Engineering of green cementitious composites modified with siliceous fly ash: Understanding the importance of curing conditions

Silicate composites have very low conductivity in general. It is possible to achieve an electrical resistivity decrease by adding an electro-conductive filler. The conductive mixture consists of cementitious binder, various types of silica sand, and graphite-based conductive fillers. One of the research focusses is partial substitution of ordinary raw materials by alternative components (waste materials by-products and secondary raw materials) and its influence on composite properties. The alternative components studied were fly ash as a partial binder replacement, waste graphite from two different sources and steel shavings as a substitute for conductive filler. Resistivity of cured conductive silicate-based specimens was analysed in relation to changes in physico-mechanical properties in context of microstructural changes in the hardened cementitious matrix (by optical and scanning electron microscopy with energy disperse analysis). Partial substitution of cement by fly ash was found to reduce the electrical resistivity of the composite. Some of the waste graphite fillers significantly reduce the resistivity of the cement composite and increase the compressive strength. It was proven, that is possible to replace primary conductive fillers by secondary raw materials.

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“… 47 it starts approx. after 90 days), the strength of the composite decreases as the amount of the substituted binder increases 48 .…”

Section: Resultsmentioning

confidence: 98%

Electrically conductive composite materials with incorporated waste and secondary raw materials

Baránek

Černý

Drochytka

et al. 2023

Sci Rep

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“…The adoption of supplementary cementitious materials (SCM) in the construction industry has become widespread and a major trend among developed and developing countries. − With the recent focus on developing low-CO 2 cementitious composites, there has been an unprecedented shift to SCMs research. − The main SCMs commercially available are fly ash (FA), , silica fume (SF), , and ground-granulated blast furnace slag (GGBFS). − However, conventional SCMs currently face challenges associated with insufficient production and geographical scarcity, mainly due to the greening of other industries and the closing of coal-powered plants for blended cements. − …”

Section: Introductionmentioning

confidence: 99%

Evaluation of the Pozzolanic Potential of Poultry Litter Ash Calcined at Different Temperatures as a Revalorized Biomass Waste

Nahuat-Sansores,

Cruz,

Escobar

et al. 2024

ACS Sustainable Resour. Manage.

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In support of the greening of the construction industry, the development of alternative composites with equal capabilities is paramount. In this study, the pozzolanic activity of poultry litter ash (PLA) calcined at three distinct temperatures (600, 700, and 800 °C) was determined by two direct methods: Frattini and Chapelle. Supporting physicochemical techniques were used to evaluate the properties and suitability of PLA as a pozzolan. The elemental composition of PLA is assessed by CHNS-analysis, while Fourier transform infrared (FTIR) spectroscopy shows functional groups. Calcium oxide is the most significant crystalline phase in the 700−800 °C temperature range. Pozzolanic tests yielded significant results in terms of Ca(OH) 2 consumption for samples calcined at 700 and 800 °C: CaO reductions above 34 and 20% in the Frattini test and 240.46 and 107.87 mg Ca(OH) 2 /g PLA in the Chapelle test, respectively. Frattini and Chapelle tests may be affected due to calcium compounds leaching and are not appropriate for CaO-dominant materials.

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“…Fly ash, one of the wastes generated from coal-fired power plants is very abundant. It can be used as a mixture of cement paste to reduce industrial waste in power plants since fly ash has similar oxide contents to Portland cement [4,5]. These materials now can be widely applicable in Indonesia since Government regulation (PP No.…”

Section: Introductionmentioning

confidence: 99%

Morphological and Properties of Portland-Composite Cements With Class C Fly Ash

Harmaji

Fadillah

2023

IJIMEAM

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Portland-composite cements (PCC) were prepared with partial substitution of 5 to 25% of class C fly ash, obtained from East Java steam power plant. Properties of the composite cements was evaluated, through the setting time (initial and final) and compressive strength (3, 7, and 28 days) compared with control PCC. Setting time is retarded in Portland-composite cements with higher fly ash content. The retardation is highest in PCC with substitution of 25% fly ash. Lower compressive strength is obtained after 3 and 7 days of curing for PCC with 5-25% fly ash substitution in comparison with control cement, since pozzolanic reaction still did not show its effect. After 28 days, compressive strength was higher than that for control cement because pozzolanic reaction show its effect, highlighted by compressive strength increase of PCC substituted by 5% and 10% fly ash, 16.48 MPa and 16.52 MPa, respectively. This attributed to the differences in the pozzolanic activity of the applied fly ash. The compressive strength increase was explained by Scanning Electron Microscope (SEM), which shows that PCC with substitution of 10% fly ash had more Tobermorite presented compared to control cement.

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Engineering of green cementitious composites modified with siliceous fly ash: Understanding the importance of curing conditions

Cited by 13 publications

References 53 publications

Electrically conductive composite materials with incorporated waste and secondary raw materials

Electrically conductive composite materials with incorporated waste and secondary raw materials

Evaluation of the Pozzolanic Potential of Poultry Litter Ash Calcined at Different Temperatures as a Revalorized Biomass Waste

Morphological and Properties of Portland-Composite Cements With Class C Fly Ash

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