scholarly journals CHARACTERIZATION OF LATERITIC SOILS FOR USE IN THE MANUFACTURE OF COMPRESSED EARTH BLOCKS (CEB)

2021 ◽  
Vol 9 (08) ◽  
pp. 768-780
Author(s):  
Cherif Bishweka ◽  
◽  
Marcelline Blanche Manjia ◽  
Francois Ngapgue ◽  
Chrispin Pettang ◽  
...  
Keyword(s):  
Thermal Inertia ◽  
Poor Performance ◽  
Physical Characteristics ◽  
Mechanical Resistance ◽  
Housing Crisis ◽  
Lateritic Soils ◽  
Earth Material ◽  
The Earth ◽  
Earth Blocks ◽  
Raw Earth

Soil is a widespread natural resource. It comes from the degradation of the mother rock, following the phenomenon of climatic and chemical erosion. Therefore, all soils have very different characteristics depending on their origin [1,2]. Today it is estimated that more than one third of the worlds population lives in earthen housing [3]. In view of the advantages offered by the earth material, several developing countries have adopted the raw earth construction in order to face the housing crisis that is intensifying nowadays. Among the advantages of raw earth, we can highlight the low energy required for its implementation, its aesthetic qualities and good thermal inertia, which allows a cool habitat in summer and retains heat in winter. But the problem with earthen constructions is that they suffer from a lack of resistance, systematic cracking due to shrinkage and problems related to their sensitivity to water [4]. From ancient times to the present day, man has sought to avoid the disadvantages of the earth material, using several means of stabilization to improve its performance and its sensitivity to water, which has given rise to several earth products: adobe, adobe, cob, compressed earth block (CEB) and others. Stabilizing the earth is to give it the properties reversible against physical stresses [5], it is currently confirmed that the stabilization of CEB by binders and bitumen improves their mechanical resistance and insensitivity to water [6]. Thus, scientific studies have been conducted on the stabilization of raw earth by mineral binders (cement and lime) for the most part [7] and by fibers (animal, vegetable and synthetic). However, the use of these mineral binders in high proportions may call into question the ecological character of the material [8]. The knowledge of the physical characteristics of lateritic soils is very important for their better use in the manufacture of compressed and stabilized earth blocks. Some social strata for the manufacture of CEB use lateritic soils without control of their physical characteristics, which leads to consequences such as progressive crumbling of walls, cracks, poor performance of plasters, and discouragement of the use of the said technology. In this study we intend to compile the most reliable experimental data on the physical properties of natural earth and the mechanical properties of CEB. We will take inventory of the performances determined in previous works by several research teams regarding the characterization and stabilization of lateritic soils to be used in the manufacture of CEB. We will give an overview of the state of knowledge concerning the different properties (physical, mechanical and hygrometric properties). Finally, a literature review will also give some orientations for future scientific research.

scholarly journals Ultrasonic, Molecular and Mechanical Testing Diagnostics in Natural Fibre Reinforced, Polymer-Stabilized Earth Blocks

2013 ◽  
Vol 2013 ◽  
pp. 1-10 ◽  
Author(s):  
C. Galán-Marín ◽  
C. Rivera-Gómez ◽  
F. Bradley
Keyword(s):  
Soil Stabilization ◽  
Ultrasonic Pulse Velocity ◽  
Mechanical Tests ◽  
Pulse Velocity ◽  
Mechanical Resistance ◽  
Chemical Compositions ◽  
Natural Polymer ◽  
Natural Polymers ◽  
X Ray ◽  
Earth Blocks

The aim of this research study was to evaluate the influence of utilising natural polymers as a form of soil stabilization, in order to assess their potential for use in building applications. Mixtures were stabilized with a natural polymer (alginate) and reinforced with wool fibres in order to improve the overall compressive and flexural strength of a series of composite materials. Ultrasonic pulse velocity (UPV) and mechanical strength testing techniques were then used to measure the porous properties of the manufactured natural polymer-soil composites, which were formed into earth blocks. Mechanical tests were carried out for three different clays which showed that the polymer increased the mechanical resistance of the samples to varying degrees, depending on the plasticity index of each soil. Variation in soil grain size distributions and Atterberg limits were assessed and chemical compositions were studied and compared. X-ray diffraction (XRD), X-ray fluorescence spectroscopy (XRF), and energy dispersive X-ray fluorescence (EDXRF) techniques were all used in conjunction with qualitative identification of the aggregates. Ultrasonic wave propagation was found to be a useful technique for assisting in the determination of soil shrinkage characteristics and fibre-soil adherence capacity and UPV results correlated well with the measured mechanical properties.

scholarly journals Identification of Housing Crisis in a Confined Settlement: A study of Mohammadpur Geneva Camp

2020 ◽  
Vol 7 (2) ◽  
pp. 125-142
Author(s):  
Masud Ur Rashid
Keyword(s):  
Low Income ◽  
Physical Environment ◽  
Economic Transformation ◽  
Physical Characteristics ◽  
Physical Growth ◽  
Housing Crisis ◽  
Economic Problems ◽  
Major Factors ◽  
Day By Day ◽  
The Way

Urdu speaking people living in Geneva camp of Dhaka have become a marginally displaced community since 1971. Geneva camp is overcrowded as they have no chance of living outside of the camps because of their statelessness. The camp is a densely-populated settlement and have its own natural physical growth in terms of social and economic transformation day by day. This brings a lot of physical, socio-cultural and economic problems.  Geneva camp is a compact and confined living place for its inhabitants. For many of them it is also income generating place and thus source of their livelihood. It is important to identify the problems of this settlement to take further necessary actions to mitigate those. This study illustrates the housing problems in different domains in the Geneva camp with their attributes. Lack of spaces and other facilities in a low-income settlement have their impact on the way of overall livelihood of the inhabitants. The physical characteristics and other major factors that affect the physical environment of settlement are discussed in this paper.

scholarly journals Methods to Test the Compressive Strength of Earth Blocks

2021 ◽  
Vol 2021 ◽  
pp. 1-11
Author(s):  
Guanqi Lan ◽  
Sisi Chao ◽  
Yihong Wang ◽  
Ying Cui
Keyword(s):  
Compressive Strength ◽  
Test Methods ◽  
Test Method ◽  
Material Strength ◽  
Specimen Preparation ◽  
Efficient Design ◽  
Full Size ◽  
The Earth ◽  
Earth Blocks ◽  
Earth Block

The efficient design of new earth structures and the restoration of old structures both require a reliable assessment of the compressive strength of earth materials. However, there is still much debate on the best method to accurately measure the compressive strength of earth blocks. To solve the problem of measuring the compressive strength of the earth block, the cube specimen, the half-block stacked specimen, and the full-size block specimen are used to measure the compressive strength of the molded adobe and rammed adobe, respectively, considering the influence of the specimen preparation process, loading direction, capping, and other factors. By comparing and analyzing the stress state, failure mode, and compressive strength of the specimen under various test methods, a compressive strength test method of earth blocks is determined, which is simple to operate, easy to standardize, and as close as possible to the actual strength of the blocks. The results show that the full-size block compression test method along the block thickness direction should be preferred to test the compressive strength of the earth block. The standard specimen obtained by cutting the full-size block is not suitable for the test of the compressive strength of the earth block; it can effectively solve the problem that the compressive strength of the small-thickness earth block cannot be directly measured by cutting the full-size block in half and stacking it, but it is not recommended to use the binder to bond the two half-blocks. When comparing the compressive strength of the earth blocks, the conversion coefficient related to the height-to-thickness ratio of the specimen cannot be used to convert the compressive strength. Still, the anisotropy of the material strength should be considered.

scholarly journals The Porosity of Stabilized Earth Blocks with the Addition Plant Fibers of the Date Palm

2020 ◽  
Vol 6 (3) ◽  
pp. 478-494 ◽  
Author(s):  
Abdelghani Idder ◽  
Abdelmadjid Hamouine ◽  
Boudjemaa Labbaci ◽  
Rabia Abdeldjebar
Keyword(s):  
Building Materials ◽  
Date Palm ◽  
Total Porosity ◽  
Mechanical Resistance ◽  
Capillary Absorption ◽  
Plant Fibers ◽  
Volume Porosity ◽  
Physical Tests ◽  
Earth Blocks ◽  
Earth Block

This work is an experimental study to analyze the physical behavior of Stabilized Earth Block (SEB) and reinforced with Plant Fibers of the Date Palm (PFDP). This is part of the valorization of local building materials (earth, fiber) and contributes to reduce the price of housing. Initially, physical tests (Density, Total Water Absorption, and Capillary Absorption) were carried out in preparation for the porosity study. However, the main objective of this study is the investigation of porosity phenomenon using several methods as well as the total porosity estimation, the total volume porosity in water and Open porosity methods, where the mechanical resistance is also considered.  In order to improve the stabilized earth block porosity analyses, various dosages are proposed for cement, lime and fiber. Thus (0%, 5%, 10%) of cement, (0%, 5%, 10%) of lime and the combination (5% cement + 5% lime) with (0%, 0.25%, and 0.5%) of fibers for each composition. The experimental results showed that the addition of fibers increases the porosity of the stabilized earth block proportionally and an increasing quantity of the stabilizer reduces the porosity of the SEB, cement is also more effective at closing pores than lime. Moreover, the compositions 10% cement and the mixture of 5% cement + 5% lime with 0% fiber showed a good results of porosity, for this reason they can be used as a durable building material and good resistance to natural and chemical aggression.

scholarly journals Compressed Stabilized Earth Block using Fly Ash and Quarry Dust

2020 ◽  
Vol 9 (1) ◽  
pp. 714-716 ◽  
Keyword(s):  
Fly Ash ◽  
Water Absorption ◽  
Building Blocks ◽  
High Rate ◽  
Partial Replacement ◽  
Earth Material ◽  
Earth Blocks ◽  
Integrated Performance ◽  
Earth Block ◽  
Quarry Dust

Buildings made of earth material is an attempt for sustainable development to overcome the threats of rapid pollution rate caused by huge application of cement in construction industry almost in all forms as building blocks, all kinds of structural elements and infrastructure. The main objective of this project is to identify the better stabilization material for stabilized earth blocks for partial replacement of cement in the manufacture of CSEB’s. The scope of work is to achieve a harmonious integrated performance of buildings with physical environment by using natural earth material for preparing building blocks. In this project fly ash and quarry dust has been compared to find out the most suited stabilization material for CSEB’s providing efficiency as well as sustainability as a substitute material for cement. In this project CSEB’s prepared using 70% laterite soil and 30% of cement has been compared with specimens in which cement is replaced with fly ash and quarry dust in ranges of 10% and 20% of its weight. The 28 days compressive strength results shows 12.5% increase in strength for 10% optimum replacement of cement using fly ash and about 7.5% increase in strength for 10% optimum replacement of cement using quarry dust. The reduced water absorption has been notified in CSEB’s using fly ash and quarry dust which will facilitate good bonding with fresh mortar by avoiding high rate of water absorption from fresh mortar by blocks finding its effective application in construction of load bearing walls for general buildings.

Starch Reinforcement of Raw Earth Constructions

2022 ◽  
Author(s):  
Julia Tourtelot ◽  
Chloé Fourdrin ◽  
Jean Baptiste d'Espinose de Lacaillerie ◽  
Ann Bourgès ◽  
Emmanuel Keita
Keyword(s):  
Mechanical Strength ◽  
Carbon Footprint ◽  
Wheat Starch ◽  
Organic Additives ◽  
High Carbon ◽  
Compressive Test ◽  
Physicochemical Interactions ◽  
The Earth ◽  
Earthen Buildings ◽  
Raw Earth

The restoration, the protection, or the creation of earthen buildings require improving the mechanical strength of the material. The first way to do that is to use inorganic additives, but these additives change the structural properties of earth and have a high carbon footprint. In contrast, the other way to consolidate is the use of organic additives such as vegetal derivatives that rearrange the minerals in the earth, with the lowest carbon footprint as they are from waste management. After preliminary tests with ten different organic additives from traditional recipes, we found that wheat starch improves the earth strength up to 50 %. In this study, we related the mechanical strengthening to the physicochemical interactions between clays and starch. We focus on three clays that represent the three main groups of clays: kaolinite, illite and montmorillonite. For this study, we mainly focused on compressive test and rheological tests. We showed that the improvement of the mechanical strength with starch is depending on clay nature and their chemistry. Then, we can recommend formulations based on the earth nature for new sustainable buildings. Furthermore, we can understand why it was an interesting way to use starch as a strengthening agent in traditional recipes and how it could be used to repair and protect buildings made of earthen material.

A unified compaction curve for raw earth material based on both static and dynamic compaction tests

2021 ◽  
Vol 54 (1) ◽  
Author(s):  
Longfei Xu ◽  
Henry Wong ◽  
Antonin Fabbri ◽  
Florian Champiré ◽  
Denis Branque
Keyword(s):  
Dynamic Compaction ◽  
Earth Material ◽  
Compaction Curve ◽  
Raw Earth

Thermal thrust accelerations on LAGEOS satellites

2020 ◽  
Author(s):  
David Lucchesi ◽  
Luciano Anselmo ◽  
Massimo Bassan ◽  
Marco Lucente ◽  
Carmelo Magnafico ◽  
...  
Keyword(s):  
Thermal Model ◽  
Radiant Energy ◽  
Thermal Inertia ◽  
Precise Orbit Determination ◽  
Energy System ◽  
Spin Model ◽  
Visible Radiation ◽  
The Earth ◽  
Model Solutions ◽  
Averaged Equations

<p>Thermal thrust forces are non-conservative forces that act on the surface of a satellite as a result of temperature gradients across its surface. In the case of the older LAGEOS satellite these kinds of perturbations have been well-known since the end of 80s. The main effects are due to the thermal inertia of the corner cube retroreflectors (CCRs) of the satellites with sources the Earth’s infrared radiation and the direct solar visible radiation modulated by the eclipses. However, the solar radiation reflected by the complex Earth-atmosphere system, i.e. the albedo, is also responsible for a non-uniform heating of the satellite surface. We reconsider such perturbations by means of a new thermal model for the satellites called LATOS (LArase Thermal mOdel Solutions), which is not based on averaged equations as those previously developed in the literature. Of course, in such analyses the attitude of the satellite plays an important key role; we modeled it by means of the LASSOS (LArase Satellites Spin mOdel Solutions) model for the evolution of the spin-vector that we have already developed within the LARASE (LAser RAnged Satellites Experiment) research program. We also included the contribution of the Earth’s albedo in the determination of the overall distribution of temperature on the surface of the satellites, that was not considered in previous works. The CERES (Clouds and the Earth’s Radiant Energy System) data have been used to account for this effect. The thermal thrust accelerations have been computed together with their effects on the orbital elements by means of the Gauss equations. These effects are compared with the orbit residuals of the satellites in the same elements, obtained by an independent Precise Orbit Determination (POD), in order to highlight the signature of the unmodeled effects. The improvement in the POD that can be achieved through a better modeling of the thermal thrust perturbations is of fundamental importance for the geophysical products that are determined by means of the analysis of the orbits of the two LAGEOS satellites. Similarly, the measurements in the field of fundamental physics that are obtained with these satellites can benefit from a more precise modeling of their orbit.</p>

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