Documents published in Scipedia

• Durable Textile-reinforced Concrete Made of Fast-setting, Mineralimpregnated Carbon-fibers (MCF) Reinforcements and Alkaline-activated Matrix

  J. Zhao, A. Ameer Hamza, M. Liebscher, A. Bartsch, E. Ivaniuk, M. Butler, V. Mechtcherine

  DBMC 2023.

  
  

  Abstract

  Textile Reinforced Concrete (TRC) is a class of material with massive potential to strengthen existing or build entirely new thin-walled structures. However, state-of-the-art polymer-based textile reinforcements commonly suffer under weak compatibility with concrete and insufficient reinforcing efficiency at elevated temperatures. Mineral-impregnated carbon-fiber (MCF) composites represent instead a promising alternative reinforcement with a wide-ranging innovation potential regarding digital and automated processability, freedom design, chemical compatibility and ecological and environmental footprints. Among the existing variants of mineral impregnation, geopolymer (GP) impregnation for carbon fiber (CF) enables stable early-age rheological properties and fast-setting by moderate-temperature activation. The paper at hand presents a methodology to automatically manufacture textile reinforcements made of MCF composites via a continuous pultrusion and robotic–assisted structuring process to meet future market demands. After an advanced geopolymerisation process by thermal curing, the resulting gridlike reinforcements were implemented in a fine-grained, alkali-activated material (AAM) based concrete matrix and characterized with respect to their uniaxial tensile performance. By further applying AAM as cement-free binder, sustainable and fireproof reinforced concrete can be designed with an evident reduction in CO2 emission as compared to conventional cementitious systems. The improved chemical affinity facilitated by GP impregnation governs the cracking phase, resulting in a finer and more diffuse pattern, whereas the higher unidirectional strength of epoxy (EP)-impregnated yarns is responsible for the higher ultimate strength of the composite.

  Abstract
  Textile Reinforced Concrete (TRC) is a class of material with massive potential to strengthen existing or build entirely new thin-walled structures. However, state-of-the-art [...]

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• Durable Structural Concrete Using Fine and Coarse Recycled Aggregates (Type A and Type B)

  C. Vintimilla, M. Etxeberria

  DBMC 2023.

  
  

  Abstract

  The use of Recycled concrete aggregate (RCA, type A) and mixed recycled aggregate (MRA, type B) is an alternative for structural concrete production to reduce natural resource exploitation and landfilling of construction waste. However, the lower quality of recycled aggregate compared to that of natural aggregate, and consequently the lower durability of recycled concrete, make it necessary to limit the percentage of replacement of raw aggregates by recycled aggregates. The objective of this study is to analyse the adequacy of using different percentages (following European standards) of coarse and fine type A and type B recycled aggregates for structural concrete production. All the concrete mixtures were produced using 300kg/m3 of cement and an effective water: cement ratio of 0.48 to be exposed to the XC1-XC4 environment. In addition, the conventional concrete (0% recycled aggregates) was also produced using an effective water: cement ratio of 0.52. The physical and mechanical properties, drying shrinkage values, and durability property of sorptivity and water penetration values were determined in all the produced concretes. It was concluded that the concrete produced with up to 60 % coarse RCA and 30 % fine RCA (type A) aggregates achieved adequate properties for structural concrete. In addition, the use of MRA mixed recycled aggregate (type B) was also possible for structural concrete production when it was employed in the replacement of natural aggregates up to 40% for coarse MRA and 15% for fine MRA simultaneously.

  Abstract
  The use of Recycled concrete aggregate (RCA, type A) and mixed recycled aggregate (MRA, type B) is an alternative for structural concrete production to reduce natural resource [...]

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• Carbon Neutral Concrete – Challenges and Solutions for Sustainable Future

  M. Plançon, Z. Shu Qiang, J. Wong

  DBMC 2023.

  
  

  Abstract

  As the climatic impact is becoming a more important topic for most of the nations which signed the COP 26 accords; many concrete and cement companies have announced their carbon reduction ambitions. Although the CO2 reduction pace varies from one country / company to the other, many of them have clearly stated their commitment towards concrete carbon neutrality in 2050. As a result, we can observe the accelerated emergence of a multitude of new technologies targeting the reduction of carbon content in concrete. The presentation proposed will go over the consequences for the concrete industry of this construction industry’s endeavor climatic impact reduction. It will explain some of the main challenges paving the cement and concrete industry’s journey towards carbon neutrality. It will deep dive in the principles and impacts of the most recent and advanced regulations in terms of low carbon construction such as, for example, RE2020 in France. It will also illustrate some of the realistic solutions currently implemented to reduce the carbon footprint of concrete and cement and adapt to this new market environment, including the use of the latest loT technology which allows the concrete producer to improve their material management, operational efficiency as well as the commercial leverage. In a world where raw materials scarcity becomes increasingly stringent, it will also explore the solutions for the concrete industry to promote circular economy. Finally, it will describe the most probable paths towards carbon neutral concrete and how they will inevitably include environmental footprint reduction beyond climatic impact.

  Abstract
  As the climatic impact is becoming a more important topic for most of the nations which signed the COP 26 accords; many concrete and cement companies have announced their [...]

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• A posteriori error estimation for second-order optimally convergent G/XFEM

  M. Bento, S. Proença, C. Duarte

  admos2023.

  
  

  Abstract

   This work presents a ZZ-BD a posteriori error estimator tailored for 3-D linear elastic fracture mechanics problems that are approximated by second-order pFEM-GFEM formulations. The proposed error estimator is shown to estimate well discretization errors in the energy norm, with the estimated discretization error converging at the same rate as the exact discretization error. Also, the computed effectivity indexes are close to the optimal value of 1 for a LEFM problem that exhibits 3-D effects.

  Abstract
   This work presents a ZZ-BD a posteriori error estimator tailored for 3-D linear elastic fracture mechanics problems that are approximated by second-order pFEM-GFEM formulations. [...]

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• Digital Twins as an enabling technology for disruptive improvement of computational methods in marine engineering.

  T. Kvamsdal

  marine2023.

  
  

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• The physical models: an embarrassment to viscous naval hydrodynamics

  M. Visonneau

  marine2023.

  
  

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• IA: Finding patterns in a stochastic marine world

  R. Molina

  marine2023.

  
  

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• Numerical Modeling to Advance Offshore Wind Energy Technology

  J. Jonkman

  marine2023.

  
  

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• Modelling and simulation of multiscale particulate flows using physics-informed data-driven methods. Applications in naval and marine engineering

  E. Oñate

  marine2023.

  
  

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• Mooring systems for Marine Renewable Energy

  K. Sharman

  marine2023.

  
  

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