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Design and installation of monitoring wells
Published in Neal Wilson, Soil Water and Ground Water Sampling, 2020
If neat cement is chosen for the grout, then in most situations Type I cement is used. The use of quick setting cements containing additives is not recommended. The setting time for Type 1 cement is usually from 48 to 72 hours, depending on water content. Neat cement grout can compromise the structural integrity of PVC casing due to the heat of hydration produced while the grout is setting up. This is especially true when a collapse of the formation material creates a large void where more grout is placed. Neat cement may shrink and crack when it dries, but cracking appears to be manifested for only a limited distance.16 Cracking appears to be most pronounced along the grout/casing interface.
Life cycle environmental impact considerations for structural concrete in transportation infrastructure
Published in John Harvey, Imad L. Al-Qadi, Hasan Ozer, Gerardo Flintsch, Pavement, Roadway, and Bridge Life Cycle Assessment 2020, 2020
Coupled with this growing material consumption to meet societal demand, there have been notable environmental impacts from the production of concrete and its constituents. Among the most discussed impacts are the high greenhouse gas (GHG) emissions from the production of cement. Conventional cement is composed of finely ground clinker, a kilned and quenched material, and mineral admixtures. The production of clinker requires high temperature heating, at ~1400°C, and results in calcination of limestone (the conversion of CaCO3 → CaO + CO2) to form a reactive material. The high levels of cement production and the GHG emissions from both energy-derived and process-derived (i.e., those from calcination) sources contribute to concrete being responsible for over 8% of anthropogenic GHG emissions (Miller et al., 2016a). As a result of both the energy resources used in the cement kilns and the raw materials in the kilns, there has also been growing concern related to air pollutant production from cement manufacture, such as SOX emissions (USEPA, 2016a). Additionally, the production of particulate matter (PM) has been noted for almost every stage of raw material acquisition through concrete production (USEPA, 1994, USEPA, 1995, USEPA, 2006). Much of the PM emissions from energy resources and cement manufacture have controls to reduce the amount of particulates that enter that atmosphere; however, fugitive emissions from sources such as handling, leakages, and transportation can still contribute notable PM emissions.
Portland Cements
Published in M. Rashad Islam, Civil Engineering Materials, 2020
Cement is the binding material primarily used in concrete mixtures. Sometimes, cement is used in asphalt concrete, as well as for soil stabilization, aggregate stabilization, etc. This chapter discusses the production, chemical components, types, properties, and standard laboratory testing methods of cement.
Stabilization of calcareous subgrade soils with polyelectrolytes: mechanisms and mechanical properties
Published in International Journal of Pavement Engineering, 2023
Jianxin Huang, Yosef Mohomad, Reginald B. Kogbara, Eyad Masad, Svetlana Sukhishvili, Dallas Little
This paper investigates two organic polymers, poly(sodium 4-styrenesulphonate) (PSS) and poly(diallyldimethylammonium chloride) (PDADMAC), as well as their polyelectrolyte complexes (PECs), which have not been used previously as stabilisers for improving the performance of the subgrade soil for pavement construction in Qatar. Subgrade stabilisation using traditional stabilisers such as cement is a typical method that is used to increase the stiffness of the pavement structure in order to withstand high traffic loads. However, the high stiffness resulting from the use of cement has drawbacks such as susceptibility of the stabilised layer to fracture and fatigue and reduction in the load transfer across cracks (Iyengar et al. 2013, Rodriguez et al. 2018). In addition, there are concerns with the use of cement as its production is associated with high emission of greenhouse gases (Latifi et al. 2017). Consequently, researchers have been investigating polymers over the past two decades as potential soil stabilisers (Yazdandoust and Yasrobi 2010, Lentz 2015, Mirzababaei et al. 2017, Georgees et al. 2018, Liu et al. 2018, Kolay and Dhakal 2019, Soldo et al. 2020, Huang et al. 2021).
Parametric investigation on the post-fire flexural behaviour of novel ferrocement panels with geopolymer mortar
Published in European Journal of Environmental and Civil Engineering, 2023
Therefore, the use of fire protection materials to enhance temperature enduring capacity of structural members is important and necessary. Many types of fire protection materials have been developed to protect structural members. The main classes of materials used for fire protection are cementitious, intumescent, fibrous and composite materials. Ferrocement is one of the cementitious composite materials, which is formed using hydraulic cement mortar reinforced with close spaced layers of continuous and relatively small sized wire mesh. Depending on the type of mesh used in the ferrocement, the strength gets variedly influenced. Of the meshes tested, welded wire mesh proves to provide the largest increase in strength. Portland cement is the primary cementitious material that is used in the construction industry worldwide. But the Portland cement mortar and conventional concrete are not resilient enough to withstand fire and easily undergo degradation on exposure to elevated temperatures (Gu et al., 2022). The cement industry accounts for 5–8% of worldwide CO2 emissions and cement industry is the largest producer of the greenhouse gases. It is estimated that manufacture of 1 ton Portland cement involves emission of 1 ton CO2 to the atmosphere (Davidovits, 1991). For the above reasons, recent research works are focusing on the feasibility of replacing cement with different types of waste products. Fly ash has gained prominence as the most commonly used waste material for partially replacing cement (Cao et al., 2017).
An efficient approach for cement strength prediction
Published in International Journal of Computers and Applications, 2023
Vilas H. Gaidhane, Nand Kumar, Ravi Kant Mittal, J. Rajevenceltha
Cement is a fundamental material used in construction works and civil engineering applications. High-quality control of the cement is of paramount importance and becoming a challenge for the manufacturing industry. The good quality cement depends on the various parameters such as capacity of equipment, human resources and the availability of the raw material. There are some factors that affect the cement manufacturing and construction engineering. These factors are classified into two categories, structured and unstructured. Structured factors are those which can be well studied and described by the fixed rules. These factors include mixed design, raw materials, and lean cement, etc. The unstructured factors such as control accuracy, manufacturing conditions, skilled manpower cannot be defined by the fixed rules. However, these types of factors greatly influence the production quality as well as quantity of the cement.