Characterization of building materials for propagation modelling: frequency and time responses

2005 ◽  
Vol 59 (6) ◽  
pp. 337-347 ◽  
Author(s):  
F. Sagnard ◽  
G. El Zein
Keyword(s):  
Building Materials ◽  
Propagation Modelling

scholarly journals Thermal Characterization of Recycled Materials for Building Insulation

Energies ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3564
Author(s):  
Arnas Majumder ◽  
Laura Canale ◽  
Costantino Carlo Mastino ◽  
Antonio Pacitto ◽  
Andrea Frattolillo ◽  
...  
Keyword(s):  
Environmental Impact ◽  
Environmental Sustainability ◽  
Building Materials ◽  
Raw Materials ◽  
Natural Fibers ◽  
Thermal Characterization ◽  
Recycled Materials ◽  
Building Insulation ◽  
Operational Phase

The building sector is known to have a significant environmental impact, considering that it is the largest contributor to global greenhouse gas emissions of around 36% and is also responsible for about 40% of global energy consumption. Of this, about 50% takes place during the building operational phase, while around 10–20% is consumed in materials manufacturing, transport and building construction, maintenance, and demolition. Increasing the necessity of reducing the environmental impact of buildings has led to enhancing not only the thermal performances of building materials, but also the environmental sustainability of their production chains and waste prevention. As a consequence, novel thermo-insulating building materials or products have been developed by using both locally produced natural and waste/recycled materials that are able to provide good thermal performances while also having a lower environmental impact. In this context, the aim of this work is to provide a detailed analysis for the thermal characterization of recycled materials for building insulation. To this end, the thermal behavior of different materials representing industrial residual or wastes collected or recycled using Sardinian zero-km locally available raw materials was investigated, namely: (1) plasters with recycled materials; (2) plasters with natural fibers; and (3) building insulation materials with natural fibers. Results indicate that the investigated materials were able to improve not only the energy performances but also the environmental comfort in both new and in existing buildings. In particular, plasters and mortars with recycled materials and with natural fibers showed, respectively, values of thermal conductivity (at 20 °C) lower than 0.475 and 0.272 W/(m⋅K), while that of building materials with natural fibers was always lower than 0.162 W/(m⋅K) with lower values for compounds with recycled materials (0.107 W/(m⋅K)). Further developments are underway to analyze the mechanical properties of these materials.

scholarly journals Characterization of a Novel CaCO3-Forming Alkali-Tolerant Rhodococcus erythreus S26 as a Filling Agent for Repairing Concrete Cracks

Molecules ◽  
2021 ◽  
Vol 26 (10) ◽  
pp. 2967
Author(s):  
Seunghoon Choi ◽  
Sungjin Park ◽  
Minjoo Park ◽  
Yerin Kim ◽  
Kwang Min Lee ◽  
...  
Keyword(s):  
Building Materials ◽  
Culture Fluid ◽  
Natural Phenomenon ◽  
Environment Friendly ◽  
Wide Range ◽  
Filling Agent ◽  
Calcium Source ◽  
Alkali Tolerance ◽  
High Alkali

Biomineralization, a well-known natural phenomenon associated with various microbial species, is being studied to protect and strengthen building materials such as concrete. We characterized Rhodococcus erythreus S26, a novel urease-producing bacterium exhibiting CaCO3-forming activity, and investigated its ability in repairing concrete cracks for the development of environment-friendly sealants. Strain S26 grown in solid medium formed spherical and polygonal CaCO3 crystals. The S26 cells grown in a urea-containing liquid medium caused culture fluid alkalinization and increased CaCO3 levels, indicating that ureolysis was responsible for CaCO3 formation. Urease activity and CaCO3 formation increased with incubation time, reaching a maximum of 2054 U/min/mL and 3.83 g/L, respectively, at day four. The maximum CaCO3 formation was achieved when calcium lactate was used as the calcium source, followed by calcium gluconate. Although cell growth was observed after the induction period at pH 10.5, strain S26 could grow at a wide range of pH 4–10.5, showing its high alkali tolerance. FESEM showed rhombohedral crystals of 20–60 µm in size. EDX analysis indicated the presence of calcium, carbon, and oxygen in the crystals. XRD confirmed these crystals as CaCO3 containing calcite and vaterite. Furthermore, R. erythreus S26 successfully repaired the artificially induced large cracks of 0.4–0.6 mm width.

scholarly journals The Influence of Cement Substitution by Biomass Fly Ash on the Polymer–Cement Composites Properties

Materials ◽  
2021 ◽  
Vol 14 (11) ◽  
pp. 3079
Author(s):  
Beata Jaworska ◽  
Dominika Stańczak ◽  
Joanna Tarańska ◽  
Jerzy Jaworski
Keyword(s):  
Fly Ash ◽  
Building Materials ◽  
Raw Materials ◽  
Combustion Process ◽  
Biomass Combustion ◽  
Cement Composites ◽  
Cement Mortars ◽  
Mineral Additive ◽  
Biomass Fly Ash

The generation of energy for the needs of the population is currently a problem. In consideration of that, the biomass combustion process has started to be implemented as a new source of energy. The dynamic increase in the use of biomass for energy generation also resulted in the formation of waste in the form of fly ash. This paper presents an efficient way to manage this troublesome material in the polymer–cement composites (PCC), which have investigated to a lesser extent. The research outlined in this article consists of the characterization of biomass fly ash (BFA) as well as PCC containing this waste. The characteristics of PCC with BFA after 3, 7, 14, and 28 days of curing were analyzed. Our main findings are that biomass fly ash is suitable as a mineral additive in polymer–cement composites. The most interesting result is that the addition of biomass fly ash did not affect the rheological properties of the polymer–cement mortars, but it especially influenced its compressive strength. Most importantly, our findings can help prevent this byproduct from being placed in landfills, prevent the mining of new raw materials, and promote the manufacture of durable building materials.

A review of waste-containing building materials: Characterization of the heavy metal

2021 ◽  
Vol 309 ◽  
pp. 125107
Author(s):  
Zongxian Huang ◽  
Kuisheng Liu ◽  
Jinsong Duan ◽  
Qiang Wang
Keyword(s):  
Heavy Metal ◽  
Building Materials ◽  
Materials Characterization

Characterization of building materials by means of spectral remote sensing: The example of Carcassonne's defensive wall (Aude, France)

2019 ◽  
Vol 23 ◽  
pp. 396-405 ◽  
Author(s):  
C. Sciuto ◽  
D. Allios ◽  
R. Bendoula ◽  
A. Cocoual ◽  
M.-E. Gardel ◽  
...  
Keyword(s):  
Remote Sensing ◽  
Building Materials

scholarly journals Novel active method for the estimation of a building wall thermal resistance

2020 ◽  
Vol 172 ◽  
pp. 14008
Author(s):  
Adrien François ◽  
Laurent Ibos ◽  
Vincent Feuillet ◽  
Johann Meulemans
Keyword(s):  
Steady State ◽  
Thermal Resistance ◽  
Building Materials ◽  
Thermal Inertia ◽  
Thermal Response ◽  
Heat Fluxes ◽  
External Temperature ◽  
Building Wall ◽  
High Thermal Inertia

The thermal resistance of a wall can be readily measured in steady-state. However, such a state is seldomly achieved in a building because of the variation of outdoor conditions as well as the high thermal inertia of building materials. This paper introduces a novel active (dynamic) method to measure the thermal resistance of a building wall. Not only are active approaches less sensitive to external temperature variations, they also enable to perform measurements within only a few hours. In the proposed methodology, an artificial thermal load is applied to a wall (heating of the indoor air) and its thermal response is monitored. Inverse techniques are used with a reduced model to estimate the value of the thermal resistance of a wall from the measured temperatures and heat fluxes. The methodology was validated on a known load-bearing wall built inside a climate chamber. The results were in good agreement with reference values derived from a steady-state characterization of the wall. The method also demonstrated a good reproducibility.

scholarly journals Development and characterization of sustainable lightweight geopolymer composites

Cerâmica ◽  
2019 ◽  
Vol 65 (373) ◽  
pp. 153-161 ◽  
Author(s):  
H. M. Khater
Keyword(s):  
Compressive Strength ◽  
Water Absorption ◽  
Aluminum Powder ◽  
Building Materials ◽  
Microstructural Characteristics ◽  
Imaging Results ◽  
Lightweight Composites ◽  
Sem Imaging ◽  
Geopolymer Composites

Abstract Production of lightweight building materials attract the attention of the scientists worldwide with the need for reducing the structure deadweight, provide better thermal insulation for buildings, and cost less to transport. The current work focused on the production of lightweight geopolymer composites by the incorporation of aluminum powder and aluminum slag in various ratios for water-cooled slag/kaolinite sand composite; the activators used were 6% of equal ratio from sodium hydroxide and sodium silicate. The properties of the produced lightweight geopolymer composites were studied by measurement of compressive strength, bulk density, water absorption, FTIR, XRD and SEM imaging. Results showed the enhancement for both physicomechanical and microstructural characteristics with using aluminum powder and aluminum slag forming lightweight composites with densities below 2.15 g/cm3 depending on the studied mix composition.

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