Artificial Lightweight Aggregate Research Articles

Properties of artificial lightweight aggregates prepared from coal and biomass co-fired fly ashes and sewage sludge fly ash

The use of solid waste such as coal and biomass co-fired fly ashes and sewage sludge fly ash instead of clay and other non-renewable resources to produce lightweight aggregates (LWAs) is conducive to sustainable development. In this study, the effects of co-fired fly ashes, sewage sludge fly ash and quartz sand proportion, sintering temperature and sintering time on the physical properties and microstructure of LWAs are studied by single factor experiment. Experimental results show that the optimal experiment conditions are the raw material ratio of co-fired fly ashes: sewage sludge fly ash: quartz sand = 9: 1: 4, 2 wt% SiC as an expansion agent, and sintering at 1060 °C for 10 min. The LWAs obtained under the above conditions have a bulk density of 0.85 g/cm3, an apparent density of 1.84 g/cm3, a 1-h water absorption of 2.71 %, and a compressive strength of 8.68 MPa, which are in accordance with the GB/T17431.1–2010 standard. Besides, the heavy metal immobilization effect of the LWAs is satisfying, where the heavy metal leaching concentrations meet the standard of GB5085.3–2007. In conclusion, it is feasible to use the raw materials to prepare the LWAs under the above sintering conditions, and the prepared LWAs have high strength and low water absorption.

A scientiometric review of artificial lightweight aggregates applying VOSviewer Software

This study aims to conduct a comprehensive scientometric review of Lightweight Artificial Aggregates ( LWAs ), using the Scopus database as the main data source. The choice of Scopus was motivated by the superior availability of documents compared to the "Web of Science", allowing the analysis of more than 510 articles related to the topic. The key expression "artificial lightweight aggregate " was used in the research, and document summaries were read to ensure their relevance to the topic. The justification for this study lies in the need to understand and map the current scientific scenario of LWAs , highlighting their growing importance in civil construction. The analysis Scientometrics adopted scientific mapping as a method, using the VOSviewer software in conjunction with the Scopus analyzer. This approach allowed a detailed assessment of the interconnections between disciplines, authors, publications and institutions, providing a comprehensive view of scientific development related to LWAs . The results revealed the location of 512 relevant articles in the bibliographic search, indicating a significant detection of research on LWAs in the last decade. Although there is progress in this field, it is highlighted that studies on LWAs are still relatively recent compared to commercial aggregates such as expanded clay This comprehensive scientific mapping contributes to a deeper understanding of the research domain, identifying recent advances and areas in need of further exploration, guiding future research and decisions in the construction sector.

Optimization of the manufacturing process and properties of alkali-activated palm oil fuel ash-based cold-bonded aggregates

Tons of palm oil fuel ash (POFA) are currently being disposed of at landfills or left untreated in the environment, taking up valuable land space and posing significant hazard to the environment. To address this issue, this study investigates the production of artificial lightweight aggregates (LWAs) using POFA as a raw material through a cold-bonded one-part alkali-activation method. High-volume of weakly pozzolanic POFA and different combinations of GGBS (0%, 10%, 30%) as precursors, and Na2SiO3.5H2O (9% and 12%) as the activator were used to produce the artificial LWAs. The granulation process was systematically investigated, where the influence of granulation parameters (the ratio of POFA and GGBS, activator content, water content, rotation angle, and rotation speed) on granulation efficiency and granulation duration were evaluated. The physical properties including loose bulk density, water absorption, and crushing strength were also investigated. In addition, the phase change after alkali-activation was evaluated. Results showed that the water demand for the aggregates with different combination ranged from 0.3 to 0.46. Increasing the GGBS and Na2SiO3.5H2O content improved the granulation efficiency up to 87.4% and shortened the granulation duration to 7 min. Response surface methodology (RSM) modeling revealed that the optimum rotation angle and rotation speed were 55° and 50 rpm, respectively, resulting in a maximum granulation efficiency of 88.2%. The loose bulk density of POFA-based alkali-activated aggregates (PFAAs) was 595.4–730.3 kg/m3, meeting the requirement of LWAs in EN13055. After 28 days curing, the PFAAs with the GGBS replacement of 30% and 12% Na2SiO3.5H2O exhibited crushing strength and water absorption of 2.4 MPa and 22.4%, respectively. Moreover, a stronger alkali-activation was achieved with 30% GGBS replacement, which improved the performance of PFAAs, as evidenced by the phase analysis.

Production, properties and life cycle assessment of artificial lightweight aggregates produced with corn straw ash (CSA) and concrete slurry waste (CSW)

Open burning of corn straw has been a long-standing environmental problem in developing agricultural countries. The development of the concrete material industry supplies a feasible consumption outlet for the bulk solid wastes from agriculture and construction fields. In this study, therefore, corn straw and concrete waste were turned into available cementitious materials: corn straw ash (CSA) and concrete slurry waste (CSW) powder. Then CSA and CSW were reused to be artificial lightweight aggregates (ALAs) by cold-bonding pelletization and carbonation curing. A multi-criteria decision-making model for ALAs was finally proposed to comprehensively evaluate the technical, environmental, and economic factors and select the most valuable candidate. The findings indicate that it is technically feasible to produce ALAs by using CSA and CSW. The optimal mechanical parameters of the disc granulator are 35 rpm and 45° inclination in the cold-bonding pelletization process of ALA production. From a technical point of view, with the increase of CSA content in ALAs, the strength of ALAs increased first and then decreased, reaching the optimum value of 14.2 MPa with the addition of 5% CSA. According to the sustainability score, the descending order of ALAs is C1, C4, C3, C2 and C0. Sustainability results show that the ALAs of the mixture of 5 wt% CSA and 95 wt% CSW is the optimal solution. The ALAs with dual-function in terms of reducing CO2 emissions and capturing CO2 is a promising candidate for low-carbon concrete production. The decision model could be suitable for the sustainable selection of artificial aggregates or recycling construction materials.

Perilaku tegangan-regangan beton yang terbuat dari agregat ringan buatan yang diperkuat dengan carbon fiber reinforced polymer

This paper describes the findings of a research study aimed at evaluating the impact of various parameters on the stress-strain behavior of concrete composed of artificial lightweight aggregates with rectangular cross-sections. The factors that were evaluated include the number of fiber-reinforced polymer (FRP) layers, the compressive strength of the concrete, and the cross-sectional shape of the concrete. A total of twenty-two test specimens were fabricated, wrapped with Fiber Reinforced Polymer (FRP), and subjected to concentric compressive loading for experimental evaluation. The experimental findings indicate that Fiber Reinforced Polymer (FRP) demonstrates an excellent wrapping technique for lightweight concrete composed of lightweight aggregate. In addition to this, the test findings indicate a positive correlation between the number of fiber-reinforced polymer (FRP) layers employed and the resultant ultimate stress and strain shown by concrete composed of artificial lightweight aggregate. The test results additionally demonstrate a clear relationship between the rise in ultimate stress and the compressive strength of concrete, while showing an inverse relationship with the ultimate strain observed. Similarly, the test results indicate that the utilization of Fiber Reinforced Polymer (FRP) wrapping has more efficacy when applied to round cross-sectional shapes as opposed to rectangular cross-sectional shapes.

Application of Stochastic Finite Element Modeling to Reinforced Lightweight Concrete Beams Containing Expanded Polystyrene Beads

Limited investigations have evaluated the effect of expanded polystyrene (EPS) beads on the structural lightweight concrete properties. EPS offers many features compared to natural or artificial lightweight aggregates including the elimination of aggregate saturation prior to concrete batching, ability to be fabricated on site, consistency in size and quality, and reduced cost. The main objective of this paper is to assess the suitability of finite element (FE) modeling based on deterministic and stochastic approaches to predict the shear strength behavior of reinforced concrete (RC) beams containing EPS additions. Test results showed that the experimental load-deflection properties recorded at failure can be well reproduced using both FE approaches. Nevertheless, the damaged-zone distribution and crack patterns that occur during the loading stages of RC beams cannot be approximated using the deterministic FE approach. In contrast, the stochastic method was quite suitable as it accounted for the concrete heterogeneity and altered spatial mechanical properties (such as compressive strength, splitting tensile strength, and Young’s modulus) due to EPS additions. Such data can be of interest to civil engineers seeking to predict the failure patterns and performance of structural lightweight members while reducing the time and resources needed to account for the concrete’s strength variability during experimental testing.

Artificial coarse aggregate from waste materials, fly ash and Msand dust through geopolymerization

Coarse aggregate is considered the most vital aspect, providing quantity and strength to the concrete. The aggregates are obtained mainly from natural resources by quarrying rocks or riverbeds. Each year, construction industries use large amounts of natural aggregates, resulting in the depletion of raw materials. Different methods, such as sintering, cold bombing, autoclaving, and geopolymerization, can prepare artificial coarse aggregates. Geopolymerization is a chemical reaction between an alkali solution and source materials containing alumina and silicate. The main objective of this study is to develop artificial aggregates with M sand dust and fly ash by geo polymerization. The ratio of Fly ash to M Sand Dust adopted is 40:60 by weight. Different molarities of sodium hydroxide was used for making the artificial aggregates with a solution-to-binder (S/B) ratio of 3.5 and a sodium silicate-to-sodium hydroxide ratio of 2.5. The mechanical properties of the developed lightweight aggregate are determined as per the specification requirement in IS 9142 (1979) for artificial lightweight aggregates for concrete masonry units. By comparison, these geopolymer aggregates are sustainable, and aggregates with 12 molarity NaOH showed better properties than other molarity NaOH aggregates based on its mechanical properties.

Investigation of various curing methods on the properties of red mud-calcium carbide slag-based artificial lightweight aggregate ceramsite fabricated through alkali-activated cold-bonded pelletization technology

Industrial solid wastes red mud and calcium carbide slag are used to prepare lightweight aggregate ceramsite by cold-bonded pelletizing technology in this study. The effects of mixing water and curing method on the physical properties of ceramsite were investigated, including natural curing (in air at 20 °C), sealed curing, water curing, hot air oven curing, steam curing, and CO2 curing. The results showed that the lightweight aggregate had the lowest cylinder crush strength, the lowest apparent density, and the highest water absorption after natural curing. The highest cylinder crush strength of 8.7 MPa was obtained by steam curing at 60 °C for 12 h, which was 180.65% higher than that of natural curing because the high temperature promoted the hydration reaction thus the formation of C-(A)-S-H gel and hydrotalcite. CO2 curing at 60 °C significantly reduced the water absorption of the lightweight aggregate by 50% and by 38.03% as compared to that obtained by natural curing and steam curing at 60 °C for 12 h, respectively. During CO2 curing, the reaction between CO2 and Ca(OH)2 from the calcium carbide slag can form a dense layer of CaCO3, increasing the structural compactness and reducing the water absorption.

Manufacture of artificial lightweight aggregates recycled from anaerobic digested sewage sludge and process optimization by machine learning modeling techniques

In this study, in an effort to manufacture lightweight aggregates recycled from anaerobic digested sewage sludge (ADSS), the firing process characteristics of artificial lightweight aggregates containing a large amount of ADSS were identified and the manufacturing process was optimized and modeled using machine learning techniques. Samples were prepared by rapid firing and according to the orthogonal arrangement experimental design, the particle density and water absorption rate were measured, and a pore analysis was conducted by 3D-CT and the mercury intrusion method. Random forest, SVR, and XGBoost techniques were used as machine learning techniques to analyze the data. As a result of the rapid firing test, samples with an ADSS content of 40 wt% or more were found to have a low density and were found not to show bloating. For aggregates containing more than 40% ADSS, a loss of organic matter played a greater role in the decreased density than bloating due to viscous behavior. Data expansion using an orthogonal arrangement table and modeling by the SVR method for the ADSS 50 mixture found an RMSE value of 0.013 with significant predicted values of the physical properties also obtained. Aggregates with a content of 50 wt% of anaerobically digested sludge were successfully prepared on a pilot scale, and this aggregate mix met EN-13055 standards.

Municipal woody biomass waste ash-based cold-bonded artificial lightweight aggregate produced by one-part alkali-activation method

The rapid industrialization process has resulted in the overconsumption of natural aggregates, leading to significant environmental concerns. Additionally, the disposal of municipal woody biomass ash (MWBA) has caused the depletion of land and further environmental pollution. Hence, production of artificial aggregate using MWBA is of great interest, as it reduces the consumption of natural aggregates and landfill area while recycling the MWBA. The main objective of this study is to determine the optimal mix design that can produce artificial aggregates with satisfactory strength and lightweight properties while maximizing the utilization of MWBA. Following that, the effects of different alkaline contents (9%, 12%, 15%) and ground granulated blast-furnace slag (GGBS) contents (0%, 10%, 20%, 30%) on the physical properties of the MWBA-based AAAs were investigated. Additionally, the pore distribution, phase and elemental compositions of the aggregates were examined to ascertain the mechanism of alkali-activation and strength development of the MWBA-based AAAs. The main result showed that at 15% Na2SiO3·5H2O content, increasing the GGBS content from 0% to 30% resulted in an increase in the loose bulk density and crushing strength of MWBA-based AAAs from 817 kg/m3 to 950 kg/m3 and from 0.84 MPa to 2.25 MPa, respectively, while decreasing the water absorption from 24.0% to 12.5%. This is due to the denser matrix observed, attributed to the GGBS addition, which enhances the effect of alkali-activation. Additionally, a new amorphous phase, namely C-A-S-H, was identified. The Si/Al ratio decreased with the GGBS content, resulting in more C-A-S-H gel formation and a denser microstructure with better performance for the AAAs. The novelty of this study is to demonstrate the feasibility of using MWBA in producing AAAs through a cold-bonded one-part alkali activation method. This method presents an alternative to natural aggregates that can be utilized in concrete.

Effects of internal CO2 curing provided by biochar on the carbonation and properties of steel slag-based artificial lightweight aggregates (SALAs)

Diffusion of CO2 strongly influenced the carbonation efficiency of steel slag. A novel approach for preparing steel slag-based artificial lightweight aggregates (SALAs) was proposed, in which biochar was employed to provide internal CO2 curing and reduce the bulk density. Owing to the additional diffusion channels and temporary storage tank for CO2 provided by the biochar, the carbonation degree of steel slag was effectively improved, leading to improved performance of SALAs as well as concrete. For instance, with the addition of 3 wt% biochar, the CO2 uptake was increased by 24.3%, the crushing resistance was 5.7 MPa, while the bulk density was reduced to 1070 kg/m3. In addition, the SALAs improved the compressive strengths and volume stability of concrete.

Development and characteristics of novel high-strength lightweight core-shell aggregate

The need for high-strength lightweight concrete for cost-effective and energy-efficient building construction drives the need to develop high-strength lightweight aggregates. In this study, a novel high-strength lightweight core–shell aggregate (HLCSA) was developed and compared with commercial available artificial lightweight aggregates (LWAs). The loose bulk density, water absorption, and crushing strength of the developed aggregate were optimized by changing the water/binder ratio of the shell, core materials, shell/core ratio, and curing methods and time. XRD, TGA, and X-CT were utilized to analyze the hydration degree, microstructure, and pore structure of the shell and core of the core–shell aggregate. The results showed that a suitable water/binder ratio of 0.20–0.22 for the shell and a core material (cenosphere) were optimal for producing the HLCSA. The size, loose bulk density, crushing strength, and strength efficiency of the pelletized aggregate were all found to increase with the shell/core ratio. The curing method and curing time played an important role in affecting the crushing strength. The microstructure and porosity of HLCSA analyzed by optical microscopy and X-CT showed that it was a hollow shell structure with a porous core that was well coated by a dense shell, which ensued the high strength and lightweight features at the same time. The developed HLCSA (with shell/core of 1.6) had a crushing strength of 6.93 MPa and a loose bulk density of 834 kg/m3 with a high strength efficiency of 8,309 Pa·m3/kg, which was much higher than the common commercial LWAs.

Structural optimisation in terms of carbon emissions using artificial aggregates

Concrete is widely used in construction, but its production has negative environmental consequences due to the significant depletion of natural resources and high carbon footprint. As a result, sustainable alternatives to traditional concrete are gaining popularity. This study examines the carbon footprints of artificial lightweight Aggregate Concrete (AA) and Bottom Ash aggregate concrete (BA) and compares them to traditional concrete. The evaluation's system boundary includes all aspects from conception through pre-construction, including component materials, concrete production, and transportation. The CO2 emissions were determined as a function of the unit binder concentration of concrete, based on the analysis of databases that included 50 and 30 datasets for AA and BA, respectively. The results show that the CO2 emissions of AA and BA constructions are higher than traditional concrete due to the significant impact of OPC quantity on CO2 emissions. The study finds that the anticipated total CO2 emissions for the AA and BA constructions were 38% and 26% higher, respectively, than for typical concrete structures. The findings highlight the importance of reducing the use of traditional concrete and transitioning to more sustainable alternatives. By using sustainable alternatives, such as AA and BA concrete, the negative environmental impact of concrete production can be significantly reduced. The study provides valuable information for policymakers, engineers, and construction professionals in their efforts to promote sustainable construction practices.

Influence of internal curing on compressive strength and drying shrinkage of super-sulfated cement mortar

The current study aims at assessing the effect of using cold-bonded fly ash based artificial lightweight aggregate (ALWA) as an internal curing (IC) agent on the compressive strength and drying shrinkage of a typical super-sulfated cement (SSC) produced with a mixture of 85% slag, 10% gypsum, and minor amount of 5% blended Portland cement (PCB). The ALWA was used as partial replacement of fine aggregate (FA) at values of 25, 50, 75, and 100 vol.%. Experimental results showed that the ALWA partially replacing FA in range of 25–100 vol.% significantly decreased both the unit weight and dried density of the fresh and hardened IC-SSC mortars at average values of 13.9% and 20.0%, when compared with the reference SSC mortar, respectively. The ALWA increment continuously reduced the compressive strengths of the hardened IC-SSC mortars. But, at 28 days of curing, the hardened IC-SSC mortar containing the ALWA amount partially replacing FA up to 50 vol.% showed compressive strength reaching 89.3%, and comparable or slightly lower drying shrinkage in comparison with the reference SSC mortar without the IC agent.

Study of physical and mechanical behavior of artificial lightweight aggregate made of Pakistani clays

This study aims to unravel the potential of Pakistan in the domain of artificial lightweight expanded clay aggregates (ALECA) and investigate the influence of pellets size, firing temperature, and admixture doses on the mechanical properties of ALECA. The five prominent and unfathomed clay fields in Pakistan were chosen. The selected clay fields include Nandipur, Multan, Mirpur, Sibbi, and DIK. After essential geotechnical characterization, the collected soil samples of chosen fields were chemically analyzed using X-ray diffraction and X-ray fluorescence tests, whereas thermal stability was assessed using thermogravimetric analysis. The characterized soil was used in the synthesis of ALECA through 120 different mixes recipes designed by varying pellet sizes, and the dose of admixed fly ash and kerosene oil. The addition of fly ash and kerosene allowed the development of a well-distributed-porous core surrounded by a very thin shell. Nandipur clay turned out to be ideal for bloating, with a bloating index of 33.33 % and a loose bulk density of 0.39 g/cm3. These lightweight aggregates will not only help preserve natural mountain reserves but also significantly impact the lifecycle costing of structures.

Development of Lightweight Geopolymer Composites by Combining Various CDW Streams

This study regards the development of lightweight geopolymer composites through the valorization of various construction and demolition wastes. Brick waste was utilized as the sole aluminosilicate precursor for the geopolymerization reactions, expanded polystyrene and polyurethane wastes were used as artificial lightweight aggregates, and short polyethylene fibers developed from CDWs reinforced the geopolymer matrix. The curing conditions of the geopolymer synthesis were optimized to deliver a robust geopolymer matrix (T = 25–80 °C, t = 24–72 h). Both raw materials and products were appropriately characterized with XRD and SEM, while the mechanical performance was tested through compressive strength, flexural strength, Poisson’s ratio and Young’s modulus measurements. Then, a comprehensive durability investigation was performed (sorptivity, wet/dry cycles, freeze/thaw cycles, and exposure to real weather conditions). In contrast to polyurethane waste, the introduction of expanded polystyrene (0.5–3.0% wt.) effectively reduced the final density of the products (from 2.1 to 1.0 g/cm3) by keeping sufficient compressive strength (6.5–22.8 MPa). The PE fibers could enhance the bending behavior of lightweight geopolymers by 24%; however, a geopolymer matrix–fiber debonding was clearly visible through SEM analysis. Finally, the durability performance of CDW-based geopolymers was significantly improved after the incorporation of expanded polystyrene aggregates and polyethylene fibers mainly concerning freeze/thaw testing. The composite containing 1.5% wt. expanded polystyrene and 2.0% v/v PE fibers held the best combination of properties: Compr. Str. 13.1 MPa, Flex. Str. 3.2 MPa, density 1.4 g/cm3, Young’s modulus 1.3 GPa, and sorptivity 0.179 mm/min0.5.

Utilization of artificial lightweight aggregate and unground rice husk ash as internal curing agents to modify performance of super-sulfated cement mortar

This study attempts to utilize cold-bonded fly ash based artificial lightweight aggregate (ALWA) and retrieved unground rice husk ash (URHA) as internal curing (IC) agents for improving performance of typical super-sulfaed cement (SSC) mortar fabricated with ternary mixture of 85% slag, 10% gypsum, and only 5% blended Portland cement (PCB). The ALWA partially replacing fine aggregate (FA) at four values of 25, 50, 75, and 100 vol.% was used. For evaluating impact of using hybrid addition of IC agents on performances of SSC mortars, the ALWA amount after being optimized was partially replaced by URHA at four levels of 25, 50, 75, and 100 vol.%. Experimental results showed that, ALWA partially replacing FA up to 50 vol.% led to the SSC mortars with remarkably increased workability and uncompromised impacts on the strengths and durability. Addition of URHA partially replacing ALWA significantly improved the fresh properties and flexural strength but it negatively impacted the durability performances of the resultant SSC mortars in terms of increased water absorption, decreased UPV, and increased drying shrinkage.

Self-foaming high strength artificial lightweight aggregates derived from solid wastes: Expansion mechanism and environmental impact

Expanded lightweight aggregates (LWAs) were produced using high content of solid waste (95 wt%) without foaming agent. The effects of sintering temperature and duration on LWA properties were studied. The optimal high-temperature liquid phase content and viscosity for producing LWAs with excellent properties were ∼70 % and 1.58 × 104 Pa·s, respectively. The LWA obtained at a sintering temperature of 1200 °C with a duration of 60 min had a water absorption of 1.03 %, a bulk density of 0.57 g/cm3, and a high compressive strength of 6.75 MPa. The leached concentrations of heavy metals from LWAs complied with the environmental standard.

Experimental study of artificial lightweight aggregates using coal fly ash and epoxy resin

A lack of natural aggregates in the future is unavoidable, which generates issues for building development. For many industries, natural resources constitute a significant source of revenue. As a result, light artificial aggregate is produced to anticipate the decreasing source of natural aggregate. Production of artificial geopolymer aggregates, fly ash from the burning of coal has been proposed. This paper investigates the optimal proportion of epoxy resin and coal fly ash-based synthetic aggregates. The artificial aggregates are produced following specific gravity and compressive strength standards that may be used as a component of lightweight structural concrete (LWC). The production polymer lightweight aggregate (PLA) comes from a combination of coal fly ash and epoxy resin. The results show that PLA 50:50 to PLA 74:26 can be used for 6 hours to make structural concrete with a strength of more than 17 MPa. PLA 80:20 could achieve compressive strength with the range of 7-17 MPa. PLA 84:16 achieves a compressive strength range of 0.35 to 7 MPa and is utilized as a non-structural element. However, the flexural strength values in concrete LWC 70:30 and LWC 80:20 are higher, at 46.1% and 7.63%, respectively.

Research on the durability and Sustainability of an artificial lightweight aggregate concrete made from municipal solid waste incinerator bottom ash (MSWIBA)

This study chooses to use three common cementing materials, Portland cement (OPC), ground granulated blast furnace slag (GGBFS) and fly ash (FA), as the binder for the production of three artificial lightweight coarse aggregates (ALCAs) through cold bonding with municipal solid waste incineration bottom ash (MSWIBA) in which MSWIBA accounts for 70% of the total content by volume. In this study, three ALCAs were used to replace 0%, 30%, 60%, and 100% of natural aggregates used in the production of concrete. Through capillary water absorption and rapid migration of chloride ions, the effect of the replacement amount of ALCAs on the durability of concrete was explored. Additionally, in accordance with the Material Sustainability Index (MSI), a statistical analysis of the CO2 emissions, energy consumption and cost of the concrete made of the three ALCAs was carried out. Studies have shown that ALCAs can improve the Interfacial Transition Zone (ITZ) and pore structure of concrete, thereby improving the ability of concrete to resist chloride ion penetration. In addition, the use of ALCAs can reduce the cost of concrete. Among the ALCAs used in this study, those which use GGBFS and FA as adhesives (without OPC) can improve the durability of concrete the most and reduce CO2 emissions.