The Early Basilica Church, El-Ashmonein Archaeological Site, Minia, Egypt: Geo-Environmental Analysis and Engineering Characterization of the Building Materials

The study of building materials constituting cultural heritage is fundamental to understand their characteristics and predict their behavior. When considering materials from archaeological sites, their characterization can provide not only relevant information for a broader understanding of the site and its importance and significance but can also increase knowledge about ancient materials and their performance. The Palace of Knossos is a very important archaeological site in the European history context, and its preservation benefits from the characterization of the constituent materials. Samples of mortars from this monument were collected under the scope of the H2020 HERACLES project, where a multi-analytical approach was chosen using established protocols for the different sample typologies. Instrumental techniques such as optical microscopy (OM), X-ray diffraction (XRD), Fourier-transform infrared spectroscopy (FTIR), and simultaneous thermogravimetry and differential thermal analysis (TG–DTA) were used for the chemical, mineralogical, and morphological characterization of these mortar samples. The results indicate that the majority are lime mortars, both aerial and hydraulic, but gypsum-based mortars were also identified. Differences in the chemical composition of the samples in distinct areas of the monument allowed us to reflect on the variety of materials used in the construction of the Palace of Knossos.

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Mechanical characterization and reinforcement of the adobe material of the Chellah archaeological site

E3S Web of Conferences ◽

10.1051/e3sconf/202015003022 ◽

2020 ◽

Vol 150 ◽

pp. 03022

Author(s):

Sana Simou ◽

Khadija Baba ◽

Nacer Akkouri ◽

Mohammed Lamrani ◽

Mohammed Tajayout ◽

...

Keyword(s):

Building Materials ◽

Mechanical Characterization ◽

Archaeological Site ◽

Mechanical Tests ◽

Actual State ◽

Historical Buildings ◽

Support Intervention ◽

Sem Study ◽

Wood Shaving

The evaluation of historical buildings has always posed significant challenges due to the difficulties associated with the characterization of complex geometries, the variability of the properties of building materials and the actual state of damage to these structures. This challenge is even more complex when it concerns historical adobe masonry buildings, because earthen masonry has a high variability and rapid deterioration over time if it is not properly maintained. In the context of the previous, it was important to provide information to support intervention projects in historic centres. This research involves the experimental analysis of the adobe material collected from the Chellah archaeological site (Rabat-Morocco), in order to study the mechanical behaviour of this material as well as that reinforced by wood shaving. A series of mechanical tests carried out, which include compressive and tensile strength on the adobe material and the mixture adobe/wood fibre in different proportions. The improvement of the mechanical properties of the reinforced adobe, led us to a SEM study, which was carried out on the surface of the test specimens to examine the morphology and observe the interfaces of the adobe/wood mixture, as well as the state of dispersion of the fibres in the adobe mixture.

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Thermal Characterization of Recycled Materials for Building Insulation

Energies ◽

10.3390/en14123564 ◽

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.

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Magnetic and chemical characterization of black pottery from Hanseong Baekje archaeological site, South Korea

Journal of Radioanalytical and Nuclear Chemistry ◽

10.1007/s10967-021-07813-w ◽

2021 ◽

Author(s):

Dong Hyeok Moon ◽

Myeong Seong Lee ◽

Hyen Goo Cho ◽

Young Rang Uhm

Keyword(s):

South Korea ◽

Chemical Characterization ◽

Archaeological Site

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

Molecules ◽

10.3390/molecules26102967 ◽

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.

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

Materials ◽

10.3390/ma14113079 ◽

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.

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