Article
Construction & Building Technology
Chun-Ran Wu, Bao-Jian Zhan, Zhi-Qiang Hong, Shi-Cai Cui, Peng Cui, Shi-Cong Kou
Summary: The hydration behavior of circulating fluidized bed fly ash (CFBFA) as a cementitious binder in a CFBFA-lime system was investigated. It was found that the hydration behavior of the mixtures changed as the lime content increased, and the hydration reaction of the mixtures could continue after Ca(OH)2 was depleted.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Wei Zhang, Xiaoming Liu, Zengqi Zhang, Yantian Li, Jiarui Gu, Yaguang Wang, Yang Xue
Summary: This study aims to increase the utilization ratio of circulating fluidized bed fly ash (CFA) in cementitious materials and reduce environmental pollution. By increasing the proportion of CFA and reducing the cement clinker content in CFA-based cementitious materials, good performance development and low concentrations of heavy metal leaching can be achieved.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Wenyan Zhang, Shuai Wang, Xiaohang Duan, Yuzhong Jin, Chunhua Feng, Jianping Zhu, Faqiang Su
Summary: This study investigated the influence of low-calcium circulating fluidized bed fly ash (LCFA) on cement-based materials and the synergistic effect with an alkali activator. The results showed that the addition of LCFA improved the compressive strength, physical properties, and carbonization resistance of cement-based materials. Furthermore, adding water glass (WG) shortened the setting time and increased the compressive strength, chloride ion penetration resistance, and carbonation resistance.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Review
Chemistry, Physical
Guanlei Li, Chengke Zhou, Waqas Ahmad, Kseniia Iurevna Usanova, Maria Karelina, Abdeliazim Mustafa Mohamed, Rana Khallaf
Summary: This study expands the knowledge on the application of fly ash as a supplementary cementitious material and discusses the characteristics of cement-based composites containing fly ash. It is found that the addition of fly ash can have favorable impacts on material properties, but there is an optimum inclusion level. Chemical activation and the addition of nanomaterials can overcome the downsides of fly ash use and allow for higher volume application. By utilizing fly ash as a SCM, sustainable development can be promoted by reducing CO2 emissions, conserving resources, managing waste effectively, and reducing environmental pollution.
Article
Engineering, Environmental
Lizheng Jin, Min Chen, Yufeng Wang, Yaqi Peng, Qi Yao, Jiamin Ding, Binbin Ma, Shengyong Lu
Summary: With the rapid development of municipal solid waste incineration, the effective disposal and recycling utilization of fly ash has become increasingly important. Mechanochemical treatment has shown good results in stabilizing heavy metals and degrading dioxins in fly ash. The use of composite additives in the treatment process has proven to be the most effective in inhibiting heavy metals, significantly reducing their leaching concentration. Additionally, the treatment process improves the activity and performance of fly ash, making it an ideal supplementary cementitious material for concrete blocks.
JOURNAL OF ENVIRONMENTAL CHEMICAL ENGINEERING
(2023)
Article
Construction & Building Technology
Kamil Tomczak, Jacek Jakubowski, Lukasz Kotwica
Summary: This study investigated the effect of modifying cement-based composites with MAFBC fly ash on self-healing, resulting in a maximum average crack width reduction of 43% and crack filling degree up to 58%. The use of optical and scanning electron microscopy revealed the presence of newly formed self-healing products in cracks, with cracks completely filled up to a width of 110mm.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
B. Cansu Acarturk, Ilgin Sandalci, Natalie M. Hull, Zeynep Basaran Bundur, Lisa E. Burris
Summary: Creating more durable concrete is important for sustainability and reducing carbon footprint. Microbially induced calcite precipitation can increase concrete density and fill cracks, reducing moisture transport. Two approaches to address the challenge of bacterial-concrete systems' longevity were investigated: sustainable binder systems and non-axenic bacterial cultures. OPC-fly ash and CSA cement mixtures showed better sustainability, cell viability, and microstructure improvements compared to OPC.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Chemistry, Physical
Wei Zhang, Chao Wei, Xiaoming Liu, Zengqi Zhang
Summary: This study aims to enhance the long-term frost resistance of circulating fluidized bed fly ash (CFA)-based multisolid waste cementitious material (CSM) by preparing CSM2 using CFA, BFS, RM, and PS. The results show that CSM2 exhibits superior strength and mass stability after 25 freeze-thaw cycles, meeting the performance requirements of fly ash Portland cement 42.5#. The major hydration products include C-S-H gel, C/N-A-S-H gel, and ettringite. In addition, CSM2 has the densest interface, micromorphology, and pore structure, which contribute to the improvement of long-term frost resistance.
Article
Environmental Sciences
Hui Zhao, Wei Sun, Xiaoming Wu, Bo Gao
Summary: The utilization of fly ash (FA) in self-compacting concrete (SCC) as a substitute for cement affects the mechanical properties and water porosity of the material, with prolonged curing time improving the long-term behavior of FA series SCC.
ENVIRONMENTAL SCIENCE AND POLLUTION RESEARCH
(2022)
Article
Construction & Building Technology
Dapeng Zheng, Dongmin Wang, Hongzhi Cui, Xiangsheng Chen
Summary: This study focused on enhancing the pozzolanic activity of circulating fluidized bed fly ash (CFBFA) through ultrafine grinding. The findings revealed that physical activation can improve the early hydration reaction and later strength of cement with CFBFA. The research provides insights for the stability improvement and large-scale application of CFBFA-based cement.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Chemistry, Physical
Wei Zhang, Xiaoming Liu, Zengqi Zhang, Yaguang Wang, Yang Xue, Xiansheng Hao, Yang Lu
Summary: This study explores the use of CFB fly ash in cementitious materials, with the addition of CFBFA improving the long-term volume stability of CMM. Sample CMM0.5 shows the highest compressive strength and lowest expansion rate under both standard and autoclaved conditions. The main hydration products in CMM0.5 are C-S-H gel, C-A-S-H gel, and Ca(OH)2.
Article
Chemistry, Physical
Wei Zhang, Chao Wei, Xiaoming Liu, Zengqi Zhang
Summary: This study reveals that phosphorus slag (PS) admixtures can improve the performance of circulating fluidized bed fly ash-based multi-solid waste cementitious material (CWM) by studying their effect on its properties and hydration mechanism. The optimal conditions for CWM2 are identified, and the main hydration products are found to improve the compactness of the micromorphology. The study also shows that physical encapsulation and charge balance promote the consolidation of certain elements, meeting the drinking water requirements. This work provides a new idea for the application of PS as an admixture in CFA-based multi-solid waste cementitious material.
Article
Green & Sustainable Science & Technology
Feng Luo, Yujie Jin
Summary: This study compares the performance of coal-based fly ash and coal gasification fly ash as supplementary cementitious materials. The results show that although coal gasification fly ash has a greater negative effect on the fluidity of cement mortar, it has a greater contribution to the strength. Additionally, ultrafine treatment of coal gasification fly ash can improve its reactivity and reduce the negative effect on fluidity.
Article
Materials Science, Ceramics
Jian Li, Zhibin Ma, Jianming Gao, Yanxia Guo, Fangqin Cheng
Summary: Using circulating fluidized bed fly ash (CFBFA) to prepare geopolymer as a substitute for cement can reduce CO2 emissions and solve environmental problems. The effects of alkali activator modulus and curing temperature on the mechanical properties of geopolymers were investigated, and their relationship with phase composition, micromorphology, and chemical structure was established. The results show that the compressive strength of geopolymer decreases with the increase of alkali activator modulus and increases with the increase of curing temperature, but decreases after 28 days. The 90 days compressive strength reaches 34.7 MPa under certain conditions.
CERAMICS INTERNATIONAL
(2022)
Article
Engineering, Environmental
Pengfei Ren, Tung-Chai Ling, Kim Hung Mo
Summary: The study investigated the pretreatment of municipal solid waste incineration fly ash with CO2 followed by its use as cement replacement in cement pastes. It was found that the carbonates formed on the surface of SC-MSWIFA particles were finer than those from DCW-MSWIFA, resulting in shorter setting time and higher early compressive strength in the SC-MSWIFA blended cement pastes. The CO2-pretreated MSWIFA can replace cement up to 30% without sacrificing the long-term strength and mechanical properties of cement pastes.
JOURNAL OF HAZARDOUS MATERIALS
(2022)
Article
Energy & Fuels
Jacek Jakubowski, Przemyslaw Fiolek
Summary: A mine shaft steelwork is a three-dimensional frame that directs vertical motion. Field and numerical investigations revealed strong stiffness and dynamic properties of these structures, indicating that overlooking guide-to-bunton connections stiffness and dynamic factors may result in incorrect design load assessments, ultimately shortening design working life or causing failure.
Article
Construction & Building Technology
Artur Lagosz, Daniel Olszowski, Waldemar Pichor, Lukasz Kotwica
Summary: Ground waste expanded perlite (WEP) is a new high-activity supplementary cementitious material that can reduce the amount of clinker while maintaining the strength and durability of mortar. Incorporating WEP into blended cements can affect carbonation depth, especially in cements with higher slag content.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Construction & Building Technology
Lukasz Kotwica, Monika Malich
Summary: The study revealed that concentrated solutions of sodium and potassium acetates, as well as sodium chloride, can cause alkali-silica reaction in CAC mortars, with acetates resulting in larger expansions compared to chloride and hydroxide solutions. Variations in alkali-silica gel were observed depending on the soaking solution, indicating that ASR can occur without calcium hydroxide and external hydroxyl ions.
ROAD MATERIALS AND PAVEMENT DESIGN
(2022)
Article
Construction & Building Technology
Kamil Tomczak, Jacek Jakubowski, Lukasz Kotwica
Summary: This study investigated the effect of modifying cement-based composites with MAFBC fly ash on self-healing, resulting in a maximum average crack width reduction of 43% and crack filling degree up to 58%. The use of optical and scanning electron microscopy revealed the presence of newly formed self-healing products in cracks, with cracks completely filled up to a width of 110mm.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Ewa Kapeluszna, Lukasz Kotwica, Wieslawa Nocun-Wczelik
Summary: The study found that ground waste expanded perlite and silica fume have different effects on the hydration of cements with different C(3)A contents, especially in the early stages of hydration. Additives can reduce the amount of Ca(OH)2, increase the formation of C-S-H, thereby increasing the compressive strength of cement and reducing porosity.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Chemistry, Physical
Ewa Kapeluszna, Lukasz Kotwica
Summary: This study investigates the influence of grinding aids on the properties of cements, their compatibility with a superplasticizer, and the rheological parameters of mortars. The presence of surfactants affects the standard properties of cements and the effectiveness of the superplasticizer. Triethanolamine increases early-age compressive strength, but grinding aids decrease the slump flow of mortars and increase their yield stress and viscosity.
Article
Chemistry, Physical
Przemyslaw Fiolek, Jacek Jakubowski
Summary: This article investigates the impact of corrosion on load-carrying capacity of steel shaft steelwork exposed to aggressive environments, using laboratory, numerical, and analytical methods on naturally corroded steel guides. The results show that numerical simulation can effectively assess the moment capacity of highly corroded steel beams with known deteriorated geometry. Production of derived models reflecting natural corrosion patterns and statistical analysis on moment capacity provide further insights into the mechanical behavior of highly corroded hot-rolled box-section beams.
Article
Chemistry, Physical
Agnieszka Rozycka, Lukasz Kotwica
Summary: This paper investigates the suitability of using waste from the cleaning of flue gases as a partial replacement for lime in the production of autoclaved aerated concrete (AAC). The results show that the addition of waste can enhance the mechanical properties of AAC and affect the pore size distribution and thermal conductivity. Furthermore, waste containing a high content of CaO can be used as a replacement for lime, leading to reduced CO2 emissions.
Article
Construction & Building Technology
Jacek Jakubowski, Przemyslaw Fiolek
Summary: This study proposes a method for fully probabilistic reliability analysis of shaft guide tracks using maintenance measurements and probability distributions, which can comprehensively consider design and operation factors, providing a modern tool for optimization of shaft steelwork.
TUNNELLING AND UNDERGROUND SPACE TECHNOLOGY
(2022)
Article
Engineering, Mechanical
Przemyslaw Fiolek, Jacek Jakubowski, Kamil Tomczak
Summary: This study presents a novel analysis of failure modes in shaft steelworks, revealing nine structural failure modes that are mostly neglected by current design procedures. The results can be used to determine failure modes for specific corrosive deteriorations and steelwork characteristics, allowing for rational, safe, and cost-effective planning of repairs and upgrades, and improving the operational safety of shaft hoist systems.
ENGINEERING FAILURE ANALYSIS
(2023)
Article
Engineering, Civil
Jacek Jakubowski, Przemyslaw Fiolek
Summary: Considering the importance of shaft steelworks for mining and personnel safety, this study investigated the load effects and structural resistance of shaft guide tracks through field and laboratory tests. The proposed methodology, incorporating simulation and modeling, offers an innovative solution for shaft-guide structural analysis and provides a foundation for modern reliability analysis of shaft steelwork.
ENGINEERING STRUCTURES
(2023)