Design Optimisation Strategies for Solid Rammed Earth Walls in Mediterranean Climates

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.

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Effect of adding insulation on the energy performances of rammed earth buildings in hot and arid climates

E3S Web of Conferences ◽

10.1051/e3sconf/202015001011 ◽

2020 ◽

Vol 150 ◽

pp. 01011

Author(s):

Wical Cheikhi ◽

Khadija Baba ◽

Abderrahman Nounah ◽

Choukri Cherradi

Keyword(s):

Good Alternative ◽

Energy Performance ◽

Simulation Software ◽

Sustainable Construction ◽

Rammed Earth ◽

Before And After ◽

Energy Consuming ◽

High Level ◽

Earth Walls ◽

Raw Earth

In a world context focused on energy efficiency and sustainable construction, returning to the use of raw earth in construction constitutes a good alternative to concrete construction, a system more energy consuming and yet more used nowadays. This return is justified by the excellent energy performance and the high level of thermal comfort provided by earth constructions in different climates. In cold climates, adding an insulation on earth walls has proven to be effective in improving their thermal performances. However, the influence of adding an insulation on the energy performance of rammed earth buildings in hot and arid climates remains to this day little explored. The present work comes in this order of ideas; it is based on a comparative study of the energetic performances of a mud building before and after the addition of the insulation. In order to compare between their performances, we have performed a simulation of the thermal behaviour of each by the dynamic thermal simulation software Design Builder.

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Vertical Rods as a Seismic Reinforcement Technique for Rammed Earth Walls: An Assessment

Advances in Civil Engineering ◽

10.1155/2019/1285937 ◽

2019 ◽

Vol 2019 ◽

pp. 1-12 ◽

Cited By ~ 4

Author(s):

Q.-B. Bui ◽

T.-T. Bui ◽

R. El-Nabouch ◽

D.-K. Thai

Keyword(s):

Compressive Strength ◽

Numerical Study ◽

Construction Material ◽

Thermal Inertia ◽

Embodied Energy ◽

Rammed Earth ◽

Seismic Action ◽

Horizontal Force ◽

The Subject ◽

Earth Walls

Rammed earth (RE) is a construction material which is manufactured by compacting soil by layers within a formwork to build a monolithic wall. RE material is the subject of numerous scientific researches during the last decade because of the significant heritage of RE buildings and the sustainable properties of this material: low embodied energy, substantial thermal inertia, and natural regulator of moisture. The seismic performance of RE buildings is an interesting topic which needs to be thoroughly investigated. This paper presents a numerical study which assesses the relevancy of a seismic reinforcement technique for RE walls by using two vertical steel rods installed at two extremities of the walls. The discrete element method (DEM) was used to model unreinforced and reinforced RE walls. These walls were first loaded with a vertical stress on the top to simulate the vertical loads and then submitted to a horizontal loading on the top to simulate the seismic action. Two current cases of RE buildings were investigated: one-storey and two-storey buildings. The results showed that the reinforcement technique enhanced the maximum horizontal force about 25% and 10%, respectively, for the cases of one- and two-storey buildings. Higher effectiveness of this reinforcement technique is expected for RE materials having higher compressive strength, for example, stabilized RE.

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Current State of Modern Rammed Construction: A Case Study of First Peoples House after Seven Years Exposure

Key Engineering Materials ◽

10.4028/www.scientific.net/kem.666.63 ◽

2015 ◽

Vol 666 ◽

pp. 63-76 ◽

Cited By ~ 2

Author(s):

Allan Kailey ◽

Gupta Rishi

Keyword(s):

Construction Material ◽

Surface Condition ◽

Infrared Camera ◽

Rammed Earth ◽

Destructive Testing ◽

Current State ◽

First Peoples ◽

Wet Climate ◽

The University ◽

Earth Walls

This paper presents a study on the current condition of the First Peoples House, located at the University of Victoria in British Columbia. The building houses two rammed earth walls that exemplify the use of stabilized rammed earth as a modern construction material. These rammed earth walls have been exposed to 7 years of natural weathering in a wet climate. A rebound hammer, infrared camera, and a new method developed to quantify surface deterioration were used in Non-Destructive Testing (NDT). The results provided insight into the compressive strength, thermal envelope and surface condition of the walls. Relationships between wind direction and wind speed are presented. It is postulated that the wall that is most exposed to a combination of both effects will exhibit the largest forms of deterioration. This hypothesis was addressed using results from NDT and local wind data.

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Using Raw Earth Construction Systems on Contemporary Buildings: Reflections on Sustainability and Thermal Efficiency

Renewable Energy and Environmental Sustainability ◽

10.1051/rees/2021041 ◽

2021 ◽

Vol 6 ◽

pp. 46

Author(s):

Bruno Marques ◽

Humberto Varum ◽

Helena Corvacho ◽

Manuel Correia Guedes ◽

Luís Baptista

Keyword(s):

Thermal Comfort ◽

Construction Material ◽

Local Environment ◽

Building Energy ◽

Good Choice ◽

Building Energy Efficiency ◽

Earth Construction ◽

European Policies ◽

Energy Efficiency Policies ◽

Raw Earth

Although the existence of building energy efficiency policies for several years, studies show that up to 74% of the participant consider their house uncomfortable. European policies favored construction solutions focused on insulating materials rather than other solutions which traditionally were used and proved to be effective. Construction system that uses earth as construction material showed for centuries that it can offer high levels of thermal comfort in a passive way, with a highly sustainable and quasi-neutral environmental impact. With this paper, a study on the thermal performance of three contemporany rammed earth buildings is presented. The aim is to analyze thermal comfort over a critical period of time. It is expected that earth construction proves to be a good choice, creating a sustainable and better integration with the local environment, with almost zero energy incorporation, promoting the local work craftmen and with a construction range price below the common construction systems.

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Assessing the Seismic Behavior of Rammed Earth Walls with an L-Form Cross-Section

Sustainability ◽

10.3390/su11051296 ◽

2019 ◽

Vol 11 (5) ◽

pp. 1296 ◽

Cited By ~ 3

Author(s):

Quoc-Bao Bui ◽

Tan-Trung Bui ◽

Mai-Phuong Tran ◽

Thi-Loan Bui ◽

Hoang-An Le

Keyword(s):

Cross Section ◽

Seismic Performance ◽

Seismic Behavior ◽

Rectangular Cross Section ◽

Construction Material ◽

Numerical Approach ◽

Rammed Earth ◽

3D Fem ◽

Earthquake Performance ◽

Earth Walls

Rammed earth (RE) is a construction material which is made by compacting the soil in a formwork. This material is attracting the attention of the scientific community due to its sustainable characteristics. Among different aspects to be investigated, the seismic performance remains an important topic which needs advanced investigations. The existing studies in the literature have mainly adopted simplified approaches to investigate the seismic performance of RE structures. The present paper adopts a numerical approach to investigate the seismic behavior of RE walls with an L-form cross-section. The 3D FEM model used can take into account the plasticity and damage of RE layers and the interfaces. The model was first validated by an experimental test presented in the literature. Then, the model was employed to assess the seismic performance of a L-form wall of a RE house at different amplitudes of earthquake excitations. Influences of the cross-section form on the earthquake performance of RE walls were also investigated. The results show that the L-form cross-section wall has a better seismic performance than a simple rectangular cross-section wall with similar dimensions. For the L-form cross-section wall, the damage observed concentrates essentially on the connection between two flanges of the wall.

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Zero Energy Houses and Embodied Energy: Regulatory and Design Considerations

ASME 2008 2nd International Conference on Energy Sustainability, Volume 2 ◽

10.1115/es2008-54290 ◽

2008 ◽

Cited By ~ 3

Author(s):

Patxi Hernandez ◽

Paul Kenny

Keyword(s):

Life Cycle ◽

Energy Demand ◽

Energy Use ◽

Construction Materials ◽

Energy Performance ◽

Embodied Energy ◽

Base Case ◽

Life Cycle Approach ◽

Zero Energy ◽

Zero Energy Buildings

Building energy performance regulations and standards around the world are evolving aiming to reduce the energy use in buildings. As we move towards zero energy buildings, the embodied energy of construction materials and energy systems becomes more important, as it represents a high percentage of the overall life cycle energy use of a building. However, this issue is still ignored by many regulations and certification methods, as happens with the European Energy Performance of Buildings Directive (EPBD), which focuses on the energy used in operation. This paper analyses a typical house designed to comply with Irish building regulations, calculating its energy use for heating and how water with the Irish national calculation tool, which uses a methodology in line with the EPBD. A range of measures to reduce the energy performance in use of this typical house are proposed, calculating the reduced energy demand and moving towards a zero energy demand building. A life-cycle approach is added to the analysis, taking into account the differential embodied energy of the implemented measures in relation to the typical house base-case, annualizing the differential embodied energy and re-calculating the overall energy use. The paper discusses how a simplified approach for accounting embodied energy of materials could be useful in a goal to achieve the lowest life-cycle energy use in buildings, and concludes with a note on how accounting for embodied energy is a key element when moving towards zero energy buildings.

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Cyclic Behavior of Confined Cement-Stabilized Rammed Earth Walls

Shock and Vibration ◽

10.1155/2018/2983052 ◽

2018 ◽

Vol 2018 ◽

pp. 1-11

Author(s):

Xinlei Yang ◽

Hailiang Wang ◽

Ziliang Zhao

Keyword(s):

Active Regions ◽

Embodied Energy ◽

Cyclic Behavior ◽

Rammed Earth ◽

Indoor Environments ◽

Test Results ◽

Rammed Earth Wall ◽

Earth Walls ◽

Moisture Buffering ◽

Strength And Ductility

Rammed earth is widely utilized in both developed and developing countries due to its low embodied energy and good natural moisture buffering of indoor environments. However, its application in seismic active regions was limited owing to its intrinsically low resistance to dynamic actions. This paper presents the test results of four cement-stabilized rammed earth walls with confining tie-column elements under cyclic loading, aiming at assessing the cyclic behavior of proposed rammed earth walls with confining tie-column elements. The test results revealed that the proposed confining tie-column elements could significantly improve the cyclic behavior of cement-stabilized rammed earth wall, exhibiting good strength and ductility.

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Assessment of the Life Cycle Energy Efficiency of a Primary School Building in Turkey

Applied Mechanics and Materials ◽

10.4028/www.scientific.net/amm.887.335 ◽

2019 ◽

Vol 887 ◽

pp. 335-343

Author(s):

Nazanin Moazzen ◽

Mustafa Erkan Karaguler ◽

Touraj Ashrafian

Keyword(s):

Energy Efficiency ◽

Life Cycle ◽

Energy Consumption ◽

Energy Demand ◽

Energy Use ◽

Human Life ◽

Energy Performance ◽

Building Envelope ◽

Embodied Energy

Energy efficiency has become a crucial part of human life, which has an adverse impact on the social and economic development of any country. In Turkey, it is a critical issue especially in the construction sector due to increase in the dependency on the fuel demands. The energy consumption, which is used during the life cycle of a building, is a huge amount affected by the energy demand for material and building construction, HVAC and lighting systems, maintenance, equipment, and demolition. In general, the Life Cycle Energy (LCE) needs of the building can be summarised as the operational and embodied energy together with the energy use for demolition and recycling processes.Besides, schools alone are responsible for about 15% of the total energy consumption of the commercial building sector. To reduce the energy use and CO2 emission, the operational and embodied energy of the buildings must be minimised. Overall, it seems that choosing proper architectural measures for the envelope and using low emitting material can be a logical step for reducing operational and embodied energy consumptions.This paper is concentrated on the operating and embodied energy consumptions resulting from the application of different architectural measures through the building envelope. It proposes an educational building with low CO2 emission and proper energy performance in Turkey. To illustrate the method of the approach, this contribution illustrates a case study, which was performed on a representative schoold building in Istanbul, Turkey. Energy used for HVAC and lighting in the operating phase and the energy used for the manufacture of the materials are the most significant parts of embodied energy in the LCE analyses. This case study building’s primary energy consumption was calculated with the help of dynamic simulation tools, EnergyPlus and DesignBuilder. Then, different architectural energy efficiency measures were applied to the envelope of the case study building. Then, the influence of proposed actions on LCE consumption and Life Cycle CO2 (LCCO2) emissions were assessed according to the Life Cycle Assessment (LCA) method.

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