Proceedings of the 4th International Conference on Service Life Design for Infrastructure (SLD4)

SLD4 is a conference on Service Life Design for Infrastructures which is jointly organised by Delft University and Tongji University as part of the RILEM week 2018 in Delft, The Netherlands. The conference builds on the success of the previous three events on this topic held in Shanghai (2006), Delft (2010) and Zhuhai (2014). Service Life Design for Infrastructure is a very broad topic involving aspects starting from the material properties and behaviour, via structural performance, serviceability and durability to integral design and asset management. All related topics from experimental research to modelling and from codes and standards to applications are welcomed to the conference. The conference consist of 3 key-note papers and 132 regular papers presented over 3 days. Parallel to the SLD4 Conference a symposium on Concrete Modelling (CONMOD2018) and a workshop honouring Professor Klaas van Breugel were organised with topics that are related to Service Life Design. In total more than 350 participants took part in the events organised during the RILEM week 2018

Ballastless Track – Minimizing the Climate Impact

Railway transportation is becoming increasingly important for transport of passengers and goods in Sweden, Europe and many parts of the world. Ballastless (slab) railway systems are increasingly in use; however, their construction is known to cause a substantial climate impact. The objective of this study was to investigate possible methods to reduce greenhouse gas (GHG) emissions of slab tracks and to provide required knowledge to identify the methods with high potential for further development. The approach adopted in this study consists of two steps. First, a comprehensive literature study was carried out, including a survey of existing methods for reducing GHG emissions for slab tracks, and of those which require further research. These methods are presented and assessed with respect to criteria related to potential benefit, possibility to use in large volumes, quality assurance and cost.In the second step, recommendations are made on which of the different methods of reducing GHG emissions are suitable to further develop in future projects. Two uncertainties identified for all methods are related to quantification of potential benefits and the associated costs. Nonetheless, structural optimization of slab tracks is found to have potential to reduce the climate impact quite substantially, with the smallest risks associated. The most promising methods for structural optimization includes: geometry optimization to focus on the use of material where it is structurally most effective; stiffness optimization to reduce the energy consumption of trains; prestressing of concrete to minimize crack width; and employing steel fiber reinforced concrete to control cracks and reduce the use of traditional reinforcement. Three solutions combining these methods in different ways are suggested for future studies. Furthermore, methods related to the use of alternative binders & materials are also recommended to reduce the climate impact; however, it is noted that such methods in general exhibit larger uncertainties than structural optimization. Of the alternatives focusing on alternative binders & materials, the following were evaluated to be most promising: textile reinforcement, other cement types (e.g. CSA, BCSA & BYF cements) as well as optimized mix design of concrete. It is to be noted that the three suggested solutions based on structural optimization can also benefit from the use of alternative binders & materials. To sum up, combination of several methods is required to minimize the environmental impact, as in the suggested solutions. The needs for future investigation for each solution are also identified in the report. The project contributes to the overall goal of increasing consideration for the environment and climate by providing knowledge and road map on how GHG emissions can be reduced for slab tracks

Damage Management of Concrete Structures with Engineered Cementitious Materials and Natural Fibers: A Review of Potential Uses

The importance of the safety and sustainability of structures has attracted more attention to the development of smart materials. The presence of small cracks (<300 µm in width) in concrete is approximately inevitable. These cracks surely damage the functionality of structures, increase their degradation, and decrease their sustainability and service life. Self-sensing cement-based materials have been widely assessed in recent decades. Engineers can apply piezoresistivity for structural health monitoring that provides timely monitoring of structures, such as damage detection and reliability analysis, which consequently guarantees the service life with low maintenance costs. However, concrete piezoresistivity is limited to compressive stress sensing due to the brittleness of concrete. In contrast, engineered cementitious composites (ECC) present excellent tensile ductility and deformation capabilities, making them able to sense tensile stress/strain. Therefore, in this paper, first, the ability of ECC to partly replace transverse reinforcements and enhance the joint shear resistance, the energy absorption capacity, and the cracking response of concrete structures in seismic areas is reviewed. Then, the potential use of natural fibers and cellulose nanofibers in cementitious materials is investigated. Moreover, steel and carbon fibers and carbon black, carbon nanotubes, and graphene, all added as conductive fillers, are also presented. Finally, among the conductive carbonaceous materials, biochar, the solid residue of biomass waste pyrolysis, was recently investigated to improve the mechanical properties, internal curing, and CO2 capture of concrete and for the preparation of self-sensing ECC

Advances and perspectives in engineered cementitious composites: a comprehensive review

Engineered Cementitious Composites (ECC) have garnered significant attention within the construction industry due to their exceptional mechanical properties and durability. This thorough review presents a meticulous analysis of the progress and prospects in ECC research. It commences by introducing the background and rationale for investigating ECC, while outlining the objectives of the review. The review provides an encompassing overview of ECC, encompassing its definition, characteristics, historical development, composition, and constituent materials. Emphasis is placed on the examination of ECC's mechanical properties, specifically its flexural behaviour, tensile behaviour, compressive strength, and resistance to environmental factors. Furthermore, the rheological properties of ECC, including workability, flowability, self-healing, crack mitigation, viscosity, and thixotropy, are discussed in detail. The review delves into the influence of fibre reinforcement on ECC, encompassing the types of fibres utilised, their impact on mechanical and structural properties, as well as fibre dispersion and orientation. Additionally, it explores the diverse applications of ECC across various fields, such as structural applications and sustainable building practices. The challenges and limitations associated with ECC, such as cost and availability, are addressed, alongside an exploration of future trends and research directions

Sustainable Designed Pavement Materials

This Special Issue “Sustainable Designed Pavement Materials” has been proposed and organized as a means to present recent developments in the field of environmentally-friendly designed pavement materials. For this reason, articles included in this special issue relate to different aspects of pavement materials, from industry solid waste recycling to pavement materials recycling, from pavement materials modification to asphalt performance characterization, from pavement defect detection to pavement maintenance, and from asphalt pavement to cement concrete pavement

2018 Scholarly Productivity Report

https://scholarsmine.mst.edu/care-scholarly_productivity_reports/1001/thumbnail.jp

Microstructural attributes and physiochemical behaviours of concrete incorporating various synthetic textile and cardboard fibres: A comparative review

The excessive use of virgin materials for manufacturing cementitious materials in the building and construction industry creates detrimental environmental effects. The integration of waste materials in composites promote sustainable opportunities within the industry. This paper presents a systematic review of the use of synthetic textile and cardboard waste fibres in concrete in conjunction with infrequently used additives such as gypsum, metakaolin, alumina and zinc oxide. The synthetic nature of polyester and nylon fibres facilitates their integration into high alkaline environments. Kraft fibres, derived from cardboard, exhibit high tensile strength but also absorb water, limiting their use in construction. However, by employing coating applications, these limitations can be mitigated. Gypsum prolongs setting times, improves workability, and enhances the sulphate resistance of concrete. Metakaolin's reactivity with calcium hydroxide results in improved strength, density, and durability. Alumina oxide can enhance the mechanical and thermal characteristics. Whereas zinc oxide, known for its UV protection and antimicrobial properties has a retarder effect and can improve the materials longevity in extreme environments. Scanning electron microscope images of the synthetic textile fibres demonstrate sustained durability features in the composite materials whereas, kraft fibres exhibited deterioration properties. Fibre bonding and deterioration aspects of the material varied within each matrix environment. This corresponded to a varied microstructural response with the fibrous materials. The findings from this review demonstrate the sustainability opportunities when integrating additive and waste materials in composite designs

High Performance Concrete

The innovations in construction materials that have been made due to the development of different varieties of concrete have led to innovations in structural applications and design. This Special Issue mainly focuses on state-of-the-art research progress in high-performance concrete, including the effect and characteristics of fibers on the properties of high-performance concrete, the CO2 curing efficiency of high-performance cement composites, and the effect of nano materials when used in ultra-high-performance concrete. This Special Issue also contains two comprehensive review articles covering the following topics: the role of supplementary cementitious materials in ultra-high-performance concrete and recent progress in nanomaterials in cement-based materials. Readers working towards conducting research on innovative construction materials will be exposed to findings related to this topic in this Special Issue

Utilizing graphene oxide in cementitious composites : a systematic review

Graphene oxide (GO) is a 2D nanoparticle with dimensions less than 100 nm and acts as nano reinforcement in cementitious composites as a filling, crack-arresting agent, and nuclei for cement hydration. GO can be utilized to improve the microstructure and mechanical properties in a variety of construction and building technology applications. Through a coherent, comprehensive mixed reviewing method, this study seeks to evaluate the research efforts on utilizing GO in cementitious composites and map the research viewpoints from available literature (bibliometric analysis and systematic review). A total of 1437 publications were screened in which 59 articles were selected upon relevancy. Bibliometric mapping is used for keyword occurrence and the tested properties of cementitious composites containing GO. The review finds that the advantage of GO as a reinforcement in cement composite is that it is more effective in controlling crack development and propagation at the nano scale level in contrast to conventional reinforcement. The use of GO in cementitious composites offers many interesting paths and provides a foundation for further optimization in concrete, mortar, engineered cementitious composites, and cement paste. On the other hand, this use has a negative influence on various features of each type of reviewed material. More research is needed to gain a better knowledge of the long-term effects of the mechanical properties and durability of GO-based cementitious composites to promote their wider use in diverse applications in the construction sector.peer-reviewe