Determination of Thermal Properties of Autoclaved Aerated Concrete Wall Sections Constructed with Distinct Mortars by the Experimental and Theoretical Data

Year 2024, , 935 - 944, 30.09.2024

Rukiye Koçkar Tuğla , Orhan Emre Örgel

https://doi.org/10.35234/fumbd.1477261

Abstract

This study investigated the thermal properties of autoclaved aerated concrete(AAC) wall sections constructed with distinct mortars. Within the scope of the study, four distinct wall sections of 25x25x5cm dimensions were created using AAC special adhesive mortar, cement mortar, lime mortar and cement-lime mortar. The thermal conductivity(λEXP) that was determined by the heat flow meter(HFM) method and bulk density(ρEXP) of each wall section was determined in the laboratory. Specific heat values(cEXP) of mortars and aerated concrete material were determined experimentally in the study. The thermal diffusivity value(αEXP), thermal effusivity value(eEXP) and volumetric heat capacity(VHCEXP) of each wall sample were calculated using the experimental data obtained in the laboratory. In addition, αTEO, eTEO and VHCTEO of each wall sample were calculated theoretically using the thermal conductivity, bulk density and specific heat value given in the literature and standards for the same wall sections. In the study, experimental data was compared to the theoretical data. As a result, the thermal properties of walls constructed with distinct mortars and thermal differences formed in the walls due to the effect of these mortars could be determined with experimental data. However, it was observed that theoretical data were insufficient to detect these thermal differences.

Keywords

Autoclaved aerated concrete wall, thermal conductivity, specific heat value, thermal diffusivity, thermal effusivity

Farklı Harçlarla İnşa Edilen Gazbeton Duvar Kesitlerine Ait Isıl Özelliklerin Deneysel ve Teorik Verilerle Belirlenmesi

Abstract

Bu çalışmada, farklı harçlar ile inşa edilmiş gaz beton duvar kesitlerinin ısıl özellikleri incelenmiştir. Çalışma kapsamında gaz beton özel yapıştırma harcı, çimento harcı, kireç harcı ve çimento-kireç harcı kullanılarak 25x25x5cm boyutunda dört farklı duvar kesiti oluşturulmuştur. Her bir duvar kesitinin, ısıl iletkenlik hesap değeri (λEXP) ısı akış ölçer (HFM) yöntemiyle ve birim hacim ağırlığı (ρEXP) standartlarda tarfilenen şekliyle laboratuvarda elde edilmiştir. Çalışma kapsamında kullanılan harçların ve gaz beton malzemenin özgül ısı değeri (cEXP,) deneysel olarak belirlenmiştir. Laboratuvarda elde edilen bu deneysel veriler kullanılarak her duvar örneğinin deneysel(EXP) termal efusivite/ısıl dağınırlık (αEXP), termal efusivite/ısıl dağınırlık (eEXP) değeri ve hacimsel ısı kapasitesi (VHCEXP) hesaplanmıştır. Aynı duvar kesitleri için literatürde ve/veya standartlarda verilen teorik ısıl iletkenlik hesap değeri, birim hacim ağırlığı ve özgül ısı değeri kullanılarak her bir duvar örneğinin termal difüzivite/ısıl yayınırlık (αTEO), termal efusivite/ısıl dağınırlık (eTEO) değeri ve hacimsel ısı kapasitesi (VHCTEO) teorik olarak belirlenmiştir. Çalışmada deneysel veriler ile teorik veriler karşılaştırılmıştır. Sonuç olarak; farklı harçlarla inşa edilmiş duvarların ısıl özellikleri ve bu harçların etkisiyle duvarlarda oluşan ısıl farklılıklar deneysel veriler ile tespit edilebilmiştir. Teorik verilerin ise bu ısıl farklılıkları tespit etmede yetersiz kaldığı görülmüştür.

Keywords

Gaz beton duvar, ısıl iletkenlik hesap değeri, özgül ısı değeri, ısıl yayınırlık, ısıl dağınırlık

Supporting Institution

Bu çalışma Tübitak 2209 Üniversite Öğrencileri Araştırma projeleri kapsamında desteklenmiştir.

References

• Andolsun S. A study on material properties of autoclaved aerated concrete (AAC) and its complementary wall elements: their compatibility in contemporary and historical wall sections. MSc, Middle East Technical University, Ankara, Turkiye, 2006.
• Grinzato E, Bison P, Tavukcuoglu A. Caratterizzazione di materiali edili, con il metodo integrato termografico-ultrasonico-analitico. AIPnD-PnD Congresso; 2009 Oct 15-17; Rome, Italy.
• TS 453. Gas and foam concrete material and elements for building. Turkish Standards Institution, Ankara, Turkiye, 2005.
• TS EN 771-4+A1. Specification for masonry units - Part 4: Autoclaved aerated concrete masonry units. Turkish Standards Institution, Ankara, Turkiye, 2015.
• Wakili GK, Hugi E, Karvonen L, Schnewlin P, Winnefeld F. Thermal behaviour of autoclaved autoclaved aerated concrete exposed to fire. Cem Concr Compos. 2015; 62: 52–58.
• RILEM. Recommended practice- RILEM Technical Committees: 78-MCA and 51-ALC. Autoclaved Aerated Concrete- Properties, Testing, and Design. S. Aroni, GJ. de Groot, MJ. Robinson, G. Svanholm and Wittman F.H. ed. Taylor& Francis Group, London and New York, 1993.
• Taşdemir C, Ertokat N. Gazbetonun fiziksel ve mekanik özellikleri üzerine bir değerlendirme. Proceedings of 1. Ulusal Yapı Malzemesi Kongresi ve Sergisi; 2002; 2, Istanbul TMMOB Mimarlar Odası Istanbul Büyükkent Şubesi. 425-437.
• Xusheng D, Zhe X, Junjiang L, Lei W. Effects of lime content on properties of autoclaved aerated concrete made from circulating fluidized bed ash. Dev Built Environ. 2024;18: 100406.
• Deng Y, Wu L. Effect of recycled concrete fine powder after calcination on the properties of autoclaved aerated concrete Case Stud Constr Mater. 2024;20: e02961.
• Pehlivanlı ZO, Uzun I, Yücel ZP, Demir I. The effect of different fiber reinforcement on the thermal and mechanical properties of autoclaved aerated concrete. Constr Build Mater. 2016;112: 325–330.
• TS 825. Thermal insulation requirements for buildings, Turkish Standards Institution, Ankara, Turkiye, 2013.
• Narayanan N, Ramamurthy K. Structure and properties of aerated autoclaved concrete: a review. Cem Concr Compos. 2000; 22; 321-329.
• Johra H. Thermal Properties of Building Materials-Review and Database Technical Report No. 289. Energy & Indoor Environment; 2021; Aalborg University Department of the Built Environment Division of Sustainability.
• Tuğla R, Tavukçuoğlu A, Arslan M. Examination of thermal properties and failures of brick walls by the use of infrared thermography and hot box method. International Conference & Exhibition on Application of Efficient & Renewable Energy Technologies in Low-Cost Buildings and Construction; 2013; Ankara, Turkiye, 180-199.
• Kosny J. Performance analysis of autoclaved aerated concrete; an example of collaboration between industry and a research lab on development of energy efficient. Build Industry Trends 1994; 10: 161–172.
• TS EN 1745. Masonry and masonry products - Methods for determining design thermal values. Turkish Standards Institution; 2020; Ankara, Turkiye.
• Horak HL. York DA. Hunn BD. Peterson JL. Roschke MA. Tucker EF. DOE-2 Reference Manual 2. Los Alamos Scientific Laboratory, 1979.
• Clarke JA, Yaneske PP, Pinney AA. The Harmonisation of Thermal Properties of Building Materials. Watford UK: Building Research Establishment, 1991.
• URL1: Integrated Environmental Solutions Limited (IESVE). Specific Heat Capacity. Available: https://tinyurl.com/eb83nadk (accessed on: 25 September 2023)
• Koçkar Tuğla R. Determination of thermal diffusivity value of building walls by quantitative infrared thermography. Ph D Thesis (Ankara: Gazi Universty) Turkiye, 2019.
• Aruntaş HY, Şahinöz M, Dayı M. Investigation of lime usage in cement paste and mortars. J Polytechnic 2021; 24(3):1045-1054.
• Michelini E, Ferretti D, Miccoli L, Parisi F. Autoclaved aerated concrete masonry for energy efficient buildings: State of the art and future developments Constr Build Mater. 2023;402: 132996.
• BS EN 12667. Thermal Performance of building materials and products- determination of thermal resistance by means of guarded hot plate and heat flow meter methods- products of high and medium thermal resistance. British Standard, 2001.
• TS 4048. Determination of Specific Heat of Thermal Insulating Materials. Turkish Standards Institution, Ankara, Turkiye, 2013.
• Çiçek P. Thermal performance assessment of historical Turkish baths. MSc, Middle East Technical University, Ankara, Turkiye, 2009.
• Çengel Y. Isı ve kütle transferi pratik bir yaklaşım (3rd Edition), Izmir: Güven Kitabevi, 2011.
• RILEM. Tentative Recommendations, Commission–25–Pem, Recommended Test to Measure the Deterioration of Stone and to Assess the Effectiveness of Treatment Methods. Mater Struct. 13(73): 173-25. 1980.
• TS EN 1936. Natural stone test methods - Determination of real density and apparent density, and of total and open porosity. Turkish Standards Institution, Ankara, Turkiye, 2007.
• URL2 Available: https://www.imo.org.tr/resimler/dosya_ekler/f7deb880ca6b4b7_ek.pdf (accessed on 06 December 2023)