Upcycling of waste concrete in eco-friendly strain-hardening cementitious composites: Mixture design, structural performance, and life-cycle assessment

2021 ◽  
pp. 129911
Author(s):  
Xiuling Li ◽  
Xiangrong Lv ◽  
Xintao Zhou ◽  
Weina Meng ◽  
Yi Bao
2018 ◽  
Vol 761 ◽  
pp. 204-209 ◽  
Author(s):  
Ildiko Merta ◽  
Ana Mladenovič ◽  
Janez Turk ◽  
Aljoša Šajna ◽  
Alenka Mauko Pranjić

Three cementitious composites containing different natural fibres (flax, hemp and sea-grass) were evaluated from an environmental perspective by means of Life Cycle Assessment (LCA) method applying the cradle-to-gate approach. The environmental impact of these composites was compared to that of cementitious composites reinforced with conventional synthetic polyacrilonitrile (PAN) fibres. The functional unit was the production of one cubic meter of cementitious composites ready-for-use. The results show that generally the environmental footprint of composite with synthetic fibres is bigger than the footprint of the composites with added natural fibres. Exceptions may only be the impacts on eutrophication and freshwater aquatic ecotoxicity, which are significantly affected by cultivation of crops. Flax and hemp cultivation is associated with emissions to soil and water. For this reason, the composite mixture with flax fibres has a significantly greater impact on eutrophication and freshwater aquatic ecotoxicity than the composite mixture with synthetic fibres. A cementitious composite mixture with sea-grass shows the lowest impacts in all impact categories. The entire life cycle of the studied composites was not included in this research since the life cycle of natural fibre composites is not straightforward and is highly dependent on the durability of the fibres within the matrix.


2021 ◽  
Vol 13 (7) ◽  
pp. 3607
Author(s):  
Hyeong-Ki Kim ◽  
Chang-Geun Cho ◽  
Sun-Ju Lee ◽  
Young Hak Lee ◽  
Taehoon Kim

Reinforced concrete (RC) shear walls are effective in improving lateral stiffness and load-carrying capacity under earthquake and wind loads. According to the level of seismic design, however, the spacing of reinforcing steel bars should be very narrow and complicated, with tight spacing of tied bars, as is the case with seismically special RC shear wall design. The purpose of this study was to investigate the applicability of strain-hardening cementitious composites (SHCCs) in structural walls in order to improve structural performance as well as the complications with reinforcement details. The SHCC was mixed, and mechanical tests showed that the SHCC exhibited high ductile tensile strains above 2.0%, while sustaining the tensile stress after cracks and developing multiple microcracks, avoiding crack localizations. Six specimens of RC and reinforced SHCC structural walls were designed and manufactured with varying reinforcement details, and experiments on wall specimens were carried out under transverse wall-loading tests. These experiments demonstrated that the use of SHCC in structural walls, despite minimum use of reinforcement ratios, showed improved responses to minimize damage and failure caused by localized cracks under bending and shear to compared with the use of normal reinforcement ratios in RC walls.


Energies ◽  
2021 ◽  
Vol 14 (22) ◽  
pp. 7515
Author(s):  
Bertrand Teodosio ◽  
Francesco Bonacci ◽  
Seongwon Seo ◽  
Kasun Shanaka Kristombu Baduge ◽  
Priyan Mendis

The need for advancements in residential construction and the hazard induced by the shrink–swell reactive soil movement prompted the development of the prefabricated footing system of this study, which was assessed and compared to a conventional waffle raft using a multi-criteria analysis. The assessment evaluates the structural performance, cost efficiency, and sustainability using finite element modelling, life cycle cost analysis, and life cycle assessment, respectively. The structural performance of the developed prefabricated system was found to have reduced the deformation and cracking by approximately 40%. However, the cost, GHG emission, and embodied energy were higher in the prefabricated footing system due to the greater required amount of concrete and steel than that of the waffle raft. The cost difference between the two systems can be reduced to as low as 6% when prefabricated systems were installed in a highly reactive sites with large floor areas. The life cycle assessment further observed that the prefabricated footing systems consume up to 21% more energy and up to 18% more GHG emissions. These can significantly be compensated by reusing the developed prefabricated footing system, decreasing the GHG emission and energy consumption by 75–77% and 55–59% with respect to that of the waffle raft.


2020 ◽  
Vol 5 (4) ◽  
pp. 223-229
Author(s):  
Yuliia Slyva ◽  
◽  
Oleksiy Verenikin ◽  

The research on the development of an innovative formula of a synthetic detergent with improved environmental properties, which meet the environmental standard of SOU OEM 08.002.12.065:2016 "Detergents and cleaning products. Environmental criteria for life cycle assessment" is carried out. The accumulated theoretical and practical experience is generalized, the general scheme of designing and development of new goods taking into account features of detergents with the improved ecological characteristics is created.


2018 ◽  
Author(s):  
Alexandra LUCA ◽  
David SANCHEZ DOMENE ◽  
Francisca ARAN AIS

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