bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fatigue Behaviour of Patch-Repaired and CFRP Strengthened Reinforced Concrete Beams
Authors: James Valontino , Moyo Pilate 
Published: November 2024

Abstract
The service life of corrosion-damaged reinforced concrete (RC) infrastructure can be improved through patch repairs and structural strengthening. However, the effect of varying corrosion damage and patch repair extent has not yet been clearly pronounced. The fatigue performance of corrosion-damaged RC beams that have been patch repaired to varying lengths and subsequently strengthened with carbon fibre-reinforced polymer (CFRP) laminates was evaluated by conducting four-point bending tests and cyclic load tests on simply supported beams. Three criteria were identified to evaluate performance: fatigue life, crack development and stiffness degradation. Various data acquisition techniques, such as neutral axis DEMEC strain targets, strain gauges, linear variable differential transducers (LVDT) and digital image correlation (DIC) were employed to investigate these performance criteria. The experimental results indicated that an increase in corrosion damage and patch repair extent lowered the ultimate static failure load and increased fatigue life. An increase in specimen stiffness was observed for the specimens with the longer damage extent compared to the specimens with the shorter damage extent, where stiffness was gauged in terms of midspan deflection, composite material strain and neutral axis shift. Moreover, the results yielded through the DIC process showed potential to identify potential failure locations, quite early in the specimen fatigue life by comparison of tangential strain, peak vertical deflection and the eventual failure location.
Emerging Materials and Technologies for Next-Generation Sustainable and Resilient Polymer Concrete
Authors: Murcia Daniel Heras , Taha Mahmoud Reda 
Published: November 2024

Abstract
Emerging materials and technologies (EMTs) are introduced to improve the sustainability and resilience of infrastructure. Polymer concrete (PC) has been used for the last 80 years in infrastructure applications where extreme environmental conditions and exposures are dominant. We suggest that EMTs can enable the development of next-generation PC that can contribute to infrastructure resilience and sustainability. This paper presents an overview of the latest developments in using innovative PC by incorporating a myriad of EMTs to improve infrastructure resilience and sustainability. These EMTs include nanotechnology, bio-based polymers, 3D printing, and textile reinforcement. Using nanotechnology, we demonstrate the possible production of a PC with superior ductility and self-sensing capabilities. We also show that a bio-based polyurethane PC with appreciable compressive strength of 20 MPa can be produced. We demonstrate rheological testing of polymer concrete leading to innovative 3D printed polymer concrete structures. We finally show the ability to produce superior flexural load capacity and textile-reinforced PC (TRPC) ductility compared with cementitious textile-reinforced concrete (TRC). We conclude by demonstrating the potential production of 3D printed TRPC. We suggest that the EMTs will enable a quantum leap in using PC to produce sustainable and resilient infrastructure.
Experimental and Numerical Investigation of Patch-Repaired and CFRP-Strengthened Beams
Authors: Moyo Pilate , Mundeli Salathiel 
Published: November 2024

Abstract
Carbon fibre reinforced polymers (CFRP) have emerged as an effective material for strengthening reinforced concrete structures. While many studies have been reported on CFRP strengthening of reinforced concrete elements subject to corrosion, there is a dearth of information on strengthening patch-repaired concrete elements. This paper reports on the experimental and numerical investigation of the behaviour of corrosion-damaged RC beams that have been patch repaired and strengthened with CFRP. Fifteen beams were cast; twelve of these were subjected to simulated corrosion of 5%, and the remaining three were used as control beams. The damage length was varied from 450 mm, 800 mm, 1300 mm and 1800 mm while keeping the depth of patch repair at 105 mm. All the CFRP-strengthened beams failed by intermidiate crack (IC) debonding. The control beams had a lower average crack density than the retrofitted beams. There was an increase in the average crack density for increasing damage lengths. Patch repair combined with CFRP strengthening retrofit method restored the damaged beams load carrying capacity but reduced the beams’ ductility compared to the control beams. The yield loads for patch repaired and strengthened (RS) results increased by 10%, 17% and 20% for beams with 450 mm, 800 mm and 1800 mm damage lengths, respectively. It was also observed that for increasing damage lengths; 450 mm, 800 mm and 1800 mm the peak loads increased by 13%, 20%, 20%, respectively. The experimental results correlated well with the finite element modelling (FEM) results.
Shear Deformability of Reinforced Concrete Beams Strengthened with the FRCM System
Authors: Vegera Pavlo , Grynyova Iryna , Blikharskyy Zinoviy , Khmil Roman , Korobko Oksana 
Published: November 2024

Abstract
The article presents the results of experimental studies of reinforced concrete beams on the shear without transverse reinforcement strengthened by the FRCM system. For the implementation of the research, four experimental samples were designed and manufactured, with cross-sectional dimensions of 200x100 mm and a length of 2100 mm. The beams are designed in such a way that even after strengthening the support areas, the failure occurs due to the shear force. None of the samples is destroyed by the bending moment. The tests were carried out according to the authors’ improved methodology, by testing each sample twice. The samples were strengthened by the FRCM composite system at load levels of 0, 0.3, and 0.5 of the bearing capacity of the control samples. Reinforced concrete beams were strengthened by gluing P.B.O. fabrics in the form of vertical strips with a width of 70 mm, for the possibility of fixing the concrete strains in the support areas. Samples strengthened by the FRCM system are destroyed more smoothly and plastically than unstrengthened beams, and there is no mass fallout of concrete particles. According to the obtained data, graphs of the strain distribution in support area and the isofield of their distribution were constructed. In accordance with the results of the research, the maximum effect of the composite system use for the shear reinforcement was established by 26…57%. With increasing the load level at which the sample is strengthened, the effect of the strengthening decreased.
Interaction Between Polymer and Cement: A Review
Authors: Wang Ru , Zhang Shiwei 
Published: November 2024

Abstract
Polymer-modified cement-based materials are commonly used in engineering applications and have achieved good results. The interactions between polymer and cement have received extensive attention. In this paper, the interaction between them is discussed and summarized by reviewing the existing technologies. Traditional experimental methods do not provide a comprehensive picture of the interaction between polymers and cement-based materials, molecular dynamics (MD) simulations were used recently in the study of inorganic-organic phase interactions. People almost reach a consensus on the modification mechanism of polymers on concrete at micro-scale. But at nano-scale, the interaction between polymers and cement is an ongoing work, researches show that it contains several aspects, i.e., chemical bonding, hydrogen bonding, van der Waals forces, etc. Different polymers may have different types of interactions with cement. Understanding these interactions is important to elucidate the relationship between the microstructure and macroscopic properties of polymer-modified cement-based materials. Molecular dynamics simulation has proved to be an effective method to study the interactions between inorganic-organic composites at this stage but has some limitations.
Evaluation of Strength and Modulus of Elasticity of Polymer-Modified Cement Concrete (PCC) Under Thermal Impact Within a Defined Service Temperature Range
Authors: Flohr Alexander , Rohde Catharina , Narayana Savitha Devarajamohalla , Osburg Andrea 
Published: November 2024

Abstract
Polymer-modified cement mortars (PCM) and concretes (PCC) are mainly used in concrete repair and restoration exhibiting improved durability, suitable chemical resistance, and beneficial adhesion strength compared to unmodified cementitious materials. Due to these favorable properties, the material is increasingly implemented in construction. Commonly, the modifiers applied to cementitious binders consist of thermoplastic polymers, which feature a change in the deformation behavior under the influence of different temperatures. Despite the distinct temperature-dependent properties of the polymers, the load-dependent deformation behavior of PCM and PCC was barely investigated within a service temperature range. To make statements about the effect of polymers on the load bearing and elastic deformation behavior of PCM and PCC, the engineering properties of the material have to be experimentally assessed under thermal conditioning. Accordingly, the compressive and flexural strength as well as dynamic and static modulus of elasticity of seven different PCM mixtures were characterized while the specimens were exposed to service temperatures of −20 ℃, 20 ℃, and 60 ℃. After the specimens were thermally conditioned in a climate chamber, the samples were transferred to the equally conditioned test machine and tested in the proposed temperature scope. The experimental results reveal influential changes in all tested mechanical attributes for the modified system within the applied service temperature range compared to an unmodified reference. This knowledge is essential to further investigate the temperature impact on the material and develop appropriate prediction models for the application of polymer-modified cementitious materials in construction and the integration in design guidelines.
Basic Study on Ultra Rapid Hardening Alkali Activated Material Using Sodium Orthosilicate
Authors: Yamada Hiroshi , Wakasugi Mikio , Kanda Toshiyuki , Seki Tomonori , Ichimiya Kazuo 
Published: November 2024

Abstract
For the purpose of developing a repair material that contributes to decarbonization, a basic study is conducted on an alkali activated material that does not require an alkaline solution. Thin study is characterized by the use of sodium orthosilicate as an alkaline source in order to achieve powder premixing, be ultra rapid hardening. Specifically, a basic study on ultra rapid hardening property and an improvement of the length change performance of the material using only ground granulated blast furnace slag were carried out. As a result, it was clarified that sufficient compressive strength at 3 h can be achieved by increasing the alkaline usage rate, and that the length change performance can be improved by using shrinkage reducing agents and expansive agents.
Testing the Performance of Vinyl Ester and Polyester Polymer Concrete Following Exposure to Artificially Induced Climatic Environments
Authors: Gulabbhai Dhruv Parbhoo , Kruger Deon , Hira Mayur Kishor 
Published: November 2024

Abstract
The exposure of polymer concrete to artificially designed environmental conditions of high-and low-temperatures, and moisture levels allowed for the assessment of strength performance and aesthetic value. Strength performance indicated the maximum capability of the product to carry a load successfully, whereas the aesthetics assessed the appearance of the product, that can be measured using spectrophotometry. In this study, materials such as water and Portland cement typically used to form traditional concrete were replaced by two polymer resins namely - vinyl ester and polyester, thus making it polymer concrete. As such, compressive strengths of cube samples were tested, the change in cubes’ masses was measured using a balance - prior and post exposure to the artificially induced environments, the colour change tests (spectroscopy analysis) were performed using the spectrophotometer tests. Compressive strengths of over 75MPa were achieved, thereby justifying promising concrete strengths. Mass losses recorded were almost negligible, thereby showing toughness to conditions presented in the artificially induced environments. Minor colour changes were noticed- thereby showing a good resistance to harsh weather conditions on the surface properties. Therefore, the assessed products displayed desired characteristics for strength performance and aesthetic value, subsequently, creating a product that promotes sustainability.
Improvement of the Thermal Shock Resistance of Epoxy Resin Coating Using Sedimented Recycled Fine Aggregate
Authors: Krzywiński Kamil , Sadowski Łukasz 
Published: November 2024

Abstract
The floors made of epoxy resin coating that are exposed to the thermal loads are usually not durable enough to be used in industrial facilities. To enhance thermal properties of the coating recycled fine aggregate was used to reduce thermal expansions in the interphase zone in between the coating and substrate. Three different types of coating were analyzed: pure epoxy, specially homogenous, and functionally graded material. The top floor was loaded with temperature to obtain heat flux and strain results. Finite element method was used to simulate the heat transfer and heat load. Simulations show that sedimentation of the aggregate reduces heat flow to the substrate during loading. It means that properly designed aggregate can improve durability of the industrial floor which can be more resistance to thermal gradient.
The Effects of Modified Andreassen Particle-Packing Model on Polymer Modified Self-Leveling Heavy-Weight Mortar
Authors: Erüz A. Orhun , Özkul M. Hulusi , Akalın Özlem , Maraşlı Muhammed 
Published: November 2024

Abstract
Heavy-weight concretes are known for their high unit weight inherited from the aggregates and developed mainly for radiation shielding. Therefore, minimal porosity besides the high unit weight is a desired property. Numerous particle-packing theories were put forward to decrease the porosity by an ideal reference curve; modified Andreassen model based on the size distribution of ingredients to adjust the fineness. This research investigates the effect of the mentioned method on heavy-weight mortars. Cement, micro and nano silica combinations, and their polymer additive mixtures were used as binders in the specimens, along with barite and finely ground magnetite aggregates. In this work, the aggregate size limit selected 3 mm and the fineness factor of q was chosen as 0.22 and 0.25, depending on the mixture. To achieve a self-levelling consistency, the w/c ratio was kept constant at 0.40, and a superplasticizer was added to maintain the workability. Consecutively, the specimens were examined for unit weight, compressive strength, and capillary water absorption. The collected results were analyzed, and the difference between groups was compared according to their composition.
Current Status of Resin Concrete in Japan
Authors: Kai Nobuhiro , Kawakami Makoto , Kido Masahisa , Ishitsuka Kei , Kuwahara Yuki 
Published: November 2024

Abstract
Resin concrete, which has high strength, high early strength development and excellent chemical resistance, has been widely applied for repair and reinforcement of concrete structures, and precast products since the 1950’s. The research and development of resin concrete in Japan have evolved in tandem with various regions and international activities. It is a common and indispensable material for infrastructures in the world at present. On the other hand, there are so many different Acts of God, such as earthquakes, typhoons, and torrential rains, that occur in Japan, and disaster measures are an important issue. In this paper, the current status and practical application of resin concrete mainly applied for sewage products in Japan were investigated and discussed. Based on the regional characteristics of Japan, a resin concrete manhole of high quality to compensate for the defects of cement concrete was developed. Furthermore, the future trends in the research and development of resin concrete including environmental issues such as carbon dioxide emissions reduction, application of recycled materials and bioplastics to replace natural aggregates and petroleum-derived resin for concrete are proposed and discussed. A homogenization analysis method is introduced particularly to bring out the ability of resin concrete as composite materials and to carry out material development efficiently.
Recycled Mixed Plastic Fine Aggregate in Cement Concrete
Authors: Lee Kevin Jia , Wong Sook Fun 
Published: November 2024

Abstract
The literature extensively examines the utilization of sorted single-type plastic waste from post-consumer waste streams as a sustainable substitute for natural sand in cement concrete. However, severe heterogeneity of plastic waste in municipal solid waste streams, including variations in polymer types, grades, shapes, sizes, and cross-contamination with other commingled waste materials, poses a significant challenge in adopting findings from prior research that necessitates high-purity single-type plastic waste for concrete applications. This paper reports the characterization of cement concrete incorporated with mixed plastic fine aggregate (rMPFA) containing an optimized blend of plastic types produced using a proprietary mixed plastic recycling process. Five concrete mixtures containing 0% (M0), 10% (M10), 20% (M20), 30% (M30), and 40% (M40) rMPFA by volume of natural sand were investigated in this study. The laboratory results show that concrete mixture M20 had comparable compressive strength and water penetration test results when compared to control mixture M0. Additionally, toxicity characterization of concrete mixture M20 demonstrated a reduction of heavy metals in the leachate solution when compared to control mixture M0. Furthermore, microplastic detection analysis results of concrete mixtures M0 and M20 were comparable and stable.
Symposium—Towards Innovative Practices in Mathematics Education: Teachers’ and Students’ Choice and Use of Digital Resources
Authors: Pepin Birgit , Rezat Sebastian 
Published: November 2024

AbstractIn this symposium we investigate students’ agency of selecting and using (digital) resources for developing their own learning paths. For that, we first review the literature related to students’ selection and use of resources in mathematics education in different pedagogical settings (presentation 1). Second, we develop insights from the different studies that participate in this symposium (presentation 2–6), at school as well as at university level. Results show that attempts have been made to provide students opportunities to develop agency of their mathematics learning, in particular with the development and provision of numerous digital tools and learning resources at university level and related to innovative pedagogical approaches. At the same time, it is not obvious how these tools and resources help students to develop deeper conceptual understandings. Certainly, students often ‘demand’ more student-centered and autonomous education approaches (e.g., at university level), also in mathematics education. Further, it seems that authentic problem-based education approaches are more motivating for students. These ‘innovative’ approaches necessitate particular types of structure and support for students. Moreover, they require different ways of providing resources that students can and want to interact with, and that help students to navigate through the curriculum to develop their own learning paths. At the same time, teachers also need support on how to orchestrate student learning with the available resources in such environments, so to be able to attend to students’ individual needs. The symposium comprised altogether six presentations:Birgit Pepin & Sebastian Rezat: Students’ agency of selecting and using (digital) resources for developing their own learning paths: An overviewAnnalisa Cusi & Agnese I. Telloni: Learning through digital curriculum resource design: students’ reflections on their role as designersVilma Mesa, Lelia Burley-Sanford, Xinyi Hao, & Carlos Quiroz: Interactive features in university textbooks and their use by teachers and studentsSebastian Rezat: Fostering university students’ reading and understanding of mathematical text in a flipped classroom approach with a digital marking toolBirgit Pepin & Ulises Salinas: Challenge/problem-based mathematics learning at university level: The case of the modeling weekFarzad Radmehr: Problem-posing: An inclusive activity for improving teaching and learning of mathematics at university level
Learning Through Digital Curriculum Resource Design: Students’ Reflections on Their Role as Designers
Authors: Cusi Annalisa , Telloni Agnese I. 
Published: November 2024

AbstractThe focus of this contribution is on the role that students could play as designers of digital curriculum resources (DCR) (Pepin et al., 2017). Our study focuses on data collected within an educational programme that involved 7 upper secondary school students (grade 12).
Research on the Quality Monitoring and Evaluation Index of Mathematics Textbooks in Basic Education
Authors: Kong Fanzhe , Zhao Xinyi 
Published: November 2024

AbstractThe construction of evaluation criteria is an important grip for the quality assurance system of textbooks. Major countries around the world have strategically reviewed and strengthened the construction and development of textbooks and made efforts to improve the quality of teaching materials. In particular, continuously increased the development and improvement of textbooks management methods, quality standards, and evaluation criteria, and have developed characteristics in terms of the basis for the development of textbooks evaluation criteria, evaluation content dimensions and specific indicators, evaluation methods and tools, etc. Analyzing the characteristics of the evaluation standards of textbooks in the world's major countries and learning from the experience of the management of textbooks in developed countries will help improve the quality standards of basic education textbooks in China and strengthen and improve the development, management, and construction of teaching materials in China.
Comparative Study of the Content of Quadrilateral in the Three Editions of Junior High School Mathematics Textbook
Authors: Chen Zhihao , Cheng Yi 
Published: November 2024

Abstract“Quadrilaterals” is an important branch of mathematics in junior middle school. This study used qualitative and quantitative research methods to analyze and compare the “Quadrilaterals” content in Chinese and American Mathematics Textbooks from the macro layout structure design and micro content difficulty. It is concluded that the arrangement order of “Quadrilaterals” chapters in the three editions of textbooks is basically the same, the GMH version has a wide range of content, while the BNUP version has a low depth of content. The discuss of this study are as follows: properly add the expansion chapters of teaching materials, appropriately enrich the teaching introduction links, optimize the course structure and tap the beauty of mathematics.