Documentații despre construcțiile din pământ

• Earth buildings in Romania. Tradition and perspectives

Abstract: Earth is one of the most commonly used traditional building materials. Recently its usage was reassessed, considering its qualities, with earth being viewed as environmentally friendly and sustainable. Extended research has been done to analyse material qualities and construction techniques. New buildings were developed, some of them with modern architecture and high aesthetic qualities. In this context, the paper proposes an interdisciplinary approach aiming to analyse earth buildings in Romania from an architectural and structural point of view. Furthermore, their potential use in contemporary architecture is evaluated. Currently, local regulations for the usage of earth as construction material are absent and there are only few examples of earth architecture in recent Romanian practice. We propose a necessary analysis for the process of retrieving a traditional building material, which has a high potential for contemporary architecture in our country. The study examines the historical usage of earth as a building material in Romania. The types of buildings and the construction techniques across various regions are identified. An analysis of the specific structural issues of earth buildings in Romania follows. Conclusions are drawn regarding the potential use of earth as a construction material in contemporary Romanian architecture.

• Earth buildings with local materials: Assessing the variability of properties measured using non-destructive methods

Abstract: The study focuses on analysing the variability of the properties for earthen materials constructed with traditional methods. Non-destructive tests are conducted on two material formulations: raw earth and raw earth mixed with hemp shives and reed. Raw earth samples exhibit coefficients of variation of 3.7%, 17.8%, 9.6%, 27.0% and 12.8% for density, electrical resistivity, thermal conductivity, volumetric heat capacity and dynamic modulus, respectively. Higher variabilities of properties are observed for the formulation that includes natural fibres: 3.7%, 25.8%, 12.1%, 23.7% and 23.3%, respectively. Correlations between properties are established and the sensitivity to fibres presence inducing heterogeneity between specimens is analysed.

• Mechanical properties of cob-earth composites: variability and focus on the different calculation methods of Young’s modulus

Abstract: Mechanical property data for earthen materials are currently lacking. Usually, only average values are available. This study investigates the mechanical properties (tensile and compressive strength, Young’s modulus) of cob. The results obtained for different cob mixes with and without fibres are analysed. Four different moduli – E_cycle, E_tan, E_mono and E_dyn – are examined. Probability density functions, mean, standard deviation and percentiles are determined for each mechanical property. Value dispersion for all the properties studied is large and the difference between mean value and 5th percentile is 82%, 81% and 77% for tensile strength, compressive strength and Young’s modulus, respectively.

titlu articol	Mechanical properties of cob-earth composites: Variability and focus on the different calculation methods of Young’s modulus
autori	Philippe Poullain, Mircea Bârnaure, Stephanie Bonnet
revista	Journal of Building Engineering, nr. 72
anul publicării	2023
editura	Elsevier
DOI	10.1016/j.jobe.2023.106622
link	link articol
limba	engleză
disponibil gratuit	da

• Crude earth: assessing the variability of densities, dynamic modulus and resistivity

Abstract: In recent years, in light of the current trend for sustainable buildings, earth was reassessed as a viable building solution. Most of the studies on earth have focused on analysing the possibility of standardising material properties by stabilising earth with cement or lime or on improving the construction methods by using modern equipment. In light of assessing the viability of using local materials and simple traditional techniques, the study focuses on analysing material variability by laboratory testing. Density, dynamic modulus, electrical resistance are measured on soil specimens constructed with traditional non-engineered methods. Non-destructive testing methods are used. An analysis in terms of variability is made based on these measurements. Comparisons are made between different specimens with or without fibres. For earth without fibres the coefficient of variation is 2%, 8.6% and 9.5 for the density, the modul us, the resistivity respectively. For the formulation with fibres, the variabil ity is greater due to the heterogeneity of the material.

titlu articol	Crude earth: assessing the variability of densities, dynamic modulus and resistivity
autori	Mircea Bârnaure, Philippe Poullain, Stephanie Bonnet
revista	Academic Journal of Civil Engineering, vol. 37, nr. 1
anul publicării	2021
DOI	10.26168/ajce.37.1.46
link	link de acces
limba	engleză
disponibil gratuit	da

• Variability of the Mechanical Properties of Earthen Composites

There is currently a lack of data concerning the mechanical properties of earthen materials. Most often only average values are established. The mechanical properties (tensile and compressive strength, Young modulus) obtained on different formulations of cob are analysed. The probability density functions and the average values, the standard deviation and the percentiles are determined. The results shows that the dispersion of the values can be large and that the difference between the mean value and the 5 th percentile can be as high as 70%. The modulus values are highly dependent on the method used to determine them.

titlu articol	Variability of the Mechanical Properties of Earthen Composites
autori	Philippe Poullain, Mircea Bârnaure, Stephanie Bonnet
revista	SSRN
anul publicării	2019
DOI	10.2139/ssrn.4159294
link	link de acces
limba	engleză
disponibil gratuit	da

• Construction Techniques and Detailing for Romanian Paiantă Houses: An Engineering Perspective

Abstract: Traditional houses represent landmarks of local cultures all over the world. In seismically prone countries, the traditional timber frames with different types of infills have shown quite good earthquake resilience, an essential feature considering their large number, their simplicity and their reduced cost, owing to the use of local materials and workmanship. In fact, their seismic behavior fostered the interest in further scientific research, including that addressing engineering aspects. Because of their diversity in layout and detailing, noticeable even among houses in the same area, developing general methods to preserve and strengthen such buildings is still a difficult task. This paper presents an overview of the traditional building construction techniques in Romania, focusing on the structural configuration and detailing of the so-called paiantă houses. Largely used all over the country, these houses have shown that they can generally withstand earthquakes at least without collapsing and, most frequently, with minor or repairable damage. Their preservation is nowadays a major challenge, as they are being gradually either demolished and replaced, or retrofitted by using invasive techniques. Their cultural and heritage value is undeniable, and there are still many things to be learned from the past craftsmanship and re-valuated in the future. Three case studies of rural buildings located in different areas of the country were chosen among the most widespread paiantă versions, and comprehensive engineering assessments were conducted to identify their detailing and degradations. Based on the most common degradations, the conclusions drawn from this study can be used to substantiate further research aimed at selecting the most appropriate construction and strengthening techniques.