Article
Construction & Building Technology
Kala Kondepudi, Kolluru V. L. Subramaniam
Summary: The study focuses on enhancing the buildability of printable alkali-activated mixtures by modifying the baseline mixture with alkaline activating solution and components like CMC, influencing the viscosity and properties of the mixture for achieving constructability in 3D concrete printing.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Construction & Building Technology
Sepehr Seyedian Choubi, Cagla Meral Akgul
Summary: This study investigates the impact of heat exposure on the performance of alkali-activated coal fly ashes (AAF). The results show that the mechanical performance varies depending on the exposure temperature and intrinsic properties of the activated ashes. Low-Ca AAFs are found to be more stable compared to high-Ca AAFs. Heat exposure also significantly reduces the thermal conductivity and volumetric specific capacity of all AAFs.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Tarik Omur, Nausad Miyan, Nihat Kabay, Burak Birol, Didem Oktay
Summary: This paper explores the utilization of ferrochrome ash (FCA) as a replacement for blast furnace slag (BFS) in the production of alkali-activated material. The addition of FCA improves the rheological properties of mixes and reduces water content, resulting in similar or superior physicomechanical properties compared to control mixtures. The setting time is affected by the initial molar ratio of SiO2/Al2O3, and FCA addition decreases compressive strength and drying shrinkage while increasing Na2O dosage enhances strength. Microstructural analysis reveals the reaction products and polymerization characteristics of the paste mixes.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Materials Science, Multidisciplinary
Fuyang Zhang, Xiao Yao, Tao Yang, Xuan Gao, Chenzi Geng, Tao Jiang
Summary: This study investigated the effect of FAM on AAS mortars for the first time, showing that FAM addition can decrease viscosity, increase fluidity, and effectively reduce ASR expansion. FAM promotes better alkali binding capacity to mitigate ASR in AAS mortars, while consuming Ca(OH)2 in OPC mortars to influence ASR development. Minor ASR products were observed in both AAS and OPC mortars modified with FAM, with stronger bonding between aggregate-paste interfaces.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Construction & Building Technology
Shizhe Zhang, Zhenming Li, Bahman Ghiassi, Suhong Yin, Guang Ye
Summary: This study comprehensively investigated the fracture properties of hardened alkali-activated slag/fly ash pastes, revealing that the fracture properties are mainly determined by the Ca/Si ratio of C-(N-)A-S-H gel and capillary porosity. Contradictions between the Ca/Si ratios and intrinsic mechanical properties suggest a cohesion/adhesion-based mechanism dominantly affecting the fracture properties.
CEMENT AND CONCRETE RESEARCH
(2021)
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
Materials Science, Multidisciplinary
Sohaib Nazar, Jian Yang, Muhammad Ashraf, Fahid Aslam, Muhammad Faisal Javed, Sayed M. Eldin, Jianhe Xie
Summary: The study investigates the influence of hydrated lime content and activator dosage on the fresh and hardened properties of one-part alkali-activated mortar based on fly ash and hydrated lime. The results show that the addition of FA/LM-based AAM enhances the reactivity and increases the compressive strength. Furthermore, the lime content affects the rheological properties, and the activator dosage affects the setting time and durability of AAM.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Construction & Building Technology
Elodie Coudert, Dimitri Deneele, Giacomo Russo, Enza Vitale, Alessandro Tarantino
Summary: This study focuses on using alkali activated fly ash-based binder to enhance the engineering properties of soft clay-rich soils. It investigates the microstructural evolution of the binder and how the presence of kaolin particles affects it. The formation of calcium-rich phases and new compounds plays a significant role in the microstructural changes observed.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Xiaodi Dai, Serdar Aydin, Mert Yucel Yardimci, R. E. N. Qiang, Karel Lesage, Geert De Schutter
Summary: The study investigates the effects of limestone powder on various aspects of alkali-activated cements, including rheological behavior, pore solution chemistry, mechanical properties, and microstructure. It was found that limestone powder enhances the structural build-up and reaction rate of the mixtures. However, the inert character of limestone powder leads to a decrease in compressive strength of the ternary mixtures.
CEMENT & CONCRETE COMPOSITES
(2021)
Article
Energy & Fuels
Priyesh Jani, Abdulmohsin Imqam
Summary: This research aims to provide an environmentally friendly alternative to Portland cement for CO2 storage wells by comparing the mechanical degradation of Portland cement and Class C fly ash-based alkali-activated cement in a high-pressure and high-temperature CO2 environment. The results showed that CO2 reacted with water to form carbonic acid, reducing the pH of the water. Portland cement exhibited a significant reduction in compressive strength over time, while Class C fly ash-based cement showed no significant reduction in compressive strength even after 14 days of exposure.
JOURNAL OF PETROLEUM SCIENCE AND ENGINEERING
(2021)
Article
Metallurgy & Metallurgical Engineering
Yuan Qiang, Huang Yan, Huang Ting-jie, Yao Hao, Wu Qi-hong
Summary: This paper investigates the effects of activator on the rheological behavior of alkali-activated cement pastes and reveals the physico-chemical mechanisms behind it. It was found that high Na2O concentration and low S/N molar ratio can improve the flowability and structural build-up rate of pastes.
JOURNAL OF CENTRAL SOUTH UNIVERSITY
(2022)
Article
Construction & Building Technology
Anvit Gadkar, Kolluru V. L. Subramaniam
Summary: Self-leveling concrete is developed using low-calcium alkali-activated fly ash binder paste, with the rheological behavior affected by silica content and modulus. Achieving self-leveling flow characteristics requires adjusting paste content and aggregate packing, while the transition from frictional to flow behavior depends on binder paste content, yielding flow without admixtures at low yield stress. Specifications for cement-based SCC are applicable for AAF-based self-leveling concrete.
ACI MATERIALS JOURNAL
(2021)
Article
Construction & Building Technology
Beibei Sun, Yubo Sun, Guang Ye, Geert De Schutter
Summary: In this study, the influence of control factors on the workability and compressive strength of BFS/FA-AAC was investigated, and a practical mix design method was established. The results showed that the mixture composition and water content significantly affect the workability of BFS/FA-AAC, while the compressive strength is determined by control factors. The accuracy of an empirical compressive strength formula for predicting BFS/FA-AAC performance was validated. This research is important for promoting the application of BFS/FA-AAC.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Prinya Chindaprasirt, Thammanun Boonbamrung, Apivich Poolsong, Wunchock Kroehong
Summary: This study investigated the mechanisms of polypropylene fiber-reinforced alkali-activated high calcium fly ash paste exposed to high temperatures. The results showed that adding 0.5% PP to the mixture resulted in the best improvement in compressive strength, while a slightly higher PP content at 1.0% was optimal for flexural strength. As the temperature increased, the pore structure of AHFP changed accordingly.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2021)
Article
Green & Sustainable Science & Technology
David Suescum-Morales, Rui Vasco Silva, Miguel Bravo, Jose Ramon Jimenez, Jose Maria Fernandez-Rodriguez, Jorge de Brito
Summary: The effect of incorporating bottom ash from municipal solid waste incineration (MIBA) as partial replacement for fly ash (FA) on alkali-activated mortars was studied. The use of MIBA resulted in a decrease of calcium silicate hydrate gel (C-S-H) and sodium aluminosilicate hydrate (N-A-S-H), affecting the macrostructural behavior of the mortars. The accelerated CO2 curing stage improved the macrostructural behavior of the mortars.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Construction & Building Technology
Wei Zhang, Xiao Yao, Tao Yang, Zuhua Zhang
ADVANCES IN CEMENT RESEARCH
(2019)
Article
Green & Sustainable Science & Technology
Tao Yang, Zuhua Zhang, Feng Zhang, Yanan Gao, Qisheng Wu
JOURNAL OF CLEANER PRODUCTION
(2020)
Article
Construction & Building Technology
Da-heng Wang, Xiao Yao, Tao Yang, Wen-rui Xiang, Ying-tao Feng, Yu Chen
Summary: A new approach is proposed to lower the hydration heat release of cement paste and ensure the early-age strength development at low curing temperature. The results showed that the addition of admixtures can improve the performance of cement paste and increase its compressive strength.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Tao Jiang, Chenzi Geng, Xiao Yao, Weikai Song, Dan Dai, Tao Yang
Summary: This study investigated the long-term performance of cement pastes modified by silica flour under high temperature and high pressure conditions, and found that 200-mesh silica flour can enhance the compressive strength of cement pastes, while 1000-mesh silica flour may reduce thermal stability.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Multidisciplinary
Fuyang Zhang, Xiao Yao, Tao Yang, Xuan Gao, Chenzi Geng, Tao Jiang
Summary: This study investigated the effect of FAM on AAS mortars for the first time, showing that FAM addition can decrease viscosity, increase fluidity, and effectively reduce ASR expansion. FAM promotes better alkali binding capacity to mitigate ASR in AAS mortars, while consuming Ca(OH)2 in OPC mortars to influence ASR development. Minor ASR products were observed in both AAS and OPC mortars modified with FAM, with stronger bonding between aggregate-paste interfaces.
MATERIALS RESEARCH EXPRESS
(2021)
Article
Construction & Building Technology
Xuan Gao, Xiao Yao, Tao Yang, Shiming Zhou, Haoguang Wei, Zuhua Zhang
Summary: In this study, the addition of calcium carbide residue (CCR) as an auxiliary activator was found to accelerate the hardening of Na2CO3-activated slag binders. The binder with 8% Na2CO3 and 2.5% CCR exhibited the maximum compressive strengths of 21.8 MPa at 1-day and 37.7 MPa at 28-day, showing significant savings in CO2 emissions, energy consumption and cost compared to PC paste.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Xuan Gao, Xiao Yao, Chunyu Wang, Chenzi Geng, Tao Yang
Summary: The study confirms that the eco-friendly AAS binders perform satisfactorily for oil well cementing operations, showing potential for a broad market outlook.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Wei Guo, Jialin Qiu, Qin Chen, Xiao Wang, Tao Yang
Summary: Hydrothermal curing before calcination can reduce the temperature required for belite-calcium sulphoaluminate cement clinker production, leading to high compressive strength in cement paste with optimal beta-C2S/C(4)A(3) ratio. The main hydration product observed was ettringite in the hydrated paste.
JOURNAL OF MATERIALS IN CIVIL ENGINEERING
(2021)
Article
Materials Science, Ceramics
Changsen Zhang, Ming Wei, Zhichao Hu, Tao Yang, Baoxiang Jiao, Huajun Zhu, Nan Sun, Haifeng Lv
Summary: This study investigates the beneficial effects of silane coupling agent (SCA) addition on the sulphate corrosion resistance of metakaolin-based geopolymer composites. The results show that the addition of SCA improves the strength, fluidity, and sulphate resistance of the geopolymer by compacting the pore structure and inhibiting the invasion of SO42-.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Multidisciplinary
Tao Yang, Xuan Gao, Jiajia Zhang, Xumin Zhuang, Hao Wang, Zuhua Zhang
Summary: The study found that higher CCR dosages significantly accelerated the degradation kinetics in Na2SO4 solution. In comparison with Na2SO4 attack, all mixtures were more susceptible to MgSO4 attack, which could be explained by two mechanisms.
COMPOSITES PART B-ENGINEERING
(2022)
Article
Construction & Building Technology
Xuan Gao, Xiao Yao, Ruofei Xie, Xiang Li, Junhua Cheng, Tao Yang
Summary: Utilization of waste CRT glass as aggregates in cement production is a sustainable recycling method, but its high potential for ASR degradation limits the recycling rate. This study compared the performance of PC and fly ash-based geopolymer mortars with CRT glass aggregate. The results showed that PC mortars suffered from severe ASR expansion, leading to structural damage and reduced compressive strength, while geopolymer mortars showed resistance to ASR degradation and even slight shrinkage. The geopolymer mortars also exhibited effective lead leaching restriction and radiation shielding properties, indicating potential applications in radiation shielding constructions.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Deng Chen, Tao Yang, Kai-Wei Liu, Ai-Guo Wang
Summary: The effects of dolomite powder with different fineness on the hydration of Portland cement were investigated. It was found that the hydration heat and compressive strength of PC can be altered by the addition of dolomite powder, depending on its fineness and amount. The formation of specific minerals may increase with the increase of dolomite powder fineness and amount.
REVISTA ROMANA DE MATERIALE-ROMANIAN JOURNAL OF MATERIALS
(2021)
Article
Construction & Building Technology
Deng Chen, Zhi-Hai He, Ai-Guo Wang, Tao Yang
Summary: The addition of 10% light-burnt dolomite calcined at 800 degrees C for 2.0 hours can effectively enhance the compressive strengths of blended cement and improve its microstructure. The hydration of periclase in light-burnt dolomite leads to the expansion of blended cement at early age, with expansion value increasing with dosage, calcination temperature, and holding time.
REVISTA ROMANA DE MATERIALE-ROMANIAN JOURNAL OF MATERIALS
(2021)
Article
Chemistry, Multidisciplinary
Changsen Zhang, Zhichao Hu, Xuesu Gu, Huajun Zhu, Tao Yang, Yu Yang, Jie Gao
UNIVERSITY POLITEHNICA OF BUCHAREST SCIENTIFIC BULLETIN SERIES B-CHEMISTRY AND MATERIALS SCIENCE
(2020)
Article
Construction & Building Technology
Tao Yang, Zuhua Zhang, Qiang Wang, Qisheng Wu
CONSTRUCTION AND BUILDING MATERIALS
(2020)
Article
Construction & Building Technology
Qi Zheng, Chengyao Liang, Jinyang Jiang, Haiyan Mao, Karen C. Bustillo, Chengyu Song, Jeffrey A. Reimer, Paulo J. M. Monteiro, Haimei Zheng, Shaofan Li
Summary: This study used scanning transmission electron microscopy to examine defects in cement particles at the single-atom level. The researchers identified different types of defects and found that they play a crucial role in cement hydration, facilitating dissolution and providing nucleation sites for hydration products.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Anuj Parashar, Shashank Bishnoi
Summary: This study investigated the hydration of siliceous fly ash, slag, and metakaolin with calcium hydroxide, and found that the rate of hydration and phase assemblage is influenced by the alkali and sulphate content, while siliceous fly ash is less affected by alkalis and sulphates.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Peimin Zhan, Juan Wang, Hanbing Zhao, Wengui Li, Surendra P. Shah, Jing Xu
Summary: This study investigates the influence of hydrothermal synthetic conditions on the properties of C-S-H seeds and reveals the correlations between C-S-H seeds properties, hydration kinetics, and paste performances. It is found that low reactant concentrations and calcium-to-silicon ratios facilitate the production of C-S-H seeds with small size and high purity. Using C-S-H seeds with high effective surface area accelerates the hydration process of cement, resulting in refined pore structure and enhanced strength.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Zhaozheng Meng, Qing-feng Liu, Neven Ukrainczyk, Song Mu, Yufei Zhang, Geert De Schutter
Summary: This study developed a numerical framework to investigate the combined attack of sulfate and chloride ions on cementitious materials in marine and saline environments. The study quantified various chemical reactions and solved the electrostatic potential caused by multi-ion coupling. The results showed that neglecting the multi-ions coupling effect could result in an underestimated chemical coupling strength in competitive chloride-sulfate binding.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Ning Li, Cise Unluer
Summary: This study aimed to improve the carbonation efficiency and reduce processing time of recycled concrete aggregates (RCAs). Wet carbonation with seawater was found to be more efficient than dry carbonation, leading to significant reduction in water absorption and increase in density of RCAs. The compressive strength of recycled aggregate concrete (RAC) prepared with 1-hour seawater carbonated RCAs was also improved. The formation of ettringite and calcite under wet carbonation contributed to the increased density and strength, as well as improved bond strength in the interfacial transition zone of RAC. Seawater presents several advantages as a medium for wet carbonation, including its abundant availability, CO2 capture capacity, and accelerated hydration and carbonation.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Yong Tao, Yining Gao, Yanjie Sun, Roland J. -M. Pellenq, Chi Sun Poon
Summary: Decalcification of calcium silicate hydrates (C-S-H) is an important issue for the long-term safety of cement-based infrastructures. Using molecular simulations, this study reveals an important mechanism of accelerated C-S-H decalcification in seawater, which involves ion exchange between surface Ca and electrical double layers, resulting in a decrease in Ca dissolution free energy. This finding enhances the understanding and prediction of cementitious materials' degradation.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Kumaran Coopamootoo, Enrico Masoero
Summary: This study uses kinetic simulations to investigate the relationship between dissolution rate and saturation index in minerals in solution. Two distinct regimes are observed, with stresses at crystallographic defects controlling the transition between them. A parameterization of the interaction potentials is proposed to obtain consistent interfacial energies with water. The findings contribute to the current discussion on controlling reactivity using materials and defects.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Faping Li, Qianshi Chen, Yiyan Lu, Yunlong Zou, Shan Li
Summary: In this study, the impact of functionalized multi-walled carbon nanotubes and a silane coupling agent on the performance and microstructure of alkali-activated fly ash/slag pastes was investigated. The results showed that the addition of these materials can prolong setting time, improve flowability and mechanical strength, and reduce mass loss and drying shrinkage.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Yaozeng Wang, Wencui Yang, Ai Zhang, Penghuan Liu, Yong Ge
Summary: Low-temperature low-field nuclear magnetic resonance was used to analyze icing in water saturated white cement paste specimens during the freeze-thaw process at different temperatures. The experimental results were compared with classical theory, showing agreement at certain temperatures but discrepancies at others. New equations were proposed based on the analysis of specimens saturated with different solutions to relate the volume of frozen water to temperature during freezing and thawing of cementitious materials.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Shengjie Yan, Yingjie Liang
Summary: This paper proposes a fractal derivative model with a non-linear distributed-order (DOFM) to describe the multi-scaling behaviors of particle diffusion in alkali-activated materials. The DOFM is tested using experimental data and is found to effectively describe the multi-scaling diffusion behaviors of particles in the materials.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Cecilia Pesce, Richard J. Ball, Marco Molinari, Shaun Reeksting, Giovanni Luca Pesce
Summary: This study evaluates the effect of ten organic additives on the microstructure of portlandite crystals during CaO hydration. It was found that the presence of carbohydrates and sulfonates can alter the structure of portlandite and the properties of lime can be controlled by adding carbohydrates. This has significant implications for the development of new binders and reducing CO2 emissions.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Daniel Jansen, Alexander German, Dominique Ectors, Frank Winnefeld
Summary: This study used X-ray diffraction and Rietveld refinement technique to investigate a hydrous carbonate-containing brucite and found that the 001 reflection of this phase split into different patterns at different temperatures. The presence of water and/or carbonate influenced the distance between the layers in the brucite structure.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Dylan Singh, Trinh Thao My Nguyen, Evann Bustamantes, Abdul Wahab, Ahmad Hamzah Yousaf, Ian Shortt, Frank W. Foss Jr, Maria Konsta-Gdoutos, Sang Soo Lee, Erika La Plante
Summary: This study analyzes the chemical structure and morphology of magnesium silicate hydrate (MSH) grown under different concentration ratios and temperatures. The results show that increasing the magnesium to silicon ratio reduces silicate polymerization in MSH, and at higher temperatures and longer reaction times, oriented attachment of nanoparticles and enhanced crystallinity are observed. These findings provide insights into the precise chemical synthesis of MSH and its widespread use as a binder in construction.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
J. C. O. Zepper, S. R. van der Laan, K. Schollbach, H. J. H. Brouwers
Summary: This study presents a method to calculate the main phases of BOF slag based on chemical composition and validates the proposed final model through quantitative model assessment and validation approaches.
CEMENT AND CONCRETE RESEARCH
(2024)
Article
Construction & Building Technology
Yierfan Maierdan, Samuel J. Armistead, Rebecca A. Mikofsky, Qiqi Huang, Lola Ben-Alon, Wil V. Srubar III, Shiho Kawashima
Summary: This research investigated the effects of sodium alginate on the stability and 3D printability of kaolinite suspensions. The findings showed that sodium alginate could enhance the stability of kaolinite and improve the strength of printable mixtures, as well as shift the printability window.
CEMENT AND CONCRETE RESEARCH
(2024)
