The effects of nanoscale expansive agents on the mechanical properties of non-shrink cement-based composites: The influence of nano-MgO addition

Moradpour, Reza; Taheri-Nassaj, E.; Parhizkar, T; Vaghefi, Mohammad

doi:10.1016/j.compositesb.2013.06.033

Cited by 78 publications

(50 citation statements)

References 45 publications

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“…Silicates, phosphates, and iron minerals are thermally stable at higher temperatures. In 450S and 650S, the twin peaks near 428 and 444 cm −1 [74,75] are from Si-O bending; the peak near 674 cm −1 is Si-O-Si bending [75]. Even in 650S and 650D spectra, the region between 1000 and 1022 cm −1 has a signal due to a combination of thermally stable silicates and phosphates [76].…”

Section: Biochar From the Individual Unmixed Substratesmentioning

confidence: 98%

Biochar from co-pyrolysis of urban organic wastes—investigation of carbon sink potential using ATR-FTIR and TGA

Nair

Mondal

Weichgrebe

2020

Biomass Conv. Bioref.

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Urban organic wastes (UOW) strain the infrastructures for solid waste treatment (SWT) in emerging economies. This study investigated biochar gained from three major UOW sources in India—banana peduncles (BP), a fibrous waste, from fruit markets; sewage sludge (SS) from wastewater treatment plants; and anaerobic digestate (AD) from food and market waste processing facilities—in terms of its potential to sequester and become long-term carbon sink in soils. Herein, the chemical properties (using ATR-FTIR) and thermal oxidative stability (using TGA) of biochars derived from these UOW and their three blends were examined. Biochar from SS and AD and the blends were found to possess more ash content, Cl, and alkali and alkaline earth metals (AAEM) than that from BP. The conventional recalcitrance index (R50) could not quantify and compare the stability of these mineral- and ash-rich biochars. Hence, a modified thermal oxidative recalcitrance index (TORi) is proposed. All the biochar from blends prepared at highest treatment temperature of 650 °C shows similar aromaticity. However, biochar from blend of 50% SS, 30%BP, and 20% AD exhibits the highest recalcitrance (TORi = 0.193) to become a long-term carbon sink in soil. More than aromaticity, the influence of Si, Fe, and AAEM on the biochar matrix affects its recalcitrance. Variations in the structural properties and recalcitrance of biochars from blends are attributable to the synergy among their constituents SS, AD, and BP. The determined TORi confirms the potential of biochar from the blends of UOW as a long-term carbon sink.

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Section: Biochar From the Individual Unmixed Substratesmentioning

confidence: 98%

Biochar from co-pyrolysis of urban organic wastes—investigation of carbon sink potential using ATR-FTIR and TGA

Nair

Mondal

Weichgrebe

2020

Biomass Conv. Bioref.

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“…In general, incorporating MgO leads to strength decrease of cement pastes, mortars and concrete. In fact, this behaviour was observed in compressive strength [ 39 , 40 , 41 , 42 , 43 , 44 , 45 , 46 ], flexural strength [ 42 , 43 , 46 , 47 ], and tensile strength [ 48 ]. The incorporation of higher amounts of MgO caused further strength decrements [ 39 , 43 , 46 , 47 , 49 ].…”

Section: Characterization Of Cementitious Materials With Additionamentioning

confidence: 99%

“…The durability behaviour of cementitious materials with MgO, studied by different researchers, is summarized in Table 4 . In general, the incorporation of MgO leads to lower water absorption [ 45 , 47 , 52 ], higher carbonation [ 41 , 48 ], higher chloride ion migration coefficient [ 41 ], higher initial expansion [ 37 , 39 , 42 , 43 , 46 , 47 , 57 , 58 ], and lower shrinkage [ 42 , 43 , 53 ].…”

Section: Characterization Of Cementitious Materials With Additionamentioning

confidence: 99%

Magnesia (MgO) Production and Characterization, and Its Influence on the Performance of Cementitious Materials: A Review

Nobre

Ahmed

Bravo³

et al. 2020

Materials

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This paper presents a literature review concerning the characteristics of MgO (magnesium oxide or magnesia) and its application in cementitious materials. It starts with the characterization of MgO in terms of production processes, calcination temperatures, reactivity, and physical properties. Relationships between different MgO characteristics are established. Then, the influence of MgO incorporation on the properties of cementitious materials is investigated. The mechanical strength and durability behaviour of cement pastes, mortars and concrete mixes made with MgO are discussed. The studied properties of MgO–cement mixes include compressive strength, flexural strength, tensile strength, modulus of elasticity, water absorption, porosity, carbonation, chloride ion penetration, shrinkage, expansion, and hydration degree. In addition, microscopic analyses of MgO-cement mixes are also assessed. Summarizing the results of different studies, it is concluded that MgO incorporation in cementitious materials generally decreases the mechanical strength and shrinkage, and increases the porosity, expansion, carbonation and chloride ion migration. However, it should be emphasized that the properties of the specific MgO used (mainly the calcination temperature, the reactivity and the surface area) have a significant influence on the characteristics of the cementitious materials produced.

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“…Investigating cementitious system containing 1 % to 5 % MgO nanoparticles by the weight of binder, Moradpour et al (2013) observed expansion below the unsoundness limit as well as increased compressive and flexural strengths, see Table 5.…”

Section: Expansive Additivesmentioning

confidence: 99%

Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review

Jafariesfad

Geiker

Gong

et al. 2017

Journal of Petroleum Science and Engineering

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Well cementing is an important operation during drilling and completion of oil wells. The cement sheath must maintain well integrity behind the casing and provide long-term zonal isolation to ensure safety and prevent environmental problems. Despite recent technological advancement in smart polymeric materials, fibers and self-healing materials, it is still a big challenge to provide adequate long-term zonal isolation in severe oil well conditions. This review provides an overview of challenges faced in oil wells compromising the long-term ability of the cement sheath to provide zonal isolation. Factors controlling the long-term performance of cement sheath are discussed, in terms of shrinkage, tensile strength and flexibility. The use of nanomaterials as cement additive to fabricate flexible, high-tensile strength, and low-shrinkage cement system are reviewed.Introduction of nanomaterials into the cement system is a promising approach to design a sealant for the entire life of the well, thereby avoiding potential remedial costs and environmental impacts.

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The effects of nanoscale expansive agents on the mechanical properties of non-shrink cement-based composites: The influence of nano-MgO addition

Cited by 78 publications

References 45 publications

Biochar from co-pyrolysis of urban organic wastes—investigation of carbon sink potential using ATR-FTIR and TGA

Biochar from co-pyrolysis of urban organic wastes—investigation of carbon sink potential using ATR-FTIR and TGA

Magnesia (MgO) Production and Characterization, and Its Influence on the Performance of Cementitious Materials: A Review

Cement sheath modification using nanomaterials for long-term zonal isolation of oil wells: Review

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