic activity. Cement and Concrete Research, 31(1), 41-49. doi:10.1016/s0008-8846(00)00434-8Villar-Cociña, E., Valencia-Morales, E., González-Rodrı́guez, R., & Hernández-Ruı́z, J. (2003). Kinetics of the pozzolanic reaction between lime and sugar cane straw ash by electrical conductivity measurement: A kinetic–diffusive model. Cement and Concrete Research, 33(4), 517-524. doi:10.1016/s0008-8846(02)00998-5Frías, M., Villar-Cociña, E., Sánchez de Rojas, M. I., & Valencia-Morales, E. (2005). The effect that different pozzolanic activity methods has on the kinetic constants of the pozzolanic reaction in sugar cane straw-clay ash/lime systems: Application of a kinetic–diffusive model. Cement and Concrete Research, 35(11), 2137-2142. doi:10.1016/j.cemconres.2005.07.005Sinthaworn, S., & Nimityongskul, P. (2009). Quick monitoring of pozzolanic reactivity of waste ashes. Waste Management, 29(5), 1526-1531. doi:10.1016/j.wasman.2008.11.010Payá, J., Monzó, J., Borrachero, M. ., Mellado, A., & Ordoñez, L. . (2001). Determination of amorphous silica in rice husk ash by a rapid analytical method. Cement and Concrete Research, 31(2), 227-231. doi:10.1016/s0008-8846(00)00466-xMartínez-Velandia, D., Payá, J., Monzó, J., & Borrachero, M. V. (2011). Effect of sonication on the reactivity of silica fume in Portland cement mortars. Advances in Cement Research, 23(1), 23-31. doi:10.1680/adcr.8.00027Tashima, M. M., Fioriti, C. F., Akasaki, J. L., Bernabeu, J. P., Sousa, L. C., & Melges, J. L. P. (2012). Cinza de casca de arroz (CCA) altamente reativa: método de produção e atividade pozolânica. Ambiente Construído, 12(2), 151-163. doi:10.1590/s1678-86212012000200010Payá, J., Monzó, J., Borrachero, M. V., Peris-Mora, E., & Amahjour, F. (2000). Mechanical treatment of fly ashes. Cement and Concrete Research, 30(4), 543-551. doi:10.1016/s0008-8846(00)00218-

Potential use of sewage sludge ash (SSA) as a cement replacement in precast concrete blocks

The present study explored the technological feasibility of re-using sewage sludge ash (SSA) as a Portland cement replacement in commercially manufactured pre cast concrete blocks. The blocks analysed were made to the guidelines laid down in Spain s National Plan for Waste Water Treatment Plant Sludge, 2001 2006, and European Union specifications (CE marking) for such products. Performance was compared in three families of blocks, with 0, 10 and 20% SSA. The findings proved that SSA is apt for pre cast concrete block manufacture and that, in addition to the economic and environmental benefits afforded, its use would improve certain of the properties of conventional block.This research was funded by the Spanish Ministry of the Environment under project A173/2007/304.4. The authors wish to thank Prefabricados Saval Hermanos, S. L. for the use of their pre cast concrete plant facilities to manufacture the blocks analysed in this study.Pérez-Carrión, M.; Baeza-Brotons, F.; Paya Bernabeu, JJ.; Saval, J.; Zornoza Gómez, EM.; Borrachero Rosado, MV.; Garcés, P. (2014). Potential use of sewage sludge ash (SSA) as a cement replacement in precast concrete blocks. Materiales de Construcción. 64(313):2-11. https://doi.org/10.3989/mc.2014.06312S21164313Inci, I., Schuurmans, M. M., Kestenholz, P., Schneiter, D., Hillinger, S., Opitz, I., … Weder, W. (2012). Long-term outcomes of bilateral lobar lung transplantation. European Journal of Cardio-Thoracic Surgery, 43(6), 1220-1225. doi:10.1093/ejcts/ezs541Artemiou, O., Wieselthaler, G., Zuckermann, A., Wisser, W., Wekerle, T., Senbaklavaci, O., … Klepetko, W. (1997). Downsizing of the donor lung: Peripheral segmental resections and lobar transplantation. Transplantation Proceedings, 29(7), 2899-2900. doi:10.1016/s0041-1345(97)00722-7Aigner, C. (2004). Lobar transplantation, split lung transplantation and peripheral segmental resection – reliable procedures for downsizing donor lungs. European Journal of Cardio-Thoracic Surgery, 25(2), 179-183. doi:10.1016/j.ejcts.2003.11.009Bisson, A., Bonnette, P., El Kadi, N. B., Leroy, M., & Colchen, A. (1994). Bilateral pulmonary lobe transplantation: Left lower and right middle and lower lobes. The Annals of Thoracic Surgery, 57(1), 219-221. doi:10.1016/0003-4975(94)90405-7Couetil, J.-P. A., Tolan, M. J., Loulmet, D. F., Guinvarch, A., Chevalier, P. G., Achkar, A., … Carpentier, A. F. (1997). Pulmonary bipartitioning and lobar transplantation: A new approach to donor organ shortage. The Journal of Thoracic and Cardiovascular Surgery, 113(3), 529-537. doi:10.1016/s0022-5223(97)70366-0Aigner, C., Winkler, G., Jaksch, P., Ankersmit, J., Marta, G., Taghavi, S., … Klepetko, W. (2004). Size-reduced lung transplantation: An advanced operative strategy to alleviate donor organ shortage. Transplantation Proceedings, 36(9), 2801-2805. doi:10.1016/j.transproceed.2004.09.066Hardy, J. D., Webb, W. R., Dalton, M. L., & Walker, G. R. (1963). Lung Homotransplantation in Man. JAMA, 186(12). doi:10.1001/jama.1963.63710120001010(1986). Unilateral Lung Transplantation for Pulmonary Fibrosis. New England Journal of Medicine, 314(18), 1140-1145. doi:10.1056/nejm1986050131418029. Helvaci A, Meydan B, Akin O, et al. Silikozis tanisiyla yapilan tek tarafli akciğer nakli: Türkiye'deki ilk başarili akciğer nakli olgusu. Türk Göğüs Kalp Damar Cerrahisi Dergisi. 2011;19:455-462.Oto, T., Date, H., Hayama, M., Ando, A., & Shimizu, N. (2005). Peripheral Lung Volume Reduction Improved Early Graft Function in Severe Size Mismatched Living Donor Lobar Lung Transplantation. Transplantation Proceedings, 37(10), 4515-4521. doi:10.1016/j.transproceed.2005.10.11911. Bowdish ME, Barr ML. Living lobar lung transplant. In: Lynch III JP, Ross JD, eds. Lung and Heart-Lung Transplant. New York, NY: Taylor & Francis; 2006:255-267

Las emociones en la enseñanza de las ciencias

En la primera parte del artículo, se incide en la importancia del estudio de las emociones desde la didáctica de las ciencias, así como en la necesidad de establecer programas de intervención metacognitivos y metaemocionales, tanto en el aprendizaje como en la formación del profesorado, para que alumnos y profesores puedan conocer sus emociones, controlarlas y autorregularlas. En la segunda parte, nos centramos en las emociones en el conocimiento didáctico del contenido del profesorado de ciencias, incluyendo algunos resultados tanto del diagnóstico emocional del profesorado, según distintas variables, como del programa de intervención de la Universidad de Extremadura.The first part of this communication highlights the importance of studying emotions in the context of science teaching. It also examines the need for programs of meta-emotional and metacognitive intervention in learning and teacher education that are aimed at both the future teachers'and their pupils' gaining awareness of, and then controlling and self-regulating, their emotions. The second part focuses on the role emotions play in science teachers' pædagogical content knowledge, with the presentation of some results concerning the University of Extremadura's intervention program and the emotional diagnosis of teachers.En la primera part de l'article, s'incideix en la importància de l'estudi de les emocions des de la didàctica de les ciències, així com en la necessitat d'establir programes d'intervenció metacognitivos i metaemocionales, tant en l'aprenentatge com en la formació del professorat, perquè alumnes i professors puguin conèixer les seves emocions, controlar-les i autorregularlas. En la segona part, ens centrem en les emocions en el coneixement didàctic del contingut del professorat de ciències, incloent alguns resultats tant del diagnòstic emocional del professorat, segons diferents variables, com del programa d'intervenció de la Universitat d'Extremadura

Mineralogical evolution of cement pastes at early ages based on thermogravimetric analysis (TGA)

[EN] Ordinary thermogravimetric analysis (TG) and high-resolution TG tests were carried out on three different Portland cement pastes to study the phases present during the first day of hydration. Tests were run at 1, 6, 12 and 24 h of hydration, in order to determine the phases at these ages. High-resolution TG tests were used to separate decompositions presented in the 100¿200 C interval. The non-evaporable water determined by TG was used to determine hydration degree for the different ages. The effect of particle size distribution (PSD) on mineralogical evolution was established, as well as the addition of calcite as mineralogical filler. Finer PSD and calcite addition accelerate the hydration process, increasing the hydration degree on the first day of eaction between water and cement. According to high-resolution TG results, it was demonstrated that ettringite was the only decomposed phase in the 100¿200 C interval during the first 6 h of hydration for all studied cements. C-S-H phase starts to appear in all cements after 12 h of hydration.Funding was provided by Colciencias (Grant No. Convocatoria 567-2012).Gaviria, X.; Borrachero Rosado, MV.; Paya Bernabeu, JJ.; Monzó Balbuena, JM.; Tobón, J. (2018). Mineralogical evolution of cement pastes at early ages based on thermogravimetric analysis (TGA). Journal of Thermal Analysis and Calorimetry. 132(1):39-46. https://doi.org/10.1007/s10973-017-6905-0S39461321Benboudjema F, Meftah JM, Torernti F. Interaction between drying, shrinkage, creep and cracking phenomena in concrete. Eng Struct. 2005;27:239–50.Holt E. Contribution of mixture design to chemical and autogenous shrinkage of concrete at early ages. Cem Concr Res. 2005;35:464–72.Darquennes A, Staquet S, Delplancke-Ogletree MP, Espion B. Effect of autogenous deformation on the cracking risk of slag cement concretes. Cem Concr Compos. 2011;33:368–79.Slowik V, Schmidt M, Fritzsch R. Capillary pressure in fresh cement-based materials and identification of the air entry value. Cem Concr Compos. 2008;30(7):557–65.Evju C, Hansen S. Expansive properties of ettringite in a mixture of calcium aluminate cement, Portland cement and ß-calcium sulfate hemihydrates. Cem Concr Res. 2001;31:257–61.Bentz DP, Jensen OM, Hansen KK. Olesen, Stang, H. Haecker, C.J. Influence of cement particle-size distribution on early age autogenous strain and stresses in cement-based materials. J Am Ceram Soc. 2001;84(1):129–35.Barcelo L, Moranville M, Clavaud B. Autogenous shrinkage of concrete: a balance between autogenous swelling and self-desiccation. Cem Concr Res. 2005;35(1):177–83.Bouasker M, Mounanga P, Turcry P, Loukili A, Khelidj A. Chemical shrinkage of cement pastes and mortars at very early age: effect of limestone filler and granular inclusions. Cem Concr Compos. 2008;30(1):13–22.Bentz DP. A review of early-age properties of cement-based materials. Cem Concr Res. 2008;38(2):196–204.Ozawa T. Controlled rate thermogravimetry. New usefulness of controlled rate thermogravimetry revealed by decomposition of polyimide. J Therm Anal Calorim. 2000;59:375–84.Ramachandran VS, Paroli RM, Beaudoin JJ, Delgado AH. Thermal analysis of construction materials. Building materials series. New York: Noyes Publications; 2003.Zanier A. High-resolution TG for the characterization of diesel fuel additives. J Therm Anal Calorim. 2001;64:377–84.Tobón JI, Payá J, Borrachero MV, Restrepo OJ. Mineralogical evolution of Portland cement blended with silica nanoparticles and its effect on mechanical strength. Constr Build Mater. 2012;36:736–42.Singh M, Waghmare S, Kumar V. Characterization of lime plasters used in 16th century Mughal Monument. J Archeol Sci. 2014;42:430–4.Majchrzak-Kuçeba I. Thermogravimetry applied to characterization of fly ash-based MCM-41 mesoporous materials. J Therm Anal Calorim. 2012;107:911–21.Silva ACM, Gálico DA, Guerra RB, Legendre AO, Rinaldo D, Galhiane MS, Bannach G. Study of some volatile compounds evolved from the thermal decomposition of atenolol. J Therm Anal Calorim. 2014;115:2517–20.Rios-Fachal M, Gracia-Fernández C, López-Beceiro J, Gómez-Barreiro S, Tarrío-Saavedra J, Ponton A, Artiaga R. Effect of nanotubes on the thermal stability of polystyrene. J Therm Anal Calorim. 2013;113:481–7.Yamarte L, Paxman D, Begum S, Sarkar P, Chambers A. TG measurement of reactivity of candidate oxygen carrier materials. J Therm Anal Calorim. 2014;116:1301–7.Borrachero MV, Payá J, Bonilla M, Monzó J. The use of thermogravimetric analysis technique for the characterization of construction materials. The gypsum case. J Therm Anal Calorim. 2008;91(2):503–9.Tobón JI, Payá J, Borrachero MV, Soriano L, Restrepo OJ. Determination of the optimum parameters in the high resolution thermogravimetric analysis (HRTG) for cementitious materials. J Therm Anal Calorim. 2012;107:233–9.Kuzielova E, Žemlička M, Másilko, J, Palou, M.T. Effect of additives on the performance of Dyckerhoff cement, Class G, submitted to simulated hydrothermal curing. J Therm Anal Calorim. Accepted 29 Oct 2017Genc M, Genc ZK. Microencapsulated myristic acid–fly ash with TiO2 shell as a novel phase change material for building application. J Therm Anal Calorim. Accepted 24 Oct 2017.Singh M, Kumar SV, Waghmare SA. The composition and technology of the 3–4th century CE decorative earthen plaster of Pithalkhora caves, India. J Archeol Sci. 2016;7:224–37.Liu L, Liu Q, Cao Y, Pan WP. The isothermal studies of char-CO2 gasification using the high-pressure thermo-gravimetric method. J Therm Anal Calorim. 2015;120:1877–82.Majchrzak-Kuce I, Bukalak-Gaik D. Regeneration performance of metal–organic frameworks TG-vacuum tests. J Therm Anal Calorim. 2016;125:1461–6.Ion RM, Radovici C, Fierascu RC, Fierascu I. Thermal and mineralogical investigations of iron archaeological Materials. J Therm Anal Calorim. 2015;121:1247–53.Rupasinghe M, San Nicolas R, Mendis P, Sofi M, Ngo T. Investigation of strength and hydration characteristics in nano-silica incorporated cement paste. Cem Concr Compos. 2017;80:17–30.Esteves PL. On the hydration of water-entrained cement–silica systems: combined SEM, XRD and thermal analysis in cement pastes. Thermochim Acta. 2011;518:27–35.Riesen R. Adjustment of heating rate for maximum resolution in TG and TMA (MaxRes). J Therm Anal. 1998;53:365–74.Lim S, Mondal P. Micro- and nano-scale characterization to study the thermal degradation of cement-based materials. Mater Charact. 2014;92:15–25.Gill PS, Sauerbrunn SR, Crowe BS. High resolution thermogravimetry. J Therm Anal. 1992;38:255–66.Mounanga P, Khelidj A, Loukili A, Baroghel-Bouny V. Predicting Ca(OH)2 content and chemical shrinkage of hydrating cement pastes using analytical approach. Cem Concr Res. 2004;34:255–65.Zeng Q, Li K, Fen-chong T, Dangla P. Determination of cement hydration and pozzolanic reaction extents for fly-ash cement pastes. Constr Build Mater. 2012;27:560–9.Parrott LP, Geiker M, Gutteridge WA, Killoh D. Monitoring Portland cement hydration: Comparison of methods. Cem Concr Res. 1990;20:919–26.Hewlett PC. Lea’s chemistry of cement and concrete. 4th ed. Oxford: Elsevier Science & Technology Books; 2004.ASTM C305 Standard practice for mechanical mixing of hydraulic cement pastes and mortars of plastic consistency. ASTM International, West Conshohocken, PA; 2012.Taylor HF. Cement chemistry. 2nd ed. Westminster: Thomas Telford; 1997.Nadelman EI, Freas DJ, Kurtis KE. Nano- and microstructural characterization of Portland limestone cement paste. In: Nanotechnology in construction. Proceedings of NICOM 5. 2015. p. 87–92

Inmobilization of Zn(II) in Portland cement pastes. Determination of microstructure and leaching performance

The aim of this paper is to study the solidification/ stabilization potential of cementitious matrices on the immobilization of Zn(II) before its disposal into the environment by determining the mechanisms of interaction between the Zn(II) ions and the binder. The results of structural and mineralogical characterization of cement pastes formed with different amounts of immobilized Zn(II) ions are presented and the study includes results from thermogravimetric analysis (TG), scanning electron microscopy, X-ray diffraction, and leaching performance. Zn(II) ions delay the hydration reaction of Portland cement due to the formation of mainly CaZn2(OH)6 2H2O , as well as Zn5(CO3)2(OH)6, Zn(OH)2, and ZnCO3 in minor proportion. Correlations between total mass loss in TG analysis and leached Zn(II) ions in long-term curing pastes have been obtained. This result is important because in a preliminary approach from a TG on an early-aged cement paste containing Zn(II), it could be possible to perform an estimation of the amount of Zn(II) ions that could be leached, thus avoiding costly and time-consuming tests.Mellado Romero, AM.; Borrachero Rosado, MV.; Soriano Martinez, L.; Paya Bernabeu, JJ.; Monzó Balbuena, JM. (2013). Inmobilization of Zn(II) in Portland cement pastes. Determination of microstructure and leaching performance. Journal of Thermal Analysis and Calorimetry. 112(3):1377-1389. doi:10.1007/s10973-012-2705-8S137713891123Mojumdar SC, Sain M, Prasad RC, Sun L, Venart JES. Selected thermoanalytical methods and their applications from medicine to construction, Part I. J Therm Anal Calorim. 2007;90:653–62.Perraki M, Perraki T, Kolovos K, Tsivilis S, Kakali G. Secondary raw materials in cement industry. Evaluation of their effect on the sintering and hydration processes by thermal analysis. J Therm Anal Calorim. 2002;70:143–50.Neves A, Dias Toledo R, de Moraes Rego E, Dweck J. Early stages hydration of high initial strength Portland cement. Part I. Thermogravimetric analysis on calcined mass basis. J Therm Anal Calorim. 2012;108:725–31. doi: 10.1007/s10973-012-2256-z .Balek V, Bydžovský J, Dufka A, Drochytka R, Beckman IN. Use of emanation thermal analysis to characterize microstructure development during Portland cement hydration. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-012-2314-6 .Zhang Q, Ye G. Dehydration kinetics of Portland cement paste at high temperature. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-012-2303-9 .Menéndez E, Vega L, Andrade C. Use of decomposition of portlandite in concrete fire as indicator of temperature progression into the material. Application to fire-affected builds. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-011-2159-4 .Galan I, Andrade C, Castellote M. Thermogravimetrical analysis for monitoring carbonation of cementitious materials. Uptake of CO2 and deepening in C–S–H knowledge. J Therm Anal Calorim. 2012. doi: 10.1007/s10973-012-2466-4 .Batchelor B. Overview of waste stabilization with cement. Waste Manag (Oxford). 2006;26:689–98.Gineys N, Aouad G, Damidot D. Managing trace elements in Portland cement-Part I: interactions between cement paste and heavy metals added during mixing as soluble salts. Cem Concr Compos. 2010;32:563–70.Erdem M, Özverdi A. Environmental risk assessment and stabilization/solidification of zinc extraction residue: II. Stabilization/solidification. Hydrometallurgy. 2011;105:270–6.Nocuń-Wczelik W, Małolepszy J. Application of calorimetry in studies of the immobilization of heavy metals in cementitious materials. Thermochim Acta. 1995;269(270):613–9.Dweck J, Buchler PM, Cartledge FK. The effect of different bentonites on cement hydration during solidification/stabilization of tannery wastes. J Therm Anal Calorim. 2001;64:1011–6.Melchert MBM, Viana MM, Lemos MS, Dweck J, Buchler PM. Simultaneous solidification of two catalyst wastes and their effect on the early stages of cement hydration. J Therm Anal Calorim. 2011;105:625–33.Vessalas K, Thomas PS, Ray AS, Guerbois JP, Joyce P, Haggman J. Pozzolanic reactivity of the supplementary cementitious material pitchstone fines by thermogravimetric analysis. J Therm Anal Calorim. 2009;97:71–6.Tommaseo CE, Kersten M. Aqueous solubility diagrams for cementitious waste stabilization systems. 3. Mechanism of zinc immobilization by calcium silicate hydrate. Environ Sci Technol. 2002;36:2919–25.Peyronnard O, et al. Study of mineralogy and leaching behavior of stabilized/solidified sludge using differential acid neutralization analysis. Cem Conc Res. 2009. doi: 10.1016/j.cemconres.2009.03.016 .Moulin I, et al. Lead, zinc and chromium (III) and (VI) speciation in hydrated cement phases. International conference on the science and engineering of recycling for environmental protection, waste materials in construction (WASCON 2000), Harrogate, England, 2000, pp. 269–280.Ziegler F, Gieré R, Johnson CA. Sorption mechanisms of zinc to calcium silicate hydrate: sorption and microscopic investigations. Environ Sci Technol. 2001;35:4556–61.Qiao XC, Poon CS, Cheeseman CR. Investigation into the stabilization/solidification performance of Portland cement through cement clinker phases. J Hazard Mater. 2007;B139:238–43.Chen QY, et al. Immobilisation of heavy metal in cement-based solidification/stabilisation: a review. Waste Manag (Oxford). 2009;29:390–403.Chen QY, et al. Characterisation of products of tricalcium silicate hydration in the presence of heavy metals. J Hazard Mater. 2007;147:817–25.Fernandez-Olmo I, Chacon E, Irabien A. Influence of lead, zinc, iron (III) and chromium (III) oxides on the setting time and strength development of Portland cement. Cem Concr Res. 2001;31:1213–9.Fernandez-Olmo I, Chacon E, Irabien A. Leaching behavior of lead, chromium (III) and zinc in cement/metal oxides systems. ASCE J Environ Eng. 2003;129:532–8.Cappuyns V, Swennenb R. The application of pHstat leaching tests to assess the pH-dependent release of trace metals from soils, sediments and waste materials. J Hazard Mater. 2008;158:185–95.Payá J, Monzó J, Borrachero MV, Velázquez S. Evaluation of the pozzolanic activity of fluid catalytic cracking catalyst residue (FC3R): thermogravimetric analysis studies on FC3R-Portland cement pastes. Cem Concr Res. 2003;33:603–9.Wang S, Yang Z, Zeng L. Study of calcium zincate synthesized by solid-phase synthesis method without strong alkali. Mater Chem Phys. 2008;112:603–6.Stumm A, et al. Incorporation of zinc into calcium silicate hydrates, Part I: formation of C–S–H(I) with C/S = 2/3 and its isochemical counterpart gyrolite. Cem Concr Res. 2005;35:1665–75.Stephan D, Mallmann R, Knöfel D, Härdtl R. High intakes of Cr, Ni, and Zn in clinker, Part II. Influence on the hydration properties. Cem Concr Res. 1999;29:1959–67.Liu Y, et al. Thermal decomposition of basic zinc carbonate in nitrogen atmosphere. Thermochim Acta. 2004;414:121–3.Wahab R, et al. Synthesis and characterization of hydrozincite and its conversion into zinc oxide nanoparticles. J Alloy Compd. 2008;461:66–71.Hatakeyama T, Liu Z. Handbook of thermal analysis. New Yok: Wiley; 2000

Ceramic tiles waste as replacement material in portland cement

Permission is granted by ICE Publishing to print one copy for personal use. Any other use of these PDF files is subject to reprint fees.The pozzolanic reactivity of real ceramic waste from different tile manufacturing companies was evaluated and its suitability as a partial Portland cement replacement was analysed. The raw material was finely ground and physicochemically characterised using X-ray fluorescence (XRF), X-ray diffraction (XRD), scanning electron microscopy (SEM) and laser analysis particle size distribution (ADL). Percentages of ceramic waste (from 15 wt% to 50 wt%) to substitute Portland cement were used to assess this material s pozzolanic behaviour, and samples were cured at 20°C for different curing times. pH tests and conductivity measurements were used to evaluate its pozzolanic character, while mortars were utilised to evaluate compressive strength behaviour. The microstructural evolution of the developed binders was assessed in pastes by XRD, thermal analysis, Fourier transform infrared spectroscopy (FTIR) and SEM analyses. A strength gain due to pozzolanic activity was observed after 28 d and 90 d curing. The results prove that mortars with up to 35 wt% of tile ceramic waste comply with the requirements established for fly ash pozzolanic materials.The authors are grateful to the Spanish Ministry of Science and Innovation for supporting this study through project GEOCEDEM BIA 2011-26947, and also to FEDER funding.Mas, MA.; Monzó Balbuena, JM.; Paya Bernabeu, JJ.; Reig Cerdá, L.; Borrachero Rosado, MV. (2016). Ceramic tiles waste as replacement material in portland cement. Advances in Cement Research. 28:221-232. https://doi.org/10.1680/jadcr.15.00021S2212322