Article
Construction & Building Technology
Xu Han, Peng Zhang, Yuanxun Zheng, Juan Wang
Summary: The geopolymer technique shows promise for the treatment of municipal solid waste incineration fly ash (MSWIFA). This study investigated the utilization of MSWIFA through geopolymerization process. Results showed that the addition of MSWIFA increased the flowability of geopolymer composites but decreased their compressive and splitting tensile strength. However, a small amount of MSWIFA accelerated the early strength development. The addition of MSWIFA also affected the microstructure of geopolymers.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Haikuan Wu, Shun Kang, Hangqi Zhang, Qiming Sun, Rongxi Shen, Zhile Shu
Summary: This study designed a composite backfilling material using coal gangue and construction solid waste as aggregates. Through laboratory experiments, it was found that the effects of reducing agent content, mass concentration, fly ash content, and substitution rate of construction solid waste on flow performance increased in that order. The addition of construction solid waste negatively affected the strength of the filling materials. The appropriate substitution ratios for FA, construction solid waste, mass concentration, and reducing agent were determined.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Lingzhi Guo, Mei Zhou, Xinyi Wang, Chao Li, Hanqing Jia
Summary: In this study, a low-cost geopolymer grouting material was prepared using industrial solid wastes. The response surface methodology was used to design macroscopic tests and analyze the performance and mechanism of action. The results showed that the optimized formulation achieved excellent performance, and microscopic analysis revealed the role of different fineness materials in improving the density of the solid body and participating in reactions at different times.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Bruna Juvencio Frasson, Janaide Cavalcante Rocha
Summary: This study investigated the possibility of using coal tailings as a primary precursor in geopolymer mortar. The effects of Portland cement on the mechanical and physical properties of the geopolymer mortar were evaluated by replacing the coal tailings with a lower amount of Portland cement. The addition of sugarcane molasses and flue gas desulfurization improved the fluidity of the material, and the inclusion of Portland cement enhanced the early strength and created a denser and heterogeneous structure.
CASE STUDIES IN CONSTRUCTION MATERIALS
(2023)
Article
Green & Sustainable Science & Technology
Gaowen Zhao, Tao Wu, Guanzhou Ren, Zhen Zhu, Yuan Gao, Mei Shi, Shijun Ding, Henghui Fan
Summary: This study investigated the effect of different contents of waste coal gangue on the dispersivity, water stability and mechanical properties of dispersive soil. It was found that waste coal gangue could restrain the dispersivity and enhance the water stability of the soil, while also improving its strength. The effect of waste coal gangue on both dispersivity modification and strength improvement of dispersive soil increased with the increase of waste coal gangue content and curing time.
JOURNAL OF CLEANER PRODUCTION
(2023)
Review
Green & Sustainable Science & Technology
Shuying Wang, Bo Liu, Qian Zhang, Quan Wen, Xuhang Lu, Kui Xiao, Christian Ekberg, Shengen Zhang
Summary: This paper reviews the latest research progress in the preparation of geopolymers from industrial solid waste containing heavy metals (ISWCHM), including preparation techniques, application, and solidification/stabilization mechanisms of heavy metals. Existing research problems are analyzed and future research and development directions are provided.
JOURNAL OF CLEANER PRODUCTION
(2023)
Article
Chemistry, Physical
Yanshao Hu, Xiaoyan Han, Zuozheng Sun, Peng Jin, Keliang Li, Fuke Wang, Jinwei Gong
Summary: This study aims to enhance the activity index of activated coal gangue and investigate its activation mechanism. The activation process was optimized through orthogonal tests, and a genetic algorithm was used to improve the Back-Propagation neural network model. The results showed that calcination temperature had the most significant effect on the strength activity index of coal gangue. Mechanical and thermal activation effectively stimulated the potential activity of coal gangue.
Article
Environmental Sciences
Yanying Bai, Weichao Guo, Jianwei Wang, Zehua Xu, Shuai Wang, Qingxin Zhao, Jinman Zhou
Summary: This study explores the improvement of early mechanical properties of geopolymer by manipulating moulding pressures and curing methods. The results show that a moulding pressure of 30 MPa significantly increases compressive strength and decreases porosity. High-temperature curing accelerates the hydration reaction and leads to higher compressive strength. Microscopic analysis reveals the formation of various gels and increased compactness. The proposed method is successfully applied to geopolymer pavement bricks, which demonstrate higher strength and environmental benefits compared to concrete bricks.
Article
Construction & Building Technology
Xuyang Shi, Qingxiang Cai, Chongchong Qi, Linglei Zhang, Xiang Lu, Wei Zhou, Binyu Zhao
Summary: The utilization of hydrated cement paste and coal gangue together can potentially solve the issues of cement waste disposal and reduction in cement consumption. However, this alternative may result in decreased flowability and compressive strength of concrete.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Green & Sustainable Science & Technology
Junyi Zhang, Tiefeng Chen, Xiaojian Gao
Summary: This study evaluates the performance of PC with varying CG dosages and curing conditions, finding that steam curing significantly affects the pozzolanic reaction of CG particles in CG-PC, mitigating negative impacts from CG addition. A suitable steam curing regime and proper CG content can achieve the production of high-quality, cost-effective, and environmentally-friendly green concretes.
JOURNAL OF CLEANER PRODUCTION
(2021)
Article
Construction & Building Technology
Ningbo Liu, Baofeng Pan, Peng Yin, Tao Liu
Summary: The development of the Coal-based synthetic natural gas industry inevitably produced lots of slags. The application of coal-based synthetic natural gas slag (CSNGS) to road base not only effectively alleviated the accumulation and pollution of CSNGS, but also reduced the consumption of resources, which had significant economic and social benefits. However, CSNGS has a higher crushing value and water absorption, thus its mix design, mechanical properties and pavement performance must be further investigated when applied as the raw material of novel cementing material and aggregate.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Yanbing Zhao, Caiqian Yang, Chengyu Yan, Jing Yang, Zhiren Wu
Summary: The feasibility of preparing coal gangue-based geopolymer mortar (CGBGM) with composite-activated coal gangue was experimentally explored in this study. The effects of water-to-binder ratio, alkali content, and slag content on the fluidity and performances of the CGBGM were investigated. The results showed that the CGBGM had superior mechanical properties compared to ordinary Portland cement mortar. The slag content had the most significant influence on the flexural and compressive strength of the CGBGM. The microstructure analysis revealed that the hydration productions filled in the crevice and healed the entrapped microcracks, forming a dense microstructure. The drying shrinkage behavior of the CGBGM was also analyzed and compared with OPCM.
Article
Materials Science, Multidisciplinary
Xingguo Feng, Ning Liu, Xiangyu Lu
Summary: The aim of this study was to produce high-strength geopolymers using an ambient-curing method and un-calcined coal gangue (G) as an additive. The results showed that the geopolymer composed solely of ground granulated blast furnace slag (S) exhibited the highest strength, while the strength dramatically decreased with an increase in the content of G in the S-G binary geopolymers. In the ternary S-A-G geopolymers, the strength was not significantly affected by the content of G until it exceeded 17%, and decreased as the G content exceeded 22%. Suitable content of G resulted in the formation of aluminosilicate gel in the ternary geopolymers, and the compressive strength of the ambient-curing ternary geopolymers reached approximately 65 MPa at 28 days.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Construction & Building Technology
Deluan Feng, Jie Wang, Yuxin Wang, Xueli Xiao, Wenjuan Hou, Shihua Liang
Summary: This study investigates the feasibility of using fly ash and bottom ash as calcium sources for preparing alkali-activated coal gangue-based geopolymers. The results show that the strength of the geopolymers initially increases and then decreases with an increase in fly ash and bottom ash content. The liquid-solid ratio and alkali solution ratio also significantly influence the strength of the geopolymers.
JOURNAL OF BUILDING ENGINEERING
(2023)
Article
Construction & Building Technology
Evaldas Serelis, Vitoldas Vaitkevicius
Summary: This research proposes a method to prepare glass shards from municipal solid waste and use them in ultra-lightweight concrete. The experimental results show that waste glass can replace a portion of Portland cement without compromising the compressive strength, thus reducing environmental impacts.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Mechanical
Xianhua Yao, Lielie Li, Junfeng Guan, Min Zhang, Zepeng Liu, Ruicong Han, Shuanghua He
Summary: This study introduces a method to determine the initial cracking strength and initial fracture toughness of concrete, providing a basis for engineering design of concrete materials through a fracture model and curve fitting technique to simultaneously determine these two parameters.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2021)
Article
Chemistry, Physical
Min Zhang, Xianhua Yao, Junfeng Guan, Lielie Li, Juan Wang, Longbang Qing
Summary: The Grey Relation Entropy (GRE) theory is used to analyze the sensitive pore size affecting the compressive strength of concrete. By revising the relationship between strength and pore structure based on sensitivity coefficient, a model is proposed to calculate the compressive strength. Validation of the model shows a larger correlation with experimental results than existing methods.
Article
Crystallography
Junfeng Guan, Meng Lu, Xianhua Yao, Qing Wang, Decai Wang, Biao Yang, Huaizhong Liu
Summary: The research has shown that increasing cement content can improve the maximum dry density and optimum moisture content of cement stabilized coal gangue, thus enhancing its mechanical performance. After freeze-thaw cycles, moisture content and cement content are critical factors affecting the compressive strength loss rate of cement stabilized gangue.
Review
Chemistry, Physical
Xianhua Yao, Junyi Xi, Junfeng Guan, Lijun Liu, Linjian Shangguan, Zhaowen Xu
Summary: This article reviews the importance of recycling wastewater from ready-mixed concrete plants and its impact on the properties of concrete. It introduces the nature of wastewater, the effects of solid content in water on concrete properties, and discusses the microscopic mechanism of action in concrete mixing with wastewater, as well as future research directions.
Article
Chemistry, Physical
Jianjun Han, Zhuangmin Xi, Rui Yu, Junfeng Guan, Yajun Lv, Guo Li
Summary: MUHPC is a concrete material with high strength and radiation shielding properties. By using magnetite fine aggregate instead of river sands, the compressive strength and linear attenuation coefficient of MUHPC are significantly improved. The addition of magnetite does not change the type of cement hydration products, but can improve the micropore structure of MUHPC and reduce its porosity and pore diameter.
Article
Construction & Building Technology
Xianhua Yao, Junfeng Guan, Lei Zhang, Junyi Xi, Lielie Li
Summary: Experimental examination of crack distribution and widths in reinforced concrete beams with different yield strength steel bars led to the determination of crack features essential for design consideration and the establishment of a unified formula for calculating maximum crack widths.
INTERNATIONAL JOURNAL OF CONCRETE STRUCTURES AND MATERIALS
(2021)
Article
Construction & Building Technology
Shanshan Chen, Hao Wang, Junfeng Guan, Xianhua Yao, Lielie Li
Summary: A study on the effect of recycled coarse aggregate on recycled aggregate concrete specimens was conducted, proposing a concept of relative size and a simplified calculation equation for fictitious crack growth length. Fracture models were developed to determine tensile strength and fracture toughness of RAC at different curing ages, providing a linear relationship between peak load and fracture parameters for predicting peak load of large-scale structures.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Weifeng Bai, Xiaofeng Lu, Junfeng Guan, Chenyang Yuan
Summary: Using recycled coarse aggregate concrete (RAC) instead of natural coarse aggregate (NCA) can mitigate environmental problems and reduce reliance on natural resources caused by building demolition. Silica fume (SF) was used to improve the properties of RAC by replacing part of the cement. Experimental results showed that with the increase of curing age, the hydration reaction became more sufficient, leading to increased peak stress and elastic modulus. The addition of SF improved the microstructure and mechanical properties of RAC.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Engineering, Mechanical
Junfeng Guan, Yue Li, Weifeng Bai, Ying Hao, Yanan Yin, Biao Yang
Summary: This study presents a simple model for determining the fracture parameters of dam concrete and analyzes the crack propagation mechanism. The results obtained from the model are consistent with laboratory experiments, and a fracture failure curve for dam concrete is established.
FATIGUE & FRACTURE OF ENGINEERING MATERIALS & STRUCTURES
(2022)
Article
Polymer Science
Jianyu Yang, Guanglin Li, Weijun Yang, Junfeng Guan
Summary: A new type of polycarboxylic acid grinding aid was prepared to improve the grinding effect and high-efficiency water-reducing function of cement. The average particle diameter of cement was reduced by 3.65 μm when 0.03 wt% of PC was added as grinding aid. Moreover, a high initial fluidity of the cement paste could be reached when 0.08 wt% of PC was added. The grinding aids can change the hydration process of cement, improving both the early and late strength of cement.
Article
Polymer Science
Lielie Li, Hekai Cao, Junfeng Guan, Shuanghua He, Lihua Niu, Huaizhong Liu
Summary: In this study, a three-parameter Weibull distribution method was used to evaluate the tensile strength and fracture toughness distribution of poly (methyl methacrylate) (PMMA) bone cement. The mean values, minimum values, and standard deviations were determined, and relationships between tensile strength, fracture toughness, and peak load were established.
Article
Engineering, Civil
Ruicong Han, Wei Meng, Junfeng Guan, Ying Hao, Xianhua Yao, Lielie Li, Shuanghua He
Summary: A fracture model is established to determine the strength and fracture parameters of materials without size effect using double symmetrical edges notched specimens of metal. The method for determining yield strength and fracture toughness is presented using experimental yield loads of small specimens. The formula of nominal stress of double symmetrical edges notched specimen is derived, considering plastic zone under uniaxial tension. The influence of different plastic zone sizes on calculating fracture and strength parameters is analyzed. The complete fracture failure curves of the metal material are obtained. The theoretical minimum size of a metal specimen satisfying the conditions of linear elastic fracture mechanics is given. The dispersion of small-size double symmetrical edges notched specimens of hot-rolled carbon steel is analyzed using the normal method to predict the fracture properties of large-size specimens. A novel approach is provided for the rational determination of realistic material parameters and the prediction of load carrying capacity of large-size structures by experimental fracture tests for small-size specimens.
ARCHIVES OF CIVIL AND MECHANICAL ENGINEERING
(2023)
Article
Construction & Building Technology
Weifeng Bai, Zhou Song, Chenyang Yuan, Junfeng Guan, Chaopeng Xie, Hu Huang, Ying Ma
Summary: This study investigated the uniaxial compressive mechanical properties and damage evolution of recycled aggregate concrete (RAC) containing silica fume (SF) under freeze-thaw cycles. The results showed that the addition of SF significantly improved the compressive strength of RAC by reducing porosity and promoting the formation of ettringite. The mesoscopic damage mechanism of RAC was analyzed, and the relationship between macroscopic mechanical properties and mesoscopic damage was established.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Xianhua Yao, Zhaowen Xu, Junfeng Guan, Lijun Liu, Linjian Shangguan, Junyi Xi
Summary: This study investigated the feasibility and impact of using high concentration wastewater as mixing water for concrete instead of potable water. The results showed that using wastewater reduced workability but had a positive effect on concrete compressive strength, durability, and pore structure. Recycling wastewater for concrete mixing is a viable and beneficial practice in terms of environmental protection, economy, and environmental benefits.
