Article
Construction & Building Technology
Hamdy A. Abdel-Gawwad, Khalil A. Khalil, Ayman A. Gouda, Abdelrahman H. Elkhoresy, Mohammed A. Arif
Summary: The individual effects of nano hydrozincite and witherite on the performance of alkali-activated slag (AAS) were evaluated. It was found that nano hydrozincite caused a retardation effect on the early hydration rate of AAS, while witherite demonstrated an acceleration effect. These effects were due to the formation of zinc and barium hydroxides through alkali-dissolution. Changes in the Ca/Si ratio within calcium silicate hydrate were observed in both AAS-nHZ and AAS-nW mixtures. The proposed approach successfully produced hardened materials with high mechanical performance using low nanomineral and NaOH contents.
JOURNAL OF BUILDING ENGINEERING
(2022)
Article
Construction & Building Technology
Tao Zhang, Peng Wu, Qina Jiang, Qing Liu, Qiang Wang, Jun Qiu, Shugang Hu, Xianjun Lyu
Summary: This article investigates the effects of varying levels of calcium chloride and calcium sulfate on alkali-activated slag cementitious materials. The study analyzed the hydration products and mechanisms of the cementitious material using pH values, X-ray diffraction, thermogravimetric analysis, and scanning electron microscopy. The research findings suggest that calcium chloride is more effective in improving compressive strength than calcium sulfate when the dosage of Ca2+ is less than 2.5%. The addition of calcium chloride significantly enhances the compressive strength of the cement paste, especially at a 2% Ca2+ dosage and a Ca2+(CaCl2)-Ca2+(CaSO4) ratio of 1:1.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Chao Du, Hongbo Tan, Shouwei Jian, Jie Wang, Tao Shi
Summary: The study found that the compressive strength of SC-activated slag mortars decreased with the addition of marble powder (MP), but remained at an acceptable level, making it suitable for the preparation of low carbon cementitious materials.
JOURNAL OF BUILDING ENGINEERING
(2021)
Article
Construction & Building Technology
Guangyan Li, Hongbo Tan, Junjie Zhang, Xiufeng Deng, Xiaohai Liu, Zhongtao Luo
Summary: The study systematically investigated the strength development of NC-activated slag-FA blends at ambient temperature, characterized the hydration products and pore structure through experiments, and the results showed that the NC-activated blends exhibited excellent mechanical properties, suitable for engineering applications.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Construction & Building Technology
Maogao Li, Hongbo Tan, Junjie Zhang, Xiufeng Deng, Xianghui Kong, Pian Chen, Shouwei Jian, Xingyang He, Jin Yang
Summary: In this study, calcium chloride (CC) and sodium chloride (SC) were used as accelerators to improve the compressive strength of carbide slag (CS) activated ground granulated blast-furnace slag (GGBFS). The addition of 5% SC and CC significantly increased the early strength, while CC also improved the strength at 28 days and 90 days. These findings provide a new approach to enhance the mechanical properties of alkali-activated GGBFS.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Zuwang Bian, Guowang Jin, Tao Ji
Summary: Utilizing a combined activator of Ca(OH)2 and Na2CO3, this study investigated the effect of combined activator content on the performance of alkali-activated ferronickel slag system. The workability decreases with the increase of Na2O equivalent, while compressive strength first increases and then decreases, with the optimal Na2O equivalent identified as 5%.
CEMENT & CONCRETE COMPOSITES
(2021)
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
Green & Sustainable Science & Technology
Pang Chen, Zhaoyue Shi, Shaojun Cao, Ping Liu, Xian Rong, Lida Wang
Summary: This study investigated the mechanical properties of alkali-activated slag lightweight aggregate concrete (AAS-LWAC) and analyzed the effects of lightweight aggregate and fiber materials on its performance.
JOURNAL OF CLEANER PRODUCTION
(2022)
Article
Construction & Building Technology
Desha Tang, Changhui Yang, Xinyuan Li, Xiaohong Zhu, Kai Yang, Linwen Yu
Summary: The addition of Ca(OH)(2) significantly reduced the efflorescence of alkali-activated slag (AAS) cement by decreasing capillary porosity and water absorption rate, reducing Na' leaching, and enhancing Na' binding through increasing C-A-S-H gel content.
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
Materials Science, Multidisciplinary
Wenxuan Huang, Ying Wang, Yaming Zhang, Wenzhong Zheng
Summary: Rational utilization of blast furnace slag improves resource utilization rate and can help in addressing environmental degradation and climate crisis. Alkali-activated slag cementitious material (AASCM) offers high temperature resistance and can be used for construction in high temperature environments and to enhance fire resistance. A study was conducted on a special type of mortar with alkali-activated slag as the cementitious material to solve the thermal incompatibility issue between the mortar and natural aggregate. The compressive and flexural strengths of the mortar decreased with increasing temperature during and after high-temperature treatment.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Chemistry, Multidisciplinary
Marcel Maslyk, Tobias Gaeb, Galina Matveeva, Phil Opitz, Mihail Mondeshki, Yasar Krysiak, Ute Kolb, Wolfgang Tremel
Summary: The study demonstrates that CO2 emissions during clinker production of cement can be reduced by utilizing a metathesis reaction at room temperature in ball-mills. This method involves forming aNaSiCC, an amorphous intermediate, by mechanochemical activation of CaCO3 and Na2SiO3. It helps understand the interplay between thermodynamics and kinetics in complex reactions of alkali-activated binders and for CaCO3 crystallization in industrial and geochemical settings.
ADVANCED FUNCTIONAL MATERIALS
(2022)
Article
Construction & Building Technology
Guodong Huang, Xukang Zhang, Meng Liu, Bing Fang, Chengcheng Wang, Huafeng Mi
Summary: Using different mineral additives and activators to prepare alkali-activated materials, the effects on mixing flowability and compressive strength, as well as the compatibility between them, were studied. The results showed that Ca(OH)2 improved compressive strength but reduced mixing flowability, CaSO4.2H2O caused a drop in compressive strength and reduced mixing flowability significantly, while CaCO3 had no influence. Furthermore, establishing a strong alkaline environment using NaOH was a prerequisite for the progress of alkali-activated reaction.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Hamdy A. Abdel-Gawwad, Taher A. Tawfik, Pawel Sikora, Mohamed Abd Elrahman
Summary: This paper focuses on synthesizing alkali-activated binders using magnesium carbonate as the precursor. The study found that different alkali sources have a significant impact on the composition and compressive strength of the final product. The effects of adding a silicate source and lead glass sludge on the properties of the binder were also investigated. The results showed that the performance of the binder can be controlled by using different alkali sources and additives.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Xiao Huang, Chen Xin, Jiang-shan Li, Ping Wang, Shuai Liao, Chi Sun Poon, Qiang Xue
Summary: Barium slag, a hazardous industrial solid waste formed during the production of barium carbonate, has accumulated over 10 million tons in China and shows promise as an admixture for alkali activated slag (AAS) cement. Incorporating barium slag enhances the mechanical strength of AAS paste, improves pore structure, and reduces Na+ leaching concentration, making it a potential sustainable solution for waste recycling in cement production.
CEMENT & CONCRETE COMPOSITES
(2022)
