Article
Construction & Building Technology
Yunqing Xing, Baomin Wang
Summary: This study aimed to solidify the harmful components in MSWI FA by alkali activation and found that the addition of converter steel slag enhanced the formation and crystallinity of the C-(A)-S-H gel. Increasing curing time reduced the leaching toxicity of heavy metals and stabilized chlorides in the alkali-activated matrix. The refinement of pore size and improvement of compressive strength contributed to the physical encapsulation of heavy metals and chlorides.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
L. E. Menchaca-Ballinas, R. Martinez-Lopez, J. Escalante-Garcia
Summary: Composite alkali activated cements of waste glass and ground granulated blast furnace slag were studied for their strength over a period of 720 days. Factors such as %WG, sodium silicate modulus (Ms), curing temperature, and %ultra-fine WG were found to influence the compressive strength. Different reaction products were observed under different compositions.
JOURNAL OF SUSTAINABLE CEMENT-BASED MATERIALS
(2023)
Article
Green & Sustainable Science & Technology
Apriany Saludung, Takumu Azeyanagi, Yuko Ogawa, Kenji Kawai
Summary: The study found that silica fume reduces the mobility of alkali in alkali-activated slag, leading to a decrease in efflorescence formation. However, almost all sodium can be leached out from the samples after immersion in water for 28 days, indicating the weak bond of sodium in the gel.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Construction & Building Technology
Xiaojuan Kang, Hailong Ye
Summary: Antimicrobial alkali-activated slag (AAS) incorporating Cu-based antimicrobial agents showed improved hydration and reduced chain length of C-A-S-H. The Cu-doped AAS exhibited excellent antimicrobial efficiency, with CuO-doped AAS inhibiting biofilm formation by 100% and reducing corrosion depth by a factor of 10. Cu ion release from C-A-S-H structure occurred initially at the outer surface, leading to structural rupturing.
CEMENT AND CONCRETE RESEARCH
(2023)
Article
Acoustics
Jing Qian, Fengbin Zhao, Jingjing Gao, LiJie Qu, Zhengbin He, Songlin Yi
Summary: Ultrasound-water, alkali, and ultrasound-alkali treatments were found to remove extractives from conduits of wood cell walls, resulting in uniform self-shrinking samples with changes in chemical components. The relative content of hemicellulose decreased significantly in ultrasound-8% NaOH treated samples, and the signal intensity of lignin showed more reductions in ultrasound-water and ultrasound-alkali treated samples. The cellulose crystallinity increased notably in ultrasound-assisted treated samples.
ULTRASONICS SONOCHEMISTRY
(2021)
Article
Engineering, Multidisciplinary
Weixi Cai, Zhipeng Xu, Zhangmin Zhang, Jie Hu, Haoliang Huang, Yuwei Ma, Zuhua Zhang, Hao Wang, Suhong Yin, Jiangxiong Wei, Caijun Shi, Qijun Yu
Summary: This study investigates the relationship between physical/chemical characteristics and chloride binding capacity of reaction products in alkali activated slag (AAS). The results show that C-S-H and C-A-S-H gels physically bind chlorides more, while LDHs have higher chloride binding capacity due to their physical binding nature.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Construction & Building Technology
Maryam Hojati, Farshad Rajabipour, Aleksandra Radlinska
Summary: Alkali activated Cement (AAC) is an environmentally friendly alternative to ordinary portland cement (OPC) for construction. This study investigated the long-term durability of AAC, particularly in relation to shrinkage and creep under constant load. The results showed that AAC with a high slag content had a larger time-dependent response and drying shrinkage. Additionally, high curing temperature affected the creep response and reduced the viscous behavior of AAC.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2022)
Article
Construction & Building Technology
Cuifang Lu, Zuhua Zhang, Jie Hu, Qijun Yu, Caijun Shi
Summary: The effects of the anionic species of the Na2O center dot 2SiO2-NaOH-Na2CO3 ternary activator on the rheology of alkali-activated slag pastes were studied. The interstitial fluid chemistry, especially the silicate species, OH- and CO32- ions, influenced the precipitation of early gels and the structural build-up by affecting the competition between dissolution and polymerization kinetics.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Chemistry, Physical
Hiroki Aizawa, Sora Kimura, Shunsei Abe, Masahito Sano
Summary: This study proposes a model of solvent movement in a gel, showing that the solvent flows easier along the gel network segment. By measuring the concentration distribution of solvents near the solid surface, adsorption on the nanometer scale can be evaluated. The experiment demonstrates the concept of gel network amplification and its usefulness for probing nanophenomena using macro-technology.
JOURNAL OF COLLOID AND INTERFACE SCIENCE
(2022)
Article
Construction & Building Technology
Ruiquan Jia, Qiang Wang, Ting Luo
Summary: This study examines the mechanisms and differences in the attacks of Na2SO4 and MgSO4 on alkali-activated phosphorus slag (AAPS). Na2SO4 causes expansion and volume stability improvement in AAPS, while MgSO4 leads to deterioration. The different binding capacities of Mg2+ and Na+ with OH- and the extent of dissolution equilibrium shift of C-N-A-S-H caused by Na2SO4 and MgSO4 contribute to the observed differences.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Tao Jiang, Ying Jin, Hailong Ye
Summary: This study investigates the phase assemblage, microstructure, and setting and mechanical properties of alkali-activated slag (AAS) under different chemical conditions. The ratio of non-bridging oxygens to tetrahedral cations is found to be an important indicator for reactivity, while it is less competent in indicating the setting performance of AAS. The variability of slag chemistry has considerable impacts on setting behaviors, but relatively insignificant effects on compressive strength. A higher amount of hydrotalcite formation tends to result in AAS with higher compressive strength.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Jiawei Lei, Wei Wee Law, En-Hua Yang
Summary: Alkali-silica reaction (ASR) is a major durability issue in ordinary Portland cement (OPC) concrete, and previous studies suggest that alkali-activated slag (AAS) concrete is less susceptible to ASR. This study found that a deficiency of calcium hydroxide is one controlling factor for the low ASR expansion of AAS mortars. The addition of calcium hydroxide substantially increased ASR expansion in AAS mortars, indicating its role in facilitating the gelation and formation of ASR products.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
D. Coffetti, S. Candamano, L. Coppola, F. Crea
Summary: The paper investigates the effect of tri-blend solid alkaline activators on the physico-chemical features and performances of activated slag pastes. The optimal alkali content was found to be close to 0.075, resulting in compact microstructure, high elasto-mechanical properties, and flowable mixtures.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Golnaz Sadeghian, Kiachehr Behfarnia, Mohammad Teymouri
Summary: This study evaluated the influence of mix design parameters on the drying shrinkage of alkali-activated slag concrete (AASC) and found that the addition of silica fume significantly reduced drying shrinkage magnitude. Furthermore, the curing regime also had an impact on drying shrinkage.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Ruilin Cao, Shunquan Zhang, Zijian Jia, Chun Chen, Zuhua Zhang, Nemkumar Banthia, Yueyi Gao, Yamei Zhang
Summary: This study investigates the effects of ferronickel slag (FNS) on the hydration heat, mechanical strength, and microstructure of alkali-activated slag (AAS). Results show that FNS has minimal influence on the reaction process of SH-activated AASF while delaying the reaction process of SS-activated AASF. The mechanism of FNS's influence on AASF reaction is unaffected by variations in alkalinity and modulus of the alkali activators. The reaction degree of FNS increases with FNS content in SH-activated AASF but has no relationship with FNS content in SS-activated AASF.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Nanoscience & Nanotechnology
Jesus Lopez-Sanchez, Alvaro Pena, Aida Serrano, Adolfo del Campo, Oscar Rodriguez de la Fuente, Noemi Carmona, Daniel Matatagui, Maria del Carmen Horrillo, Juan Rubio-Zuazo, Elena Navarro, Pilar Marin
Summary: Defective few-layered graphene mesostructures (DFLGMs) are produced from graphite flakes by high-energy milling processes, providing a functional material for microwave absorption purposes. By combining them with amorphous Fe73.5Si13.5B9Cu1Nb microwires (MWs), an improvement in reflection loss coefficient (RLmin) of 47% (-53.08 dB) and an enhancement in effective absorption bandwidth (EAB) of 137% (4 dB) are achieved compared to MW-based paints.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Ceramics
Rocio Estefania Rojas-Hernandez, Fernando Rubio-Marcos, Aida Serrano, Sara Roman-Sanchez, Jose Francisco Fernandez, Irina Hussainova
Summary: In this study, (hk0)-textured ZnAl2O4: Nd, Ce sub-micron films were synthesized using a screen printing technique assisted by a molten salt flux and deposited over the sapphire substrate. The focus was on controlling the Ce concentration in the emitting layers and determining the key parameters for the development of efficient ZnAl2O4-based films with remarkable optical properties. The degree of crystallinity and precise adjustment of texture were found to be crucial for improving NIR luminescence efficiency. Specifically, (hk0)-textured films developed at a sintering temperature of around 1300 degrees C exhibited higher NIR emission intensity compared to (hkl)-untextured films. This research demonstrates a feasible approach to achieve high NIR emission performance and validates its applicability for a wide range of applications.
CERAMICS INTERNATIONAL
(2023)
Review
Chemistry, Physical
Aida Serrano, Olga Caballero-Calero, Cecilia Granados-Miralles, Giulio Gorni, Cristina Manzano, Marta Rull-Bravo, Alberto Moure, Marisol Martin-Gonzalez, Jose F. Fernandez
Summary: This study demonstrates the use of a cold sintering process (CSP) to sinter CoSb3-based thermoelectric materials for the first time. The CSP yields samples with a relative density of 86% at 150℃ with a uniaxial pressure of 750 MPa, which is increased to around 92% after a post-annealing at temperatures ≥ 500℃ in Ar atmosphere. The CSP produces Te doped-CoSb3 nanocomposites with similar morphological and structural characteristics to the starting nanopowders obtained by ball milling in air atmosphere. The sintered thermoelectric nanocomposites exhibit a maximum figure of merit of 0.12(3) at room temperature.
JOURNAL OF ALLOYS AND COMPOUNDS
(2023)
Article
Materials Science, Ceramics
C. Granados-Miralles, A. Serrano, P. Prieto, J. Guzman-Minguez, J. E. Prieto, A. M. Friedel, E. Garcia-Martin, J. F. Fernandez, A. Quesada
Summary: Due to their various applications, lithium ferrites are important materials for emerging technologies. The lithium content in lithium ferrites greatly affects their physical properties and the performance of devices based on these materials. In this study, magnetic lithium ferrite powders with different Li:Fe ratios were synthesized and the Li content was accurately determined using two independent methods. The sintering process led to substantial grain growth and the presence of trapped pores, while the magnetic properties and density of the ceramics were measured. The results provide valuable insights into the synthesis and characterization of lithium ferrites.
JOURNAL OF THE EUROPEAN CERAMIC SOCIETY
(2023)
Article
Chemistry, Physical
Ali Saffar Shamshirgar, Maria Fernandez Alvarez, Adolfo del Campo, Jose Francisco Fernandez, Rocio E. Rojas Hernandez, Roman Ivanov, Johanna Rosen, Irina Hussainova
Summary: This study incorporates graphene-augmented alumina nanofibers into epoxy resin to fabricate a tunable absorption multilayer structure for electromagnetic interference shielding and RF absorption. Highly aligned graphene augmented alumina nanofibers were produced using a hot wall one-step catalyst-free chemical vapor deposition method. The highest loss tangent of 0.4 was achieved in a composite containing 1 vol% of randomly oriented nanofibers. A superposed three-layer structure was fabricated, offering an absorption of >90% in the entire X-band and an absorption peak of -25 dB at around 11 GHz. The hybrid nanofibers with a dual loss function show potential for versatile design options in RF absorption.
Article
Chemistry, Physical
Lukas Kalina, Vlastimil Bilek, Martin Sedlacik, Vladislav Caba, Jiri Smilek, Jiri Svec, Eva Bartonickova, Pavel Rovnanik, Josef Fladr
Summary: Protection of concrete against aggressive influences is important for its durability. Lithium silicate densifiers are popular concrete densifiers that increase hardness and impermeability. This study analyzes the chemical composition of the densifiers and the structure of the formed gel using Fourier-transform infrared spectroscopy. The research finds that the gelation process is influenced by the SiO2 to Li2O ratio, affecting the macro characteristics and durability of treated concretes.
Article
Materials Science, Multidisciplinary
Fernando Rubio-Marcos, Paula Pamies, Adolfo Del Campo, Jordi Tiana, Jonathan Ordonez-Pimentel, Michel Venet, Rocio E. Rojas-Hernandez, Diego A. Ochoa, Jose F. Fernandez, Jose E. Garcia
Summary: A clear correlation between optical absorption and light-induced strain in ferroelectrics is shown. The phenomenon of photoinduced electronic reconstruction at charged domain walls is proposed as the primary physical mechanism. These results provide a new pathway for designing ferroelectric-based devices with new functionalities, such as thickness gradient-based photo-controlled nanoactuators.
APPLIED MATERIALS TODAY
(2023)
Article
Nanoscience & Nanotechnology
Victor Fuertes, Adolfo del Campo, Nicolas Gregoire, Philippe Labranche, Jose Francisco Fernandez, Younes Messaddeq
Summary: An in-depth study of nanoparticle-doped optical fibers using confocal Raman microscopy, Rayleigh light-scattering microscopy, and scanning electron microscopy (SEM) reveals the crystallization structures and size-dependent Raman shifts of YPO4 nanocrystals in the fiber core. The study also evaluates the Raman properties of the nanocrystals at different temperatures, observing linear phonon softening behavior. These findings provide new insights into the characteristics of nanoparticle-doped optical fibers and open up possibilities for further research in this field.
ACS APPLIED MATERIALS & INTERFACES
(2023)
Article
Materials Science, Multidisciplinary
A. Moure, P. Val-Gomez, A. del Campo, J. F. Fernandez, F. Rubio-Marcos
Summary: In this study, the stress dynamics and its temperature dependence arising from the Orthorhombic-Tetragonal Polymorphic Phase Boundary (PPB) in lead-free potassium sodium niobate (KNN)-based ceramics were investigated. The growth of Orthorhombic phases is limited by the high-temperature tetragonal phase distributions, and two main mechanisms regulate the decrease of stress processes: microstructural effects hinder the formation of non-180° domains, while ferroelectric domain distribution and local structural heterogeneity contribute to the phase transition widening.
MATERIALS & DESIGN
(2023)
Article
Instruments & Instrumentation
Alessio Sacco, Luisa Mandrile, Li-Lin Tay, Nobuyasu Itoh, Ankit Raj, Alberto Moure, Adolfo Del Campo, Jose F. Fernandez, Keith R. Paton, Sebastian Wood, Hyuksang Kwon, Tehseen Adel, Angela R. Hight Walker, Erlon Henrique Martins Ferreira, Ralf Theissmann, Thomas Koch, Andrea Mario Giovannozzi, Chiara Portesi, Andrea Mario Rossi
Summary: This article presents an interlaboratory comparison on Raman spectroscopy as a reliable method for quantification of TiO2 phases. Raman spectroscopy is a fast, non-invasive technique that can differentiate and measure TiO2 without the need for special reagents or sample preparation.
Article
Chemistry, Multidisciplinary
Jesus Carlos Guzman-Minguez, Cecilia Granados-Miralles, Patrick Kuntschke, Cesar de Julian Fernandez, Sergey Erokhin, Dmitry Berkov, Thomas Schliesch, Jose Francisco Fernandez, Adrian Quesada
Summary: This study aims to explore the magnetic properties of hard-soft composite permanent magnets and their correlation with microstructure. The experimental results show that increasing the particle size of the soft phase can enhance the remanence in injection molded magnets. Through experimental analysis and simulations, it is revealed that the interaction between the hard and soft phases is of a dipolar nature.
Article
Chemistry, Physical
Rocio E. Rojas-Hernandez, Fernando Rubio-Marcos, Jallouli Necib, Mati Danilson, Jose F. Fernandez, Irina Hussainova
Summary: Near-infrared (NIR) emitting phosphors are in high demand for their applications in various fields. This study focuses on synthesizing ZnAl2O4:Ce/Nd films of nanometer thickness for NIR emission using a cost-efficient approach. The use of polycrystalline alumina substrates enhances emission intensity. The concentration of Ce4+ influences NIR emission. The findings contribute to understanding film production processes and guide future studies on NIR emitters.
PHYSICAL CHEMISTRY CHEMICAL PHYSICS
(2023)
Article
Biochemistry & Molecular Biology
I. Mena-Prado, J. J. Reinosa, M. Fernandez-Garcia, J. F. Fernandez, A. Munoz-Bonilla, A. del Campo
Summary: In this study, biobased composite materials based on poly(lactic acid) (PLA) and poly(butylene adipate-co-tera-phthalate) (PBAT) were developed for antibacterial and compostable food packaging films. The incorporation of sodium hexametaphosphate microparticles (E452i) as antimicrobial filler and acetyl tributyl citrate (ATBC) as plasticizer improved the thermal stability, crystallinity, and mechanical properties of the films. The E452i particles also provided antimicrobial properties against Listeria innocua and Staphylococcus aureus, with bacterial reduction percentages higher than 50% in films with 5 wt% of particles. The films maintained their disintegradability under industrial composting conditions.
INTERNATIONAL JOURNAL OF BIOLOGICAL MACROMOLECULES
(2023)
Article
Engineering, Environmental
S. Marin-Cortes, M. Fernandez-Alvarez, A. Moure, J. F. Fernandez, E. Enriquez
Summary: This study proposes a method for quantifying mixed construction materials through homogenization and chemometric modeling. It successfully applies this method to real CDW samples, enhancing their recycling potential in the ceramic industry and promoting CDW valorization and sustainability.
RESOURCES CONSERVATION AND RECYCLING
(2023)
Article
Construction & Building Technology
Diego J. De Souza, Leandro F. M. Sanchez, Juarez Hoppe Filho, Marcelo H. F. Medeiros
Summary: This paper evaluates the physical and chemical properties of mortar mixtures with different binders and exposed to different sulphate solutions. A theoretical approach to describe the susceptibility of cementitious mixtures against sulphate attack is proposed. The results show that the amount of portlandite and the potential of ettringite formation are well correlated with the expansion and damage caused by sulphate attack.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Yu Chen, Hossein Rahmani, Erik Schlangen, Og uzhan Copurog
Summary: This study presents a method to accelerate the production of limestone-calcined clay-based cementitious materials using Ca(NO3)2 solution in 3D printing, and investigates the effects of adding Ca(NO3)2 solution on the material's properties. The results show that adding Ca(NO3)2 solution can improve buildability, accelerate initial setting, and increase compressive strength.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Jing Xu, Xianzhi Wang, Wu Yao, Qing Chen, Hehua Zhu, Surendra P. Shah
Summary: Concrete cracks in marine engineering are caused by the hostile seawater environment, leading to serious deterioration of infrastructures. Microbial induced carbonate precipitation (MICP) is an effective and environmentally friendly approach for self-healing of concrete cracks. However, the formation and structure of MICP products for crack healing in seawater are still unclear, which hinders the application of MICP in marine structures.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Zhenbo Wang, Peng Sun, Yurun Fan, Yudong Han, Yudong Hu
Summary: This study investigates the potential use of engineered cementitious composites (ECCs) with strain-hardening and self-healing characteristics as a cover material in wet coral sand exposure. The results show that ECCs can effectively close cracks, reduce water permeability, and restore the load-carrying capacity of structures. Additionally, lower strain levels are associated with decreased rebar corrosion.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Zhengxian Yang, Xiaoli Xiong, Kang Li, Bruno Briseghella, Giuseppe Carlo Marano, Shanghong Chen
Summary: This study investigates the long-term volume stability and strength development of engineered cementitious composites (ECC) containing high-volume steel slag (SS). It is found that the strength of ECC with SS starts to decline after 90 days, while the decline is more significant compared to the matrix. The expansion of SS reduces the fracture toughness of the matrix, leading to an increase in toughness and ductility of the ECC. The introduction of ground granulated blast furnace slag (GGBFS) and PVA fibers can reduce the volume expansion and strength loss caused by SS expansion.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Bin Xi, Zhewen Huang, Salam Al-Obaidi, Liberato Ferrara
Summary: This study investigates the self-healing capabilities of Ultra-High Performance Concrete (UHPC) under the combined influence of mechanical and environmental factors. The results reveal that UHPC with narrow cracks exhibits a higher degree of self-healing, especially when exposed to tap water. Furthermore, prolonged exposure mitigates the inhibitory effect of aggressive ions on self-healing.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Zhichao Xu, Huayang Sun, Yanlin Huo, Minjie Jia, Zhitao Chen, Yingzi Yang
Summary: In this study, MXene was used to modify the surface of polyethylene fiber, improving the interfacial properties and tensile properties of strain hardening cementitious composites. The MXene-coated fiber showed increased tensile stress and strain, reduced crack width and spacing, and enhanced frictional bond strength between the fiber and matrix.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Bao Lu, Yeqiang Zhou, Lei Jiang, Zhensen Liu, Guihua Hou
Summary: This study investigated the leaching rate of Ca2+ from magnesium slag (MS) and developed a leaching-carbonation method to convert MS into high-purity vaterite and supplementary cementitious materials. The wet carbonation process with glycine as a crystal modifier successfully produced spherical vaterite with high purity and surface area. The leachate solid residue (LSR) obtained from the leaching process of MS showed a smaller size destruction and higher surface area compared to Portland cement, leading to accelerated hydration process and improved compressive strength and pore structure development. This work provides a novel treatment method for MS and enables its high value-added utilization.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Gustavo Henrique Nalon, Jose Carlos Lopes Ribeiro, Leonardo Goncalves Pedroti, Roberto Marcio da Silva, Eduardo Nery Duarte de Araujo, Gustavo Emilio Soares de Lima
Summary: The mechanical behavior of mortar joints is crucial for masonry's structural performance. This study investigated the effects of different lime/cement ratios and carbon black nanoparticles content on the properties of mortars. The results showed that increasing lime content decreased mortar strength but increased self-sensing properties at the end of the percolation zone.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Yifei Wang, Lei Lei, Caijun Shi
Summary: The effects of DEIPA and EDIPA at dosages of 0.02% and 0.05% on the hydration and strength development of cement-fly ash-limestone ternary blend were investigated. It was found that both dosages of DEIPA and EDIPA promote the chemical effect of limestone and the hydration of aluminates from cement and fly ash. The hydration of silicates was accelerated by 0.02% of DEIPA or EDIPA but delayed by 0.05% due to excessive aluminates hydration. DEIPA and EDIPA also refine the pore structure and increase compressive strength of the blend mortar.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Du Pan, Ditao Niu, Zongjin Li
Summary: A thick-walled cylinder model was developed in this study to analyze the cracking behavior of seawater sea-sand concrete (SSC) cover. Damage variables were introduced to determine the extent of damage for each cracked ring, and a predictive model for the cracking time of SSC cover was established. The accuracy of the model was verified using the Digital Image Correlation (DIC) technique.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Jiangyu Wu, Hong S. Wong, Hao Zhang, Qian Yin, Hongwen Jing, Dan Ma
Summary: This study explores a method of strengthening cemented rockfill by using well-graded gangue and partially replacing Portland cement with fly ash and a premixed low-alkalinity activator. The research investigated the effects of activator dosage and curing time on the mechanical properties, composition, and microstructure of cemented rockfill. Results show improved performance with low cement content and the use of a low-cost activator. The addition of premixed activator to fly ash enhanced the formation of specific minerals and caused densification of the microstructure. The study reveals an effective and low-cost method for recycling mining wastes and reducing cement.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Juntao Dang, Xiaosong Tang, Jianzhuang Xiao, Aihong Han
Summary: This study proposes a solution to improve the fresh stability and thermal insulation of alkali-activated foamed concrete by adding recycled brick powder. The study investigates the effects of activator modulus and Na2O concentration on the properties of alkali-activated foamed concrete with different bases. The presence of alkaline activator negatively affects the foamability and foam stability, but adjusting the activator concentration can achieve shorter initial setting time and higher fluidity loss. In addition, the increased activator concentration resulted in changes in the pore structure of the foamed concrete.
CEMENT & CONCRETE COMPOSITES
(2024)
Article
Construction & Building Technology
Jiandong Zuo, Bo Wu, Biqin Dong, Feng Xing, Jun Ma, Guanqi Wei
Summary: Nitrite ion intercalated Ca-Al and Mg-Al layered double hydroxides (LDHs) were successfully synthesized using two modified methods. The Ca-Al LDH synthesized by hydrothermal method (H-C-LDH) exhibited the best properties. The intercalated LDHs improved the mechanical properties, chloride penetration resistance, and permeability resistance of cement mortars without affecting the fluidity. Additionally, the intercalated LDHs provided better corrosion resistance.
CEMENT & CONCRETE COMPOSITES
(2024)
Review
Construction & Building Technology
Jingbin Yang, Zhenping Sun, Nele De Belie, Didier Snoeck
Summary: This review paper provides an overview of internal curing mechanism, common internal curing agents, and the most promising agent-superabsorbent polymers in alkali-activated materials (AAM) systems. The introduction of voids by internal curing agents typically has a negative impact on mechanical properties, but continuous water release during internal curing counteracts this effect by promoting hydration. While the effect of internal curing in reducing autogenous shrinkage of AAM systems has been well-established, the impact on drying shrinkage varies widely in different studies.
CEMENT & CONCRETE COMPOSITES
(2024)