Limestone Filler Research Articles

Investigating the environmental and mechanical properties of sustainable asphalt mastic solutions for road flexible pavements

The circular economy is restorative in nature, and it aims to maintain the utility of products, components and materials for as long as possible while also retaining their value. It thus minimizes the need for new inputs of virgin materials and energy, while reducing environmental pressures linked to resource extraction, emissions and waste management. The research focus on the investigation of an innovative procedure for reusing the jet grouting waste (JGW) obtained from soil consolidation activities to produce high-performing sustainable road asphalt mastics (filler plus neat bitumen). The mastics under analysis were made at three different filler over bitumen ratios of 0.5, 1 and 1.5, in particular six were obtained with neat bitumen and other six at the same f/b ratios mixed with an aged bitumen after the RTFO procedure. The rheological properties of the mastics were investigated using a dynamic shear rheometer, and the performance of the innovative mastics was compared with that of the neat bitumen and traditional mastics made up of bitumen and limestone filler (LF). The main results of the initial step of the analysis showed that, at temperatures from 0 to 30°C, the shear moduli of the mastics containing JGW (MJGW) averaged 30% higher than the limestone mastic (ML) blended with an f/b ratio of 0.30. The life-cycle assessment impact category indicators were then calculated, highlighting the considerable environmental benefits of the innovative hot asphalt mastics in question. The primary outcomes showed that compared with the asphalt mastics containing LF, the asphalt mastic solution lowered terrestrial ecotoxicity by 53% and the freshwater eutrophication potential by up to 97%.

Comparison of density of asphalt concrete mixture with fly ash and limestone filler

The road construction industry is one of the strategic industries of Ukraine. Currently, the issue of quality and availability of basic building materials for road construction is particularly acute, which is directly related to its high material intensity. Known stocks of conditioned raw materials that could be used as components of asphalt concrete are constantly decreasing, so it is necessary to look for alternative sources of raw materials for construction materials and study the possibility of their use. In this regard, the most effective use of local raw materials is the use of industrial production waste, which can become one of the solutions to the problem of the lack of raw materials of inorganic origin. In Ukraine, about 30% of all electricity is generated by burning solid fuels such as coal, oil shale, and peat. There are about 15 operating thermal power plants in Ukraine, which generate about 5-6 million tons of ash and slag waste per year. Thus, the fuel and energy complex waste generated at thermal power plants is a huge accumulation of ash in the form of dusty residues and lumpy sludge, as well as various ash and slag mixtures. These products of high-temperature treatment (1200-1700 °C) of the mineral part of the fuel are widely used in many countries and given the global trend towards an increase in the share of the secondary market for the use of secondary industrial products, an increase in the rate of their processing in Ukraine should be predicted.

Uso de residuos mineros en la producción de hormigones asfálticos

Los residuos mineros constituyen un serio problema ambiental en todos los países donde se realice explotación minera. Teniendo en cuenta la gran cantidad de residuos mineros procedentes de la explotación y procesamiento de las lateritas niquelíferas en Cuba, el trabajo toma como hipótesis que, si demuestra la posibilidad real de emplear dichos residuos como sustituto parcial de los áridos en la producción de hormigón asfáltico, se pudiera disminuir el impacto ambiental negativo que provocan los mismos en los lugares donde se encuentran depositados. El objetivo del trabajo es demostrar la aptitud de los residuos mineros procedentes de presas de los procesos de beneficio de níquel y cobalto en los municipios de Moa y Nicaro, en la provincia de Holguín, Cuba. Tales residuos proceden de procesos de Lixiviación Carbonato Amoniacal y Lixiviación Ácida Presurizada. La metodología de investigación partió de la toma de muestras representativas en las presas de residuos, su posterior caracterización física, química y mineralógica, se realizó la caracterización de los áridos y cemento asfáltico utilizados en las mezclas objeto de estudio. Se realizó el diseño de las mezclas de hormigón asfáltico mediante el método Marshall. Posteriormente se hizo un análisis comparativo del comportamiento de los hormigones asfálticos realizados con fíller calizo y fíller de los residuos mineros investigados. Se demostró, a partir de ensayos de laboratorio, que es posible la fabricación de hormigones asfálticos con el empleo de residuos mineros del procesamiento de las lateritas niquelíferas de Moa y Nicaro, cumpliendo satisfactoriamente con los parámetros técnicos exigidos.

Influence of limestone filler on technological parameters of mixtures for 3D concrete printing

This paper focuses on the use of fine-ground limestone filler (LP) from Rakke Limestone production (R0) as SCM in 3D Concrete Printing (3DCP) mixtures to partially replace OPC. Important technical aspects of the mixture, such as flowability, extrudability and buildability, are explored and investigated. To properly deploy 3DCP, two conflicting material qualities must be balanced. On one hand, the mix must be pumpable enough to be delivered by hose from the mixer to the nozzle, and on the other, after extrusion, the mix must retain its shape without any supporting formwork while bearing the load from succeeding filaments. In cooperation with MIRA Ehitusmaterjalid OÜ experimental mixtures with various OPC replacements were produced, which were printed on a gantry printer at Tallinn University of Applied Sciences. A comparison was made using industrial mixtures from Weber Saint-Gobain - Beamix 145-2 and ESL. LP has been found to enhance mix printability despite higher water requirement. This can be attributed to additional finely dispersed flocculation centres provided by LP additive. With the same, LP reduces buildability of the mixtures caused by slower yield stress growth and retarded stiffening.

Micromechanics prediction of dynamic modulus for asphalt mastic considering filler distribution characteristic: A new perspective

This study aims to provide a new perspective into the consideration of filler distribution characteristic in micromechanical modeling of asphalt mastic through combining fractal microstructure. To do this, three viscoelastic micromechanical models were improved by the preliminarily combination between micromechanical equivalence and fractal statistic principles. Particle size distribution (PSD) of filler was tested by a laser particle size analyzer. Asphalt mastics with different filler concentrations were fabricated. Dynamic shear moduli of asphalt and asphalt mastics was tested by a dynamic shear rheometer. The PSD of the circles intercepted by the plane and dimensionless area of the intercepted asphalt matrix were analyzed. The dynamic shear modulus ratio of asphalt mastic to binder were calculated based on the improved models. The effects of various parameters on the distribution of the ratio were investigated. Results show that the shifted R-R distribution function is capable of capturing the PSD of filler. The dimensionless area increases with increasing dimensionless diameter, but decreases with increasing filler volume fraction. The shear modulus ratio shows a three-stage reduction trend with dimensionless diameter, replying that the shear modulus of asphalt mastic appears as a random distribution in space. Meanwhile, the spatial distribution is influenced by filler volume fraction and thus there has difference between the stiffening effects of filler on various local regions in asphalt mastic. Poisson’s ratio of binder plays an enhanced role in the stiffening effect of filler, which is affected by the spatial locations within asphalt mastic. Modulus and Poisson’s ratio of limestone filler and modulus of binder have little effect on the distribution of the shear modulus ratio. The combination of micromechanical modeling and fractal characteristic is capable of determining the spatial distribution characteristic of effective properties for asphalt mastic. The local homogenization of asphalt mastic in terms of the modulus and its influence on properties of asphalt mixture should be focused on and conducted in future.

Improving the Self-Compacting Concrete Properties by Incorporating a New Micronized Limestone Filler

Abstract Self -compacting concrete composition results from several approaches to satisfy specific criteria. SCCs must be able to fill small, confined formwork without the need for vibration. To ensure the homogeneity and mechanical characteristics of the concrete, they must have good resistance to segregation throughout the setting time. The self-compacting aspect is controlled by a high volume of paste and an important fines content ensured by incorporating mineral additions that are expensive and not always available. The main objective of this paper is to utilize a new type of micronized limestone filler that may be characterized and incorporated into concrete to guarantee self-compacting quality. In the first part, a detailed characterization of the limestone filler was carried out to investigate its effects on the concrete properties. The identification has been physical, chemical, and specific to the concrete’s formulation. The second part is devoted to the experimental tests on different SCCs mixed with various amounts of filler to determine the optimal incorporation percentage. Moreover, a parametric study, involving the content of filler, the granular structure, and the quantity of superplasticizer, allowed an evaluation of the effect of limestone filler incorporation on fresh and hardened concrete characteristics. Through this study, it was demonstrated that with a proportion of limestone filler of about 25% of the quantity of cement used, the quality of the concrete has recognized appreciable improvements.

Life cycle assessment to produce LC³ cements with kaolinitic waste from the Amazon region, Brazil

The present study was developed with the aim of determining the environmental impact of the production process (cradle-to-gate) of Limestone Calcined Clay Cements (LC³) produced with kaolinitic residues from the Brazilian Amazon, through a life cycle assessment (LCA). For this purpose, 6 LC³ mixtures were prepared from combinations of clinker, gypsum, and metakaolin: limestone filler in the ratios 2:1, 1.5:1 and 1:1, replacing 45% and 60% Ordinary Portland Cement (OPC). The LC³ cements were compared with two cements already produced industrially. CO2 emissions associated with the transportation of raw materials to produce LC³ cements increased significantly, especially for the cements where 60% clinker was substituted, with CO2 emissions up to 2–3 times higher than for the reference cements. Despite that, LC³ cements showed a reduction in energy demand of up to 28% and total CO2 emissions of up to 38% compared to commercial cements. In this way, the conducted study demonstrates the high environmental potential of LC³ cements with kaolinitic residues from the Amazon region for reducing pollutant emissions in the manufacture of cement.

Designing Self-Compacting Concrete Using Local Materials from the Arid Region of Adrar, Algeria

Abstract In the construction sector, the non-renewable world resource of sand is largely used to produce mortar and concrete. It has been estimated that over 10 billion tons of sand have been produced, with 1.2 billion tons used in concrete over the last decade, which leads to a progressive reduction of available construction materials and environmental impacts. Since desert sand resources are abundant in arid region of Adrar (Southern Algeria), it would be viable to use desert-sand as an alternative material for the production of self-compacting concrete. Therefore, self-compacting concrete is experiencing significant demand in that arid region since it offers socio-technical and economic solutions to stakeholders in the construction and public works industry. Furthermore, the present study aims to address the concerns of these stakeholders. The results obtained showed that the self-compacting concrete that was made with local materials, behave correctly, both in the fresh and hardened states. This concrete included a 1% super plasticizer dosage, a gravel-to-sand (G/S) ratio varying between 0.8 and 1.1, and additions of limestone fillers up to 50% relative to the mass of cement for self-compacting concrete made with dune sand, while this percentage could go up to 38% for self-compacting concrete made with corrected sand (63% crushed sand with 37% dune sand).

Predicting optimal dispersant (superplasticiser) content for cement–limestone pastes from rheological tests

Currently, one of the most important trends in concrete technology is the use of inert fine particles (fillers) to decrease cement content, increase packing in the paste and increase flowability, with gains in technological, environmental and cost aspects. The advance in dispersion technology (using superplasticisers) is one of the technical issues that allows pastes to be mixed without the expected increase of water content – which decreases compressive strength – caused by the filler's high surface area. However, the use of no more than the optimal dispersant (superplasticiser) content (lowest content that provides the lowest viscosity) is crucial owing to cost constraints. This paper evaluates the possibility of predicting optimal dispersant content in cement–limestone filler systems from the optimal dispersant content previously measured in the pure raw materials. Owing to the need for only a few sets of tests, this can optimise the design timing and accuracy of efficient pastes for lower binder concretes.

Performance evaluation of asphalt mixture using brake pad waste as aggregate

Utilizing brake pad waste (BPW) in asphalt mixture can not only reduce the consumption of natural mineral material, but also alleviate the environmental pollution problem caused by such solid waste. This paper concentrates on the feasibility and strategy of using BPW as aggregate in asphalt mixture. Firstly, BPW aggregate within five different particle sizes were separately used to replace the limestone aggregate or filler with different proportions (25%, 50%, 75% and 100%) in asphalt mixture by the volume control method. The corresponding optimum asphalt contents of 21 kinds of asphalt mixtures were determined by the Marshall design procedure. Due to its high asphalt-absorption, BPW aggregate would increase the optimum asphalt content of asphalt mixture, which depends on the particle size of BPW aggregate. To meet the Chinese Standard Specification for asphalt mixture, the maximum substitution proportions for the BPW aggregates of 0–0.075 mm, 0.075–2.36 mm, 2.36–4.75 mm, 4.75–9.5 mm, 9.5–16 mm were 75%, 50%, 25%, 100%, and 100%, respectively. On this basis, BPW mixture simultaneously using the BPW aggregate with different sizes and the corresponding maximum substitution proportions were prepared and evaluated by a series of laboratory tests as well. Results implied that BPW mixture (BPW-M) outperformed the limestone asphalt mixture (Control-M) in term of the moisture stability, the high-temperature performance, the low-temperature property, and the fatigue life. Furthermore, dynamic modulus test results indicated that BPW-M mixture was more stiffness at relative low frequency (high temperature) and more flexible at relative high frequency (low temperature). Overall, this study verifies the feasibility and provides a reference datum of using BPW materials as aggregate in asphalt mixture.

Effect of Limestone and Quartz Fillers in UHPC with Calcined Clay

Ultra-high-performance concrete (UHPC) is a material developed to maximize the engineering characteristics of hydraulic concrete, in terms of durability and mechanical properties, but the adoption of this technology in practice has not turned out as desired, mainly due to the high amounts of cement and silica fume required for its production, and for its consequences on both economic and ecological costs. As an option to improve the impact of UHPC, both on costs and on sustainability, this work evaluates four UHPC series with metakaolin additions of 5%, 10%, 15% and 20%, and the substitution of 37.5% of the Portland cement volume by limestone or quartz filler. The compressive strength, the bulk electrical resistivity and a set of tests for microstructural characterization (TGA, XRD and quantitative EDS) were utilized to better understand the role of calcite on the hydration and pozzolanic reactions in ternary Portland cement-metakaolin-limestone filler. Results indicate that the reaction of calcite is scarce and should be considered as a mere filler, as no increase in AFm phases were found. Nevertheless, the ternary mixture with 15% of metakaolin in addition to cement, and with 37.5% of the Portland cement volume substituted by limestone filler, was the one that presented the best performance in terms of compressive strength and bulk electrical resistivity. The results of the microstructural characterization indicate that the high kaolin content in the metakaolin originated the most significant hydration and pozzolanic reactions development between the ages of 7 and 28 days, as between 28 and 91 the reaction remained dormant. In general, the whole set of results included in this work indicate that limestone filler doesn't act as a better filler than other kind of powders when used in ternary Portland cement-metakaolin- filler systems.

Utilization of calcium carbide slag as alternative filler in asphalt mastic: Filler characteristics, rheological and adhesion properties

Calcium carbide slag (CCS), a solid waste generated from a production process of acetylene gas, is considerably growing every year. It is necessary to expand application scope of CCS to improve its consumption. Feasibility of CCS as a substitute for natural limestone (NL) fillers and asphalt mastic properties was studied in this work. Properties of CCS powder and NL powder were characterized by laser particle size analyzer, scanning electron microscope (SEM), X-ray diffraction (XRD), X-ray fluorescence (XRF), and acid-base analyses. Asphalt mastic characteristics were evaluated using a viscosity test, rheological test, and adhesion test. The results show that CCS has a greater particle size than NL, yet the CCS surface is rougher, which can facilitate its bonding with asphalt. In addition, high relative intensity of calcium in CCS provides excellent conditions for application as filler. Viscosity, complex modulus (|G*|), rutting factor (|G*|/sin δ), recovery percentage (R), and bonding strength can be enhanced with an increase in CCS content. While phase angle (δ) and non-recoverable creep compliance (Jnr) decrease, indicating CCS enhanced the stiffness and elastic behavior of asphalt mastic. CCS can improve rheological properties of asphalt mastic and mastic-aggregate interface adhesion, decrease moisture sensitivity and costs of asphalt mixtures. Therefore, CCS has promising applications in asphalt pavement engineering as a substitute for NL, which contributes to environmental protection.

A Comprehensive Review on the Effect of Filler Materials on Engineering Properties of Asphalt Concrete Mixes

The effect of filler materials on the properties of bituminous concrete was reviewed in this paper. Flexible pavement layer is made up of asphalt concrete. It is the commonest type of pavement in the world. Asphalt concrete contains aggregates, bitumen binder and fillers. The Asphalt concrete has voids which needs to be filled for better performance of its functions. Fillers help to fill voids and change the physical and chemical properties of asphalt concrete and bitumen combines with filler to forms mastic that holds the aggregates together. Asphalt Institute recommended 4-8% fillers for use. The recent developments in technology is geared towards the use waste materials as fillers in concrete production. It was revealed in this review that Marble dust and Calcium Carbide Residue (CCR) can be used in bituminous mix as alternative to conventional fillers in asphalt mixes. The waste bagasse and coconut peat fillers give mastic viscosity similar to limestone filler but higher than granite filler. Concrete dust and brick dust as fillers in bituminous mix improve flow value, Marshall stability and physical characteristic of bitumen. The conclusion of this review analysis shows that fillers in bituminous mix reduces the problem associated with waste disposal and high concentration of calcium carbonate in waste ash can help to reduce rutting and moisture damage potentials.

Prediction of the Compressive Strength of Waste-Based Concretes Using Artificial Neural Network.

In the 21st century, numerous numerical calculation techniques have been discovered and used in several fields of science and technology. The purpose of this study was to use an artificial neural network (ANN) to forecast the compressive strength of waste-based concretes. The specimens studied include different kinds of mineral additions: metakaolin, silica fume, fly ash, limestone filler, marble waste, recycled aggregates, and ground granulated blast furnace slag. This method is based on the experimental results available for 1303 different mixtures gathered from 22 bibliographic sources for the ANN learning process. Based on a multilayer feedforward neural network model, the data were arranged and prepared to train and test the model. The model consists of 18 inputs following the type of cement, water content, water to binder ratio, replacement ratio, the quantity of superplasticizer, etc. The ANN model was built and applied with MATLAB software using the neural network module. According to the results forecast by the proposed neural network model, the ANN shows a strong capacity for predicting the compressive strength of concrete and is particularly precise with satisfactory accuracy (R² = 0.9888, MAPE = 2.87%).

Exploring the effect on the environment of encapsulated micro- and nano-plastics into asphalt mastics for road pavement

A new environmental problem is represented by the huge transformation of plastic waste released into the environment into small fragments, the so called micro- and nano-plastics, due to atmospheric phenomena. The smaller the size of the plastic fragments, the more their spreading into environmental compartments. The aim of this study is to test encapsulation into asphalt mastics of waste plastic material (WPM) as sustainable strategy to obtain road flexible pavements and to evaluate the potential release in water of micro and nano plastics.A new mastic mixing method was developed to blend the WPM with the bitumen contained into a bitumen emulsion (BE60/40) by adopting low mixing temperatures. Three different WPM contents, equal to 5, 10 and 20% by the weight of the bitumen contained in the BE60/40, were adopted to produce the mastics; the mastics’ rheological properties, obtained by frequency sweep and multiple stress creep and recovery tests, were compared to those of a traditional asphalt mastic containing limestone filler. The aging of asphalt mastics was analyzed by soaking them in water and gradually lowering and raising temperature between −10 and 60 °C at predefined intervals.The addition of WPM improved greatly the asphalt mastic performance; in particular, for a WPM content of 10%, the rheological response in terms of stiffness remained unchanged after the mastic underwent thermal excursions in water.Encapsulation of micro and nano plastics into mastics reduced of more than 99% their potential water release.

Influence of iron tailing filler on rheological behavior of asphalt mastic

• Limestone filler (LF) was substituted by iron tailing filler (ITF) in mastics under different f/b ratios. • The interaction between ITF and asphalt matrix was primarily physical. • ITF possessed a superior stiffening effect on mastics than LF. • A new index Δ T d was proposed to quantify the low-temperature performance of ITF mastics. • The substitution of ITF should be controlled within 1.0 f/b ratio. Iron tailings, one kind of widespread solid waste, were preliminarily regarded as a potential substitute for mineral filler in asphalt mixtures. However, the overall rheological properties of asphalt mastics incorporating iron tailing filler (ITF) and the effect mechanism of ITF remain unclear, which is detrimental to the generalized utilization of ITF in asphalt pavement. To fill this gap, the present study selected ITF and limestone filler (LF) to fabricate mastics with four filler/asphalt weight (f/b) ratios (0.6, 0.8, 1.0, 1.2). The blending mechanism and surface morphology of mastics were revealed by Fourier transform infrared spectroscopy and scanning electron microscopy, respectively. The rotational viscosity test, dynamic shear rheometer test as well as bending beam rheometer test, were conducted to comprehensively study the rheological behavior of mastics. A new index Δ T d was proposed to quantify the influence of ITF on low-temperature cracking performance. Results show that the interaction between ITF and asphalt matrix is predominantly physical, and ITF possesses a smaller particle size which is beneficial to stiffening the mastics. However, the worse infiltration and distribution uniformity of ITF in mastics than that of LF may result in poorer adhesion. Regarding the rheological behavior, the substitution of ITF can highly improve the viscosity, complex modulus, and creep stiffness while slightly decrease the phase angle, viscosity-temperature susceptibility, and m -value of mastics, indicating a higher stiffness and elasticity of ITF mastics. Notably, the plateau region of phase angle may appear in ITF mastics with high filler concentration at low frequencies, representing a more significant elastic response. Besides that, Δ T d remains between −3.5 and −1.1 ℃. These results prove that the substitution of ITF is advantageous for the anti-rutting performance of asphalt pavement but may jeopardize its workability and low-temperature cracking resistance in particular with the excessive incorporation (f/b ratio > 1.0) of ITF.

The Effects of Air-Entraining Agent on Fresh and Hardened Properties of 3D Concrete

Three-dimensional concrete printing (3DCP) is becoming more common in the construction industry nowadays; however, the aspect of durability of printed concrete is not well-studied yet. Frost resistance is a very important factor for durability of concrete structures located in northern regions. Since air-entraining agents (AEAs) are widely used in conventional concrete, this paper focuses on exploring the potential of using AEAs in 3D concrete as well—the main objective is to determine how it affects fresh and hardened properties, including frost resistance of 3D concrete. Three different mixes were printed and cast—the dry mix consisted of ordinary Portland cement (OPC), limestone filler (LF), sand, as well as viscosity modifying agent (VMA) and superplasticizer (SP). Two mixes contained different amounts of AEA, the third one was used as reference. First, fresh state properties were tested—air content, density, and mini cone flow test. Second, 28-day compressive and flexural strength tests were carried out; bulk and particle densities were also determined. Next, both cast and printed concrete samples were subject to freeze–thaw cycles according to provisions of CEN/TS 12390-9, mass loss due to surface scaling was determined for each sample. As a result, printed concrete samples containing AEA in the amount of 0.06% of binder mass showed the highest frost resistance—addition of AEA decreased both flexural and compressive strength of this printed concrete mix by 30–40%. To conclude, the obtained results give an insight of how addition of AEA to printed concrete mix affects its properties both in long and short term. Further research of certain aspects, for instance, the air void system and pore distribution is needed to gain a deeper understanding on how to increase durability of 3D concrete.

Designing general use cement with calcined illite and limestone filler

Common raw clays are widely available and develop pozzolanic properties after suitable thermal treatment, and combined with limestone filler, contribute to developing a sustainable general use cement (GUC). A Calcined illite Clay (CC) is introduced as a new SCM in the design of GUC. The GUC formulated with the combination of CC (< 35% by mass), and Limestone Filler (LF) (< 20% by mass) as a partial replacement of Ordinary Portland Cement (OPC) was studied using an experimental design based on surface response. The select properties for the GUC design were the paste flow, flow-loss, and compressive strength at 2, 7, 28, and 90 days. The performance of properties is based on the progress of cement hydration measures as the non-evaporable bound water that cause the reduction of the volume of permeable pores. At an early age, LF stimulates the hydration of OPC, compensating partially the dilution effect. The large proportion of CC acts as a diluent of cement at an early age reducing the strength. However, an increase of strength occurs for composite cements with high CC-content and a low LF-content when the pozzolanicity of cement is confirmed. Finally, using the embodied CO2 for a given property's goals, the best eco-efficiency GUC is obtained for LF ≤ 10% and CC-content from 17.5 to 30% as a complement of LF content.

Effect of Processed Volcanic Ash as Active Mineral Addition for Cement Manufacture.

In the last quarter of 2021, there was a very significant eruption of the Cumbre Vieja volcano on the island of La Palma, belonging to the Canary Islands, Spain. It generated a large amount of pyroclastic volcanic materials, which must be studied for their possible applicability. This work studies the properties and applicability of the lava and volcanic ash generated in this process. The need for reconstruction of the areas of the island that suffered from this environmental catastrophe is considered in this study from the point of view of the valuation of the waste generated. For this purpose, the possibility of using the fine fraction of ashes and lava as a supplementary cement material (SCM) in the manufacture of cement is investigated. The volcanic material showed a chemical composition and atomic structure suitable for replacing clinker in the manufacture of Portland cement. In this study, the cementing and pozzolanic reaction characteristics of unprocessed volcanic materials and those processed by crushing procedures are analysed. To evaluate the cementitious potential by analysing the mechanical behaviour, a comparison with other types of mineral additions (fly ash, silica fume, and limestone filler) commonly used in cement manufacture or previously studied was carried out. The results of this study show that volcanic materials are feasible to be used in the manufacture of cement, with up to a 22% increase in pozzolanicity from 28 to 90 days, showing the high potential as a long-term supplementary cementitious material in cement manufacturing, though it is necessary to carry out crushing processes that improve their pozzolanic behaviour.

Tools for designing the early-age properties of fly ash and limestone filler ternary systems

The design of ternary systems with ordinary portland cement (OPC) and supplementary cementitious materials (SCMs) in terms of clinker factor is interesting to obtain a compressive strength improvement with lower CO2 emissions; however, until now, a methodology has not been developed to establish the optimal design. In this sense, the early-age properties of binary and ternary pastes and mortars with different proportions of limestone filler (LF) and fly ash (FA) were analyzed to evaluate which parameters have greater relevance in optimizing these systems. The results show that predicting the flowability and the 2-days compressive strength in mortars is possible using the paste film thickness (PFT) and cumulative heat at 48 h, respectively. This approach makes it possible to design systems with LF and FA based on the desired performance.