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Recovery of Value-Added Materials from Iron Ore Waste and Steel Processing Slags with Zero-Waste Approach and Life Cycle Assessment
Published in Hossain Md Anawar, Vladimir Strezov, Abhilash, Sustainable and Economic Waste Management, 2019
Hossain Md Anawar, Vladimir Strezov
The ground-granulated iron blast furnace slag (GGBFS), a by-product of iron and steel-making, can replace 30–50% of Portland Cement in ‘normal’ concrete as a supplementary cementitious material, but can replace up to 70% in specialist applications such as marine concrete because of the powerful latent hydraulic property, low heating speed when reacting with water, and high chemical durability. It has a glassy structure and can be used as a fine aggregate or binder. GBFS is commonly used in the manufacture of blended cements where it is inter-ground (lower performance) or blended separately (better performance) with cement (Wood, 1981) usually at a 20%–40% proportion. It reduces the heat of hydration in mass concrete pours, the permeability of concrete, life-cycle costs and maintenance costs, but improves the durability properties of concrete in resistance to aggressive environments, makes concrete more sustainable and enhances the performance characteristics of concrete. The combination of ground granulated slag and lime were the earliest cements made from slag (Lewis, 1981). Their properties were tested and used in the United States and different European countries as PuzzoIan and Portland cement. But their production ceased in most countries due to their sensitivity to deterioration in storage and the low strength in comparison to present-day Portland cements (Lea, 1971).
Design Requirement for Temperature Control in Mass Concrete
Published in Suchintya Kumar Sur, A Practical Guide to Construction of Hydropower Facilities, 2019
Thermal behavior of Mass Concrete makes it vulnerable and susceptible, differentiating it from other forms of concrete. Exothermic reactions release energy in the form of heat to the surroundings; this reaction between water and cement increases temperature within Mass Concrete and the heat generated is lost to its surroundings. Ideal conditions make the amount of heat lost equal to the amount of heat gained. However, this situation becomes critical when heat lost is much less than heat gained within the concrete during the reaction process, and this high amount of unreleased heat get stored within Mass Concrete. Tensile stress and strain is developed within concrete due to changes of volume. Concrete is weak in tension, and is subjected to surface cracking. This thermal cracking affects the Mass Concrete, and Mass Concrete tends to lose its virtues such as durability, water tightness, and serviceability. Precautionary measures should be adopted to prevent Mass Concrete from cracking to improve performance and to retain structural integrity.
Concrete Technology in the Century of the Environment
Published in K. Sakai, Integrated Design and Environmental Issues in Concrete Technology, 2014
Vitharana, N.D.(1994) Evaluation of Early-Age Behaviour of Concrete Wall Sections: Hydration & Shrinkage Effects, Report No. 94/I, Civil Engineering Research Institute, Sapporo, Japan. ACI Committee 207. (1970) Mass concrete for dams and other massive structures, ACI Journal, Apr. 1970, pp.273-309.Rastrup, E. (1954) Heat of hydration in concrete, Magazine of Concrete Research, Vol. 6, No. 17, pp.79-92.Vitharana, N.D. (1995) Prediction of temperature and stress developments in high-strength concrete columns under heat-of-hydration effects, Concrete’95, FIP International Conference, Brisbane, Australia, pp.211-22.Vitharana, N.D. and Sakai, K. (1995) Single and multi-stage concrete placements for large foundations: hydration-induced thermal stresses, EASEC5, Gold Cost, Australia, pp.2311-15.Vitharana, N.D. (1995) Rational evaluation of shrinkage and swelling-induced loadings in cylindrical concrete reservoir walls, EASEC-5, Gold Coast, Australia, pp.963-68.
Evaluation of soil insulation effect on thermal behavior of drilled shafts as mass concrete
Published in Cogent Engineering, 2018
Sangyoung Han, Sanghyun Chun, Kukjoo Kim, Adrian M. Lawrence, Mang Tia
Thermal cracking is a primary concern in areas of mass concrete and there are several relevant requirements in current specifications for mass concrete applications. Mass concrete is defined by the ACI 116 (ACI 116, 2005) that any volumeof concrete with dimensions large enough to require that measures be taken to cope with generation of heat from hydration of the cement and attendant volumechange to minimize cracking. Also, the FDOT defines mass concrete in drilled shafts and stated that all drilled shafts with diameters greater than 6 ft shall be designated as mass concrete (FDOT, 2016b). Any drilled shafts with a diameter greater than 1.8 m (6.0 ft) would, therefore, require the submission of a Technical Special Provision (TSP). The TSP in this particular case generally takes into account the form of a mass concrete temperature control plan since the size of the diameter (i.e., typically an elongated shape due to a relatively long height compared to the diameter) directly produces a high volume-to-surface area (V/A) ratio, which leads to a much higher potential for thermal cracking (Do, 2014; Tia et al., 2013; Ulm & Coussy, 2001).
A comparison of concrete quantities for highway bridge projects: preconstruction estimates vs onsite records
Published in Sustainable and Resilient Infrastructure, 2022
Bolaji A. Olanrewaju, Daman K. Panesar, Shoshanna Saxe
1) Mass concrete for substructure construction: Mass concrete refers to large quantities of concrete used for filling voids, for example, excavated trenches. It also comprises significant volumes of concrete with dimensions large enough to require that measures be taken to cope with the generation of heat from the hydration of the cement and attendant volume change to minimize cracking (American Concrete Institute, 2016). Structural components with a member thickness of about 900 mm or more are often identified as mass concrete (Alper & Jijina, 2018). Additional mass concrete quantities were ordered at the construction stage of 10 case studies, B3a, B6a, B6b, B7, B10, B12, B13a, B13b, B14a, and B14b as reported in Table 4-2.