The Apparent Thermal Conductivity of Pozzolana Concrete

Bessenouci, M.Z.; Triki, N E Bibi; Khelladi, Sofiane; Draoui, Belkacem; Abene, A.

doi:10.1016/j.phpro.2011.10.010

Cited by 11 publications

(6 citation statements)

References 4 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…[25] mostraram que a condutividade térmica de argamassas com resíduos inorgânicos (20 MPa aos 28 dias), naturais (não pozolânicos) e tratados (pozolânicos) é menor que a da amostra padrão (25 MPa aos 28 dias). Como a condutividade depende da natureza do material e da presença de vazios, isto é, varia diretamente com a massa específica [26], os resultados obtidos estariam relacionados, também, à presença de vazios na microestrutura [27].…”

Section: Resultsunclassified

Influência do uso de lama de vidro na difusividade térmica de argamassas estruturais utilizando termografia

et al. 2020

View full text Add to dashboard Cite

RESUMO O vidro soda-cal-sílica é um material com alto potencial de reciclagem. No entanto, o seu beneficiamento gera micropartículas que ficam suspensas na água utilizada para resfriamento das ferramentas. Esse resíduo é inerte e, comumente, não reaproveitado. Para seu descarte é feita a decantação das micropartículas de vidro utilizando floculantes, sendo a lama produzida depositada em aterros sanitários. De acordo com a literatura, essas micropartículas de vidro poderiam atuar como material cimentício suplementar na produção de cimento Portland. Contudo, as informações sobre o desempenho térmico desses materiais são escassas. Neste estudo investiga-se a difusividade térmica de argamassas para fins estruturais confeccionadas com cimento Portland e lama de vidro soda-cal-sílica com características pozolânicas. Foram produzidas argamassas com e sem substituição do cimento por 10 e 20% de lama in natura e lama lavada para retirada do floculante. As argamassas foram caracterizadas quanto à resistência mecânica e difusividade térmica. Também, foram determinadas a massa específica, a condutividade térmica e o perfil de aquecimento das amostras, parâmetros necessários para avaliar a difusividade térmica. Os resultados indicam que a lama de vidro, com e sem floculante, poderia ser utilizada em substituição ao cimento sem comprometer a resistência mecânica devido às suas características pozolânicas. Nas argamassas com 10% de lama sem floculante se observa um aumento de aproximadamente 8% na resistência. Contudo, em todas as amostras com lama de vidro, lavada ou não, observa-se uma diminuição de 3 a 4% na massa específica e de 17 a 18% na condutividade térmica, indicando que a reação pozolânica não ocorreu em toda a sua extensão. A difusividade, determinada com auxílio da termografia infravermelha, apresenta resultados compatíveis com a literatura e indica que o uso do resíduo não influencia significativamente a inércia térmica das argamassas. Dessa forma, a lama de vidro em substituição a 10% e 20% de cimento Portland poderia ser utilizada em argamassas estruturais sem comprometer o desempenho térmico do sistema, além de contribuir com o meio ambiente ao dar destino adequado ao resíduo e reduzir a retirada de matérias primas para a produção de cimento.

show abstract

Section: Resultsunclassified

Influência do uso de lama de vidro na difusividade térmica de argamassas estruturais utilizando termografia

et al. 2020

View full text Add to dashboard Cite

show abstract

“…Without force convection, the heat transfer rate inside the PC decreases sharply after 50% porosity, at higher porosity the heat transfer is led by convection rather than conduction inside the porous body. The heat transfer rate of PC increases with decreasing porosity of its structure (Bessenouci et al ., 2011). Therefore, PC is expected to offer a more stable temperature profile when incorporated into an HRG design, resulting in an extensive hydroponic green roof (EHGR) system with different structural components.…”

Section: Feasibility Of Pc As An Hgr Componentmentioning

confidence: 99%

Prospects of porous concrete as a plant-growing medium and structural component for green roofs: a review

Rahman

MacPherson

Lefsrud

2022

Renew. Agric. Food Syst.

View full text Add to dashboard Cite

Green roof technology can partially mitigate the adverse effects of urbanization by controlling stormwater runoff, pre-filtering water, minimizing climate change outcomes and reducing heat island effects. However, improvements to current green roof systems and innovative approaches are paramount to advancing environmental benefits and consumer acceptance of this technology. Regular green roofs are hindered by high cost and mass, as well as the incorporation of large amounts of polymers. Hydroponic green roofs (HGRs) require specific setups, maintenance and frequent replacement of plant-growing substrate, with limited energy savings in the heating and cooling load of the building due to the space between the roof surface and the hydroponic setup. In this review, a comparison of regular and HGRs is provided, and research into the environmental benefits of these technologies, including stormwater control, water purification and lifecycle assessment, is summarized. Following this, the prospect of porous concrete (PC), as a combined plant-growth substrate and structural layer in a novel extensive hydroponic green roof (EHGR) design is proposed, through a compilation and analysis of recent studies reporting the feasibility of this construction material for different applications. The mechanical, hydrological and vegetative properties of PC are discussed. Finally, a new green roof system that incorporates both PC and hydroponics, termed the EHGR system, is presented. This new green roof system may help offset the effects of urbanization by providing stormwater and pollution control, runoff delay and physical and thermal benefits, while concurrently producing biomass from a reusable substrate.

show abstract

“…Various studies have demonstrated that the addition of pozzolanic materials to concrete composites lowered their thermal conductivity (Stefanidou et al, 2010;Wongkeo et al, 2012). This observation could be ascribed to their high silica content (Raheem et al, 2011) and the high porosity of the concrete upon addition of CCA (Bessenouci et al, 2011). Overall, the study by Raheem et al (2011) concluded that adding Memon et al (2019) To investigate the ecofriendly use of CCA as a partial replacement for sand in concrete.…”

Section: References Objective Of the Study Parameters/ Reaction Conditions Findings/conclusionmentioning

confidence: 99%

Utilization of Corn Cobs Ash as Cementitious and Binary Cementitious Materials in Concrete and Cement-based Composites: A Review

2021

DRCSF

View full text Add to dashboard Cite

This paper reviews the utilization of corn cobs ash (CCA) as pozzolanic, cementitious, and binary cementitious materials in concrete. CCA is the grey-to-brown, inorganic or heterogeneous residual material derived from the high- temperature incineration or combustion of corn cobs (CC). Despite the typical problematic nature of biomass ash, the chemical composition of CCA renders it a potential pozzolanic material. Therefore, numerous studies have critically examined the process technologies and operational conditions for CCA production and its application as a partial replacement for cement in concrete. Other studies have extensively characterized the physicochemical, morphological, microstructure, and thermal properties of CCA through various analytical techniques. Potential pozzolanic materials must meet the condition: SiO2 + Al2O3 + Fe2O3 ≥ 70%, according to ASTM C618, to which CCA complies satisfactorily. Hence, the use of CCA as a replacement for cement has been investigated over the years. Findings indicate that the partial replacement of cement with CCA decreases compressive strength, thermal conductivity, ultrasonic pulse velocity, and density of the hardened concrete at normal temperatures. Nevertheless, the thermal treatment (calcination) of CCA and extended curing enhances compressive strength owing to higher silica content and extended surface area. Besides, the partial replacement of cement with CCA enhances the insulation properties of mortar, which improves thermal comfort, costs and energy savings in buildings. Hence, the partial replacement of cement with CCA provides an environmentally friendly, low cost, and sustainable approach for valorizing CC residues whilst addressing CO2 emissions in construction.

show abstract

The Apparent Thermal Conductivity of Pozzolana Concrete

Cited by 11 publications

References 4 publications

Influência do uso de lama de vidro na difusividade térmica de argamassas estruturais utilizando termografia

Influência do uso de lama de vidro na difusividade térmica de argamassas estruturais utilizando termografia

Prospects of porous concrete as a plant-growing medium and structural component for green roofs: a review

Utilization of Corn Cobs Ash as Cementitious and Binary Cementitious Materials in Concrete and Cement-based Composites: A Review

Contact Info

Product

Resources

About