3D Printable Ca(OH)2-based geopolymer concrete with steel fiber reinforcement

IF 3.4 3区工程技术 Q2 CONSTRUCTION & BUILDING TECHNOLOGY

Materials and Structures Pub Date : 2025-02-20 DOI:10.1617/s11527-025-02600-5

Youssef Mortada, Ahmad Hammoud, Laith Masoud, Mateusz Wyrzykowski, Davide Sirtoli, Pietro Lura, Bilal Mansoor, Eyad Masad

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引用次数: 0

Abstract

This study investigates the impact of varying steel fiber (SF) content (0%, 0.8%, 1.0%, and 1.2% by volume) on the mechanical and durability properties of 3D-printed Ca(OH)₂-activated geopolymer concrete (GPC). The addition of 1.2% SF improved flexural strength by 69% at 7 days and 16% at 28 days, while tensile strength more than doubled to 3.75 MPa at 28 days. Although compressive strength remained unaffected at 43 MPa, SF enhanced interlayer bond strength by 20%, which is crucial for layer cohesion in 3D-printed structures. Additionally, the elastic modulus increased by 7%, contributing to improved stiffness. Durability assessments, including autogenous shrinkage and self-induced stress, indicated a slight reduction in shrinkage of SF-reinforced samples, with no significant effect on self-induced stress. Microstructural analysis using scanning electron microscopy (SEM) and X-ray micro-computed tomography (µCT) demonstrated the crack-bridging behavior of steel fibers, enhancing ductility and fracture resistance. There was a slight increase in porosity (5.34%) of SF-reinforced samples without negatively affecting their mechanical properties. Notably, SF improved early-age toughness and controlled crack propagation across printed layers, addressing a critical challenge in 3D-printed concrete. The novelty of this work lies in successfully reinforcing 3D-printed Ca(OH)₂-activated GPC with recycled steel fibers, enhancing mechanical properties, interlayer bonding, and durability without compromising printability. This study offers a sustainable reinforcement strategy for 3D printing in construction.

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来源期刊

Materials and Structures 工程技术-材料科学：综合

CiteScore

6.40

自引率

7.90%

发文量

222

审稿时长

5.9 months

期刊介绍： Materials and Structures, the flagship publication of the International Union of Laboratories and Experts in Construction Materials, Systems and Structures (RILEM), provides a unique international and interdisciplinary forum for new research findings on the performance of construction materials. A leader in cutting-edge research, the journal is dedicated to the publication of high quality papers examining the fundamental properties of building materials, their characterization and processing techniques, modeling, standardization of test methods, and the application of research results in building and civil engineering. Materials and Structures also publishes comprehensive reports prepared by the RILEM’s technical committees.