scholarly journals Effect of Moisture Content on the Compressive strength of a Local Rammed Earth Construction Material

2022 ◽  
pp. 10-13
Author(s):  
Omar M. Alsudays ◽  
Omar M. Alawad ◽  
Sherif M. Elkholy
Keyword(s):  
Compressive Strength ◽  
Moisture Content ◽  
Construction Material ◽  
Rammed Earth ◽  
Earth Construction ◽  
Effect Of Moisture

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 A Study on the Red Clay Binder Stabilized with a Polymer Aqueous Solution

Polymers ◽  
2020 ◽  
Vol 13 (1) ◽  
pp. 54
Author(s):  
Jinsung Kim ◽  
Hyeonggil Choi ◽  
Hyeun-Min Rye ◽  
Keun-Byoung Yoon ◽  
Dong-Eun Lee
Keyword(s):  
Compressive Strength ◽  
Microstructural Analysis ◽  
Silica Particles ◽  
Rammed Earth ◽  
Aggregate Formation ◽  
Red Clay ◽  
Earth Construction ◽  
Performance Requirements ◽  
Polymer Aqueous Solution ◽  
Structure And Microstructure

In this study, the performance evaluation was performed by adding a polymer aqueous (PA) solution as a new additive of the red clay binder for use in the rammed-earth construction method. The evaluation items were compressive strength, water erosion, shrinkage, crystal structure, and microstructure. As a result of the experiment, the binder was improved by efficiently bonding the silica particles by the polymerized polymer. It was confirmed that adding a PA solution to red clay enhances the compressive strength, which is further improved when 5 wt% poly(Acrylic acid(AA)-co-Acrylamide(AM)) is added to the PA solution. Microstructural analysis indicated that the addition of a PA solution facilitates effective bonding of the silica particles of red clay to form hydrogen bonding with poly(AA-co-AM) and encourages aggregate formation. Therefore, the study confirmed that PA solution can be applied to satisfy the performance requirements of the rammed-earth construction by improving the durability and strength of the binder.

scholarly journals Experimental and FEM Investigation of Cob Walls under Compression

2018 ◽  
Vol 2018 ◽  
pp. 1-13 ◽  
Author(s):  
Enrico Quagliarini ◽  
Gianluca Maracchini
Keyword(s):  
Compressive Strength ◽  
Mechanical Behaviour ◽  
Poisson’S Ratio ◽  
Construction Material ◽  
Strong Dependence ◽  
Environmental Benefits ◽  
Poisson's Ratio ◽  
Experimental Program ◽  
Rammed Earth ◽  
Crack Model

Earth has been used as construction material since prehistoric times, and it is still utilized nowadays in both developed and developing countries. Heritage conservation purposes and its intrinsic environmental benefits have led researchers to investigate the mechanical behaviour of this material. However, while a lot of works concern with rammed earth, CEB, and adobe techniques, very few studies are directed towards cob, which is an alternative to the more diffused rammed earth and adobe in specific geographic conditions. Due to this lack, this paper presents an experimental program aimed at assessing the failure mode and the main mechanical properties of cob earth walls (compressive strength, Young’s modulus, and Poisson’s ratio) through monotonic axial compression tests. Results show that, if compared with CEB, adobe, and rammed earth, cob has the lowest compressive strength, the lowest modulus of elasticity, and Poisson’s ratio. Differences are also found by comparing results with those obtained for other cob techniques, underlining both the high regional variability of cob and the need of performing more research on this topic. A strong dependence of material properties on loading rate and water content seems to exist too. Finally, the ability of a common analytical method used for masonry structures (an FEM macromodelling with a total strain rotating crack model) to represent the mechanical behaviour of cob walls is showed.

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

2019 ◽  
Vol 2019 ◽  
pp. 1-12 ◽  
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.

scholarly journals Effect of Moisture Content on the Mechanical Properties of Watermelon Seed Varieties

2021 ◽  
Vol 2 (2) ◽  
pp. 308-320
Author(s):  
Paul Chukwuka EZE ◽  
Eze CHIKAODILI ◽  
Ide PATRICK EJIKE
Keyword(s):  
Mechanical Properties ◽  
Compressive Strength ◽  
Moisture Content ◽  
Compressive Force ◽  
Deformation Energy ◽  
Vertical Loading ◽  
Watermelon Seed ◽  
Horizontal Loading ◽  
Effect Of Moisture ◽  
And Storage

The effect of moisture content on the mechanical properties of agricultural material is essential during design and adjustment of machines used during harvest, cleaning, separation, handling and storage. This study determined some mechanical properties of Black and Brown colored of watermelon seed grown in Nigeria under different moisture contents range of 6.5 to 27.8% (d.b). The results for the mechanical properties obtained ranged from 15.68-29.54 N for compressive force; 1.95-3.40 mm for compressive extension; 0.13-0.33 N mm-2 for compressive strength; and 0.17-1.93 kJ for deformation energy at vertical loading position while at horizontal loading position, results obtained ranged from 14.71-38.36 N for compressive force; 1.94-4.20 mm for compressive extension; 0.16-0.32 N mm-2 for compressive strength; and 1.47-76.39 kJ for deformation energy for Black colored watermelon seed. The compressive force, compressive extension, compressive strength, deformation energy ranged from 14.18-36.49 N, 1.85-5.20 mm, 0.19 0.76 N mm-2, 26.23-189.75 kJ at vertical loading position and 16.47-41.82 N, 1.68-11.08 mm, 0.34- 0.57 N mm-2, 27.67-319.99 kJ at horizontal loading position for Brown colored watermelon seed. The correlation between the mechanical properties and moisture content was statistically significant at (p≤0.05) level. It is also economical to load Black colored in vertical loading position at 27.8% moisture content and Brown colored in vertical loading position at 27.8% moisture content to reduce energy demand when necessary to crack or compress the seed. This research has generated data that are efficiently enough to design and fabricate processing and storage structures for Black and Brown water melon seeds.

scholarly journals Feature Importance of Stabilised Rammed Earth Components Affecting the Compressive Strength Calculated with Explainable Artificial Intelligence Tools

Materials ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2317 ◽  
Author(s):  
Hubert Anysz ◽  
Łukasz Brzozowski ◽  
Wojciech Kretowicz ◽  
Piotr Narloch
Keyword(s):  
Artificial Intelligence ◽  
Compressive Strength ◽  
Mean Squared Error ◽  
Construction Material ◽  
Drop Out ◽  
Sustainable Construction ◽  
Solid Base ◽  
Rammed Earth ◽  
Prediction Errors ◽  
Explainable Artificial Intelligence

Cement-stabilized rammed earth (CSRE) is a sustainable construction material. The use of it allows for economizing on the cost of a structure. These two properties of CSRE are based on the fact that the soil used for the rammed mixture is usually dug close to the construction site, so it has random characteristics. That is the reason for the lack of widely accepted prescriptions for CSRE mixture, which could ascertain high enough compressive strength. Therefore, assessing which components of CSRE have the highest impact on its compressive strength becomes an important issue. There are three machine learning regression tools, i.e., artificial neural networks, decision tree, and random forest, used for predicting the compressive strength based on the relative content of CSRE composites (clay, silt, sand, gravel, cement, and water content). The database consisted of 434 samples of CSRE, which were prepared and crushed for testing purposes. Relatively low prediction errors of aforementioned models allowed for the use of explainable artificial intelligence tools (drop-out loss, mean squared error reduction, accumulated local effect) to rank the influence of the ingredients on the dependent variable—the compressive strength. Consistent results from all above-mentioned methods are discussed and compared to some statistical analysis of selected features. This innovative approach, helpful in designing the construction material is a solid base for reliable conclusions.

scholarly journals Performance Evaluation of Red Clay Binder with Epoxy Emulsion for Autonomous Rammed Earth Construction

Polymers ◽  
2020 ◽  
Vol 12 (9) ◽  
pp. 2050 ◽  
Author(s):  
Jinsung Kim ◽  
Hyeonggil Choi ◽  
Keun-Byoung Yoon ◽  
Dong-Eun Lee
Keyword(s):  
Compressive Strength ◽  
Construction Method ◽  
Rammed Earth ◽  
Labor Costs ◽  
Red Clay ◽  
Construction Methods ◽  
Earth Construction ◽  
Construction Techniques ◽  
Alternative Means ◽  
Epoxy Emulsion

 Existing rammed earth construction methods have disadvantages such as increased initial costs for manufacturing the large formwork and increased labor costs owing to the labor-intensive construction techniques involved. To address the limitations of the existing rammed earth construction methods, an autonomous rammed earth construction method was introduced herein. When constructing an autonomous rammed-earth construction method, an alternative means of assuring the performance at the initial age of the binder in terms of materials is needed. In this study, in order to satisfy the performance of the red clay binder, epoxy emulsion was added to analyze the compressive strength, water loosening, shrinkage, rate of mass change, and microstructure in the range of the initial age. As a result of the analysis, the applicability of the epoxy emulsion was confirmed as a new additive for application to an autonomous rammed-earth construction method.

scholarly journals The Influence Of Loam Type And Cement Content On The Compressive Strength Of Rammed Earth

2015 ◽  
Vol 61 (1) ◽  
pp. 73-88 ◽  
Author(s):  
P. L. Narloch ◽  
P. Woyciechowski ◽  
P. Jęda
Keyword(s):  
Compressive Strength ◽  
New Zealand ◽  
Portland Cement ◽  
Research Methods ◽  
Cement Content ◽  
Construction Material ◽  
Rammed Earth ◽  
Rapid Rise ◽  
Earth Material ◽  
American Standard

AbstractCurrently, a worldwide dynamic rise of interest in using soil as a construction material can be observed. This trend is evident in the rapid rise of the amount of standards that deal with soil techniques. In 2012 the number of standards was larger by one third than five years prior. To create a full standardization of the rammed earth technique it is necessary to take into account the diversity of used soil and stabilizing additives. The proportion of the components, the process of element production and the research methods must also be made uniform. The article describes the results of research on the compressive strength of rammed earth samples that differed from each other with regards to the type of loam used for the mixture and the amount of the stabilizer. The stabilizer used was Portland cement CEM I 42.5R. The research and the analysis of the results were based on foreign publications, the New Zealand standard NZS 4298:1998, the American Standard NMAC14.7.4 and archival Polish Standards from the 1960’s that dealt with earth material.

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