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Material properties
Published in Charles E. Reynolds, James C. Steedman, Anthony J. Threlfall, Reynolds's Reinforced Concrete Designer's Handbook, 2007
Charles E. Reynolds, James C. Steedman, Anthony J. Threlfall
Drinking water is suitable, of course, and it is usual simply to obtain a supply from the local water utility. Some recycled water is being increasingly used in the interests of reducing the environmental impact of concrete production. Seawater has also been used successfully in mass concrete with no embedded steel. Recycled water systems are usually found at large-scale permanent mixing plants, such as precast concrete factories and ready-mixed concrete depots, where water that has been used for cleaning the plant and washing out mixers can be collected, filtered and stored for re-use. Some systems are able to reclaim up to a half of the mixing water in this way. Large volume settlement tanks are normally required. The tanks do not need to be particularly deep but should have a large surface area and, ideally, the water should be made to pass through a series of such tanks, becoming progressively cleaner at each stage.
Activation of cement hydration with carbon dioxide
Published in Journal of Sustainable Cement-Based Materials, 2018
Sean Monkman, Paul A. Kenward, Greg Dipple, Mark MacDonald, Mati Raudsepp
The environmental impact of concrete production is an acute concern in light of the approximately 5% of global carbon dioxide emissions associated with the manufacture of cement [1]. However, carbon dioxide can be used beneficially in the production of concrete [2–4]. The purposeful treatment of curing concrete with CO2 was found to significantly improve strength, reduce water absorption, improve salt permeability resistance, and improve freeze–thaw performance [5–7]. Industrially sourced CO2 can be purposefully supplied to freshly mixing and hydrating ready mixed concrete to react with the cement paste [8]. The chemical reaction can lead to increased concrete strength. Such an approach can potentially be used to reduce the carbon footprint of the concrete so produced; first through the direct usage of waste CO2 and secondly through a mix design optimization that takes advantage of the strength increase to more efficiently proportion the cement.
Experimental investigation on paver blocks of fly ash-based geopolymer concrete containing silica fume
Published in Road Materials and Pavement Design, 2023
Rishabh Bajpai, Vedant Soni, Anshuman Shrivastava, Dipankar Ghosh
The global demand for cement has been increasing rapidly for recent years, and consequently, the production of cement is escalating at about 9% every year (U.S. Geological Survey, 2018), with India producing 7% of the world’s total cement and second-highest only behind China (Andrew, 2018), and hence, it causes high emission of greenhouse gasses (GHGs) and huge consumption of natural resources (Meyer, 2009). Thus, recent research has been focusing on the utilisation of alternative cementitious materials (geopolymer, etc.) to reduce environmental impacts of concrete (Firdous et al., 2018; Mehta & Siddique, 2016; Provis, 2014; Singh et al., 2015).
Comparative life cycle assessment (LCA) of concrete mixtures: a critical review
Published in European Journal of Environmental and Civil Engineering, 2023
Alireza Habibi, Hossein Tavakoli, Amin Esmaeili, Abooali Golzary
Due to the excessive consumption of natural aggregates and generation of huge amount of wastes and greenhouse gases, the researchers have significantly raised concerns on the sustainable development and reduction of environmental impact of concrete. The related work on the LCA of concrete provides a strong foundation to evaluate the environmental burdens and efficiency and resource demands, however, it lacks the durability studies and the potential in the use stage assessments. Therefore, this work is dedicated to identifying the existing issues in the LCA of concrete materials as shown in Figure 1 by reviewing the corresponding literatures.