scholarly journals Raw earth-based building materials: An investigation on mechanical properties of Floridia soil-based adobes

2021 ◽  
Vol 52 (2) ◽  
Author(s):  
Monica Parlato ◽  
Simona M.C. Porto ◽  
Giovanni Cascone
Keyword(s):  
Mechanical Properties ◽  
Building Materials ◽  
Research Work ◽  
Base Material ◽  
Rural Landscape ◽  
Embodied Energy ◽  
Mix Design ◽  
Soil Composition ◽  
Building Components ◽  
Raw Earth

Raw earth, like wood and stone, is one of the oldest building materials used across the world. Nowadays, given the growing role of circular economy, researchers are ever more interested in raw earth-based building materials, because they are widely available and environmentally friendly. The use of this traditional material has positive environmental consequences, especially in traditional rural building reuse and in rural landscape preservation. In fact, raw earth is locally available and totally recyclable and, thanks to its perfect integration into the landscape, it improves site visual perception. Additives and/or chemical stabilizer agents (i.e., Portland cement) are often used in the production of raw earthbased building components in order to increase their mechanical performance and durability. This production process reduces the environmental sustainability of the base material and causes a relevant increase on the embodied energy (i.e., the total energy required for the extraction, processing, manufacturing, and delivery of building components). This research work aimed at investigating how to improve the mix-design of earth-based building materials in order to increase their mechanical properties without any addition of chemical agents. A physical stabilization was performed on an original texture soil by adding various particle sizes. Mechanical tests were carried out on five different soil mixes by changing soil composition, aggregates, and water. Specimens made with mix-design 5 offered the best results in terms of flexural and compressive strength values which were 1.65 MPa and 6.74 MPa, respectively. Mix 3 obtained the lowest linear shrinkage rate (6.04%). Since raw earth-based materials are highly sensitive to soil composition and aggregates, this study attempted to obtain a repeatable process to produce semi-industrial adobes by optimizing and controlling various natural materials (i.e., soils, aggregates, and water).

scholarly journals Design Optimisation Strategies for Solid Rammed Earth Walls in Mediterranean Climates

Energies ◽  
2021 ◽  
Vol 14 (2) ◽  
pp. 325
Author(s):  
Giada Giuffrida ◽  
Maurizio Detommaso ◽  
Francesco Nocera ◽  
Rosa Caponetto
Keyword(s):  
Energy Demand ◽  
Construction Material ◽  
Base Material ◽  
Energy Performance ◽  
Embodied Energy ◽  
Rammed Earth ◽  
Earth Construction ◽  
Material Choice ◽  
Earth Walls ◽  
Raw Earth

The renewed attention paid to raw earth construction in recent decades is linked to its undoubted sustainability, cost-effectiveness, and low embodied energy. In Italy, the use of raw earth as a construction material is limited by the lack of a technical reference standard and is penalised by the current energy legislation for its massive behaviour. Research experiences, especially transoceanic, on highly performative contemporary buildings made with natural materials show that raw earth can be used, together with different types of reinforcements, to create safe, earthquake-resistant, and thermally efficient buildings. On the basis of experimental data of an innovative fibre-reinforced rammed earth material, energy analyses are developed on a rammed earth building designed for a Mediterranean climate. The paper focuses on the influences that different design solutions, inspired by traditional bioclimatic strategies, and various optimised wall constructions have in the improvement of the energy performance of the abovementioned building. These considerations are furthermore compared with different design criteria aiming at minimising embodied carbon in base material choice, costs, and discomfort hours. Results have shown the effectiveness of using the combination of massive rammed earth walls, night cross ventilation, and overhangs for the reduction of energy demand for space cooling and the improvement of wellbeing. Finally, the parametric analysis of thermal insulation has highlighted the economic, environmental, and thermophysical optimal solutions for the rammed earth envelope.

scholarly journals Global Sustainability and the New Zealand House

2021 ◽  
Author(s):  
◽  
J. Andrew Alcorn
Keyword(s):  
New Zealand ◽  
Building Materials ◽  
Co2 Flux ◽  
Hot Water ◽  
Embodied Energy ◽  
Wind Generators ◽  
Electricity Use ◽  
Building Components ◽  
Energy Emissions ◽  
Definition Of

<p>"How do you build a sustainable house in New Zealand? - is it even possible?" This thesis is structured in three parts to answer this question. The first part asks, then answers, "What is sustainability?", "How do you measure sustainability?" and "How do you know when you have reached sustainability - what is its limit?" The second part describes the methodologies for conducting embodied energy and CO2 analysis. The third part applies the results of the sustainability definition, and the energy and CO2 methodologies to a series of house designs. Part 1 defines, measures, and establishes a limit for sustainability. It reviews the history of sustainability and sustainable development. A distillation of what is being sought by the various parties to the sustainability debate then contributes to a checklist of essential requirements for a functional definition of sustainability. Addressing climate change is shown to be the major requirement. The checklist enables answers to the questions about measuring sustainability, and knowing when its limit has been reached, and leads to a functional definition: Sustainability meets the needs of the present without annual CO2 emissions exceeding what the planet can absorb. The requirements for sustainability indicator methods are examined. A robust way of comparing environment impacts is introduced. Several common sustainability indicators are examined against the requirements, but are found wanting, while two are found to be effective: energy and CO2 analysis. Human population and annual global carbon absorption are used to identify global and per-capita sustainability limits, which can be applied at many scales to many activities. They are applied to New Zealand's housing sector to identify a sustainable annual per-house emissions target, including construction, maintenance, and operation. Part 2 reviews the methodologies to measure and delimit sustainability using embodied energy and embodied CO2 analysis. A new, fast, accurate, and reliable process-based hybrid analysis method developed for this research is used to derive embodied energy and CO2 coefficients for building materials. Part 3 applies the results of the sustainability definition and limit, and the energy and CO2 methodologies and coefficients from analysing building materials, to a series of house designs within New Zealand and global contexts. A spreadsheet-based calculator developed for this analysis that has potential beyond this thesis is described. A method is presented for annualising emissions to fairly account for differing building components' lifetimes. Finally, a sustainable house is shown to be possible by combining several strategies to meet the challenging sustainable emissions target. Technologies that reduce grid electricity use - solar hot water, PV, and wind-generators - are crucial, cutting emissions the most. Bio-based materials sequestering carbon are the second most important strategy: strawbale insulation to ~R10, and timber for framing, cladding, windows, linings, and roofing. Efficient appliances, lighting, and other low-emission materials were also helpful. Other key outcomes were: hot water heating emits the most CO2, double any other category; heating energy emissions are smaller than any other category; CO2-optimal conventional insulation levels are ~R5; CO2 flux of materials is double operating energy CO2 for sustainable houses.</p>

Effect of Pre and Post Weld Heat Treatment on the Mechanical Properties of Friction Stir Welded AA6061-T6 Joint

2020 ◽  
Vol 17 (2) ◽  
pp. 7882-7889 ◽  
Author(s):  
J.C. Verduzco Huarez ◽  
R. Garcia Hernandez ◽  
G. M. Dominguez Almaraz ◽  
J.J. Villalón López
Keyword(s):  
Mechanical Properties ◽  
Heat Treatment ◽  
Tensile Strength ◽  
Aluminum Alloy ◽  
Friction Stir Welding ◽  
Research Work ◽  
Base Material ◽  
Welding Process ◽  
Post Weld Heat Treatment ◽  
Friction Stir

This research work focuses on the study of the improvement of mechanical properties, specifically the tensile strength of 6061-T6 aluminum alloy on prismatic specimens with 9.5 mm thickness that has been subjected to friction stir welding process and two heat treatments; solubilized and aging before or after the welding process. Three cases studied and evaluated were, welding of the base material without heat treatment (BMW), solubilized heat treatment and partial aging of the base material before welding (HTBW), and heat treatment of solubilized and aging of the base material after welding (HTAW). The obtained results show an increase of about 10% (20 MPa) of tensile strength for the HTBW process, compared to BMW case. In addition, for the case of HTAW, the obtained tensile resistance presents a joint efficiency of 96%, which is close to the tensile strength of the base material (»310 MPa).

scholarly journals Mechanical and Durability Properties of No Aggregate Concrete using Silica Fume

2020 ◽  
Vol 9 (3) ◽  
pp. 246-249
Keyword(s):  
Mechanical Properties ◽  
20Th Century ◽  
Silica Fume ◽  
Rapid Growth ◽  
Research Work ◽  
Chemical Durability ◽  
Mix Design ◽  
Waste Products ◽  
Aggregate Concrete ◽  
Durability Properties

India is a developing country which has been showing an enormous growth in different aspects like industrialization, urbanization and communication since 20th century. This development is leading to the decay of environment by polluting it. The huge disposal of various waste products from different industries is playing a prominent role in the rapid growth of pollution. No aggregate concrete (NAC) is another kind of concrete where the utilization of totals are completely maintained a strategic distance from for safeguarding the regular stone, hillocks and slopes. The utilization of sand is additionally maintained a strategic distance from to save the waterway beds. This is a regular research work serving the plan of economical advancement. To reduce the use of aggregates in concrete, No Aggregate Concrete for different grades of concrete is desired. The purpose of this project is to obtain mix design, understand Mechanical properties and Chemical durability properties of different mixes developed.

scholarly journals Hygrothermal Properties of Raw Earth Materials: A Literature Review

2019 ◽  
Vol 11 (19) ◽  
pp. 5342 ◽  
Author(s):  
Giuffrida Giada ◽  
Rosa Caponetto ◽  
Francesco Nocera
Keyword(s):  
Thermal Performance ◽  
Natural Fibers ◽  
Embodied Energy ◽  
Recycled Aggregates ◽  
Low Carbon ◽  
Interior Spaces ◽  
Base Materials ◽  
Building Components ◽  
Earthen Architecture ◽  
Raw Earth

Raw earth historic and contemporary architectures are renowned for their good environmental properties of recyclability and low embodied energy along the production process. Earth massive walls are universally known to be able to regulate indoor thermal and hygroscopic conditions containing energy consumptions, creating comfortable interior spaces with a low carbon footprint. Therefore, earth buildings are de facto green buildings. As a result of this, some earthen technologies have been rediscovered and implemented to be adapted to the contemporary building production sector. Nevertheless, the diffusion of contemporary earthen architecture is decelerated by the lack of broadly accepted standards on its anti-seismic and thermal performance. Indeed, the former issue has been solved using high-tensile materials inside the walls or surface reinforcements on their sides to improve their flexural strength. The latter issue is related to the penalization of earth walls thermal behavior in current regulations, which tent to evaluate only the steady-state performance of building components, neglecting the benefit of heat storage and hygrothermal buffering effect provided by massive and porous envelopes as raw earth ones. In this paper, we show the results of a paper review concerning the hygrothermal performance of earthen materials for contemporary housing: great attention is given to the base materials which are used (inorganic soils, natural fibers, and mineral or recycled aggregates, chemical stabilizers), manufacturing procedures (when described), performed tests and final performances. Different earth techniques (adobe, cob, extruded bricks, rammed earth, compressed earth blocks, light earth) have been considered in order to highlight that earth material can act both as a conductive and insulating meterial depending on how it is implemented, adapting to several climate contests. The paper aims to summarize current progress in the improvement of thermal performance of raw earth traditional mixes, discuss the suitability of existing measurement protocols for hygroscopic and natural materials and provide guidance for further researches.

scholarly journals DEVELOPMENT OF LIME BASED, LOAD-BEARING MATERIALS FOR WALL CONSTRUCTION

2020 ◽  
Vol 7 (1) ◽  
Author(s):  
Fin O'Flaherty ◽  
Faraj Khalaf ◽  
Vincenzo Starinieri
Keyword(s):  
Building Materials ◽  
Construction Materials ◽  
Base Material ◽  
Energy Criterion ◽  
Embodied Energy ◽  
Hemp Fiber ◽  
Load Bearing ◽  
Hemp Fibers ◽  
Concrete Blocks ◽  
The Uk

Construction of buildings in the UK is traditionally done using building materials such as concrete blocks, bricks and less so, timber. Although timber is a sustainable product, concrete blocks and bricks require a lot of energy input during fabrication, concrete especially being a large producer of CO2 during its manufacture. Reducing energy consumption either domestically or industrially is an important part of achieving the UK Government’s legally binding commitment to reducing greenhouse gas emissions by at least 80% (relative to 1990 levels) by 2050. New, low embodied energy construction materials are urgently required to enable the construction industry to revolutionize and drastically decrease its carbon footprint. The constituents of the materials investigated were selected based on low embodied energy criterion. To achieve this, lime was selected as the base material with hemp (fibers and shives) and PVAc used as additives. Specially selected nanomaterials were used as fillers. The constituents were combined in a manner, which led to different materials being developed, all exhibiting different characteristics. One characteristic was strength (load bearing) to eliminate the use of timber studding during construction. The results show that the highest strengths were achieved by mixing 10 wt. % hemp fiber, 4 wt. % nanozinc oxide and 12 wt. % PVAc at a 0.4 W/L ratio, yielding 17.7 MPa in compression and 7.3 MPa in flexure.

scholarly journals Global Sustainability and the New Zealand House

2021 ◽  
Author(s):  
◽  
J. Andrew Alcorn
Keyword(s):  
New Zealand ◽  
Building Materials ◽  
Co2 Flux ◽  
Hot Water ◽  
Embodied Energy ◽  
Wind Generators ◽  
Electricity Use ◽  
Building Components ◽  
Energy Emissions ◽  
Definition Of

<p>"How do you build a sustainable house in New Zealand? - is it even possible?" This thesis is structured in three parts to answer this question. The first part asks, then answers, "What is sustainability?", "How do you measure sustainability?" and "How do you know when you have reached sustainability - what is its limit?" The second part describes the methodologies for conducting embodied energy and CO2 analysis. The third part applies the results of the sustainability definition, and the energy and CO2 methodologies to a series of house designs. Part 1 defines, measures, and establishes a limit for sustainability. It reviews the history of sustainability and sustainable development. A distillation of what is being sought by the various parties to the sustainability debate then contributes to a checklist of essential requirements for a functional definition of sustainability. Addressing climate change is shown to be the major requirement. The checklist enables answers to the questions about measuring sustainability, and knowing when its limit has been reached, and leads to a functional definition: Sustainability meets the needs of the present without annual CO2 emissions exceeding what the planet can absorb. The requirements for sustainability indicator methods are examined. A robust way of comparing environment impacts is introduced. Several common sustainability indicators are examined against the requirements, but are found wanting, while two are found to be effective: energy and CO2 analysis. Human population and annual global carbon absorption are used to identify global and per-capita sustainability limits, which can be applied at many scales to many activities. They are applied to New Zealand's housing sector to identify a sustainable annual per-house emissions target, including construction, maintenance, and operation. Part 2 reviews the methodologies to measure and delimit sustainability using embodied energy and embodied CO2 analysis. A new, fast, accurate, and reliable process-based hybrid analysis method developed for this research is used to derive embodied energy and CO2 coefficients for building materials. Part 3 applies the results of the sustainability definition and limit, and the energy and CO2 methodologies and coefficients from analysing building materials, to a series of house designs within New Zealand and global contexts. A spreadsheet-based calculator developed for this analysis that has potential beyond this thesis is described. A method is presented for annualising emissions to fairly account for differing building components' lifetimes. Finally, a sustainable house is shown to be possible by combining several strategies to meet the challenging sustainable emissions target. Technologies that reduce grid electricity use - solar hot water, PV, and wind-generators - are crucial, cutting emissions the most. Bio-based materials sequestering carbon are the second most important strategy: strawbale insulation to ~R10, and timber for framing, cladding, windows, linings, and roofing. Efficient appliances, lighting, and other low-emission materials were also helpful. Other key outcomes were: hot water heating emits the most CO2, double any other category; heating energy emissions are smaller than any other category; CO2-optimal conventional insulation levels are ~R5; CO2 flux of materials is double operating energy CO2 for sustainable houses.</p>

scholarly journals Mortars with Recycled Aggregates from Building-Related Processes: A ‘Four-Step’ Methodological Proposal for a Review

2021 ◽  
Vol 13 (5) ◽  
pp. 2756
Author(s):  
Federica Vitale ◽  
Maurizio Nicolella
Keyword(s):  
Building Materials ◽  
Thermal Analyses ◽  
Construction Materials ◽  
Physical And Mechanical Properties ◽  
Research Trends ◽  
Mix Design ◽  
Recycled Aggregates ◽  
Design Parameters ◽  
Natural Aggregates ◽  
By Products

Because the production of aggregates for mortar and concrete is no longer sustainable, many attempts have been made to replace natural aggregates (NA) with recycled aggregates (RA) sourced from factories, recycling centers, and human activities such as construction and demolition works (C&D). This article reviews papers concerning mortars with fine RA from C&D debris, and from the by-products of the manufacturing and recycling processes of building materials. A four-step methodology based on searching, screening, clustering, and summarizing was proposed. The clustering variables were the type of aggregate, mix design parameters, tested properties, patents, and availability on the market. The number and the type of the clustering variables of each paper were analysed and compared. The results showed that the mortars were mainly characterized through their physical and mechanical properties, whereas few durability and thermal analyses were carried out. Moreover, few fine RA were sourced from the production waste of construction materials. Finally, there were no patents or products available on the market. The outcomes presented in this paper underlined the research trends that are useful to improve the knowledge on the suitability of fine RA from building-related processes in mortars.

scholarly journals Analysis of Different Complex Multilayer PACVD Coatings on Nanostructured WC-Co Cemented Carbide

Coatings ◽  
2021 ◽  
Vol 11 (7) ◽  
pp. 823
Author(s):  
Danko Ćorić ◽  
Mateja Šnajdar Musa ◽  
Matija Sakoman ◽  
Željko Alar
Keyword(s):  
Mechanical Properties ◽  
Surface Layer ◽  
Base Material ◽  
Single Layer ◽  
Production Costs ◽  
Structural Defects ◽  
Cemented Carbides ◽  
Material System ◽  
Tin Coating ◽  
Ticn Coating

The development of cemented carbides nowadays is aimed at the application and sintering of ultrafine and nano-sized powders for the production of a variety of components where excellent mechanical properties and high wear resistance are required for use in high temperature and corrosive environment conditions. The most efficient way of increasing the tribological properties along with achieving high corrosion resistance is coating. Using surface processes (modification and/or coating), it is possible to form a surface layer/base material system with properties that can meet modern expectations with acceptable production costs. Three coating systems were developed on WC cemented carbides substrate with the addition of 10 wt.% Co using the plasma-assisted chemical vapor deposition (PACVD) method: single-layer TiN coating, harder multilayer gradient TiCN coating composed of TiN and TiCN layers, and the hardest multilayer TiBN coating composed of TiN and TiB2. Physical and mechanical properties of coated and uncoated samples were investigated by means of quantitative depth profile (QDP) analysis, nanoindentation, surface layer characterization (XRD analysis), and coating adhesion evaluation using the scratch test. The results confirm the possibility of obtaining nanostructured cemented carbides of homogeneous structure without structural defects such as eta phase or unbound carbon providing increase in hardness and fracture toughness. The lowest adhesion was detected for the single-layer TiN coating, while coatings with a complex architecture (TiCN, TiBN) showed improved adhesion.

Sign in / Sign up

Export Citation Format

Share Document