56 research outputs found
The Dimension of Sustainability: A Comparative Analysis of Broadness of Information in Italian Companies
In recent years, sustainability has become one of the key dimensions of business performance. The results obtained in terms of sustainability must be adequately communicated in suitable reports, the quality of which is determined by several factors. One of these, the breadth of information provided, plays a significant role. The aim of this paper is to measure the broadness of non-financial information in sustainability reports and correlate this to some selected variables that refer to corporate governance, i.e., the presence of an internal sustainability committee and of female directors; the characteristics of the report e.g., Sustainable Development Goals (SDG) citation; company features, number of employees, revenues, and Return On Assets ROA. For this purpose, 134 Italian companies were studied and a score based on the conformity of the NFD (non-financial disclosure) with the GRI (Global Reporting Initiative) standards was created. To test the research hypotheses, univariate analysis and multivariate regression analysis were performed. The results showed different behaviors by the companies in terms of sustainability policies. The GRISC (Global Reporting Initiative Score) has a greater concentration on mean values. Positive correlations were found between GRISC and the presence of an internal sustainability committee, SDG citation in the NFD and company size. This study offers support for policy makers and practitioners as it provides a measure of the breadth of sustainability information and relates this to the variables analyzed. The latter depend on regulatory interventions or company policies which are implemented, or could be implemented, to improve the extent of the NFD
An analytical approach for pull-out behavior of TRM-strengthened rammed earth elements
Rammed earth constructions, beyond being largely spread in the built heritage, are known for their high seismic vulnerability, which results from high self-weight, lack of box behavior and low mechanical properties of the material. Hence, to mitigate this seismic vulnerability, a compatible textile reinforced mortar (TRM) is here proposed as a strengthening solution, because of its reduced mass and high ductility. The few research about the structural behavior of TRM-strengthened rammed earth elements addresses the global behavior, overlooking the local behavior of the system. An analytical approach to infer the bond stress-slip relationship following the direct boundary problem is proposed. Based on a previous series of pull-out tests, an adhesion-friction constitutive law is portrayed considering also a damage model that considers the degradation of the reinforcing fibers due to friction.This work was partly financed by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth - PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737). The support from grant SFRH/BD/131006/2017 is also acknowledged
Effectiveness of a TRM solution for rammed earth under in-plane cyclic loads
To evaluate the effectiveness of a TRM-strengthening solution for rammed earth walls subjected to in-plane cyclic loads, an experimental program was conducted on a strengthened mock-up previously damaged. The experimental results are discussed in comparison with the previous unstrengthened model in terms of cracking pattern, damage identification, displacements, base shear coefficient, stiffness degradation, and energy dissipation; in addition, simplified equivalent linear and bi-linear systems are inferred to assess the performance. The outcomes highlighted the effectiveness of the TRM solution in improving the in-plane shear capacity, the ductility and the dissipated energy of the mock-up.This work was partly financed by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth - PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737). The support from grants SFRH/BD/131006/2017 and SFRH/BPD/97082/2013 is also acknowledged. Acknowledgments are addressed to the Laboratory of Structures (LEST) of the University of Minho and to João Bernardino, Lda. and TERRACRUA - Construções Ecológicas Unipessoal, Lda for building the rammed earth model
Early-age shrinkage and bond of LC-TRM strengthening in rammed earth
The wide dissemination of earth-based structures as contemporary, vernacular or heritage constructions in re-gions with important seismic hazard demands the design of solutions that improve the typical low structural performance resulting from intrinsic material limitations. Only in this way, it is possible to promote a comprehensive seismic protection of this heritage and of the life of their inhabitants. One relevant and innovative solution proposed recently to address this problem consists in the strengthening with low-cost textile meshes embedded in a mortar matrix (LC-TRM). The purpose of this solution is similar to that of fibre reinforced polymers (FRP) systems used in masonry structures, where it works as an externally bonded reinforcement. Nevertheless, LC-TRM is addressed to elements constituted by materials with low mechanical properties, such as rammed earth and adobe. The further development of this strengthening solution demands comprehending with detail the interaction between the substrate and the matrix, where the shrinkage behaviour is relevant for the success of the system. The capacity of non-destructive tests based on digital image correlation (DIC) suggest the possibility of using this technique to monitor mortar shrinkage in LC-TRM strengthened rammed earth walls. On this regard, an experimental program was conducted and provided many important conclusions, among which are that DIC provides an adequate monitoring of the shrinkage behaviour of LC-TRM strengthened systems and that the strengthening mesh is a key element for controlling shrinkage development. Additionally, the interaction between the substrate and the LC-TRM system was characterised by the means of pull-off tests, favouring a discussion on the suitability and limitations of these tests on rammed-earth/LC-TRM systems.This work was partly financed by FEDER funds through the Opera-tional Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth-PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737) . This research was partly funded by the Portuguese Foundation for Science and Technology (FCT) through the Grant No PD/BD/150385/2019. The funding provided by the Erasmus ELARCH (Euro Latin-America Partnership in Natural Risk mitigation and protection of the Cultural Heritage) 552129-EM-1-2014-1-IT-ERA MUNDUS-EMA21 Program is also gratefully acknowledged
Performance of rammed earth subjected to in-plane cyclic displacement
Rammed earth structures are worldwide spread, both as architectural heritage and new constructions. Yet, rammed earth buildings present, in general, high seismic vulnerability. Despite the several studies conducted on the mechanical characterisation of rammed earth and on the numerical modelling of structural elements built with this material, further in-plane cyclic tests on rammed earth sub-assemblies are required to characterise their hysteretic behaviour. In this framework, an experimental program was conducted where cyclic in-plane tests were performed on a large-scale rammed earth wall. The geometry of the wall was defined to represent a sub-assembly commonly found in rammed earth dwellings from Alentejo (Southern Portugal). The wall was subjected to cyclic shear displacements with increasing amplitude, imposed in both positive and negative directions. To detect the dynamic properties of the wall and to assess the development of the structural damage, dynamic identification tests were conducted along the experimental programme. The results are analysed in terms of crack pattern, dynamic properties, displacement capacity, base shear performance and stiffness degradation. Further discussion is led on the dissipated energy, while a bi-linear and linear equivalent systems are proposed as simplified modelling approach. In conclusion, degradation of structural capacity was observed due to cyclic loads, while adequate energy dissipation and base shear coefficient were obtained.This work was partly financed by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth-PTDC/ECM-EST/2777/2014 (POCI-01-0145-FEDER-016737). The support from grants SFRH/BD/131006/2017 and SFRH/BPD/97082/2013 is also acknowledged. Acknowledgments are addressed to the Laboratory of Structures (LEST) of the University of Minho, Joao Bernardino, Lda, and TERRACRUA-Construcoes Ecologicas Unipessoal, Lda for building the rammed earth model
Seismic behaviour and strengthening of rammed earth constructions
The widespread use of earthen buildings can be accredited to the local availability of the raw material, sustainability of the building process, and low cost. Earthen structures suffer from high seismic vulnerability, resulting from the low strength of the material, high mass, and lack of engineering approaches in design and building. Despite the extensive use of rammed earth structures, the structural behaviour of such buildings is still not well known, particularly concerning the in-plane and out-of-plane response under cyclic loads. Moreover, proper strengthening solutions are still required to reduce seismic vulnerability. In this context, an experimental program was conducted on the in-plane and out-of-plane cyclic performance of rammed earth structural sub-assemblies. The prototypes, after being damaged, were strengthened by employing a TRM-based solution and subjected to further testing. The experimental results are reported and discussed in terms of cracking pattern and peak base shear coefficient. Finally, the effectiveness of the proposed strengthening solution was evaluated against the performance of the unstrengthened mockups. The outcomes highlighted the effectiveness of the TRM solution in improving the ductility and the in-plane shear capacity of the mockups.This work was partly financed by FEDER funds through the Operational Programme Competitiveness Factors (COMPETE 2020) and by national funds through the Foundation for Science and Technology (FCT) within the scope of project SafEarth—PTDC/ECM-EST/2777/2014 (POCI-01–0145-FEDER-016737). The support from
grants SFRH/BD/131006/2017 and SFRH/BPD/97082/2013 is also acknowledged. Acknowledgments are addressed to the Laboratory of Structures (LEST) of the University of Minho, João Bernardino Lda and TERRACRUA Lda for building the rammed earth model
Production procedures and mechanical behaviour of interlocking stabilized compressed earth blocks (ISCEBs) manufactured using float ram 1.0 press
This paper illustrates an innovative manufacturing procedure for producing handcrafted interlocking stabilized compressed earth blocks (ISCEBs). A comparison of the mechanical
properties of ISCEBs is conducted to assess the influence of varying components. The ISCEBs are manufactured by employing different block densities with three distinct mixtures (earth, earth and lime, earth and straw) and by using a human-powered machine named Float RAM 1.0 Press. The manual press was conceived for regions with limited access to technology and allows the production of interlocking blocks via two modes of compaction: mono-directional and bi-directional. A production average of approximately 30 blocks/hour corresponding to the work of three people is achieved. Three-point bending tests and uniaxial compression tests are carried out to investigate the ISCEB mechanical behaviour. The improvements obtained by incorporating additives into the subset of ISCEBs made from a pure earth mixture are tested. The aim of this work is to identify, for this specific technology, the relationship between production parameters and the consequent behaviour of different stabilization methods. A correlation is found between the compaction force and the compression strength of ISCEBs. The addition of lime increases strength and causes the blocks to exhibit a brittle behaviour. Moreover, the incorporation of straw fibres improves the tensile strength and ductility without significantly affecting the compression strength of the blocks. Energy-based parameters are obtained for all the tests, allowing the assessment of the ISCEB mechanical and dissipation properties
Evaluating the seismic behaviour of rammed earth buildings from Portugal: From simple tools to advanced approaches
Despite the use of rammed earth became marginal in the second half of the past century, Portugal still holds an important built heritage. Recently, a growing use of rammed earth has been observed in modern constructions, but it is putting aside the roots of traditional rammed earth construction. The seismic behaviour of rammed earth buildings is still insufficiently comprehended, constituting a matter of great concern, since most of the traditional dwellings are built on regions with important seismic hazard. Moreover, the complex architecture of modern rammed earth buildings is expected to make their seismic behaviour even more fragile. This paper intends to provide a better comprehension on the seismic behaviour of rammed earth constructions from Portugal. For this purpose, twenty traditional dwellings were evaluated on the basis of a simplified approach, while a modern construction was investigated by means of destructive and non-destructive testing approaches. The main findings of these approaches are discussed in detail, but it can be highlighted that the architectural features of traditional rammed earth buildings benefit their seismic behaviour, while the complex architecture of modern rammed earth buildings demands using advanced engineering tools for their seismic assessment.This work was partly financed by FEDER funds through the Competitivity Factors Operational Programme - COMPETE and by national funds through FCT Foundation for Science and Technology within the scope of projects POCI-01-0145-FEDER-007633 and POCI-01-0145-FEDER-016737 (PTDC/ECM-EST/2777/2014). The support from grant SFRH/BPD/97082/2013 is also acknowledged. The authors wish also to express gratitude to Eng. Sergio Morgado and Mr. Francisco Seixas for providing access to the house of Forjales and conditions to perform the destructive and non-destructive tests.info:eu-repo/semantics/publishedVersio
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