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Dr. Moisés Frías
Eduardo Torroja Institute for Construction Sciences - CSIC

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0 Cement
0 Cement Replacement Materials,
0 cement microstructure characterization
0 Recycled materials for civil engineering
0 Recycled cosntruction and demolition wastes

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Journal article
Published: 03 July 2021 in Cement and Concrete Research
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Converting construction and demolition waste (CDW) into secondary raw materials is one of the priorities of environmental policy and circular economy strategy. This study analysed the variation in eco-efficient paste reactivity with OPC replacement ratio (5% to 10%) and hydration time (2 d, 28 d and 90 d). Three types of CDW were explored: two (calcareous and siliceous) consisting of fine (<5 mm) concrete waste and one in laminated glass (<40 mm). Further to the mineralogical phases identified at the aforementioned percentages, the four materials, i.e., the three types of CDW-blended cements and the OPC reference, were similarly reactive. The primary hydration products, C-S-H gels, C4AH13 and C4AcH11, ettringite and portlandite, were the same as observed in OPC hydration. These findings attest to the scientific viability recycling such CDWs as mineral additions in eco-cement manufacture and consequently eliminating the need for stockpiling these materials at recycling/storage plants.

ACS Style

M. Frías; S. Martínez-Ramírez; R. Vigil de la Villa; L. Fernández-Carrasco; R. García. Reactivity in cement pastes bearing fine fraction concrete and glass from construction and demolition waste: Microstructural analysis of viability. Cement and Concrete Research 2021, 148, 106531 .

AMA Style

M. Frías, S. Martínez-Ramírez, R. Vigil de la Villa, L. Fernández-Carrasco, R. García. Reactivity in cement pastes bearing fine fraction concrete and glass from construction and demolition waste: Microstructural analysis of viability. Cement and Concrete Research. 2021; 148 ():106531.

Chicago/Turabian Style

M. Frías; S. Martínez-Ramírez; R. Vigil de la Villa; L. Fernández-Carrasco; R. García. 2021. "Reactivity in cement pastes bearing fine fraction concrete and glass from construction and demolition waste: Microstructural analysis of viability." Cement and Concrete Research 148, no. : 106531.

Journal article
Published: 27 June 2021 in Applied Sciences
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Cement-based materials decay with exposure to aggressive agents, a development that raises infrastructure operation and maintenance costs substantially. This paper analyses the inclusion of ultrafine construction and demolition (UC&DW) and biomass-fuelled power plant (BA) waste as pozzolanic additions to cement in pursuit of more sustainable and eco-respectful binders and assesses the durability of the end materials when exposed to seawater, chlorides (0.5 M NaCl) or sulphates (0.3 M Na2SO4). The effect of adding silica fume (SF) at a replacement ratio of 5% was also analysed. Durability was determined using the methodology proposed by Koch and Steinegger, whilst microstructural changes were monitored with mercury intrusion porosimetry (MIP), X-ray diffraction (XRD) and scanning electron microscopy (SEM) for a fuller understanding of decay processes. According to the findings, the new blended cements containing 20%UC&DW + 10%BA or 20%UC&DW + 20%BA + 5%SF resist the attack by the aggressive media studied, with a 56-d corrosion index of over 0.7. The composition of the reaction products generated with the attack is essentially the same in OPC and the SCM-bearing materials. The results show that the optimal replacement ratio for SCM is 30%.

ACS Style

Isabel Sáez del Bosque; María Sánchez de Rojas; Gabriel Medina; Sara Barcala; César Medina. Durability of Ternary Cements Based on New Supplementary Cementitious Materials from Industrial Waste. Applied Sciences 2021, 11, 5977 .

AMA Style

Isabel Sáez del Bosque, María Sánchez de Rojas, Gabriel Medina, Sara Barcala, César Medina. Durability of Ternary Cements Based on New Supplementary Cementitious Materials from Industrial Waste. Applied Sciences. 2021; 11 (13):5977.

Chicago/Turabian Style

Isabel Sáez del Bosque; María Sánchez de Rojas; Gabriel Medina; Sara Barcala; César Medina. 2021. "Durability of Ternary Cements Based on New Supplementary Cementitious Materials from Industrial Waste." Applied Sciences 11, no. 13: 5977.

Journal article
Published: 29 May 2021 in Materials
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In this research work, the quantitative characterization of a binary blend comprised of two pozzolans (sugar cane straw (SCSA)–sugar cane bagasse ashes (SCBA), bamboo leaf ash (BLAsh)–SCBA and paper sludge (PS)–fly ash (FA)) taking into account the calculated values of the kinetic parameters of the reaction in the pozzolan/calcium hydroxide system is shown. The paper shows the most significant and important results obtained by the authors in the quantitative assessment (calculation of kinetic parameters) of the pozzolanic reaction of different mixtures of pozzolanic materials that are residues from agriculture or industrial processes. This allows a direct and rigorous comparison of the pozzolanic activity of the binary combinations of materials. The values of the kinetic parameters (reaction rate constant or activation free energy) constitute a very precise quantitative index of the pozzolanic activity of the binary combinations of materials, which is very useful for its employment in the elaboration of ternary cements. This paper shows that the binary blends 1SCBA60Blash40, 1SCBA50Blash50, 1SCBA70Blash30 have a very high pozzolanic reactivity followed by PSLSFA, 2SCBA50SCSA50, PSISFA and SCWI.

ACS Style

Ernesto Villar-Cociña; Moisés Frías; Holmer Savastano; Loic Rodier; María Sánchez de Rojas; Isabel Sáez del Bosque; César Medina. Quantitative Comparison of Binary Mix of Agro-Industrial Pozzolanic Additions for Elaborating Ternary Cements: Kinetic Parameters. Materials 2021, 14, 2944 .

AMA Style

Ernesto Villar-Cociña, Moisés Frías, Holmer Savastano, Loic Rodier, María Sánchez de Rojas, Isabel Sáez del Bosque, César Medina. Quantitative Comparison of Binary Mix of Agro-Industrial Pozzolanic Additions for Elaborating Ternary Cements: Kinetic Parameters. Materials. 2021; 14 (11):2944.

Chicago/Turabian Style

Ernesto Villar-Cociña; Moisés Frías; Holmer Savastano; Loic Rodier; María Sánchez de Rojas; Isabel Sáez del Bosque; César Medina. 2021. "Quantitative Comparison of Binary Mix of Agro-Industrial Pozzolanic Additions for Elaborating Ternary Cements: Kinetic Parameters." Materials 14, no. 11: 2944.

Journal article
Published: 08 March 2021 in Materials
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This work analyses the influence of fine concrete fractions (<5 mm) of different natures —calcareous (HcG) and siliceous (HsT)—obtained from construction and demolition waste (C&DW) on the behaviour of blended cement pastes with partial replacements between 5 and 10%. The two C&DW fractions were characterised by different instrumental techniques. Subsequently, their lime-fixing capacity and the physico-mechanical properties of the blended cement pastes were analysed. Lastly, the environmental benefits of reusing these fine wastes in the manufacture of future eco-efficient cement pastes were examined. The results show that HsT and HcG exhibit weak pozzolanic activity, owing to their low reactive silica and alumina content. Despite this, the new cement pastes meet the physical and mechanical requirements of the existing regulations for common cements. It should be highlighted that the blended cement pastes initially showed a coarser pore network, but then they underwent a refinement process between 2 and 28 days, along with a gain in compressive strength, possibly due to the double pozzolanic and filler effect of the wastes. The environmental viability of the blended cements was evaluated in a Life Cycle Assessment (LCA) concluding that the overall environmental impact could be reduced in the same proportion of the replacement rate. This is in line with the Circular Economy goals and the 2030 Agenda for Sustainable Development.

ACS Style

Laura Caneda-Martínez; Manuel Monasterio; Jaime Moreno-Juez; Sagrario Martínez-Ramírez; Rosario García; Moisés Frías. Behaviour and Properties of Eco-Cement Pastes Elaborated with Recycled Concrete Powder from Construction and Demolition Wastes. Materials 2021, 14, 1299 .

AMA Style

Laura Caneda-Martínez, Manuel Monasterio, Jaime Moreno-Juez, Sagrario Martínez-Ramírez, Rosario García, Moisés Frías. Behaviour and Properties of Eco-Cement Pastes Elaborated with Recycled Concrete Powder from Construction and Demolition Wastes. Materials. 2021; 14 (5):1299.

Chicago/Turabian Style

Laura Caneda-Martínez; Manuel Monasterio; Jaime Moreno-Juez; Sagrario Martínez-Ramírez; Rosario García; Moisés Frías. 2021. "Behaviour and Properties of Eco-Cement Pastes Elaborated with Recycled Concrete Powder from Construction and Demolition Wastes." Materials 14, no. 5: 1299.

Journal article
Published: 05 January 2021 in Sustainability
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One of the growing demands in concrete manufacture is the availability of natural fine aggregates, which account for 35% to 45% of the total concrete. An alternative method of disposal of fine recycled concrete aggregates (FRCA) generated from demolition and construction waste (C&DW) is their usage in mortar and the development of recycled mortar. The main aim of this research work is to evaluate the viability of incorporating FRCA from urban C&DW for the manufacture of cement-based mortars. Simple processing techniques like washing and sieving are adopted to improve the FRCA quality. Physical and chemical characterization of ingredients is carried out. In total four mixes of 1:3 (cement: sand) mortar with partial replacement of normalized sand with FRCA (0%, 25%, 50%, and 100%) are evaluated for mechanical properties. Water to cement ratio for all four mortar mixes are determined by fixed consistency. Mechanical and physical properties like density, compressive strength, and flexural strength are studied for various curing periods, and the result is that the optimum usage of FRCA is 25% based on a 90-day curing period.

ACS Style

Rebeca Martínez-García; María Rojas; Julia Pozo; Fernando Fraile-Fernández; Andrés Juan-Valdés. Evaluation of Mechanical Characteristics of Cement Mortar with Fine Recycled Concrete Aggregates (FRCA). Sustainability 2021, 13, 414 .

AMA Style

Rebeca Martínez-García, María Rojas, Julia Pozo, Fernando Fraile-Fernández, Andrés Juan-Valdés. Evaluation of Mechanical Characteristics of Cement Mortar with Fine Recycled Concrete Aggregates (FRCA). Sustainability. 2021; 13 (1):414.

Chicago/Turabian Style

Rebeca Martínez-García; María Rojas; Julia Pozo; Fernando Fraile-Fernández; Andrés Juan-Valdés. 2021. "Evaluation of Mechanical Characteristics of Cement Mortar with Fine Recycled Concrete Aggregates (FRCA)." Sustainability 13, no. 1: 414.

Journal article
Published: 29 December 2020 in Construction and Building Materials
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Coal washing waste was studied as supplementary cementitious material to evaluate it as new raw materials for ecocements. The influence of temperature (room temperature, 450, 650, and 800 °C) and residence time in the muffle furnace (1, 2, and 3 h) on the mineralogy and pozzolanic properties of coal washing waste was analyzed. Different characterization techniques such as PSD, XRF, XRD, FTIR, and elemental analysis were employed. In addition, the degree of structural order–disorder of the kaolinite and the amount of amorphous material in each calcined sample were determined. Subsequently, blended cements were prepared by replacing 20% with calcined waste, and their physical and mechanical behavior were analyzed (water demand, setting time, expansion, pozzolanicity, and compressive strength). The results obtained show that despite the low kaolinite content in the coal waste (14%), it is possible to obtain optimal eco-pozzolans when they are subjected to a thermal activation process above 600 °C, with an optimal temperature around 800 °C. The blended cements comply with the specifications for Type II/A cements, reaching relative compressive strength up to 0.99%. A good correlation between the compressive strengths and amorphous content of the thermally activated waste was obtained.

ACS Style

Jose Rodríguez; Moisés Frías; Jorge I. Tobón. Eco-efficient cement based on activated coal washing rejects with low content of kaolinite. Construction and Building Materials 2020, 274, 122118 .

AMA Style

Jose Rodríguez, Moisés Frías, Jorge I. Tobón. Eco-efficient cement based on activated coal washing rejects with low content of kaolinite. Construction and Building Materials. 2020; 274 ():122118.

Chicago/Turabian Style

Jose Rodríguez; Moisés Frías; Jorge I. Tobón. 2020. "Eco-efficient cement based on activated coal washing rejects with low content of kaolinite." Construction and Building Materials 274, no. : 122118.

Journal article
Published: 16 December 2020 in Applied Sciences
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To address some of the gaps in the present understanding of the behavior of new supplementary cementitious materials such as bottom ash (BA) from biomass-fired electric power plants in cement manufacture, this study explored the effect of this promising material on the sulfate resistance of the end product. Cement paste prepared with 10% or 20% (previously characterized for mineralogy and chemical composition) BA was Köch–Steinegger tested for sulfate resistance. The hydration products, in turn, were analyzed before and after soaking the reference and experimental cements in sodium sulfate to determine whether the use of the addition hastened microstructural, mineralogical, or morphological decay in the material. The 56 days findings showed that the presence of BA raised binder resistance to sulfate attack. Köch–Steinegger corrosion indices of 1.29 and 1.27 for blended cements OPC + 10 BA and OPC + 20 BA, respectively, were higher than the 1.26 recorded for ordinary Portland cement (OPC). In addition, weight gain was 20.5% and volume expansion was 28.5% lower in the new materials compared to OPC. The products resulting from the external sulfate-cement interaction, gypsum and ettringite, were deposited primarily in the pores present in the pastes. The conclusion drawn is that binders bearing 10% or 20% BA are, a priori, apt for use in the design and construction of cement-based elements exposed to sulfate-laden environments.

ACS Style

José M. Medina; María Isabel Sánchez De Rojas; Isabel F. Sáez Del Bosque; Moisés Frías; César Medina. Sulfate Resistance in Cements Bearing Bottom Ash from Biomass-Fired Electric Power Plants. Applied Sciences 2020, 10, 8982 .

AMA Style

José M. Medina, María Isabel Sánchez De Rojas, Isabel F. Sáez Del Bosque, Moisés Frías, César Medina. Sulfate Resistance in Cements Bearing Bottom Ash from Biomass-Fired Electric Power Plants. Applied Sciences. 2020; 10 (24):8982.

Chicago/Turabian Style

José M. Medina; María Isabel Sánchez De Rojas; Isabel F. Sáez Del Bosque; Moisés Frías; César Medina. 2020. "Sulfate Resistance in Cements Bearing Bottom Ash from Biomass-Fired Electric Power Plants." Applied Sciences 10, no. 24: 8982.

Journal article
Published: 09 November 2020 in Construction and Building Materials
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The concept of construction and demolition waste (CDW) embodies a vast amount of residues, among which the ceramic materials (mainly, bricks and tiles) are an important part as, in many countries of the European Union, they represent more than 50% of the total. Therefore, the reutilization of this type of waste is one of the most important challenges faced by the construction sector within the circular economy paradigm. This research work deals with a dual reutilization of the CDW ceramic fraction: firstly, as coarse recycled aggregates and, secondly, through the use of clay brick powder as a pozzolanic addition to the cement. Thus, two different recycled concrete mixtures were produced: (1) with a 50% partial substitution of the natural coarse aggregates (RC-RA) and (2) with a 50% substitution of the natural coarse aggregates and a 25% substitution of the ordinary Portland cement (RC-RAC). The mechanical performance (consistency, density and compressive strength) and microstructural properties such as porosity, elemental mapping analysis, hydration products and interfacial transition zones (ITZ) were assessed and compared with a control concrete (CC). It was revealed that the recycled concretes incorporating ceramic as secondary materials have a comparable performance level to the one exhibited by the conventional concrete at 28 days, in part due to their pozzolanic characteristics but also due to a lower effective w/c ratio, which demonstrates their potential for reuse and possible contribution to the circular economy.

ACS Style

Andrés Juan-Valdés; Desirée Rodríguez-Robles; Julia García-González; M. Isabel Sánchez De Rojas Gómez; M. Ignacio Guerra-Romero; Nele De Belie; Julia M. Morán-Del Pozo. Mechanical and microstructural properties of recycled concretes mixed with ceramic recycled cement and secondary recycled aggregates. A viable option for future concrete. Construction and Building Materials 2020, 270, 121455 .

AMA Style

Andrés Juan-Valdés, Desirée Rodríguez-Robles, Julia García-González, M. Isabel Sánchez De Rojas Gómez, M. Ignacio Guerra-Romero, Nele De Belie, Julia M. Morán-Del Pozo. Mechanical and microstructural properties of recycled concretes mixed with ceramic recycled cement and secondary recycled aggregates. A viable option for future concrete. Construction and Building Materials. 2020; 270 ():121455.

Chicago/Turabian Style

Andrés Juan-Valdés; Desirée Rodríguez-Robles; Julia García-González; M. Isabel Sánchez De Rojas Gómez; M. Ignacio Guerra-Romero; Nele De Belie; Julia M. Morán-Del Pozo. 2020. "Mechanical and microstructural properties of recycled concretes mixed with ceramic recycled cement and secondary recycled aggregates. A viable option for future concrete." Construction and Building Materials 270, no. : 121455.

Journal article
Published: 14 September 2020 in Materials
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This study explores the effect on sulfate resistance of the use of ornamental granite industry waste as a supplementary cementitious material (at replacement ratios of 10% and 20%) in cement manufacture. The present paucity of scientific knowledge of the behaviour of these new cements when exposed to an external source of sulfates justifies the need for, and the originality of, this research. After characterising the waste chemically and mineralogically, cement paste specimens were prepared in order to determine the durability of the newly designed eco-cements using Köch–Steinegger corrosion indices. The new hydration products, which might induce microstructural, mineralogical, or morphological decay in the specimens, were also analysed by comparing the samples before and after soaking in a sodium sulfate solution for different test periods. Respect to the results, the damage to pastes bearing 10% granite sludge (GS) is the same as observed in OPC, whilst the former exhibit a higher Köch-Steinegger corrosion rate (1.61) than both OPC and OPC+20GS. Soaking the pastes in sodium sulfate induces matrix densification due to ettringite formation and gypsum precipitation in the pores. Further to those results, at an optimal replacement ratio of 10%, these alternative, eco-friendlier materials can be used in the design and construction of non-structural cement-based (mortar or concrete) members exposed to an external source of sulfate.

ACS Style

Gabriel Medina; Isabel F. Sáez Del Bosque; Moisés Frías; María Isabel Sánchez De Rojas; César Medina. Sulfate Resistance in Cements Bearing Ornamental Granite Industry Sludge. Materials 2020, 13, 4081 .

AMA Style

Gabriel Medina, Isabel F. Sáez Del Bosque, Moisés Frías, María Isabel Sánchez De Rojas, César Medina. Sulfate Resistance in Cements Bearing Ornamental Granite Industry Sludge. Materials. 2020; 13 (18):4081.

Chicago/Turabian Style

Gabriel Medina; Isabel F. Sáez Del Bosque; Moisés Frías; María Isabel Sánchez De Rojas; César Medina. 2020. "Sulfate Resistance in Cements Bearing Ornamental Granite Industry Sludge." Materials 13, no. 18: 4081.

Journal article
Published: 30 June 2020 in Minerals
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This study analysed the fine particle (4AH13, C4AcH12) were identified during the pozzolanic reaction in CDW/lime system. Therefore, this type of waste can be reused as supplementary cementitious material with low-medium pozzolanic activity.

ACS Style

Moisés Frías; Raquel Vigil De La Villa; Sagrario Martínez-Ramírez; Lucía Fernández-Carrasco; Ernesto Villar-Cociña; Rosario García-Giménez. Multi-Technique Characterization of a Fine Fraction of CDW and Assessment of Reactivity in a CDW/Lime System. Minerals 2020, 10, 590 .

AMA Style

Moisés Frías, Raquel Vigil De La Villa, Sagrario Martínez-Ramírez, Lucía Fernández-Carrasco, Ernesto Villar-Cociña, Rosario García-Giménez. Multi-Technique Characterization of a Fine Fraction of CDW and Assessment of Reactivity in a CDW/Lime System. Minerals. 2020; 10 (7):590.

Chicago/Turabian Style

Moisés Frías; Raquel Vigil De La Villa; Sagrario Martínez-Ramírez; Lucía Fernández-Carrasco; Ernesto Villar-Cociña; Rosario García-Giménez. 2020. "Multi-Technique Characterization of a Fine Fraction of CDW and Assessment of Reactivity in a CDW/Lime System." Minerals 10, no. 7: 590.

Journal article
Published: 28 April 2020 in Journal of Cleaner Production
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Industrial waste and by-products are being widely used by the cement industry to enhance process efficiency and sustainability, in keeping with EU circular economy guidelines. This study assessed the properties of newly designed cements bearing fired clay-based C&DW against European standards. The findings showed that the blended cements met all the chemical, physical and mechanical requirements presently in place. They were also observed to qualify as type II and type IV cements, inasmuch as they contained waste that reacted with the calcium hydroxide released during cement hydration to generate the respective products. In addition, the inclusion of 10% or 20% C&DW yielded cements that could be classified as European standard strength classes 42.5 and 52.5. With a 30% C&DW, the resulting binder was a low heat of hydration cement. The present research confirmed the pozzolanic behaviour of waste in cement/C&DW systems, attested to by the reduction in both pore size and portlandite content. The new hydration products forming as a result of the pozzolanic reaction enhanced the flexibility and plasticity of the mortars prepared with the new cements relative to the mortars bearing unadditioned cement. Patent ES2512065 was awarded on the grounds of the results of this study.

ACS Style

Eloy Asensio; César Medina; Moisés Frías; María Isabel Sánchez de Rojas. Fired clay-based construction and demolition waste as pozzolanic addition in cements. Design of new eco-efficient cements. Journal of Cleaner Production 2020, 265, 121610 .

AMA Style

Eloy Asensio, César Medina, Moisés Frías, María Isabel Sánchez de Rojas. Fired clay-based construction and demolition waste as pozzolanic addition in cements. Design of new eco-efficient cements. Journal of Cleaner Production. 2020; 265 ():121610.

Chicago/Turabian Style

Eloy Asensio; César Medina; Moisés Frías; María Isabel Sánchez de Rojas. 2020. "Fired clay-based construction and demolition waste as pozzolanic addition in cements. Design of new eco-efficient cements." Journal of Cleaner Production 265, no. : 121610.

Journal article
Published: 15 April 2020 in Construction and Building Materials
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Photoluminescence Spectroscopy was used in order to further understand cement hydration within the first hours of hydration (1 until 1024 min). The results showed a formation of C-S-H initially after 1 min of hydration and a growing process up to 32 min. This growth process fluctuates in a sinusoidal trend with the crystallographic arrangement (structural order/disorder), allowing the monitoring of cement hydration. The same sinusoidal tendency was observed for other chemical compounds such as CaCO3, C-H as well and confirmed by Thermogravimetric Analysis and Infrared Spectroscopy. The same process was observed for calcium and silicon ions by the use of different techniques as Atomic absorption spectrometry and ionic conductivity, in order to validate the method. All the used methods show very satisfying alignment.

ACS Style

Valdemir dos Santos; Gustavo Henrique Denzin Tonoli; Gonzalo Mármol; Moisés Frías; Holmer Savastano. Monitoring the dynamics of Portland cement hydration through photoluminescence and other correlated spectroscopy techniques. Construction and Building Materials 2020, 252, 119073 .

AMA Style

Valdemir dos Santos, Gustavo Henrique Denzin Tonoli, Gonzalo Mármol, Moisés Frías, Holmer Savastano. Monitoring the dynamics of Portland cement hydration through photoluminescence and other correlated spectroscopy techniques. Construction and Building Materials. 2020; 252 ():119073.

Chicago/Turabian Style

Valdemir dos Santos; Gustavo Henrique Denzin Tonoli; Gonzalo Mármol; Moisés Frías; Holmer Savastano. 2020. "Monitoring the dynamics of Portland cement hydration through photoluminescence and other correlated spectroscopy techniques." Construction and Building Materials 252, no. : 119073.

Journal article
Published: 07 April 2020 in Cement and Concrete Composites
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The present research study analyses, for the first time, the viability of using thermally activated ichu grass as a supplementary cementitious material for the design of future eco-cements. To this end, the ichu ash resulting from the activation was characterised and its pozzolanic activity, the evolution of its mineralogical phases during the pozzolanic reaction and the physical-mechanical behaviour of the blended cementitious matrices were analysed. The results show that ichu ash exhibited high pozzolanic activity in a pure pozzolan/lime system as a consequence of its high reactive silica content. Conversely, its use in a pozzolan/cement system gave rise to negative effects due to the presence of important alkali contents in the ash (9.6% Na2O eq). The blended cements presented greater water demand, reduced capillary absorption, increased resistivity and lower mechanical properties (10–14%) as well as reduced average pore size than the reference mortar. These blended cement matrices comply with the physical-mechanical requirements established in the standards for the production of eco-cements.

ACS Style

Moisés Frías; Laura Caneda-Martínez; M. Isabel Sánchez de Rojas; Carlos Tenazoa; Elena Flores. Scientific and technical studies on eco-efficient binary cements produced with thermally activated ichu grass: Behaviour and properties. Cement and Concrete Composites 2020, 111, 103613 .

AMA Style

Moisés Frías, Laura Caneda-Martínez, M. Isabel Sánchez de Rojas, Carlos Tenazoa, Elena Flores. Scientific and technical studies on eco-efficient binary cements produced with thermally activated ichu grass: Behaviour and properties. Cement and Concrete Composites. 2020; 111 ():103613.

Chicago/Turabian Style

Moisés Frías; Laura Caneda-Martínez; M. Isabel Sánchez de Rojas; Carlos Tenazoa; Elena Flores. 2020. "Scientific and technical studies on eco-efficient binary cements produced with thermally activated ichu grass: Behaviour and properties." Cement and Concrete Composites 111, no. : 103613.

Journal article
Published: 16 November 2019 in Applied Clay Science
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One of the problems addressed by the scientific community in connection with cement matrix hydration is the evolution of hydrated phases under certain, primarily temperature-related, curing conditions. Such conditions are of utmost importance when the cement generates metastable hydrated phases that develop into stable phases, inducing substantial physical-mechanical changes in the matrix. One such instance arises during the pozzolanic reaction between metakaolinite and calcium hydroxide at 60 °C when metastable hexagonal phases co-exist with cubic stable phases. Such processes are well understood in the short and medium term (<5 years). Evolution at longer curing times has not been studied, however. This paper describes the evolution of the initial (stable and metastable) mineral phases in the metakaolinite / Ca(OH)2 reaction toward a zeolite-like phase after 15 year curing at 60 °C. An understanding of such mineralogical changes is scientifically significant, given their direct impact on the engineering properties of cement-based matrices.

ACS Style

M. Frías; R. Vigil De La Villa; S. Martínez-Ramírez; R. García-Giménez; M.I. Sánchez De Rojas. Mineral phases in metakaolin-portlandite pastes cured 15 years at 60 °C. New data for scientific advancement. Applied Clay Science 2019, 184, 105368 .

AMA Style

M. Frías, R. Vigil De La Villa, S. Martínez-Ramírez, R. García-Giménez, M.I. Sánchez De Rojas. Mineral phases in metakaolin-portlandite pastes cured 15 years at 60 °C. New data for scientific advancement. Applied Clay Science. 2019; 184 ():105368.

Chicago/Turabian Style

M. Frías; R. Vigil De La Villa; S. Martínez-Ramírez; R. García-Giménez; M.I. Sánchez De Rojas. 2019. "Mineral phases in metakaolin-portlandite pastes cured 15 years at 60 °C. New data for scientific advancement." Applied Clay Science 184, no. : 105368.

Journal article
Published: 01 November 2019 in Cement and Concrete Composites
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ACS Style

Laura Caneda-Martínez; César Medina; M. Isabel Sánchez de Rojas; Moisés Frías. Water transport in binary eco-cements containing coal mining waste. Cement and Concrete Composites 2019, 104, 1 .

AMA Style

Laura Caneda-Martínez, César Medina, M. Isabel Sánchez de Rojas, Moisés Frías. Water transport in binary eco-cements containing coal mining waste. Cement and Concrete Composites. 2019; 104 ():1.

Chicago/Turabian Style

Laura Caneda-Martínez; César Medina; M. Isabel Sánchez de Rojas; Moisés Frías. 2019. "Water transport in binary eco-cements containing coal mining waste." Cement and Concrete Composites 104, no. : 1.

Journal article
Published: 18 October 2019 in Construction and Building Materials
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The identification of new supplementary cementitious materials (SCMs) for use in blended cements is an area of major interest to the scientific community. The industry is equally keen for, given the vast amounts of raw materials and emission of large volumes of greenhouse gases involved in cement manufacture, it is under pressure to reduce its environmental footprint. This study explored hydration in blended cements bearing 20 wt% bottom ash (BBA) from three biomass-fired power plants. The results showed that the OPC-BBA blended and the neat OPC pastes exhibited similar degrees of hydration (~90%) and their C-S-H gels similar Al/Si ratios (0.08–0.09), while the mean chain length of the C-S-H gels was slightly higher in the former (5.15–5.30 for blended cement vs. 4.71 for OPC). The presence of pozzolanic activity in the BBA pastes, in turn, was confirmed by their lower CH and higher C-S-H gel content than would be expected on the grounds of the dilution of the amount of cement used.

ACS Style

I.F. Sáez del Bosque; J.M. Medina; M. Frías; M.I. Sánchez de Rojas; C. Medina. Use of biomass-fired power plant bottom ash as an addition in new blended cements: Effect on the structure of the C-S-H gel formed during hydration. Construction and Building Materials 2019, 228, 117081 .

AMA Style

I.F. Sáez del Bosque, J.M. Medina, M. Frías, M.I. Sánchez de Rojas, C. Medina. Use of biomass-fired power plant bottom ash as an addition in new blended cements: Effect on the structure of the C-S-H gel formed during hydration. Construction and Building Materials. 2019; 228 ():117081.

Chicago/Turabian Style

I.F. Sáez del Bosque; J.M. Medina; M. Frías; M.I. Sánchez de Rojas; C. Medina. 2019. "Use of biomass-fired power plant bottom ash as an addition in new blended cements: Effect on the structure of the C-S-H gel formed during hydration." Construction and Building Materials 228, no. : 117081.

Journal article
Published: 28 August 2019 in Powder Technology
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Blending supplementary cementitious materials with portland cement is one of the current strategies for producing more eco-efficient binders by lowering the energy consumption and CO2 emissions intrinsic to OPC manufacture. The effect of such additions on heat of hydration and energy performance is a subject of particular interest, for higher heat may reduce the service life of a concrete structure, whilst energy consumption per tonne of binder or megapascal may prove not to be energy-efficient. This paper explores the energy performance of granite sludge (GS) as an active addition to clinker and the effect of this by-product on heat of hydration and eco-efficiency. The findings show that maximum heating and total heat released are lower in the additioned than in the conventional material, with the difference widening at higher replacement ratios. At 35% GS, maximum heating was 36% lower than in OPC and total heat released 24% lower. Optimal energy performance is observed at ratios of 15% to 30% (both inclusive), with the experimental materials requiring less energy (−1.6 kW·h·t−1/MPa – 0.8 kW·h·t−1/MPa) than ordinary cement per megapascal (MPa) of strength. Cements with 15% to 30% granite sludge are consequently eco-efficient. With 15% GS they can be classified as ordinary (>270 J/g at 41 h), with 20% to 30% as low heat cements (<270 J/g at 41 h) and with 35% as very low heat cements (<220 J/g at 41 h).

ACS Style

G. Medina; I.F. Sáez del Bosque; M. Frías; M.I. Sánchez de Rojas; C. Medina. Energy performance and calorimetric behaviour of cements bearing granite sludge. Powder Technology 2019, 356, 517 -527.

AMA Style

G. Medina, I.F. Sáez del Bosque, M. Frías, M.I. Sánchez de Rojas, C. Medina. Energy performance and calorimetric behaviour of cements bearing granite sludge. Powder Technology. 2019; 356 ():517-527.

Chicago/Turabian Style

G. Medina; I.F. Sáez del Bosque; M. Frías; M.I. Sánchez de Rojas; C. Medina. 2019. "Energy performance and calorimetric behaviour of cements bearing granite sludge." Powder Technology 356, no. : 517-527.

Journal article
Published: 24 July 2019 in Construction and Building Materials
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This study explores the effect of replacing 10% and 20% of portland cement with BBA from three biomass-fired power plants on new design cement sorptivity, capillary absorption, electrical resistivity, drying shrinkage, expansion and heat of hydration. The findings show that although this addition induces an increase in water uptake due to its effect on the pore system, it does not compromise cement quality, which is international recommendation-compliant. As these new cements have the same or higher resistivity than the reference material, they are at least as corrosion-resistant as OPC. Binders bearing BBA exhibit less shrinkage and swelling than conventional cement and their peak heating, rate of heat release and total heat flow values are lower, particularly at the higher replacement ratio. The conclusion drawn is that the durability of the recycled product, which qualifies as a strength class 42.5, type II/A cement, is unaffected by the partial replacement of clinker with BBA.

ACS Style

J.M. Medina; I.F. Sáez del Bosque; Moises Frías; M.I. Sánchez de Rojas; C. Medina. Durability of new blended cements additioned with recycled biomass bottom ASH from electric power plants. Construction and Building Materials 2019, 225, 429 -440.

AMA Style

J.M. Medina, I.F. Sáez del Bosque, Moises Frías, M.I. Sánchez de Rojas, C. Medina. Durability of new blended cements additioned with recycled biomass bottom ASH from electric power plants. Construction and Building Materials. 2019; 225 ():429-440.

Chicago/Turabian Style

J.M. Medina; I.F. Sáez del Bosque; Moises Frías; M.I. Sánchez de Rojas; C. Medina. 2019. "Durability of new blended cements additioned with recycled biomass bottom ASH from electric power plants." Construction and Building Materials 225, no. : 429-440.

Journal article
Published: 23 July 2019 in Cement and Concrete Composites
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The use of biomass to produce electric power and heat will intensify in the years to come, in pursuit of sustainable growth. Stockpiling the vast amounts of fly and bottom ash generated in that process wastes resources and has an adverse impact on the environment. The viability of bottom ash as a supplementary cementitious material in new eco-efficient cements is studied, including its effect on binder chemical, rheological, mechanical and microstructural properties. The findings show that these additions induce improvements in later age mechanical performance relative to conventional mortars. An ANOVA conducted to determine the impact of waste type, replacement ratio and curing time on compressive and flexural strength reveals that the latter two have a significant effect on mechanical properties. The new cements meet the requirements laid down in EN 197-1 for CEM II/A and CEM IV/A cements, making them apt for use in construction.

ACS Style

J.M. Medina; I.F. Sáez del Bosque; M. Frías; M.I. Sánchez de Rojas; C. Medina. Design and properties of eco-friendly binary mortars containing ash from biomass-fuelled power plants. Cement and Concrete Composites 2019, 104, 103372 .

AMA Style

J.M. Medina, I.F. Sáez del Bosque, M. Frías, M.I. Sánchez de Rojas, C. Medina. Design and properties of eco-friendly binary mortars containing ash from biomass-fuelled power plants. Cement and Concrete Composites. 2019; 104 ():103372.

Chicago/Turabian Style

J.M. Medina; I.F. Sáez del Bosque; M. Frías; M.I. Sánchez de Rojas; C. Medina. 2019. "Design and properties of eco-friendly binary mortars containing ash from biomass-fuelled power plants." Cement and Concrete Composites 104, no. : 103372.

Journal article
Published: 01 May 2019 in International Journal of Concrete Structures and Materials
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Non-fossil alternative fuels from biomass (agro-industrial, forestry and fodder plants) focus on getting cleaner, cheaper and more environmentally friendly energy sources directly related to the sustainable development of future societies. The resulting ash produced from the biomass calcination is a viable alternative for use as supplementary cementing materials in the construction industry. This study explores the scientific knowledge of calcium-silicate hydrate (C-S-H) gel formation during pozzolanic reaction between the biomass ash and calcium hydroxide through nuclear magnetic resonance technique with two different types of elephant grass ash that have different microstructure. The ash with the highest initial percentage of Q4 and Q3 units was found to react most actively and give rise to gels with the greatest inter-tetrahedral connectivity. In contrast, ash with higher content of total SiO2, exhibited lower reactivity and the C-S-H gel formed is characterised by low inter-tetrahedral connectivity from the earliest ages. Evaluation of C-S-H gel by nuclear magnetic resonance (NMR), as main hydrated phase for the engineering properties, revealed the potential of this tool to determine the effectiveness of this type of grass as raw material in cementing matrices through the evolution of the microstructure of the gel C-S-H formed.

ACS Style

Sagrario Martínez-Ramírez; Moisés Frías; Erika Y. Nakanishi; Holmer Savastano. Pozzolanic Reaction of a Biomass Waste as Mineral Addition to Cement Based Materials: Studies by Nuclear Magnetic Resonance (NMR). International Journal of Concrete Structures and Materials 2019, 13, 31 .

AMA Style

Sagrario Martínez-Ramírez, Moisés Frías, Erika Y. Nakanishi, Holmer Savastano. Pozzolanic Reaction of a Biomass Waste as Mineral Addition to Cement Based Materials: Studies by Nuclear Magnetic Resonance (NMR). International Journal of Concrete Structures and Materials. 2019; 13 (1):31.

Chicago/Turabian Style

Sagrario Martínez-Ramírez; Moisés Frías; Erika Y. Nakanishi; Holmer Savastano. 2019. "Pozzolanic Reaction of a Biomass Waste as Mineral Addition to Cement Based Materials: Studies by Nuclear Magnetic Resonance (NMR)." International Journal of Concrete Structures and Materials 13, no. 1: 31.