Concretes with synthetic aggregates for sustainability

Tekin, İlker; Durgun, Muhammed Yasin; Gençel, Osman; Bilir, Turhan; Brostow, Witold; Lobland, Haley E. Hagg

doi:10.1016/j.conbuildmat.2016.12.110

Cited by 30 publications

(12 citation statements)

References 27 publications

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“…Calcium silicate hydrate phases such as tobermorite and xonotlite are important binding agents in building materials including concrete and lime-sand stone. 5,6 One can obtain calcium silicate hydrate at room temperature with the relative humidity of 60% in a reaction between the silicate phases of Portland cement and water, or else during the replacement of cement with a pozzolan, such as a fly ash from coal power plants and/or different types of aggregates. 5,7,8 Synthesis of pure tobermorite and xonotlite is possible in hyper-alkaline and hydrothermal conditions only.…”

Section: Introductionmentioning

confidence: 99%

“…5,6 One can obtain calcium silicate hydrate at room temperature with the relative humidity of 60% in a reaction between the silicate phases of Portland cement and water, or else during the replacement of cement with a pozzolan, such as a fly ash from coal power plants and/or different types of aggregates. 5,7,8 Synthesis of pure tobermorite and xonotlite is possible in hyper-alkaline and hydrothermal conditions only. 9,10 Especially, xonotlite-based materials are suitable for many high-temperature applications due to their high thermal shock resistance and also chemical durability.…”

Section: Introductionmentioning

confidence: 99%

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Modified xonotlite–type calcium silicate hydrate slabs for fire doors

Levinskas

Lukošiūtė

Baltušnikas

et al. 2018

Journal of Fire Sciences

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Xonotlite-type calcium silicate hydrate slabs were examined under the thermal shock conditions in a solar furnace at the Plataforma Solar de Almeria which can reach a peak of 300 W/cm 2. We have studied the original slabs as well as those modified with a mixture of liquid sodium silicate including montmorillonite as thermal insulation materials for fire doors applications. The slabs were kept at 950°C for 1 h. We performed X-ray diffraction, thermogravimetry and differential scanning calorimetry analysis, scanning electron microscopy, Fourier transform infrared spectroscopy, and thermal conductivity measurements and determined N 2 adsorption/desorption isotherms. X-ray diffraction shows that during the thermal shock at 950°C xonotlite is converted to wollastonite. Specific surface areas of xonotlite slabs decrease due to release of crystalline water molecules. It is possible to maintain temperatures of the back door not exceeding 70°C while the front door is subjected to 950°C for 1-h time periods. The standard requires no more than 140°C at the back door.

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Section: Introductionmentioning

confidence: 99%

Section: Introductionmentioning

confidence: 99%

Modified xonotlite–type calcium silicate hydrate slabs for fire doors

Levinskas

Lukošiūtė

Baltušnikas

et al. 2018

Journal of Fire Sciences

Self Cite

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“…ARAs such as rice husk ash, sugarcane bagasse ash, and corn stover ash contain an enormous amount of silica which makes these ashes an effective pozzolanic material. e silica present in these materials reacts with calcium hydroxide (CH), a hydration product of cement, resulting in the formation of additional hydration products [1]. Among various ARAs, rice husk ash (RHA), due to their high silica content and low cost, is the extensively used pozzolan [2][3][4][5][6].…”

Section: Introductionmentioning

confidence: 99%

Performance Evaluation of the Fiber-Reinforced Cement Composites Blended with Wheat Straw Ash

Qudoos

Ullah

Rehman

et al. 2019

Advances in Materials Science and Engineering

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Increasing demand for cement in the construction industry is posing a serious threat to the environment. This necessitates the utilization of supplementary cementitious materials such as silica fume, fly ash, rice husk ash, and wheat straw ash as a cement replacement material. Additionally, fiber-reinforced cement composites can be efficiently used in repair and rehabilitation works. In this study, we have investigated the performance of fiber-reinforced cement composites blended with wheat straw ash. Wheat straw ash has been proved to be an effective pozzolanic material. Cement was replaced by 20% (weight) wheat straw ash. Polypropylene fibers were added at a dosage of 0%, 0.5%, 1%, and 2% by weight of cement. Mortar specimens were fabricated and investigated for the compressive, flexure, and indirect tensile strengths, ultrasonic pulse velocity, chloride migration resistance, and carbonation resistance. The results demonstrate that the addition of fibers caused a reduction in the compressive strength, pulse velocity, chloride migration resistance, and carbonation resistance; however, flexure and indirect tensile strengths were significantly enhanced. Moreover, the incorporation of fine size wheat straw ash particles compensated the negative effect of fiber inclusion.

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“…However, the positive utilisation of fly ash is impossible when it is used as an alternative cementitious material of cement owing to its early delayed strength development [23]. Hence, a method of replacing fine aggregate with fly ash was proposed [24][25][26][27][28][29][30]. Because fly ash replaces part of the fine aggregate, part of the fly ash act as a cementitious material to fill pores and increase the compactness, while the remaining produce a volcanic ash effect, which is attributed to the presence of SiO 2 and Al 2 O 3 .…”

Section: Introductionmentioning

confidence: 99%

Experimental Investigation of Neutralisation of Concrete with Fly Ash as Fine Aggregate in Freeze‐Thaw Environment

Zhang

Mao

Yang

et al. 2019

Advances in Civil Engineering

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To study the durability of concrete with fly ash as fine aggregate under alternate freeze-thaw and carbonation, freeze-thaw and carbonation cyclic tests are conducted to explore variation characteristics such as relative dynamic modulus of elasticity and neutralisation depth. The influence coefficient (λC) of carbonation on concrete freeze-thaw damage and the influence coefficient (λF) of freeze-thaw on concrete neutralisation are introduced. In addition, scanning electron microscopy is performed to reveal the deterioration mechanism of the alternating effect. Finally, through a regression analysis of test data, the mathematical expression of the composite damage coefficient kF under alternate freeze-thaw and carbonation is obtained. Based on these findings, a prediction model of the neutralisation depth of concrete is established with number of freeze-thaw cycles and water-cement ratio as parameters. The values calculated through this model and the values measured in the tests are highly correlated. This provides a theoretical reference and basis for the analysis of concrete durability in a multifactor environment.

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Concretes with synthetic aggregates for sustainability

Cited by 30 publications

References 27 publications

Modified xonotlite–type calcium silicate hydrate slabs for fire doors

Modified xonotlite–type calcium silicate hydrate slabs for fire doors

Performance Evaluation of the Fiber-Reinforced Cement Composites Blended with Wheat Straw Ash

Experimental Investigation of Neutralisation of Concrete with Fly Ash as Fine Aggregate in Freeze‐Thaw Environment

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