Minimizing the Carbon Footprint by Using Rammed Earth Technique

The construction sector holds a large of share in carbon dioxide emissions. in pursuit of minimizing the carbon footprint, it started applying new building techniques and employing environmentally friendly materials One of those applications is rammed earth wall which was originally a traditional construction method that uses soil as the main material. The purpose of this study is to propose the rammed earth technique as an alternative approach for minimizing carbon footprint. It is also discussed its thermal behaviour and required energy to construct. The advantages and disadvantages are stated accordingly. This paper help architects to rethink the traditional techniques which use soil as the main material and how they can reuse it in their design of more sustainable buildings. As a result, minimizing the carbon footprint in the built environment.

Seismic performance test of rammed earth wall with different structural columns

Rammed earth wall load-bearing dwellings are widely distributed in western China. Rammed earth has the advantages of warm in winter and cool in summer, and it is a kind of sustainable construction material. In recent years, in previous earthquakes, the collapse of rammed earth buildings is serious, resulting in huge losses of personnel and property. To improve the seismic performance of rammed earth buildings and retain the characteristics of local buildings, a reinforcement measure with additional structural columns is proposed in this article. Three kinds of structural columns are designed, which are cast-in-place concrete, square steel tube, and concrete-filled square steel tube core column. Through the quasi-static experimental study on the rammed earth wall, the effects of different structural columns on the failure shape, bearing capacity, deformation capacity, and energy dissipation capacity of the wall are compared. The test results show that adding structural columns on both sides of the wall can effectively restrain the rammed earth wall, restrain its brittle failure, significantly improve the energy dissipation capacity of the wall, and obviously improve the seismic performance of the wall. This measure is applicable to rammed earth buildings and provides theoretical support for improving the seismic performance of traditional dwellings.

PRELIMINARY STUDIES TO VALUE ENHANCEMENT OF THE OLD CITADEL IN ORIA, ALMERIA, SPAIN

During the Nasrid Kingdom of Granada, the alcazaba of Oria (Old citadel) was considered one of the most outstanding medieval defensive ensembles in the province of Almeria. This defensive complex, located in the Almanzora Valley at an altitude of over a thousand metres, was built around the 12th-14th centuries and has been registered as an Asset of Cultural Interest since 1985. Nevertheless, unfortunate decisions to intervene in the monument and lack of maintenance facilitated the loss of most of its wall, which had been preserved until the twentieth century. Despite the critical situation of the complex, two sections of the rammed-earth wall are currently identified as standing. This study represents an opportunity to broaden the knowledge of this relevant wall structure and the characterisation of the rammed-earth reinforced wall with lime mortar layers. As a preliminary step towards the rammed-earth walls analysis, the graphic representation of wall elevations by photogrammetry tools is proposed. This technique allows to graphically define the morphology of the rammed-earth wall, to perform its typological analysis and constructive characterisation; and furthermore, to evaluate the state of constructive elements conservation by means of the identification of its damages. The information and results obtained will allow to establish the appropriate laboratory tests for the rammed-earth materials characterisation and to define a report that justifies the inexcusable need to consolidate and preserve them.

Rammed Earth Construction: A Proposal for a Statistical Quality Control in the Execution Process

Unlike other common contemporary construction materials such as concrete, mortars, or fired clay bricks, which are widely supported by international standards and regulations, building with rammed earth is barely regulated. Furthermore, its quality control is usually problematic, which regularly encourages the rejection of this technique. In the literature, many authors have suggested ways to safely build a rammed earth wall, but only a few of them have delved into its quality control before and during the construction process. This paper introduces a preliminary methodology and establishes unified criteria, based in a statistical analysis, for both the production and the quality control of this constructive technique in cases dealing with both samples and walls.

Uncertainty and sensitivity analysis applied to a rammed earth wall: evaluation of the discrepancies between experimental and numerical data

Due to the environmental impact of building materials, researches on sustainable materials, such as bio-based and earth materials, are now widespread. These materials offer numerous qualities such as their availability, recyclability and their ability to dampen the indoor relative humidity variations due to their hygroscopicity. As these materials can absorb large amount of humidity, numerical and experimental studies of their hygrothermal behaviour are crucial to assess their durability. To validate a hygrothermal model, numerical and experimental data have to be confronted. Such confrontation must take into consideration the uncertainties related to the experimental protocol, but also to the model. Statistical tools such as uncertainty and global sensitivity analysis are essential for this task. The uncertainty analysis estimates the robustness of the model, while the global sensitivity analysis identifies the most influential input(s) responsible for this robustness. However, these methods are not commonly used because of the complexity of hygrothermal models, and therefore the prohibitive simulation cost. This study presents a methodology for comparing the numerical and experimental data of a rammed earth wall subjected to varying temperature and relative humidity conditions. The main objectives are the investigation of the uncertainties impact, the estimation of the model robustness, and finally the identification of the input(s) responsible for the discrepancies between numerical and experimental data. To do so, a recent and low-cost global variance-based sensitivity method, named RBD-FAST, is applied. First, the uncertainty propagation through the model is calculated, then the sensitivity indices are estimated. They represent the part of the output variability related to each input variability. The output of interest is the vapour pressure in the middle of the wall to confront it to the experimental measurement. Good agreement is obtained between the experimental and numerical results. It is also highlighted that the sorption isotherm is the main factor influencing the vapour pressure in the material.