This study presents the development and optimisation of a standardised rheological test method based on rotational rheometry for the characterisation of cementitious mixtures designed for 3D printing. Tests were performed using a Discovery HR-20 rotational rheometer (TA Instruments, New Castle, DE, USA) equipped with a concentric-cylinder cup-and-paddle geometry. A high-early-strength Portland cement (ASTM C1157 Type HE) with a constant water-to-cement ratio (w/c) of 0.35 was employed. The methodological framework comprised five sequential stages: (i) assessment of the pre-conditioning effect; (ii) standardisation of the static shear test; (iii) optimisation of pre-conditioning parameters; (iv) standardisation of the dynamic shear test; and (v) evaluation of the influence of sample volume. Optimal conditions were determined as follows: for pre-conditioning, a shear rate of 50 s−1, holding time (Ht) of 30 s, and rest period of 180 s; for the static shear test, a shear rate range of 0.05–0.10 s−1 with a Ht of 60 s; for the dynamic shear test, a 30 s ramp up/down, maximum shear rate of 100 s−1, and Ht of 90 s. An optimal sample volume ranging between 150 and 175 mL was established. The proposed method represents a robust and reproducible experimental protocol for evaluating, comparing, and optimising the rheological behaviour of cementitious mixtures using rotational rheometry, providing a reliable tool for the formulation of mixtures tailored to additive manufacturing or 3D printing processes.

Self-compacting concrete offers significant advantages in terms of ease of placement, reduced construction time, and improved quality control. However, its production typically requires higher amounts of cement and chemical admixtures. At the same time, the valorisation of construction and demolition waste has emerged as a key strategy to reduce environmental impacts and promote circular economy practices in the construction sector. In accordance with the above, this study presents the design and evaluation of a hybrid SCC incorporating ceramic waste and recycled aggregates, combined with an alkali-activated cementitious matrix as a sustainable alternative. Two concrete systems were developed in this study: a reference mixture containing Portland cement and ceramic filler, and a sustainable mixture incorporating 85

Palm oil production generates substantial amounts of waste, including palm oil fuel ash (POFA), which is frequently disposed of without further utilization. In the present study, the viability of POFA as a precursor in the production of alkali-activated Portland blended cement was assessed. The material was synthesized from POFA and waste clay brick powder (WCBP) in varying proportions (45, 55, and 65% as replacement of POFA). Additionally, 10% of Portland cement (OPC) was incorporated into all mixes, in order to avoid the necessity of thermal curing. Potassium hydroxide (4, 6, and 8%) and a solution of KOH and potassium silicate (Ms = 0.63 and 1.15) were utilized as alkali-activators. The hybrid mortar was produced by incorporating natural and glass sand (WG) as fine aggregate. The chemical and mineralogical composition of the precursors was analyzed by XRF and XRD, while SEM was used to characterize their morphology. The findings demonstrated that HM with a composition of 25% POFA, 65% WCBP, and 10% OPC, activated with a solution modulus of Ms = 0.63, and incorporating natural sand has higher compressive strength (12.39 MPa) than those with WG (9.12 MPa). However, the flexural strength performance of the latter was slightly superior. The mortar furthermore exhibited low thermal conductivity (0.91 W/m·K) and diffusivity (0.59*10−6 m2/s), along with a high specific heat capacity (1.57 kJ/kg.K). These properties suggest its potential application as an insulating non-structural material in the construction sector. This study demonstrates the feasibility of transforming agro-industrial waste into sustainable construction materials, in accordance with the principles of the circular economy.

A bacterial self-healing system for 3D printing of mortars to mitigate shrinkage cracking and improve the durability of printed elements is presented. In this study, the impacts of incorporating Bacillus subtilis (BS) cultures and calcium lactate (CL), optimizing their concentrations, and using biocarriers (natural sand (NS), recycled sand (RS) and bentonite (Ben)) for the biomineralization process were evaluated. The optimal system was subsequently implemented in mortars for 3D printing and evaluated under real exposure conditions (weathering). The results revealed that a bacterial concentration of 1 × 108 cells/ml and a CL content of 4% resulted in the greatest precipitation of CaCO3, achieving an adequate balance between metabolic activity and mechanical performance. The combination of RS and Ben as biocarriers significantly improved the bacterial survival and crack sealing efficiency rates because of their high porosity levels and nucleation capacities. The developed self-healing mortar (Mix-6–3D) exhibited adequate rheological properties for 3D printing, along with a reduction in porosity and increases in mechanical strength (compression and flexural strength). Additionally, the printed walls exposed to weathering (60 days) exhibited shrinkage cracks that were subsequently sealed significantly by biomineralization. Taken together, the results reveal the feasibility of integrating bacterial self-repair systems into cementitious mixtures for 3D printing processes, constituting an effective strategy for improving the durability of printed structures.

Rice husk ash (RHA), from a rice mill in the Cauca Valley region, was used in the synthesis of alkaline silicates, which were validated in the production of precipitated silica and geopolymers. Rice husk ash (RCA) was obtained from chemical (TQ) and thermal (TT) treatments of the CA and characterized by means of techniques such as electron microscopy, thermogravimetric analysis and X-ray diffraction to determine its quality. The results showed that CCA-TQ (density of 2.03 g/cm3) presents higher amorphous silica content and higher specific area compared to CCA-TT (density of 2.13 g/cm(3)), however, in both cases they contain more than 94% of SiO2 in their composition. The application of optimization of hydrothermal synthesis variables (NaOH/SiO2, H2O/SiO2 molar ratios, temperature, and time) to the CCA produced alkaline silicates with high SiO2 content and low alkalinity, which are suitable for the generation of precipitated silica with 98% purity and geopolymers that can reach compressive strengths up to 37.9 MPa, being 45.8% higher than geopolymers produced with a national commercial silicate.

El control de las propiedades de las mezclas de impresión 3D aptas para emplear en procesos constructivos es un gran reto para la ingeniería y la ciencia de los materiales, ya que se requiere el uso de aditivos para facilitar su extrusión e impresión capa a capa. El objetivo fue analizar los diseños de mezclas reportados en la literatura científica relacionados con el uso de aditivos. La metodología empleada consistió en la revisión en la base de datos Scopus sobre aditivos utilizados en mezclas basadas en cemento Portland, geopolímeros y arcillas. Los tipos de aditivos incluyen: 1) aditivos superplastificantes y reductores de agua que influyen sobre la fluidez, límite elástico y resistencia mecánica, favoreciendo la bombeabilidad y capacidad de extrusión; 2) aditivos modificadores de la viscosidad y propiedades reológicas, que afectan el esfuerzo de fluencia estático y dinámico, la tixotropía, y contribuyen al aumento de la edificabilidad y calidad de la impresión; y 3) aditivos reguladores de fraguado y endurecimiento, que modifican el proceso de hidratación del cemento, teniendo una influencia directa sobre el tiempo abierto (open time) de las mezclas. El análisis de los resultados permitió identificar las propiedades reológicas críticas que deben ser optimizadas durante el diseño de la mezcla, como la viscosidad, la tixotropía y el tiempo de extrusión. Además, se destaca que, aunque los estudios sobre estos aditivos y sus efectos son abundantes, persisten limitaciones en la evaluación detallada de sus interacciones y su impacto a largo plazo en la durabilidad de las estructuras impresas. Se concluye la importancia de considerar estos factores al seleccionar los aditivos necesarios para mezclas de impresión 3D, especialmente cuando se usan materiales alternativos como geopolímeros y arcillas. La información reportada en esta revisión es fundamental para diseñadores, investigadores y productores interesados en utilizar la manufactura aditiva de materiales de construcción.

One of the most significant challenges for 3D printing of construction elements from cementitious materials is the control of cracking caused by various contraction–shrinkage mechanisms, such as drying, chemical, plastic and autogenous shrinkage. This study addresses the effects of incorporating fine aggregates (maximum size ≤ 1.18 mm), both natural and recycled, as well as short (6 mm long) polypropylene (PP) fibres on the control of cracking in cementitious mixtures based on Portland cement. Admixtures and/or mineral additions (modifiers), such as metakaolin, micro-silica, calcium carbonate, and fine powders obtained from construction and demolition wastes were used in the mixtures. Mini-slump, flow rate and buildability tests were used to characterize the mixtures in their fresh state. Extrudability was evaluated using laboratory-scale 3D printing tests conducted with a plunger–piston extrusion system. It was demonstrated that the physical characteristics of the aggregates directly influence the extrusion capacity. Mixtures containing natural aggregates exhibited greater fluidity and lower water demand than those containing recycled aggregates. The results indicated that the maximum allowable volume of fibres was 0.75%. To evaluate the cracking susceptibility of the mixtures, both with and without reinforcement, hollow beams composed of seven layers were printed, and subsequently the elements were exposed to the outdoor natural environment and inspected for a period of 90 days. The inclusion of the PP fibres effectively prevented the occurrence of fissures and/or cracks associated with shrinkage phenomena throughout the inspection period, unlike in unreinforced mixtures, which cracked after 14 days of exposure to the environment.

Rice husk (RH), an abundant agro-industrial by-product, was processed via controlled milling and calcination to obtain rice husk ash (RHA), from which sodium silicate (SS) was prepared by alkaline digestion. SS served as the precursor to synthesize silica aerogels via a sol-gel route under ambient pressure. The aerogels were characterized by XRF, XRD, FTIR, UV-Vis, TGA-DTA, BET, helium pycnometry, SEM, TEM and zeta potential. The resulting materials exhibited mesoporosity, high specific surface area (>470 m(2)/g), notable porosity (>90 %), and a significant density of surface functional groups and structural defects. Antibiotic removal was evaluated for amoxicillin (AMX) and erythromycin (ERY) in water at neutral pH, using an adsorbent dose of 1 g center dot L-1, initial concentrations of 1-20 mg center dot L-1, UV irradiation (6 W), and exposure times of 10-60 min. The RHA-derived aerogels achieved up to similar to 90 % AMX removal (q(e) = 9.0 mg center dot g(-1)) and similar to 60 % ERY removal (q(e)= 8.0 mg center dot g(-1)) within 60 min. The enhanced performance is primarily attributed to defect-driven adsorption, while UV pre-irradiation may contribute to the activation of surface sites as a complementary mechanism. These findings position RHA-derived silica aerogels as low-cost, sustainable materials for pharmaceutical pollutant removal, highlighting the role of surface functionality and defect-mediated interactions in water remediation.

Cascarilla de arroz (CA), proveniente de una arrocera de la región del Valle del Cauca, fue empleada en la síntesis de silicatos alcalinos, los cuales fueron validades en la producción de sílice precipitada y geopolímeros. La Ceniza de cascarilla de arroz (CCA) fue obtenida a partir de tratamientos químicos (TQ) y térmicos (TT) de la CA, y caracterizada por medio de técnicas como microscopia electrónica, análisis termogravimétrico y difracción de rayos X para conocer su calidad. Los resultados mostraron que la CCA-TQ (densidad de 2,03 g/cm3) presenta mayor contenido de sílice amorfa y mayor área específica en comparación de CCA-TT (densidad de 2,13 g/cm3), sin embargo, en ambos casos contienen más de 94% de SiO2 en su composición. La aplicación de optimización de variables de síntesis hidrotermal (relaciones molares NaOH/SiO2, H2O/SiO2, Temperatura, y Tiempo) a las CCA produjo silicatos alcalinos con alto contenido de SiO2 y baja alcalinidad, los cuales son aptos para la generación de sílice precipitada con 98% de pureza y geopolímeros que pueden alcanzar resistencias a compresión de hasta 37.9 MPa, siendo un 45,8% superior a geopolímeros producidos con un silicato comercial nacional.

In recent years, there has been great interest in sustainable construction, which has led to an increased interest in 3D printing or additive manufacturing. However, the use of this technique with conventional materials is not enough to reduce the large environmental impact generated by the construction sector. Although most of the research and advances are focused on the 3D printing of Portland concrete, this review has been oriented towards the 3D printing of building materials based on soils and clays, which can provide an affordable (as it is a locally available material in many regions of the planet), environmentally sustainable, and low-cost approach, which is highly beneficial for housing construction. This paper has been oriented towards the search of scientific literature and prototypes that have been elaborated using ancestral materials, such as soil-clay-sand-sand-fibers like straw and water, for the elaboration of constructive pieces such as 3D printed walls or adobes. The objective of this paper is to close the gap on the use of mixtures based on soils, which, although they seem to have been fully studied for several centuries, to date their application in 3D printing is reduced. Readjustments in properties of soil mixtures such as fluidity for pumping or extrusion, buildability and good working time are variables that are reported in this paper. In addition, this review describes the mixtures that have been developed for 3D printing from soils and clays, and the main characteristics that have been found. Finally, the challenges that still remain for the blends to be applied on a massive industrial scale are presented.

En los últimos años, se ha generado gran interés en la construcción sostenible, lo que ha llevado a un mayor interés en la impresión 3D o manufactura aditiva. Sin embargo, el uso de esta técnica con materiales convencionales no es suficiente para disminuir el gran impacto ambiental que genera el sector de la construcción. Aunque la mayoría de las investigaciones y avances están centralizadas en la impresión 3D de concreto Portland, esta revisión se ha trabajado orientada hacia la impresión 3D de materiales de construcción basados en suelos y arcillas, los con los cuales se puede proporcionar un enfoque asequible (ya que es un material localmente disponible en muchas regiones del planeta), sostenible ambientalmente, y con bajo costo, lo cual es altamente beneficioso para la construcción de viviendas. Este documento se ha orientado hacia la búsqueda de literatura científica y prototipos que se han elaborado utilizando materiales ancestrales, como son suelos-arcillas-arena-fibras como paja y agua, para elaboración de piezas constructivas tipo muros o adobes impresos en 3D. El objetivo de este documento es cerrar la brecha sobre la utilización de mezclas basadas en suelos, que, aunque parezcan totalmente estudiadas por varios siglos, a la fecha su aplicación en impresión 3D es reducida. Reajustes en propiedades de las mezclas de suelos como la fluidez para el bombeo o extrusión, edificabilidad y buen tiempo de trabajo, son variables que se reportan en este documento. Además, en esta revisión se describen las mezclas que han sido desarrolladas para impresión 3D a partir de suelos y arcillas, y las principales características que se han encontrado. Finalmente, se presentan los desafíos que aún persisten para que las mezclas puedan aplicarse a una escala industrial masiva.

This study explores the use of two industrial residues: spent bleaching earth (SBE) and glass sediment (GS), as alternative raw materials in the production of ceramic materials from fired clay. The mixtures incorporating 0%, 10%, 30%, and 50% by weight of these residues, were examined. The impact of quantity and type of waste on product properties (density, water absorption, compressive strength, and thermal conductivity) was assessed against NTC 4205 standards. Incorporating 50% SBE reduced thermal conductivity by 35%, but increased porosity affected compressive strength. Glass sediment incorporation increased thermal conductivity but surpassed pure clay in mechanical behavior. The triphasic mix (20% GS, 10% SBE with lime) demonstrated optimal mechanical performance, meeting fired clay masonry unit standards. An eco-product prototype based on this mix was successfully manufactured, affirming that industrial waste is a viable alternative raw material, yielding ceramic materials with properties meeting or surpassing Colombian construction industry standards.

This paper analysed the possibility of using recycled powders (<75 µm) and recycling fine aggregates (<1.18 mm) obtained during the crushing and grinding of concrete waste (CoW), ceramic waste (CeW) and red clay brick waste (RCBW) when designing cementitious pastes and mortars for 3D printing. The effects of the type of powder (CoW-powder, CeW-powder and RCBW-powder) and of the liquid/solid (L/S) ratio on the mixture properties in the fresh and hardened states were studied. In the fresh state, the level of flowability (mini-slump), flow index (flow table), buildability and setting time characteristics of the cementitious pastes were evaluated. In addition, the rheological behaviour was analysed through a rotational rheometer. In the hardened state, the compressive strength was determined at 3, 7, 28 and 90 days. The effects of the type of recycled fine aggregate (RFA − CoW, RFA − CeW and RFA − RCBW) were evaluated for mortars with a cement:aggregate ratio of 1:0.5. Based on the results obtained, the most suitable mixtures were selected to carry out 3D printing tests on a laboratory scale. From the 3D printing of beam-type specimens, it was possible to determine the flexural and compressive strengths (28 days) of the selected mixtures. The results obtained validated the possibility of using recycled powders (CoW, CeW and RCBW) to replace 30 % of ordinary Portland cement (OPC) and to incorporate 100 % recycled fine aggregates in the design of cementitious materials (pastes and mortars) for 3D printing. In this regard, the recycled powders and recycled fine aggregates increase the buildability and thixotropy of cementitious mixtures. With an adjustment in the L/S (liquid/solids) ratio, their application in 3D printing becomes feasible. This alternative for the use of powders and fine aggregates from construction and demolition waste (CDW) could be considered a contribution towards the sustainability of the sector and the implementation of a circular economy.

La utilización de cementantes alternativos y el aprovechamiento de residuos industriales, como materiales suplementarios o agregados en la producción de concretos y elementos estructurales que garanticen buenas prestaciones mecánicas, disminución de la carga muerta y un elevado confort térmico, están en concordancia con los principios de economía circular en el sector de la construcción. Por ello, el objetivo de esta investigación fue desarrollar un cemento híbrido basado en la activación alcalina con sulfato de sodio (NS) de una mezcla de ceniza volante (CV), humo de sílice (HS) y cemento portland de uso general (OPC, por sus siglas en inglés), en proporciones (CV+HS)/OPC del 70/30 %. La metodología empleada consistió en desarrollar el cementante hibrido, el cual fue clasificado como de moderado calor de hidratación (tipo MCH), y posteriormente utilizarlo, en proporciones de 500 kg/m3 y 600 kg/m3 para producir concretos estructurales incorporando en la mezcla agregados reciclados gruesos (AGR) y finos (AFR), obtenidos a partir de residuos de construcción y demolición (RCD). La mezcla 600 R a 28 días de curado alcanzó un valor de 18,9 MPa, y reporto un módulo de elasticidad de 27 GPa. Este concreto se validó en la producción de bloques perforados estructurales y, con el fin de mejorar el confort térmico de los concretos, se realizó sustitución del 10 % y 20 % en volumen de agregado fino reciclado por corcho reciclado. La introducción de corcho en la mezcla, aunque redujo la resistencia a compresión del bloque en un 29 %, permitió disminuir la conductividad térmica en un 32 %. Basado en los resultados obtenidos, se concluye que el uso de un 10 % en volumen de corcho como reemplazo del agregado fino en la mezcla de concreto híbrido permite obtener un bloque estructural con características de confort térmico. Las proporciones de la mezcla considerada óptima fueron de 52,5 CV+17,5 HS+30 OPC, 4 % NS, 70 % AGR, 20 % AFR, y 10 % corcho.

Cementitious mixtures for 3D printing require specific rheological properties in the fresh state, which is why it is necessary to incorporate admixtures and/or mineral additions (modifiers) into such mixtures. The objectives of this article were to compare the effects of bentonite (Ben) (1 %-5 %) and mineral additions, such as metakaolin (MK) (5 % and 10 %), microsilica (MS) (5 % and 10 %) and calcium carbonate (Ca) (5 % and 10 %), on the rheological properties in the fresh state and to determine the printability of cementitious mixtures based on ordinary Portland cement (OPC). Among the rheological properties, the static yield stress (tau 0), flow behavior, viscosity (eta) and thixotropic of the mixtures were evaluated. Complementarily, the properties of materials in the fresh state, such as the settlement (minislump), flow rate (flow table) and buildability, were determined. The printability was evaluated through laboratory-scale additive manufacturing tests by printing from a hollow cylinder (unfilled) 50.8 mm in diameter and 208 mm in height (approximate to 52 layers). The results showed that the incorporation of Ben between 1 % and 5 % had a significant effect on the rheological properties of the mixtures in the fresh state, increasing tau 0 to 203.8 % (5 % Ben) and structural regeneration (thixotropy) to 98.5 %. Ben decreased the fluidity of the mixtures while significantly increasing the buildability. Among the mineral additions used, MS and MK increased the rheological properties of the mixtures as a function of the amount incorporated (5 % and 10 %, respectively), while Ca had a fluidifying effect on the mixtures, thereby affecting the buildability during the 3D printing process. This phenomenon was corrected by simultaneous adding 3 % Ben. The results obtained were considered a starting point for the design of OPC-based 3D printing mixtures with these modifiers (Ben, MK, MS and Ca).

Portland cement (OPC) has been commonly used in concrete production. However, it has been questioned for its excessive consumption of natural resources and energy, and the high emissions generated in its production process. On the other hand, the construction sector also contributes to the environmental impact by generating construction and demolition waste (CDW) that is not used. This has motivated the development of alternative cements with a lower carbon footprint and the reuse of CDW to comply with the Sustainable Development Goals (SDG) and the principles of Circular Economy. Here we demonstrated the feasibility of producing alkali-activated hybrid concrete using a mixture of powders from CDW grinding. As alkaline activators, we used a solution of sodium hydroxide and silicate (NaOH+Na2SiO3) and sodium sulfate (Na2SO4). The OPC proportion was 10% and 30%, respectively. For an integral CDW use, we used 100% recycled aggregates. The designed concrete had the mechanical strength required by the NSR-10 Seismic Resistant Standard to be classified as structural. Additionally, its global warming potential (GWP) was 68% lower than that of an OPC-based concrete with the same specification. This concrete was used in the production of precast elements such as solid blocks, vertical perforation blocks, and paving stones that met the specifications required by the Colombian technical standards.

Metal oxide (MOx) gas sensors have attracted considerable attention from both scientific and practical standpoints. Due to their promising characteristics for detecting toxic gases and volatile organic compounds (VOCs) compared with conventional techniques, these devices are expected to play a key role in home and public security, environmental monitoring, chemical quality control, and medicine in the near future. VOCs (e.g., acetone) are blood-borne and found in exhaled human breath as a result of certain diseases or metabolic disorders. Their measurement is considered a promising tool for noninvasive medical diagnosis, for example in diabetic patients. The conventional method for the detection of acetone vapors as a potential biomarker is based on spectrometry. However, the development of MOx-type sensors has made them increasingly attractive from a medical point of view. The objectives of this review are to assess the state of the art of the main MOx-type sensors in the detection of acetone vapors to propose future perspectives and directions that should be carried out to implement this type of sensor in the field of medicine.

The environmental impact of construction demolition wastes (CDW) is high since it represents between 45 and 65 % of the solid wastes that reach landfills. These wastes can be concrete, bricks, ceramic, wood, glass, plastic, metals, and others. Specifically, the glass wastes are considered 100 % recyclable, nevertheless, in the United States it is estimated that the recycling rate is only 33.1 %, compared to the European average of 42.6 %. In this research, the use of waste glass in the synthesis of geopolymers from different precursors such as brick wastes (BW), ceramic tiles wastes (CW) and metakaolin (MK) was evaluated. Glass wastes were studied as: (i) precursor, (ii) alkaline activator and (iii) fine aggregate (FG). The results showed that, in the pastes, the best strength is reached when they are made with SS alkali activator, reaching compressive strength above 25 MPa; in pastes with 50 wt% glass as precursor reaches strength up to 15 MPa, but when using 100 wt% glass as solid activator the strength does not exceed 1 MPa. Calorimetry results showed that the use of glass (at 25 degrees C) does not release enough heat. The formation of hybrid reaction gels (N,CASH) were identified in the CW-SS activated pastes. However, in the mortars made with G and FG, an improvement in strength was found compared to their respective pastes, which is attributed to the fact that the microns G particles that did not react with the alkaline activation can act as fillers, allowing them to support higher loads. Finally, mortars with strengths of similar to 10-15 MPa were successfully applied as render mortar and in the elaboration of architectonic tiles.

The materials used for the architectural shielding of civil structures must protect against impacts, explosions, and fire. However, Portland cement-based concrete (OPC) degrades when exposed to high temperatures. These requirements and the limitations of OPC promotes research on alternative concretes for ballistic and fire protection uses. Therefore, this research analyzes the potential application of slurry infiltrated fiber concrete (SIFCON) in constructing structures resistant to both fire and ballistic impacts. The SIFCON is based on the alkaline activation of ceramic waste (Ce) with the incorporation of short steel fibers (38 mm). Ballistic tests were conducted using 9 mm caliber ammunition with two types of weapons: the CZ 10P pistol (5 impacts) and the Beretta CX4 submachine gun (1 burst of 3 impacts). The results indicate that SIFCON-Ce exhibits greater thermal stability and fire resistance compared to SIFCON-OPC. Specifically, the residual flexural strength at 900 degrees C was 75.1 % for SIFCON-Ce and 46.1 % for SIFCON-OPC. Additionally, the inclusion of steel fibers enhanced the material's ability to resist impacts (9 mm caliber) generated by the CZ 10P pistol and Beretta CX4 submachine gun, leading to the classification of SIFCON as a suitable material for architectural armor, with protection levels of type II-A and IIIA according to the NIJ 0108.01 standard.

This review article includes a description of additive manufacturing from its advantages and opportunities for the construction sector, highlighting the definition of a design methodology for cementitious material mixes suitable for 3D printing and the properties required of them. Included among the materials analyzed are conventional ones based on Ordinary Portland Cement (OPC) and non-conventional ones, with alkali-activated materials (geopolymers) to the fore. In United States, Europe and Asia this technology has interesting construction projects, however, in Latin America, 3D printing is still in the experimental phase, so it can be considered as a technology that is in the process of being adopted. The results obtained in the development and research phase in different countries such as Mexico, Brazil, Chile, Colombia, Guatemala, Peru, among others, are promising and it is projected as an industrial reality in the near future. This paper presents the main challenges and opportunities in implementing additive manufacturing.