Thermal Performance Assessment of Walls Made of Three Types of Sustainable Concrete Blocks by Means of FEM and Validated through an Extensive Measurement Campaign

Abstract

The thermal behavior of three different walls, made with and without by-products, is assessed by means of the Finite Element Method, aiming to evaluate its performance in terms of the sustainable construction of the blocks. Results were compared to those obtained from an experimental campaign, aiming at validation of the model. The by-products used for the blocks were “lime sludge” and “sawdust”, whose performance was compared against the traditional blocks made of concrete as a reference, aiming to demonstrate its sustainability, showing decreases of the thermal transmittance up to 10.5%. Additionally, following the same methodology, the thermal behavior of these above-mentioned blocks but now with added internal insulation made of “recycled cellulose” was assessed, showing higher decreases up to 25.5%, increasing sustainability by addressing an additional reduction in waste, so the right combination of using by-products and the insulating filler in their cavities has been revealed as a promising way of optimizing the walls, offering a relevant improvement in energy savings. Finally, when comparing the U-values of the blocks made of concrete without insulation versus those made of by-products, with insulation, improvements up to 33.3% were reached. The adaptation of the procedure through a moisture correction factor was also incorporated.

Application of sawdust concrete in construction

“…Sawdust concrete block with 5% fine sawdust. Source: [16] Due to different physical and chemical properties, direct connections between concrete and wooden elements are not used in construction. However, with proper preparation and combination of these materials, sawdust concrete is obtained, which is suitable for use in construction.…”

Thermomechanical Performance Analysis of Novel Cement-Based Building Envelopes with Enhanced Passive Insulation Properties

“…Most of the works in the literature tackle the insulation design of building envelopes by means of PCMs [ 29 ]. These include experimental [ 30 , 31 , 32 , 33 ] and numerical approaches [ 34 , 35 , 36 , 37 ], mainly based on the use finite element method (FEM). Moreover, the FEM becomes a powerful method when dealing with coupled physical phenomena, such as heat transfer and solid mechanics [ 38 , 39 ].…”

Thermal Performance Assessment of a Wall Made of Lightweight Concrete Blocks with Recycled Brick and Ground Polystyrene

“…The main issues of building stock within the European Union (EU) are vast energy consumption and greenhouse gas emissions [1], since the EU building sector is responsible for approximately 40% of energy consumption and 36% of CO 2 emissions [1,2]. Existing buildings were constructed mostly in the 1970s, whereby 35% of the existing buildings are over 50 years old, and 75% of building stock is energy inefficient [3]. The issue becomes even greater, since 75-90% of existing buildings will stand in 2050 [3].…”

“…Existing buildings were constructed mostly in the 1970s, whereby 35% of the existing buildings are over 50 years old, and 75% of building stock is energy inefficient [3]. The issue becomes even greater, since 75-90% of existing buildings will stand in 2050 [3]. Actions undertaken during the building operational stage can be either refurbishment or retrofit, where refurbishment implies the necessary modifications to return a building to its original state, while retrofit includes the necessary actions that will improve the building's energy and/or environmental performance [1].…”

“…Partial or complete replacement of natural aggregate with secondary materials not only reduces the carbon footprint, but also reduces strain on already overflowing waste disposal sites. Previous research has also demonstrated that incorporating waste material of low thermal conductivity also improves thermal performance [3] of innovative building materials made from waste materials. By using the agricultural and industrial by-products or wastes, significant contributions can be made towards sustainable construction [4].…”