Additive manufacturing using cement has evolved rapidly in recent decades, revolutionizing the construction industry. This technology automates building structures through computer-aided design, offering benefits such as reduced material waste, optimized material distribution, and the ability to use composite materials. This paper aims to examine the potential of using copper-slag-based geopolymers in 3D printing.
View Article and Find Full Text PDFThis paper presents a research program aimed towards developing a method of producing lightweight, porous geopolymer composites for the construction industry based on industrial wastes. A direct method involving the addition of chemicals is currently most commonly used to produce the porous mineral structure of a geopolymer matrix. This relies on a reaction in a highly alkaline environment of the geopolymer to produce a gas (usually hydrogen or oxygen) that forms vesicles and creates a network of pores.
View Article and Find Full Text PDFThis paper focuses on the development of thin-walled panels with specific properties for applications such as water-tight structures. The authors propose the use of textile-reinforced concrete (TRC) as a composite material and highlight its advantages, which include high tensile strength, improved crack resistance, and design flexibility. The study presents a novel approach which combines TRC with reactive powder concrete (RPC) as a matrix and a lightweight aggregate.
View Article and Find Full Text PDFRecent years have witnessed a growing global interest in 3D concrete printing technology due to its economic and scientific advantages. The application of foamed concrete, renowned for its exceptional thermal and acoustic insulation properties, not only holds economic attractiveness but also aligns seamlessly with the principles of sustainable development. This study explores various solutions related to 3D printing technology in construction, discussing the design, production, and properties of foamed concrete mixtures.
View Article and Find Full Text PDFAlkali-activated materials (AAM) are binders that are considered an eco-friendly alternative to conventional binders based on Portland cement. The utilization of industrial wastes such as fly ash (FA) and ground granulated blast furnace slag (GGBFS) instead of cement enables a reduction of the CO emissions caused by clinker production. Although researchers are highly interested in the use of alkali-activated concrete (AAC) in construction, its application remains very restricted.
View Article and Find Full Text PDFThe purpose of this study was to investigate the properties of hardened alkali-activated concrete, which is considered an eco-friendly alternative to Portland cement concrete. In this paper, the precursors for alkali-activated concrete preparations are blends of fly ash and ground-granulated blast-furnace slag in three slag proportions: 5%, 20%, and 35%, expressed as a percentage of fly ash mass. Thus, three concretes were designed and cast, denominated as AAC5, AAC20, and AAC35.
View Article and Find Full Text PDFThere are no standards for testing the properties of 3D-printed materials; hence, the need to develop guidelines for implementing this type of experiment is necessary. The work concerns the development of a research methodology for interlayer bond strength evaluation in 3D-printed mineral materials. In additive manufactured construction elements, the bond strength is a significant factor as it determines the load-bearing capacity of the entire structural element.
View Article and Find Full Text PDFGeopolymer concretes can be a viable alternative to conventional Portland cement-based materials. In their design, it is important to maintain an appropriate liquid-to-solid ratio (L/S), which affects several properties, such as the compressive strength, water absorption, and frost resistance. The objective of this paper is to analyze the influence of the fly-ash and metakaolin precursor types for three different L/S ratios: 0.
View Article and Find Full Text PDFMineral geopolymer binders can be an attractive and more sustainable alternative to traditional Portland cement materials for special applications. In geopolymer technology the precursor is a source of silicon and aluminium oxides, the second component is an alkaline solution. In the synthesis of geopolymer binders the most commonly used alkaline solution is a mixture of sodium or potassium water glass with sodium or potassium hydroxide or silicate solution with a low molar ratio, which is more convenient and much safer in use.
View Article and Find Full Text PDFProduction of concrete is connected to extensive energy demands, greenhouse gases production or primary sources depletion. Reflecting current economical, social, or environmental trends, there is strong pressure on mitigation these requirements and impacts. The exploitation of secondary- or waste materials in production processes has therefore a great potential which is not related solely to binders but also to fillers.
View Article and Find Full Text PDFDue to the need to reduce the CO emissions of mineral binders, researchers are considering the use of alkali-activated materials (AAMs) as an alternative to cementitious binders. The properties of AAMs can be more advantageous than those presented by cementitious binders, and thus they can replace Portland cement binders in some applications. Mechanical tests of AAMs are being conducted on an ongoing basis; however, durability issues related to reinforcing steel in conditions in which steel members interact with chloride ions remain unsolved.
View Article and Find Full Text PDFConcrete is prone to spalling when exposed to fire. During fire tests, the strains of concrete elements are hard to identify, both from the fire-exposed face and the non-exposed face. This paper presents a field experiment which employed the original CivEng digital image correlation (DIC) method developed at the Cracow University of Technology to measure the strain fields of elements exposed to heating by a pin-point gas burner.
View Article and Find Full Text PDFThe explosive behaviour of concrete in fire is observed in rapidly heated concrete. The main factors controlling the occurrence of spalling are related to the material's low porosity and high density as well as the limited ability to transport gases and liquids. Thus, for high-strength, ultrahigh-strength, and reactive powder concrete, the risk of spalling is much higher than for normal-strength concrete.
View Article and Find Full Text PDFThe paper presents experimental investigations concerning the influence of the cement type (CEMI 42.5 R Portland cement and CEMIII/A 42.5 N slag cement-with 53% granulated blast furnace slag) on the mechanical and transport properties of heated concretes.
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