Papers by Keyword: Concrete

Abstract: Massive structures are exposed to the risk of high temperatures due to cement hydration. With the requirement for sustainable development, the clinker content of conventionally manufactured cements is being reduced, resulting in the development of blended cements, which are gradually being introduced into production. Therefore, the development of temperatures in massive concrete structures containing modern blended cement is the subject of an experimental program. Its results are evaluated not only in terms of the properties of the resulting concrete, but also in terms of the possibility of concrete production and the technology of mixing. Finally, recommendations are given for the design of concrete mixtures for massive structures. Furthermore, the article deals with the comparison of the measured values with the thermal analysis of the structures.

Abstract: The paper presents a research object of a portal realized using the method of 3D printing of cement composite. The object serves as an experimental portal redefining the relationship between a building element and ornament. The form of the portal is generated by a Möbius transformation of part of the load-bearing wall. This transformation allows the basic structural logic of the wall to be converted into an ornamental layer without losing material logic and continuity. The load-bearing material of the object is a cement composite, optimized for robotic printing without formwork. Printing enabled the production of complex elements with high geometric precision. Thanks to digital control, the shape can be deconstructed into a precise printing trajectory, eliminating the human factor and streamlining production even for complex segments. The resulting object combines the structural and visual roles of the elements without the need for secondary division into load-bearing and aesthetic parts. The aim of the research is to verify the possibilities of robotic printing in the production of architectural elements from cement composite that transcend the traditional dichotomy of structure and decoration. The process shows that even highly individualized elements can be produced efficiently, repeatedly, and with material savings. Special attention is paid to detailed parameterization of the mold, surface quality, and layering during printing, which fundamentally affects the resulting mechanical and aesthetic properties. The paper offers a practical view of the application of robotic 3D concrete printing in architectural and engineering applications and its potential for transforming current construction approaches.

Abstract: This paper presents the numerical modeling of a reinforced concrete deep beam (DB) with dimensions of 1100mm, 400mm, and 150mm under two-point loading conditions using the same reinforcement technique. The study evaluates specimens cast from three distinct concrete types: normal-weight concrete (NWC), lightweight concrete (LWC), and high-strength concrete (HSC), while maintaining identical reinforcement configurations. The analysis indicates that the concrete grade significantly influences the ultimate load-bearing capacity of the members. Specifically, the LWC specimens exhibited a 40–41% reduction in capacity compared to the NWC specimens. Conversely, the NWC beams demonstrated a 15–21% lower capacity than the HSC beams. Despite these variations in peak load, all specimens displayed similar failure mechanisms and crack propagation patterns. A comparison between the numerical results and experimental data showed strong correlation, validating the accuracy of the proposed model.

Abstract: Concrete cracking behavior under distributed forces is influenced by several factors such as material properties, crack initiation, propagation, and the impact of external loads. This paper aims to explore the relationship between concrete surface conditions and concrete material shape and concrete crack patterns under compressive loads. The literature review method uses general search queries with the most important keywords from academic databases, from reputable source Scopus and Science Direct. Following is an example of a query applied in a database for extraction: “rough AND surface AND contact”; “fracture AND mechanics AND of AND concrete”; “pressure AND test AND system”; “concrete AND crack AND pattern AND modeling”; “concrete AND crack AND pattern AND concrete AND compression AND test”; “surface AND contact AND in AND compression AND test”; “surface AND contact AND in AND concrete AND compression AND test”. The literature is limited from 2000 to 2025, obtaining the following three general topic groups: “rough surface contact” with 7347 articles, “compression testing system” with 2108 articles and “concrete crack mechanics” with 4307 articles. The resultss is then further filtered out by applying four groups: “concrete crack pattern in compression test” with 35 articles, “concrete crack pattern modeling” with 60 articles, “surface contact in compression test” with 31 articles and “surface contact in concrete compression test” with 5 articles. A total of 137 identified articles were entered into the Mendeley database in .ris format and then evaluated them using Vosveiwer application to see the most frequently appearing and relevant keyword relationships for the proposed research. Mapping results acwuires keywords “numerical simulation”, “concrete”, “fracture” and “crack propagation” most frequently occurring and interconnected. A systematic sythesis are then implemented and compiled for a comprehensive review article relates in a meningful literature.

Abstract: This study evaluates the effect of acid attack on the behavior of concrete containing bentonite and fly ash. The concrete mixes contain varying dosages of bentonite mixed with a constant ratio of 10% fly ash. The concrete mixes include A0, A1, A2, A3, A4, and A5, which contain 0%, 10%, 20%, 30%, 40%, and 50% bentonite, respectively. Experimental results reveal that the addition of 10% fly ash along with 10% bentonite can show significant resistance toward acid attack. The concrete mix A1, containing 10% fly ash and 10% bentonite, loses only 1.1% of its mass as compared to the controlled mix of concrete, which shows a significant loss of its mass up to 8.4%. Microstructural analysis of concrete specimens reveals significant changes in hydration products using scanning electron microscopy (SEM). The addition of 10% bentonite along with fly ash creates a denser microstructure due to the formation of calcium silicate hydrate gel and refines the internal pores of the concrete, which provides a significant resistance towards acid attack. In addition, higher dosages of bentonite lead to a porous and loose microstructure, which becomes susceptible to microcracking and spalling.

Abstract: Concrete is a primary construction material consisting of aggregate, cement, and water. The significant demand for conventional materials is a major factor influencing housing delivery in Nigeria. This has driven research into the utilization of alternative construction materials. Coarse aggregate is a key component in the production of concrete used for various construction projects, including infrastructure development, residential buildings, and both low-and high-rise structures. This study focuses on utilizing coconut shells as coarse aggregate in concrete by replacing conventional coarse aggregate with coconut shells at varying proportions of 0%, 5%, 10%, 15%, 20%, and 25% by weight. A mix ratio of 1:2:4 was adopted, and a total of 72 concrete cubes of standard size were prepared.

Abstract: The partial substitution of cement with ground blast furnace slag (GGBS) and silica fume (HS) in the concrete mix has the potential to reduce the carbon footprint associated with cement production. The objective of this study is to evaluate the feasibility of this partial replacement as a strategy to promote greater sustainability in construction. The research looks at four replacement percentages with different ratios: 10% HS, 10% GGBS, a combination of 10% GGBS and 10% HS, and 13% GGBS with 10% HS. The results indicate that the mixtures obtained not only reach but exceed the required strength of f´c=280 kg/cm² and have a reduced carbon footprint compared to conventional concrete. This highlights the environmental benefits of using industrial by-products as partial replacements in concrete manufacturing, helping to mitigate the negative impacts of cement production.

Abstract: This review utilizes bibliometric analysis to examine global research trends and the chronological development of studies on the incorporation of mine wastes and tailings in concrete. A total of 345 publications were extracted from the Web of Science (WOS) database, and their analysis revealed a clear upward trajectory in scientific output since 2000. Respectively, China, India, Canada, and the USA were identified as the countries contributing the most to this research area. Among the 1139 author keywords extracted from the collected papers, 103 keywords with a minimum of three occurrences were analyzed using the VOSviewer software. VOSviewer further supports identifying research gaps and emerging trends by visualizing relationships among authors, publications, and keywords, facilitating a deeper understanding of the dynamics within the field. The analysis of keyword occurrences shows convergence towards research that focuses on the development of sustainable and high-performance materials that equate environmental responsibility with industrial economy demands. The current review also uses Biblioshiny, a web-based tool that explores topic timelines. It reflects that, in recent years, research focuses have shifted toward more sustainability, advanced materials, and performance optimization in the use of mine tailings in concrete.

Abstract: In Lima, many concrete structures experience accelerated deterioration due to physical and chemical factors, limiting their durability. This study evaluates the effect of recycled glass powder (RGP) and a nanosilica additive (1.5 %) on concrete with f’c = 27.5 MPa (280 kg/cm²), focusing on optimizing its mechanical properties, durability, and economic feasibility. Mixtures with 10 %, 15 %, and 20 % cement replacement by RGP were prepared, assessing compressive, tensile, and flexural strength, as well as permeability and water absorption. The mixture with 10 % RGP (RGP-10) showed the best early age mechanical performance, increasing compressive strength by 39.1 %, tensile strength by 12.7 %, and flexural strength by 26.2 % compared to the concrete control. Mixtures with 15 % and 20 % RGP showed lower initial strength, although future gains are expected due to delayed pozzolanic reactions. Regarding durability, RGP-10 reduced permeability by 9.02 % and water absorption by 6.45 %, while RGP-15 and RGP-20 achieved even greater reductions, with permeability decreasing by 11.48 % and 9.84 %, and water absorption by 8.68 % and 10.56 %, respectively. Although the nanosilica additive increases the initial cost, its combination with RGP produces significant improvements in mechanical properties and durability, contributing to a reduction in maintenance related costs, resulting in a durable, sustainable, and economically viable material.

Abstract: To support responsible production and consumption while building sustainable cities and communities, using local resources can help curb the ever-increasing carbon footprint of the construction and cement industries. This study provides baseline estimates of the availability of waste fibers from abaca and pineapple leaf fiber (PALF) production that could be tapped in implementing fiber-reinforced concrete designs. Additionally, this study offers a new perspective on how incorporating waste fibers into concrete mix design can lead to reduced cement usage and a potential reduction in carbon emissions. Approximately 50 kt/yr of waste fibers are generated and remain untapped. Given their availability, using waste fibers from abaca and PALF production in the Philippines could displace between 1 to 25 kg cement/m³ of concrete, potentially resulting in an annual emissions reduction of 20 to 30 kt CO_2-eq.