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.

Stabilization of Raw Earth through Alkaline Activation

2014 ◽  
Vol 600 ◽  
pp. 215-224 ◽  
Author(s):  
Leandro Santos de Oliveira ◽  
Normando Perazzo Barbosa ◽  
Fabiana Silva Santos ◽  
Carlos Maviael de Carvalho
Keyword(s):  
Portland Cement ◽  
Mechanical Strength ◽  
Room Temperature ◽  
Alkaline Activation ◽  
The Earth ◽  
Earthen Construction ◽  
First Results ◽  
Earth Block ◽  
Raw Earth ◽  
Made In

Stabilization is important in earthen construction in order to improve mechanical strength, volumetric stability, workability and even ductility. Currently, the products used to stabilize the earth are lime, Portland cement and bitumen emulsions. Due to the environmental problems that the mankind faces nowadays, the use of earthen construction is increasing. Adobe is the most traditional type of block used in masonry. To improve strength against water, a new way to stabilize this kind of unburned earth block is proposed by the alkaline activation of earth. This paper presents the first results about the experimentation made in the stabilization of soil with alkali activator. Two cure temperatures were tested: room temperature and oven at 50°C. The amounts of stabilizer used were 3% and 6% activator by mass of earth. Results show that it is possible for adobe blocks to be resistant to water action using the alkaline activation.

scholarly journals Influence of Biopolymers on the Mechanical Behavior of Earth-Based Building Materials

2021 ◽  
Vol 03 (03) ◽  
pp. 1-1
Author(s):  
Julia Tourtelot ◽  
◽  
Ann Bourgès ◽  
Emmanuel Keita ◽  
◽  
...  
Keyword(s):  
Compressive Strength ◽  
Building Materials ◽  
Construction Materials ◽  
Wheat Starch ◽  
Low Carbon ◽  
Food Industries ◽  
The Earth ◽  
Construction Techniques ◽  
Paris Region ◽  
Raw Earth

Currently, the largest among the earth excavation sites in Europe are located in the Paris region. The soils excavated from these sites are often considered waste and are not valorized. With an increasing focus on sustainable development, the demand for low-carbon building materials is rising. Although construction using raw earth is a vernacular technique, the diversity in the behavior of the raw earth building materials warrants better control of their mechanical properties. The construction techniques differ depending on the location of the site, the composition of the earth, and the stabilizers used. Plant-based fibers and compounds extracted from plants are commonly used for reinforcing raw earth. Since such byproduct solutions have been developed worldwide, they differ significantly, and it becomes difficult to set a benchmark. The majority of the reported studies have directly used organic waste, rendering it difficult to characterize the material and extend the obtained results to other contexts. In order to reduce these variabilities, it becomes important to study the reinforcement of earth-based building materials with biopolymers that constitute the active molecules of the bio-based solutions. In the present study, different biopolymers derived from various vernacular techniques were utilized to increase the compressive strength of the construction soil collected from the Paris region. It was revealed that cellulose fibers and wheat starch increased the compressive strength of the earth from 3.5 MPa to 5.5 MPa and 4.5 MPa, respectively. In addition, the interactions of these biopolymers with clay were analyzed. The biopolymers identified as suitable for use in construction materials in the present study are widely available as wastes from paper, agricultural, or agro-food industries. These identified biopolymers would contribute to the development and standardization of construction using earth-based building materials.

scholarly journals Taiwan’s ecological footprint and overshoot day

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Yung-Jaan Lee ◽  
Lei Chai ◽  
Po-Shu Wu
Keyword(s):  
Sustainable Development ◽  
Carbon Footprint ◽  
Ecological Footprint ◽  
Sustainable Development Goals ◽  
Climate Change Policy ◽  
The Earth ◽  
Change Policy ◽  
Conversion Rates ◽  
Development Goals ◽  
Global Population

AbstractThis study examines Taiwan’s ecological footprint (EF) and its Overshoot Day from 2000 to 2018. The latest EF calculation method is used to determine the conversion rates and equivalent factors of bioproductive lands in each year to establish a database of Taiwan’s EF in that period. The results reveal that Taiwan’s EF was 7.69 gha/person in 2000, dropping steadily to 6.46 gha/person in 2018. Taiwan’s carbon footprint accounted for about 61% of Taiwan’s total EF, slightly higher than the world average (60%). The carbon footprint as a proportion of the total EF has been increasing annually. This study adopts social communication tools, such as the overshoot day and the earth clock, to promote sustainable development goals and climate change policy initiatives. Global Footprint Network (GFN) updates the overshoot day of each country in its database yearly, based on each country’s EF and biocapacity. Since Taiwan is not included in GFN, this study adopts the same method and finds out that Taiwan's Overshoot Day in 2018 was March 14th, meaning that on March 14th, 2018, Taiwan exhausted all of the biological resources that its bioproductive lands can regenerate in the year. If the global population lived like Taiwanese, four Earths would be required to provide the resources used. This result not only reflects the consumption of natural resources in Taiwan, but also indicates that Taiwan should focus on sustainable development and reduce that consumption.

scholarly journals Better Wettability of Pandanus Utilis Alkaline Treated Fibres Tead to Higher Tensile Strengths of Composites.

2021 ◽  
Author(s):  
Laurent L'Entete ◽  
Hareenanden Ramasawmy
Keyword(s):  
Tensile Strength ◽  
Composite Materials ◽  
Carbon Footprint ◽  
Fibre Length ◽  
Natural Fibre ◽  
Engineering Properties ◽  
Aggressive Treatment ◽  
High Carbon ◽  
Reinforcing Agent ◽  
Internal Angle

Abstract Composite materials made with synthetic fibres like E-glass, Kevlar or carbon have helped to provide a wide array of products to society with specific engineering properties. However, these materials have a high carbon footprint as well as being non-biodegradable. The use of natural fibre, as a substitution to these man-made fibres, has been studied and encouraging results are being obtained.In this study, the use of ‘Pandanus utilis’ fibre as a reinforcing agent in plastic was investigated with the aim of exploring specific properties such as the tensile strength of the fibre, its wettability and the effect of fibre length after treating the fibre with two different NaOH solutions. Results have shown that better reinforcement was obtained for the composites (11.10 ± 2.53MPa) with fibres subjected to a more aggressive treatment (2.5%NaOH for 2h) compared to the composite made with fibres having maximum tensile strength (168 ± 12MPa at 0.5% NaOH for 14h), due to a better hydrophilicity of the alkaline treated fibre (87.37° internal angle). Within the range of short chopped fibre length tested (6 to 15 mm), it was shown that there was a general decrease in the tensile strength of the composite.

scholarly journals Past climates inform our future

Science ◽  
2020 ◽  
Vol 370 (6517) ◽  
pp. eaay3701
Author(s):  
Jessica E. Tierney ◽  
Christopher J. Poulsen ◽  
Isabel P. Montañez ◽  
Tripti Bhattacharya ◽  
Ran Feng ◽  
...  
Keyword(s):  
Climate Change ◽  
Carbon Dioxide ◽  
Model Evaluation ◽  
Future Climate Change ◽  
Earth System ◽  
High Carbon ◽  
The Earth ◽  
The World ◽  
Earth System Models ◽  
High Carbon Dioxide

As the world warms, there is a profound need to improve projections of climate change. Although the latest Earth system models offer an unprecedented number of features, fundamental uncertainties continue to cloud our view of the future. Past climates provide the only opportunity to observe how the Earth system responds to high carbon dioxide, underlining a fundamental role for paleoclimatology in constraining future climate change. Here, we review the relevancy of paleoclimate information for climate prediction and discuss the prospects for emerging methodologies to further insights gained from past climates. Advances in proxy methods and interpretations pave the way for the use of past climates for model evaluation—a practice that we argue should be widely adopted.

scholarly journals DEVELOPMENT OF CERAMIC MICROFILTRATION SUPPORT FROM MOROCCAN SAHARA CLAY

2018 ◽  
Vol 24 (4) ◽  
pp. 19-27
Author(s):  
NOURLYAQUIN EL QACEMI ◽  
NABIL SAFFAJ ◽  
RACHID MAMOUNI ◽  
NOURREDINE EL BARAKA ◽  
HAMID ZIDOUH ◽  
...  
Keyword(s):  
Mechanical Strength ◽  
Slip Casting ◽  
Organic Additives ◽  
Casting Method ◽  
Textile Effluents ◽  
Extrusion Processing

The new ceramic microfiltration support prepared from Moroccan clay (Laayoune region, South of Morocco) is reported in this paper. To optimize the support elaboration conditions, the powder clay is mixed with organic additives and water. The formed paste is shaped by using an extrusion processing and then sintered at 950 °C. The ceramic supports present a porosity and mechanical strength of 44 % and 12MPa respectively. The layer filtration deposition has been carried out by the slip casting method, in order to test its operation in textile effluents treatment.

scholarly journals Effect of cement fineness and polycarboxylate dosage on the rheological and mechanical behavior of a mortar

2018 ◽  
Vol 149 ◽  
pp. 01037
Author(s):  
Didouche Zahia ◽  
Ezziane Karim
Keyword(s):  
Mechanical Strength ◽  
Mechanical Behavior ◽  
Rheological Behavior ◽  
Organic Additives

The use of certain organic additives in the production of mortar and concrete influences the workability and the hydration kinetic of mortar. This results in a modification of some properties, namely rheological behavior and mechanical strength. The objective of this work is to evaluate the rheological and mechanical behavior of a mortar by varying the fineness of the cement and using the superplasticizer Polycarboxylate.

Ancient Materials and Techniques to Improve the Earthen Building Durability

2014 ◽  
Vol 634 ◽  
pp. 357-366 ◽  
Author(s):  
Rute Eires ◽  
Aires Camões ◽  
Said Jalali
Keyword(s):  
Water Vapour ◽  
Weather Conditions ◽  
Substantial Part ◽  
Vapour Permeability ◽  
New Methods ◽  
The Earth ◽  
The World ◽  
Earthen Buildings ◽  
Alternative Solutions ◽  
New Buildings

A substantial part of the world building heritage has been performed by earthen building. The durability of this existing heritage and mainly of the new buildings built with earth is particularly conditioned by the erosion caused by water action, especially in countries with high levels of rainfall. This research aims to contribute to the increase of knowledge about the ancient building techniques that provide enhanced durability. It is possible to analyse the ancestral practices used to protect the earth material from the water action in order to understand how the old earthen buildings were preserved over the centuries, resisting to harsh weather conditions. Among these techniques are: the incorporation of biopolymers (such as oils or fats from animal or vegetable origin); the addition of some minerals; and the earth stabilization with lime. However, this knowledge seems to be forgotten, probably due to the prejudice related to earthen constructions, which several times are associated with a poor building. This research also focuses on the study of new methods of earth stabilization with lime and biopolymers, adapting the ancient knowledge to improve the durability related to the water action. Therefore, alternative solutions can be obtained to improve the performance of earthen buildings, mainly the resistance of the material in the presence of water, reducing its permeability to water. In addition, with the proposed solutions it is possible to obtain good levels of water vapour permeability, one of the major advantages of the construction with earth.

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