Article
Polymer Science
Peng Zhang, Shiyao Wei, Yuanxun Zheng, Fei Wang, Shaowei Hu
Summary: This study investigates the workability and compressive strength of geopolymer composites and the effects of superplasticizer, polyvinyl alcohol fiber, and Nano-SiO2 on their properties. The results show that the addition of polyvinyl alcohol fiber and Nano-SiO2 significantly improves the compressive strength of the composites.
Article
Construction & Building Technology
Arnab Kumar Sinha, Sudip Talukdar
Summary: The study aims to regulate the fast setting of high-volume slag based geopolymer mortar by utilizing mineral admixture for better engineering performance. Test results show that GM containing a high volume of UBFS exhibits prompt setting and significant mechanical strength when activated by SHSS solution, with the addition of Borate successfully controlling the setting and improving fluidity of the material.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Materials Science, Ceramics
Ana Carolina Constancio Trindade, Flavio de Andrade Silva, Waltraud M. Kriven
Summary: A potassium-based geopolymer (KGP) was produced by combining metakaolin with K-based alkali metasilicate solution, and two types of silane-coated basalt fibers were used to investigate their effects. The addition of superplasticizer improved workability and allowed for greater incorporation of fibers, leading to high flexural strengths in both composites. Fibers designed for epoxy applications showed greater compatibility in higher content, indicating potential for enhanced reinforcement in specific contexts.
JOURNAL OF THE AMERICAN CERAMIC SOCIETY
(2021)
Article
Construction & Building Technology
Rachid Belhadi, Alexandre Govin, Philippe Grosseau
Summary: This study investigated the impact of citric acid, PCE, and their combination on the hydration and workability of CSA, finding that citric acid could help retain the dispersion efficiency of PCE over time, although it also decreased the initial dispersion efficiency. A dispersion model was proposed to describe the mechanism of action of these admixtures on CSA.
CEMENT AND CONCRETE RESEARCH
(2021)
Article
Construction & Building Technology
Chenchen Luan, Xiaoshuang Shi, Kuanyu Zhang, Nodir Utashev, Fuhua Yang, Jinxin Dai, Qingyuan Wang
Summary: This study proposed a new mix design method for geopolymer concrete, specifically low calcium fly ash geopolymer concrete, which allows for achieving high strength and excellent workability simultaneously. The workability is mainly influenced by the water content, while strength is affected by the water to alkaline activator ratio.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Multidisciplinary Sciences
Amgad Alhamoud, Hossein Tajmir Riahi, Abdolreza Ataei
Summary: This study successfully designed a procedure for preparing one-part geopolymer concrete by modifying the ACI method, and found that water-to-binder ratio and aggregate size have significant effects on material properties.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2023)
Article
Construction & Building Technology
Umer Sajjad, M. Neaz Sheikh, Muhammad N. S. Hadi
Summary: The study found that the addition of graphene can significantly improve the compressive strength of geopolymer mortar. Among the five different percentages tested, 1.0% of graphene was considered the optimum proportion for enhancing the compressive strength.
CONSTRUCTION AND BUILDING MATERIALS
(2021)
Article
Multidisciplinary Sciences
Mohammed Alghannam, Abdulrahman Albidah, Husain Abbas, Yousef Al-Salloum
Summary: This study investigated the properties of metakaolin-based geopolymer concrete through 16 mixes, aiming to optimize the mix proportions and understand the influences of various parameters on its behavior. Insights were provided into the curing conditions, molarity, and ratios of materials, and a model for water to solids ratio based on total aggregate percentage was proposed for workable geopolymer mixes.
ARABIAN JOURNAL FOR SCIENCE AND ENGINEERING
(2021)
Article
Chemistry, Multidisciplinary
Catarina C. Novo, Luciano Senff, Maria P. Seabra, Rui M. Novais, Joao A. Labrincha
Summary: This study aims to reduce the environmental impact of alkali-activated materials by replacing a commercial activator with industrial wastewater. The results show that the use of industrial wastewater decreases the workability and setting times of the materials, but does not compromise their mechanical performance.
APPLIED SCIENCES-BASEL
(2022)
Article
Materials Science, Multidisciplinary
Van Su Le, Artem Sharko, Oleksandr Sharko, Dmitry Stepanchikov, Roberto Ercoli, Thang Xiem Nguyen, Doan Hung Tran, Katarzyna Ewa Buczkowska, Petra Dancova, Piotr Los, Petr Louda
Summary: This study presents an approach to synthesizing a mathematical model for determining the composition of geopolymer foams. The focus is on improving the accuracy of multi-criteria optimization for metakaolin-based geopolymer composite composition. The proposed model combines various mathematical models and methods to optimize the composition of foamed geopolymers, resulting in improved mechanical, thermal, and technological properties.
JOURNAL OF MATERIALS RESEARCH AND TECHNOLOGY-JMR&T
(2023)
Article
Construction & Building Technology
Ali Ihsan Celik, Yasin Onuralp Ozkilic
Summary: This study aims to improve the production of geopolymer concrete by addressing its limitations in workability, setting time, and strength. The addition of NaOH solution improves workability and setting time, while the use of recycled steel fibers from waste tires enhances strength. The substitution of basalt powder for fly ash and the addition of recycled steel fibers also improve the environmental aspect of geopolymer concrete.
STEEL AND COMPOSITE STRUCTURES
(2023)
Article
Construction & Building Technology
Aparna Sai Surya Sree Nedunuri, Salman Muhammad
Summary: This study investigates the effects of zinc sulfate on the rheological, setting, and mechanical behavior of alkali-activated fly ash and ground granulated blast furnace slag mixtures. It is found that the addition of zinc sulfate can delay setting time, increase workable time, reduce yield stress and viscosity, and have minimal effects on storage modulus.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Aparna Sai Surya Sree Nedunuri, Salman Muhammad
Summary: In this study, zinc sulphate was used as a retarder in alkali activated ground granulated blast furnace slag and fly ash (AASFA) mixtures, resulting in delayed setting time, increased workable time, reduced yield stress and apparent viscosity, and minimal secondary increase in storage modulus. Furthermore, the compressive strength of AASFA mixtures decreased at early ages with an increase in the zinc sulphate content, but eventually reached over 80% of the control strength at 28 days and beyond.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Elie Mahfoud, Walid Maherzi, Khadim Ndiaye, Mahfoud Benzerzour, Salima Aggoun, Nor-Edine Abriak
Summary: This study explores the use of dredged sediments in the design of geopolymer mixtures. Different aluminosilicate sources were prepared by substituting fly ash with sediment at varying ratios. The mixtures were thermomechanically treated and combined with sodium silicates and sodium hydroxide to form geopolymers. Optimal mixtures were identified based on mechanical strength measurements and various characterizations. Results indicate that incorporating sediments improves the mechanical performance of geopolymers and can serve as a source of aluminosilicate.
CONSTRUCTION AND BUILDING MATERIALS
(2023)
Article
Construction & Building Technology
Guangping Huang, Rajender Gupta, Wei Victor Liu
Summary: Sodium gluconate effectively extends the setting time and improves the workability of CSAB cement, with low dosages enhancing compressive strength but high dosages leading to a significant reduction in strength due to delayed hydration and looser microstructure.
JOURNAL OF SUSTAINABLE CEMENT-BASED MATERIALS
(2022)
Article
Construction & Building Technology
Arun R. Arunothayan, Behzad Nematollahi, Ravi Ranade, Kamal H. Khayat, Jay G. Sanjayan
Summary: An eco-friendly 3DP-UHPFRC has been developed by replacing a high volume of cement component with fly ash and/or ground granulated blast furnace slag. These mixtures show significantly higher environmental sustainability while maintaining mechanical performance comparable to traditional 3DP-UHPFRC. A material efficiency index was proposed to compare the suitability of the eco-friendly mixtures, showing that mixtures with slag replacement have the highest index.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Construction & Building Technology
Shin Hau Bong, Behzad Nematollahi, Ming Xia, Seyed Hamidreza Ghaffar, Jinlong Pan, Jian-Guo Dai
Summary: This study systematically investigates the enhancement of flexural strength of 3D-printed geopolymer by adding natural microfiber wollastonite. The results show that an appropriate level of wollastonite replacement can improve the rheological properties and static yield stress of the mixture, leading to enhanced printability and flexural strength.
CONSTRUCTION AND BUILDING MATERIALS
(2022)
Article
Construction & Building Technology
Kala Kondepudi, Kolluru V. L. Subramaniam, Behzad Nematollahi, Shin Hau Bong, Jay Sanjayan
Summary: The rheological behavior of concrete mixtures made with AAFS binder paste was investigated, and its relation with 3D Concrete Printing performance was analyzed. The thixotropy of the mixtures mainly depended on the composition of the AAFS binder paste, regardless of aggregate content. Additives like nano-clay were used to control the rheology of the paste and enhance internal structure buildup. The yield stress of the concrete mixture was influenced by paste content, aggregate surface area, and solid packing.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Construction & Building Technology
Viktor Mechtcherine, Kim van Tittelboom, Ali Kazemian, Eric Kreiger, Behzad Nematollahi, Venkatesh Naidu Nerella, Manu Santhanam, Geert de Schutter, Gideon Van Zijl, Dirk Lowke, Egor Ivaniuk, Markus Taubert, Freek Bos
Summary: This article focuses on characterizing the properties of additively manufactured, cement-based materials in their hardening and hardened states. It is important for material development, structural design, and quality control of 3D-printed elements. The challenges lie in the anisotropy and inhomogeneity caused by the layered structure of the printed material. Destructive testing and non-destructive testing are discussed, along with the need for guidelines and standards.
CEMENT AND CONCRETE RESEARCH
(2022)
Article
Construction & Building Technology
Shin Hau Bong, Behzad Nematollahi, Venkatesh Naidu Nerella, Viktor Mechtcherine
Summary: This paper presents a 3D-printable strain-hardening alkali-activated composite (3DP-SHAAC) that shows pseudo-ductile behaviour under direct tension, which is composed of a one-part alkali-activated binder made of slag (GGBFS), fly ash (FA) and solid activators. The curing temperature has influence on the mechanical properties of both 3D-printed and mould-cast SHAACs. The 3DP-SHAAC exhibits superior flexural performance, higher tensile strength, and comparable tensile strain capacity to the mould-cast counterpart.
CEMENT & CONCRETE COMPOSITES
(2022)
Article
Materials Science, Multidisciplinary
Mehdi Chougan, Seyed Hamidreza Ghaffar, Behzad Nematollahi, Pawel Sikora, Tobias Dorn, Dietmar Stephan, Abdulrahman Albar, Mazen J. Al-Kheetan
Summary: This study investigates the effects of natural and calcined halloysite clay minerals on the performance of 3D printed alkali-activated materials. The results demonstrate that the addition of calcined halloysite clay enhances the shape stability, buildability, and mechanical properties of the printed materials, indicating its potential for practical applications.
MATERIALS & DESIGN
(2022)
Review
Green & Sustainable Science & Technology
Darshana Jayasooriya, Pathmanathan Rajeev, Jay Sanjayan
Summary: This study investigates the effects of graphene and graphene oxide on cement-based composites, particularly continuously reinforced concrete pavements (CRCP). Graphene-based nanomaterials show promise in overcoming various CRCP distresses, and the possibilities and hinderances of using graphene as reinforcement in cement-based composites are discussed. The potential of using graphene in CRCP is explored.
Correction
Construction & Building Technology
Kala Kondepudi, Kolluru V. L. Subramaniam, Behzad Nematollahi, Shin Hau Bong, Jay Sanjayan
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Arun R. Arunothayan, Behzad Nematollahi, Kamal H. Khayat, Akilesh Ramesh, Jay G. Sanjayan
Summary: The rheological behavior of 3DP-UHPFRC was investigated, and it was found that the inclusion of steel fibers and nano-clay reduced workability and increased static yield stress, dynamic yield stress, and apparent viscosity. However, the effects became negligible at higher fiber or NC contents.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Nan Zhang, Jay Sanjayan
Summary: This study presents theoretical formulations for concrete extrusion resistance as a function of nozzle parameters. Results show that the extrusion resistances are related to the extrusion velocity of concrete and the cone angle and length of the nozzle. Based on the results, a customized nozzle was used to investigate the effects of print parameters on printing quality. It was found that the reduction of printing speed increased the limits of layer thickness.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Automation & Control Systems
Boda Ning, Qing-Long Han, Qiang Lu, Jay Sanjayan
Summary: This article focuses on the cooperative control of double-integrator type multirobot systems with uncertain control gain. Three different collective behaviors are investigated, including leaderless consensus, leader-following consensus, and formation control. Novel continuous controllers are designed based on sliding variables to achieve finite-time state agreement and leader tracking. Experimental studies are conducted to demonstrate the effectiveness of the proposed controllers for formation control of nonholonomic mobile robots.
IEEE TRANSACTIONS ON INDUSTRIAL INFORMATICS
(2023)
Article
Construction & Building Technology
Nan Zhang, Jay Sanjayan
Summary: Quick mixing technology at the nozzle is a potential approach to improve productivity in 3D concrete printing. This study investigated the effects of rheological modifiers, CMC and nano-clay, on concrete mixing. Results showed that mixing resistance varied with different modifiers, with CMC being more influential. The quick mixing method resulted in better dispersion of modifiers but required more energy.
CEMENT & CONCRETE COMPOSITES
(2023)
Article
Construction & Building Technology
Nan Zhang, Jay Sanjayan
Summary: Quick Nozzle Mixing is a technique that solves the conflicting rheological requirements of buildability and pumpability in 3D concrete printing. The study investigates the mixing mechanism of concrete and the properties of mixing water with five surfactants. The results show that the surfactants play a significant role in mixing efficiency, with varying degrees of wetting ability.
CEMENT & CONCRETE COMPOSITES
(2023)
Review
Construction & Building Technology
Roshan Jayathilakage, Pathmanathan Rajeev, Jay Sanjayan
Summary: This study provides a comprehensive review of traditional and non-traditional methods for characterizing the rheological parameters of 3D concrete printing (3DCP) material. Experimental studies were conducted to compare different testing methods and identify their similarities, dissimilarities, pros, and cons. It was found that standard rheology measurement techniques have limitations when used for 3DCP material due to its unique properties, and non-conventional and novel techniques are needed for accurate rheological characterization.