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Two-dimensional (2D) MXenes are widely acknowledged as highly adaptable materials for flexible supercapacitors due to their high electronic conductivity, tunable surface chemistry, structural adaptability, and excellent mechanical strength. However, pure MXene nanosheets have a tendency to stack together, which decreases the mechanical and electrochemical properties for flexible devices. Herein, inspired by the structure of modern architecture, MXene/MWCNT/2,2,6,6-tetramethylpiperidine-1-oxyl (TEMPO) radical-mediated oxidized cellulose nanofibers (TOCNFs) (MMT) composite film (MMT-X, the content of MWCNT and TOCNFs is X% of the total weight of the film) is manufactured using a simple vacuum filtration method. In MMT, two-dimensional (2D) MXene is severed as nanometer "bricks", one-dimensional (1D) TOCNFs is used as a nanometer "mortar" between MWCNTs and MXene based on synergistic electrostatic forces and hydrogen bonding to build a three-dimensional (3D) composite structures with excellent mechanical strength. The flexible MMT-8 film is used as a supercapacitor electrode with specific capacity 856 F cm−3. Furthermore, at a volume power density of 335.5 W L−1, the assembled flexible all-solid-state supercapacitor (ASSC) could provide a volumetric energy density of 11.64 Wh L−1 with good cycle stability. [Display omitted] • A MXene/MWCNT/TOCNF film with structure similar to "modern architecture" was manufactured using vacuum filtration method. • The mechanical properties of MXene/MWCNT/TOCNF films are improved. • The MXene/MWCNT/TOCNF film show excellent electrochemical properties for flexible supercapacitor. [ABSTRACT FROM AUTHOR]

The applications of alkali-activated slag (AAS) face challenges such as poor workability, rapid setting, and high autogenous shrinkage, which require chemical admixtures (CAs) to adjust the performance of AAS. Unfortunately, there are limited specific CAs available to tune AAS properties. To address this gap, this study proposes using a ubiquitous, naturally occurring compound, L-ascorbic acid (LAA), as a multifunctional performanceenhancing additive for AAS to overcome the major challenges of AAS. The findings showed that LAA can function as a retarder, plasticizer, strength enhancer, and autogenous shrinkage reducer for AAS. When 0.5% LAA was added, the compressive strengths of AAS mortars at 3 and 28 days increased by 28.9% and 19.6%, respectively, and the 28-day autogenous shrinkage decreased by 43.1%. Both surface adsorption and ion complexation have been confirmed as the working mechanisms of LAA in hydrated AAS. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Nanchang University (Engineering & Technology) is the property of Nanchang University and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

A ferrocement layer, which consists of a wire mesh and cement mortar, is a popular retrofitting method for existing structural elements, particularly wall or slab panels. This paper presents a study on the effectiveness of different configurations of ferrocement for seismic retrofitting of confined masonry through finite element analysis. The masonry panel was modeled using expanded brick-unit elements, where the element was expanded in size by as much as half of the mortar thickness, and an interacting zero-thickness interface was applied to mimic the elastic-plastic and damage behavior during tension, shear, and compression. The concrete damage plasticity (CDP) model was used to model the confining reinforced concrete frame and overlay mortar in the ferrocement layer, and the reinforcing bars and wire mesh were modeled using elastic-plastic behavior. In the present numerical study, nine models were subjected to cyclic and pushover shear test simulations, considering the effects of the number of ferrocement layers and the wire mesh orientation. The volumetric ratio of the wire mesh to the masonry (ρwm) ranged from 0.48% to 1.92%, whereas the ratio of the mortar overlay to the masonry (ρmo) varies from 10.42% to 41.66%. Based on the increase in the lateral strength, the model with the largest volume of the ferrocement layer exhibited the largest increase in strength. However, the most cost-effective retrofitting configuration was presented by model DS-1-45, in which a single layer of ferrocement was applied on both sides of the wall using 45° of wire mesh orientation. The DS-1-45 model provided a lateral strength increase of more than 6 times compared to the original unreinforced model. [ABSTRACT FROM AUTHOR]

In Poland, the prevailing protocols for examining the alkali reactivity of aggregates are based on indirect methodologies such as petrographic appraisal, in addition to direct methodologies including the measurement of expansion in mortar and concrete specimens containing the aggregate under investigation. The available research methods exhibit certain deficiencies, which have been mitigated under the experimental conditions delineated in the novel accelerated approach for ascertaining the reactivity of aggregates, otherwise known as the MCPT – Miniature Concrete Prism Test. The methodology of MCPT has the potential to become an alternative for the existing procedures of quality assessment for both fine and coarse aggregates. This work presents the assessment results of the alkaline reactivity of indigenous fine quartz aggregate, examined in accordance with the protocols established by the Polish General Directorate for National Roads and Motorways along together the novel, expedited MCPT methodology. [ABSTRACT FROM AUTHOR]

Nowadays, the construction industry requires an ample quantity of non-renewable materials resulting in the excavation of natural beds and thus creating an imbalance in our environment. Besides this, plenty of waste material such as plastic waste in the forms of powder, fiber, etc. is produced daily. Sustainable disposal of this waste has appeared as a tough task across the world. The current work was undertaken to reduce the issue of plastic waste mainly polyethylene terephthalate, disposal by its effective utilization in cement mortar mixes without affecting their physical, chemical, mechanical, durability, and microstructural properties. For this, a total of ten cement mortar mixes with 1:3 and 1:6 mix proportions were prepared by using polyethylene terephthalate plastic waste [1mm (68%), 2mm (22%), 3mm (6%), and 4mm (4%)] in place of fine aggregate upto 20% replacement at an interval of 5%. These mortar mixes were evaluated for their workability, water absorption, compressive strength, flexural strength, acid attack, and shrinkage properties. Effects on internal structure were monitored by microstructural analysis such as Xray diffraction, scanning electron microscopy, and Fourier transform infrared spectroscopy techniques. With 5% polyethylene terephthalate instead of river sand, the mixes displayed improved strength with the highest recorded 8.03 MPa and 2.36 MPa for 1:3 and 1:6 mixes respectively, and also obtained workability with increased density and homogeneity of structure. Benefits from polyethylene terephthalate were confirmed through microstructural analysis techniques except that there was a reduction in drying shrinkage. The results recommend that polyethylene terephthalate can be a reliable material in advanced construction applications offering enhanced structural parameters to save natural resources. [ABSTRACT FROM AUTHOR]

Palm oil empty fruit bunch (OEB) is the largest source of waste in the production of crude palm oil. Utilizing this waste in various applications can help reduce its volume and mitigate adverse environmental effects. In this study, fibers from OEB without any chemical treatment are introduced into Ordinary Portland Cement (OPC)-based mortar to partially replace fine aggregates, aiming to reduce the mortar's density. The goal of this experimental study is to observe the mechanical and physical performance of the samples according to the effect of the addition of OEB. The composite samples were made by replacing 1%, 2%, and 3% of the weight of quartz sand as the fine aggregate with OEB (fine and coarse). The hardened composites were further tested to determine their compressive strength, and it was found that the replacement of sand with OEB led to a decrease in compressive strength and flowability while alleviating the mortar's density and affecting the setting time. The decrease in compressive strength was attributed to cavities present in the samples. Flexural tests and 28-day drying shrinkage measurements were carried out on the samples with 1% replacement of sand with OEB. The experiments showed that OEB fibers increased the flexural strength, functioned as a crack barrier, and reduced drying shrinkage. [ABSTRACT FROM AUTHOR]

Copyright of Environmental & Social Management Journal / Revista de Gestão Social e Ambiental is the property of Environmental & Social Management Journal and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Materiały Budowlane is the property of Wydawnictwo SIGMA-NOT and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Extrudability and constructability are two important, yet contradictory issues pertaining to the construction of three-dimensional (3D) printing concrete. Extrudability is easily achieved when 3D printing cement mortar has a high water content and low cohesion, but the printed structure is easily collapsible. However, a 3D printing cement mortar with a low water content and high cohesion has a relatively stable printed structure although the cement mortar might not be extrudable. This study proposes a particle-based method to simulate 3D printing mortar extrusion and construction as an overall planning tool for building design. First, a discrete element model with time-varying liquid bridge forces is developed to investigate the microscopic effects of these forces on global rheological properties. Next, a series of numerical simulations relevant to 3D printable mortar extrudability and constructability are carried out. The study demonstrates that the effects of time-varying liquid bridge forces on rheological properties and the resulting extrudability and constructability of 3D printing mortar are considerable. Furthermore, an optimized region that satisfies both the extrusion and construction requirements is provided for 3D printing industry as a reference. [ABSTRACT FROM AUTHOR]

Global warming is one of the most important issues that the world is currently facing. The cement industry accounts for around 7% of total global CO2 emissions. According to the 13th United Nations Sustainable Development Goals, cement plants must become carbon neutral by 2050. This neutrality may be achieved by a reduction in CO2 emissions complemented with carbon capture, utilization and storage (CCUS) technologies. In accordance with these sustainable goals, several approaches have been studied. This paper investigates life cycle carbon of mortars produced with carbonated recycled aggregates. In previous works, the carbon dioxide capture capacity of construction and demolition waste (CDW) was analysed, and mortars with CDW recycled aggregates submitted to high levels of CO2 were evaluated in terms of their mechanical performance. This paper focus on the life cycle carbon impact assessment (LCCA) of industrial mortar formulations in a cradle-to-gate boundary. This assessment is carried out through a global warming potential environment impact assessment, since it represents the amount of CO2 equivalent that is sent to the atmosphere and contributes to the "greenhouse effect". This LCCA includes the impacts associated with the treatment and additional transportation routes of the recycled aggregates. With this work, it was found that mortars with carbonated recycled aggregates have a considerably lower global warming potential impact than mortars without recycled aggregates. The mortars with recycled aggregates presented lower CO2 emissions of up to 6.31% for 100% incorporation of non-carbonated recycled aggregates. These values were incremented with the carbonation of the recycled aggregates, achieving a reduction of CO2 emissions of up to 36.75% for 100% of incorporation. [ABSTRACT FROM AUTHOR]

This study examined the effects of silane-modified polyimide polymer (PIS) on cement mortar. The PIS was added to replace cement in a specified ratio. Obtained results revealed that the PIS caused retardation on setting time, and accelerated UPV mostly by encapsulating unhydrated cement particles, filling pores, or reacting with C–S–H and Ca(OH)2 with shifting to Si–O vibrations. SEM results showed a good compact interface without forming considerable agglomeration and voids on the microstructure, and this improved flexural and compressive strength properties. In conclusion, silane-modified polyimide as an admixture or cement replacement can be recommended for construction industries to enhance the properties of cement mortar. [ABSTRACT FROM AUTHOR]

Copyright of Journal of Railway Science & Engineering is the property of Journal of Railway Science & Engineering Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In this study, the capacitance-based stress self-sensing properties of fly ash-based geopolymer mortar are investigated for the first time. A coplanar electrode configuration is employed for capacitive measurements. Variations in capacitance are determined by subjecting the geopolymer mortar to both low (1.34–6.7 kPa) and relatively high (5.37–26.85 kPa) cyclic stress regimes. Before the tests, the capacitance and resistance of the test specimen are measured, yielding values of 412.7 pF and 34.17 kΩ, respectively. As stress levels progressively increase, the capacitance gradually decreases, and the resistance gradually increases. Specifically, the stress sensitivity, represented as the fractional change in capacitance per unit stress, is found to be 1.8 × 10−7 P−1 for low-stress regimes and 1.3 × 10−7 P−1 for high-stress regimes. It is worth noting that capacitive stress self-sensing is observed to be more effective in low-stress conditions. [ABSTRACT FROM AUTHOR]

In the late antique period (fourth-seventh centuries AD), lime was produced and consumed in great quantities for use in building, medicine, tanning, fulling, mortuary practices, and as an agricultural fertiliser. As a result, lime kilns (and associated slaking pits) are common features of late antique contexts – both in urban and rural environments and involving public institutions and private enterprise. In this paper we consider the archaeological remains of lime production and use in the eastern Mediterranean, a region in which dozens of lime production sites have been recorded. Focusing on the example of lime mortar production specifically, and following evidence for the associated chaîne opératoire, we demonstrate the versatility of the lime production process and how it frequently involved and even relied upon multiple industries. [ABSTRACT FROM AUTHOR]

This study introduces an innovative approach by modifying a commonly used filler with a natural compound, PEI. Fine aggregates within the filler were treated with different contents of PEI solutions. This research thoroughly examined the filler's pore structure, mineral composition, physical characteristics, and surface morphology. Additionally, this study explored the effects of PEI-treated fine aggregates on the macroscopic features of recycled cement mortar, focusing on aspects like flowability, compressive strength, capillary water absorption, and chloride ion permeability. The findings revealed that treating the fine aggregates with PEI decreased the pore volume by up to 28.2% compared to untreated samples. This improvement in the microstructure may originate from the formation of calcite and its by-products, which occupy the pores with nanoparticles generated in situ. Furthermore, the modification with polyethyleneimine resulted in a wavy, plate-like structure that not only enhanced the surface morphology but also improved the compressive strength and chloride ion permeability. Furthermore, it significantly reduced capillary water absorption by 32% to 51%, thereby enhancing the material's durability. The present study underscores the superior advantages of PEI modification as a promising strategy to enhance the viability of public fine aggregates. [ABSTRACT FROM AUTHOR]

Cement production is responsible for approximately 7% of global carbon dioxide emissions. Despite our efforts, we have not been able to find a competitive substitute that is both reliable and environmentally friendly. The easiest way to solve the issue is to rationalize resources and try to minimize their use by replacing them with other materials. The current market shortage and reduced initial strength have limited the availability of blends that contain a significant amount of fly ash. Given the current economic, political, and environmental circumstances, it is predicted that a solution may be ternary blends with cement, fly ash, and MTK. Despite being "ancient" materials, there have been no recent global performance assessments. In this context, an investigation was carried out with ternary blend mortars. A significant volume of cement has been replaced with fly ash and metakaolin. The results show that these blends' performance is promising because they offer a wide range of possibilities for replacing cement, maintaining or even improving its properties. MTK and fly ash's synergies significantly enhance mechanical performance and durability. Furthermore, the global sustainability analysis shows that ternary blends are 36% more efficient than binary blends of cement and fly ash or metakaolin. [ABSTRACT FROM AUTHOR]

Rubberized cement-based materials are widely utilized because of their good ductility, impact resistance, and fatigue resistance. This research investigated the effect of the rubber aggregates content, particle size of rubber aggregates, and water–cement ratio on the early-age mechanical properties and deformation behaviors of mortar through laboratory tests, and strength reduction coefficient fitting models were established according to the testing results. The results show that the compressive strength growth rate of cement mortar is about 15% slower than that of flexural strength. The existence of rubber aggregates lowers the strength increase rate of mortar. The reduction coefficient of strength decreases with increasing rubber aggregates content and increases with the age of mortar. Increasing rubber aggregates content and decreasing particle size of rubber aggregate can lower the autogenous shrinkage in the initial stage, but the autogenous shrinkage of the later stage increases as the rubber aggregates content increases, with a turning point between 30 h and 50 h. After 3 days, the dry shrinkage of mortar accounts for about 70–80% of the total shrinkage, and it increases with higher rubber aggregate content, smaller particle size of rubber aggregates, and higher water–cement ratios. [ABSTRACT FROM AUTHOR]

Ladle furnace slag (LFS) is used as a supplementary cementitious material (SCM) due to its high calcium oxide (CaO) content. Its binding properties are enhanced in the presence of siliceous materials, such as metakaolin (MK), forming a ternary mixture that can directly replace ordinary Portland cement (OPC). However, despite this blend having already been evaluated in alkali-activated mixtures, knowledge about this mixture in situations of direct replacement of OPC by slag is still lacking. This study evaluates the synergistic effects of combining LFS and MK in cementitious mortars. Due to an insufficient hydration reaction observed in the short term, this study focuses on assessing the long-term performance of these mortars. Both the fresh and hardened states at 28 and 180 days are evaluated, and the resulting microstructural characteristics and constituent phases are also examined. After 180 days of curing, the mortar with MK exhibits superior binding activity compared to the results at 28 days. Although the nominal resistance does not show a clear advantage with the application of MK, a significant reduction in the porosity of the mortar is observed. Microstructural analysis indicates that the addition of MK increases the hydration compounds when mixed with LFS. Importantly, the sample containing MK and LFS showed a 42% reduction in cement consumption, highlighting the potential for resource efficiency. Thus, this study contributes to promoting a circular economy between the steelmaking and civil construction sectors. [ABSTRACT FROM AUTHOR]

The main objective of this study was to determine the impact of glass waste as a valuable additive in cement mortars. As part of this study, three mortars with different glass waste contents were designed with the addition of 10, 20, and 30% glass waste, as well as a reference mortar without the additive. The selected characteristics of the mixtures were determined, including the consistency, density, air content, and strength properties of the mortar. Strength tests (bending and compressive strength) were performed after 28 and 56 days of maturation. Mortars with the lowest waste content (MC10%) achieved flexural strength of 26% and compressive strength of 18% compared to the average value of standard mortar, whereas MC20% mortars showed a decrease in bending strength of 30% and compressive strength of 24%. Studies have also been conducted to determine the parameters of air trapped in the mortar microstructure and its possible impact on mortar durability in a freezing/thawing environment. A group of experimental studies involved microstructure studies aimed at assessing the changes that occur in mortars containing glass waste. The negative effects of glass waste on the compressive and bending strengths and the positive effect at low temperatures were clearly demonstrated. [ABSTRACT FROM AUTHOR]

In order to explore the feasibility and efficacy of reed-fiber-modified bitumen (RFMB), three lengths and three dosages of reed fibers were selected to modify bitumen and bituminous mortar, while the physicochemical properties of RFMB and RFMB mortar were analyzed. In this work, FTIR spectroscopy was employed to characterize the chemical impact of fiber on bitumen. The viscidity and rheology of RFMB and the tensile strength of RFMB mortar were evaluated using a Brookfield viscometer, dynamic shear rheometer, and monotonic tensile test. The results showed that adding fibers primarily affects the physical structure rather than the chemical composition of bitumen, confirmed by FTIR spectroscopy. RFMB viscosity increased with higher fiber dosage and fiber length. Rheological evaluations showed an enhanced complex shear modulus for RFMB, suggesting improved performance at higher temperatures but increased stiffness at lower temperatures, with the latter indicating reduced flexibility. RFMB also demonstrated superior fatigue and rutting resistance, albeit with compromised stress sensitivity. Tensile tests on RFMB mortar highlighted significant improvements, especially with longer fibers, while shorter 0.4 mm fibers showed modest reinforcement effects, possibly due to uneven distribution during sample preparation. [ABSTRACT FROM AUTHOR]

Throughout history, the architecture of worship structures has been shaped based on different cultures and belief systems during the Roman, Seljuk, Anatolian Principalities, and Ottoman periods. Additionally, it is understood that the sociocultural and ritual structure in which the worship place is built plays a significant role in church architecture. In province of Ordu, rich in historical and cultural heritage, historical structures outside the city center have not been well preserved. In recent years, neglected historical structures have been restored through various methods with public investments, aiming to reintegrate them into urban life. Through chemical and mineralogical (by microscopy) examinations aimed at determining the types of historical structural materials used for this purpose, the preservation of historical structures in Ordu province and their transfer to future generations is targeted. Church structures, holding a distinct significance in the region's history, exhibit various characteristics in terms of location, climate, and sociocultural and ritual aspects in the Black Sea region. In this regard, the restoration of the historical Taşbaşı Church in the Altınordu district of Ordu province has been carried out considering scientific techniques and methods, serving as a guide for similar studies in the region in terms of laboratory analysis, studies, planning, project development, and implementation stages. [ABSTRACT FROM AUTHOR]

The need to construct environmentally friendly buildings to meet current environmental and ecological standards is urgent. This study introduces a new multi-layer construction material with two outer layers of ordinary mortar and an inner layer of a pozzolane-limes composite to meet this need. The thermal efficiency of this material in building construction is investigated using TRNSYS18 simulations for two distinct climatic zones in Morocco, with a particular focus on its impact on heating dynamics. The primary objective is to evaluate the thermal performance of multi-layered pozzolanic materials, for which mortar samples are meticulously prepared as a reference in the two different climatic zones (Azilal and Errachidia). Using the asymmetric hot plate method under both stable and transient conditions, the authors conduct thermal characterization experiments. The results underscore the improvement in thermal performance made possible by the incorporation of pozzolan as an aggregate in the multi-layer material compared to ordinary mortar. Specifically, thermal conductivity improves significantly, from 0.735 W m−1 K−1 for ordinary mortar to 0.4 W m−1 K−1 for multi-layered pozzolanic materials, representing a 46% mass gain. Additionally, effusivity decreases from 730 to 604 J m−2 K−1 s−1/2, while diffusivity decreases from 3.78 to 2.23 × 10−7 m2 s−1, further attesting to the material's thermal efficacy. TRNSYS18 simulations corroborate the viability of using multi-layered materials as building envelopes, revealing potential annual heating gains of 25% in Azilal and 5% in Errachidia. These findings underscore the promising prospects of integrating these materials into sustainable construction practices. [ABSTRACT FROM AUTHOR]

Synthetic fibers can effectively inhibit the formation and propagation of micro-cracks in concrete, significantly reducing the number and scale of cracks within the concrete matrix, thereby enhancing the concrete's crack resistance and seepage prevention capabilities. In this study, two types of synthetic fibers, polyvinyl alcohol (PVA) and polypropylene (PP), were incorporated into cement mortar to investigate their microstructural evolution at elevated temperatures and their influence on the mechanical properties of the mortar. Both fibers were added at a volume content of 0.5%. The mortar samples were subjected to the following temperature conditions: 20 °C (ambient), 200 °C, 400 °C, and 500 °C. The results indicate that the synthetic fibers employed in this study improved the tensile properties of the mortar at room temperature (20 °C). This enhancement persisted up to 400 °C, beyond which, at 500 °C, the mechanical properties of the fiber-reinforced mortar deteriorated significantly. At 400 °C, the tensile strength of the PVA group increased by approximately 16% compared to the unblended fiber group (JZ) and by about 45% compared to the PP group. After treatment at 500 °C, the tensile strength of mortar specimens in the PVA group and the PP group decreased by 36.47% and 24.14%, respectively, compared with that at 20 °C. The porous structure formed due to the high-temperature ablation of the synthetic fibers contributed to relieving the internal pressure within the mortar. [ABSTRACT FROM AUTHOR]

Some wrong decisions and faulty practices applied during the repair and restoration of traditional buildings cause more damage to the structures due to the materials used in the repair. The aim of this study is to establish a scientific basis for material selection in the repair of traditional buildings in the Konuralp region through chemical and petrographic analyses. In this study, brick, mortar, plaster, and wood samples were taken from one registered building in the Konuralp neighborhood of Düzce Province that has survived to the present day by preserving its original structural features and reflecting the characteristics of traditional housing. Chemical and petrographic analyses were carried out on the samples. In line with these analyses, a scientific basis was created for selecting material properties in the repair and reuse processes of traditional buildings and suggestions are made for the analysis of materials specific to traditional buildings in Konuralp. [ABSTRACT FROM AUTHOR]

Archaeological investigations in the rural settlements of the Po Valley in the Piedmont region of Northern Italy, particularly in the Monferrato area, have revealed a wide range of structures dating from the Roman to the Early Medieval periods. This rural architecture is of great heritage value, as it provides insights into the historical development of Piedmont. This paper focuses on the analysis of lime, one of the oldest and most important building materials, used as binder of bedding mortars of three archaeological rural buildings sites dating from the Early Roman imperial Period to the Late Antique phases of medieval fortified centers of Piedmont region. A low-cost and efficient diagnostic geochemical-based method based on the characterization of two oxides present in the lime of mortars and in carbonate rocks of the area (MgO and CaO) is presented. Exploited limestone quarries exploited often have a fairly constant chemical composition and therefore a typical geological Mg/Ca ratio. The variation in this ratio is useful for the relative dating of building walls and for identifying of geological formations and quarries possibly used during the different architectural phases. This paper focuses on this second objective: the study of potential supply areas across the ages related to the ancient communication routes. [ABSTRACT FROM AUTHOR]

Abstract The concept of sustainability has become a crucial concern for safeguarding the planet. The current research has focused on developing affordable and eco-friendly mortar by using industrial wastes. This study explores the use of fly ash (FA) and ground granulated blast furnace slag (GGBFS), byproducts of steelmaking and coal burning, in mortar production. It examines their impacts on the compressive strength and setting times, when utilizing varying proportions of the materials. The study also evaluates water requirements for the workability, thus demonstrating the sustainability of these waste products in construction. The cementitious materials were employed in finely ground form and were replaced with further tertiary mixes including both supplements at 10%, 30%, and 50% of each. The mixtures were allowed to cure for 7, 14, and 28 days by immersion in water. The results showed improvements in the compressive strength of mortar samples incorporating FA and GGBFS at various curing ages. However, the water requirement and workability of mortar samples were altered as a result of utilizing these supplementary cementitious materials (SCMs). These findings will serve as a standard for environmentally responsible mortar using GGBFS and/or FA as SCMs.

Abstract This research aimed to examine the effects of an acidic environment on the mechanical properties and durability of bio-mortar (BM) encapsulated with Bacillus subtilis bacteria, in comparison to normal mortar (NM). The results at 28 days indicated that both 3% and 6% HCl significantly increased the compressive strength of the BM by 25% and 50%, respectively, compared with that of the NM. However, when 11% HCl was introduced, the compressive strength of the BM decreased to 50% lower than that of the NM. Furthermore, the water absorption rate of the BM was 33% lower than that of the NM. The mass loss for both 3% and 6% HCl was comparable, whereas at 11% HCl, BM experienced a mass loss that was 68% greater than that of NM. These findings suggest that with 3% and 6% HCl, the microbially induced calcium carbonate precipitation (MICP) process effectively generated CaCO3, which filled the pores and enhanced the structural integrity of the BM, leading to improved compressive strength and durability. Conversely, at 11% HCl, the MICP benefits in BM were diminished due to adverse environmental conditions that negatively affected the bacterial cells, highlighting the limitations of the HCl concentration for optimizing MICP efficiency in mortar.

Abstract This study helps in managing waste glass and greening the environment by incorporating laboratory waste glass into mortar production to make an eco-friendly shielding material against gamma rays. The efficiency of using waste glass powder as a cement replacement or addition in mortar production was studied by using two waste glass sizes: micro glass (particle size range from 10.09 to 24.73 μm) and nano glass (particle size range from 10.57 to 26.42 nm) to design different mortar specimens with varying percentages of fine glass powder from 0 to 30%. Compressive strength and flexure strength were evaluated to determine mechanical properties. The results indicated that adding WGP to mortar positively affects the characteristics of cementitious composites. The linear and mass attenuation coefficients of the samples were experimentally determined using a NaI detector and various radioactive sources (Am-241, Ba-133, Eu-152, Cs-137, and Co-60) with gamma energies ranging from 59.53 to 1332 keV. The obtained coefficients were then compared to the theoretical values of the composites using XCOM software to verify their accuracy. Additionally, the half-value layer, tenth-value layer, mean free path, and effective atomic number were computed. Furthermore, the results revealed that the mortar sample with 30% nano additive glass was the most effective in reducing gamma radiation.

Abstract In the context of the mounting crisis of waste management and environmental sustainability, coal bottom ash (CBA) emerges as a pioneering solution in the field of construction. This study, which is a pioneering investigation, delves into the transformative impact of integrating CBA into the fabric of various concrete compositions, which range from traditional mortar to avant-garde geopolymer concrete. A comprehensive evaluation of mechanical properties, including compressive strength, flexural strength, and modulus of elasticity, is conducted alongside a spectrum of durability indicators such as water absorption, chloride ion resistance, and sulfate fortitude. Benchmarks set by global standards such as ASTM and EN serve as our yardstick, revealing that a strategic substitution of up to 10% of sand with CBA not only aligns with these rigorous norms but occasionally surpasses them. For cement, concrete, and geopolymer, the optimal replacement levels of CBA are between 10 and 30%. This enhances mechanical properties and promotes environmental sustainability. Our findings demonstrate the dual benefits of CBA: enhancing the structural integrity and durability of concrete while promoting ecological stewardship. This study not only validates the suitability of CBA as a superior construction material but also encourages the construction industry to pursue a more sustainable and waste-minimizing future.

Abstract The aim of this study is to evaluate the potential use of wood ash as a cement additive. Four wood specimens from Yaoundé city of (Cameroon) were used namely: Sapelli, Iroko, Movingui and Padouk. Five mortar were produced, with cement substitutions of 0%, 5%, 10%, 15% and 20%. The fresh rheological, mechanical and hardened durability properties of various mortar were obtained after 7, 14, 28 and 56 days. The results showed that cement paste consistency and the cuing time increases with the addition of ash. At 28 days, the mortars obtained from the 5% and 15% Padouk and Movingui ash substitutes, respectively, showed optimum compressive strength (9%, 6%) and flexural strength (5%, 3%) compared with the control mortar. Due to continuous pozzolanic activity, this flexural gain is multiplied by 3 for Movingui mortar (9%) at 56 days. Compared with the 28-day and 56-day compressive strength results, there were increases of 5% and 4% respectively for the 5% and 15% ash substitutions in Padouk and Movingui mortars. Durability results were evaluated through absorption, which showed relatively identical rates in mortars containing ash from Padouk and Movingui wood, due to their water content for normal consistency. Chemical attack with H2SO2 and NaCl proved that the incorporation of ash improved the mortars' resistance to chemical attack. Thermal analyses and microscopic observations were performed with the optimum.

A nonlinear dynamic model of a train–bridge-longitudinal track coupling system considering the dynamic contact of the bridge–track interface (BTI) is established. Based on the previously established BTI contact characterization model and train–bridge coupling joint simulation model, the proposed model is verified from both static and dynamic perspectives. Accordingly, the dynamic displacement variation law of the bridge–track structure before, during and after the train passing through the side pier settlement area, the additional stress dynamic variation law and the interlayer connection dynamic variation law are analyzed. Moreover, the amplification effect of the wheel repeated "beating effect" on the dynamic contact force of "disengagement-closure-redisengagement" of the BTI void area is also analyzed. The results show that the accuracy of the proposed model can be verified from both static and dynamic perspectives. During the train passes through the settlement area, the dynamic deformation of track is the largest. Before and after the train passes through the settlement area, the dynamic deformation of track is basically the same. During the train passes through the settlement area, the BTI completes a dynamic contact process of "disengagement-closure-redisengagement". The static effect of the side pier settlement on the dynamic bonding force of sliding layer is much larger than the dynamic effect of the train load. The dynamic effect of the train load is much larger than the static effect of the side pier settlement on the dynamic bonding force of the CA mortar and fasteners. The side pier settlement has a dynamic amplification effect on the train wheelset. Along the mileage direction, there are interface voids and contact areas in the dynamic bonding force of sliding layer and CA mortar, while there are no voids and contact areas in the dynamic bonding force of fasteners. [ABSTRACT FROM AUTHOR]

Sulfate resistance is evaluated in mortars containing sulfate-resistant cementitious materials (SRCMs) developed by mixing ground granulated blast furnace slag, fly ash, silica fume and desulfurisation gypsum. Compressive strength testing, X-ray diffraction analysis, differential thermal analysis and mercury intrusion porosimetry are carried out. Results show that the sulfate resistance of mortars mixed with SRCMs at a replacement percentage of 74 wt% is superior to that of mortars with 30 wt% fly ash when exposed to drying–wetting cycles in sodium sulfate solution, because adding SRCMs decreases the calcium hydroxide content, causing a reduction in gypsum formation. Moreover, reducing the water-to-binder ratio (W/B) from 0.50 to 0.35 increases the loss of compressive strength ratio (Lf) of mortars with SRCMs immersed in ammonium–magnesium sulfate complex solution. Specifically, the Lf values of mortars with W/B of 0.50 and 0.35 are 42.7% and 36.0% after 100 days of immersion, respectively. Furthermore, the main component of samples subjected to complex solution is identified as gypsum. In addition, both Lf and porosity exhibit a strong linear positive correlation with W/B. Finally, the findings confirm that optimising the composition of cementitious materials and lowering W/B could improve the sulfate resistance of concretes used for a sulfate-rich sewage environment. [ABSTRACT FROM AUTHOR]

In this study, the use of meta-schist as an alternative to sand–clay in preparing cement raw mixtures was investigated for the first time. To produce the highest quality Portland cement clinker by examining the mineral and chemical properties of meta-schists, two different raw meal samples were prepared, utilising conventional cement clay as a baseline sample ((PC)Ref) and the other with meta-schist ((PC)MSC). The effects of both raw mixtures on burnability tests and reactivity were evaluated based on the unreacted lime content in samples after they had been sintered at 1200, 1300, 1350, 1400 and 1450°C. The porosity amount, distribution, grain structure of silicate phase crystals, and equivalent crystal diameters and amounts of meta-schist clinker phases (C3S, C2S, C3A and C4AF) examined by polarising optical microscope showed that they are suitable for the production of PC. The hydration products of the cement mortars were determined by scanning electron microscopy and energy-dispersive X-ray analysis at 2, 7 and 28 days. In addition, the compressive strength test results of (PC)MSC and (PC)Ref mortars after 28 days of curing ranged between 57 and 55.5 MPa, and the cement produced was classified as CEM I 42.5R. [ABSTRACT FROM AUTHOR]

The aim of this work is to provide a new composite material for applications in the thermal insulation of buildings. The composite was made with mortar reinforced with natural fibres extracted from the petiole of the Washington robusta (WR) palm tree. The fibres used were first chemically characterised by energy-dispersive X-ray spectroscopy, scanning electron microscopy, X-ray and infrared diffractometry spectroscopies alongside tensile testing to discover their morphological structure. Afterwards, the fibres were incorporated into mortar with mass percentages varying from 0 to 4% to determine experimentally the thermomechanical properties of the manufactured samples. The chemical findings indicated that WR fibres are rich in cellulose, hemicellulose and lignin, and possess a high crystallinity index, which enhances the mechanical properties and durability of the composite. The density obtained for the composite W2RC4% is 1305 kg/m3 and less than 2000 kg/m3; this composite can thus be classified as a lightweight concrete according to the standard NF EN 206 + A2/CN (2022). The thermal conductivity and thermal effusivity dropped by about 60% and 42%, respectively. Moreover, the WR reduces the compressive strength (76%) and the flexural strength (36%) to minimum values, respectively, of 5.9 MPa and 3.8 MPa. These values meet the mechanical requirements of lightweight concretes (> 3.5 MPa). [ABSTRACT FROM AUTHOR]

Lime-based materials are found in archaeological contexts across many world regions. The earliest evidence of lime production was discovered in the Levant dating to about 16,000 cal BP. Methods for transforming limestone, shells, and corals into slaked lime varied depending on region, culture, and period. Similarly, the use of lime had an extensive variation of applications such as hafting, plastering, mortars, flooring, plastering skulls, decorating, and making frescos. Each step of the lime production process—from raw materials sourcing to the mixing of finished materials—results in specific archaeological assemblages, each capable of delivering critical insight into the knowledge of the people who created them. Here, we review approaches and methodologies used to analyze each production step, and, specifically, those targeting raw materials selection and firing conditions. For investigating effectively raw materials selection and firing conditions of archaeological lime-based materials, we propose a methodological approach based on the integration of petrography and Fourier transform infrared microscopy (mFTIR) that uses chemical and mineralogical reference libraries prepared using experimental lime produced with provenienced raw materials. [ABSTRACT FROM AUTHOR]

The Monastery of Alcobaça houses in reserve the ceramic tiles that adorned the floor of the church's apse. These tiles were removed during rehabilitation works and many preserve part of their original fixing mortars. A comprehensive analysis of 21 samples was conducted using a multi‐analytical approach (X‐ray fluorescence, X‐ray diffraction, scanning electron microscopy–energy‐dispersive X‐ray spectroscopy, μ‐Raman spectroscopy, thermogravimetry–differential thermal analysis, optical microscopy, and colorimetry). Results suggest compositional variations in the samples from the back and sides of the ceramic tiles; however, the mineralogy and general characteristics of the aggregates remained consistent between the samples and are coherent with the local geology, suggesting a shared historical origin. [ABSTRACT FROM AUTHOR]

Microbial cement (MC) can generate biocalcium carbonate on the surface of mortar in the liquid environment, which shows potential advantages to enhance the surface property of prefabricated components. This paper is aimed to investigate the cementation solution (CS) concentrations (0.5, 1.0, 1.5 M) and treatment times (3, 6, 9, 12 time) on capillary water absorption coefficient (coefficient k) and compressive strength of MC treated mortar, and attempted to point out the macroproperties and microstructure evolution mechanism of mortars based on adsorption and deposition of MC. The results indicated that when CS concentration was 0.5 M, the reduction rate of coefficient k increased from 29% to 76% with increasing treatment times from 3 to 12, and the growth rate of compressive strength also increased from 7.4% to 27.5%. For a CS concentration of 1.5 M, shorter less treatment times resulted in a significant reduction in coefficient k, whereas it had little effect on compressive strength. The adsorption and deposition of MC treated mortar surface led to an increase in the pore volume fraction of less harmful and harmless pore (<50 nm) in the near-surface layer by filling the pores with calcite and altering the content of hydration products. This process decreased the content of portlandite and increased that of calcite. Increasing the content of surface deposition was beneficial for reducing coefficient k, whereas improving the inner pore structure was beneficial for increasing compressive strength. [ABSTRACT FROM AUTHOR]

The high shrinkage of metakaolin-based geopolymers (MKGs) dramatically limits their application as high-performance green cementitious materials. In this study, microscopic tests and microstructure analysis of the polymerization reaction products are employed to examine the drying shrinkage properties of MKG under different alkali equivalents. The results indicate an enhancement in the strength of MKG mortar with increasing alkali equivalent; however, it undergoes shrinkage in the later stages. Notably, the drying shrinkage increases with the alkali equivalent, mainly attributed to the fact that the increase in alkali equivalent does not change the types of hydration products in MKG. Instead, it promotes the dissolution of active silicon oxide and alumina in metakaolin (MK) particles, accelerating the hydration reaction process and, resulting in a higher amount of sodium aluminosilicate hydrated gel (N─ A─ S─ H) gel. Furthermore, the alkali equivalents modify the pore size distribution, leading to an increase in the 10–50-nm pore volume and capillary negative pressure, ultimately causing an increase in drying shrinkage. [ABSTRACT FROM AUTHOR]

Using steel slag in architectural three-dimensional (3D) printing not only enhances its utilization efficiency but also significantly reduces cement consumption, thereby mitigating carbon emissions. This study evaluated the substitution of steel slag for cement in 3D printing and examined its impact on rheological properties, fluidity, green strength, and early hydration microstructure based on alkalinity level, particle-size distribution, and blending quantity. The relationship between the early properties of 3D-printed steel slag cementitious materials and their pore microstructures was investigated using low-field nuclear magnetic resonance (NMR) tests. The results showed that high-alkalinity steel slag has superior rheological characteristics and generates a larger amount of gel water within the initial 30 min of hydration. Steel slag particles ranging from 5 to 20 μm had the most significant influence on enhancing the rheological properties of 3D-printed steel slag cementitious materials by facilitating the formation of a flocculated mesh structure during early hydration. Optimal rheological performance was achieved with a dosage level of 10% steel slag, effectively reducing porosity and improving compactness in the mortar. [ABSTRACT FROM AUTHOR]