The Experts below are selected from a list of 153 Experts worldwide ranked by ideXlab platform
Abdelhamid Guettala - One of the best experts on this subject based on the ideXlab platform.
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the mechanical and physical properties of Compressed Earth Block stabilized with lime and filled with untreated and alkali treated date palm fibers
Construction and Building Materials, 2016Co-Authors: Bachir Taallah, Abdelhamid GuettalaAbstract:Abstract Most developing countries have an urgent need to construct and build houses that are more durable at a low cost. The Compressed Earth Block (CEB) has been identified as a low-cost material with the potential to redress the problem and reverse the shelter backlog. While its properties, using cement and lime, are well understood, the use of vegetal fibers with chemical stabilizers still raises a lot of questions. The principal objective of this research is to investigate the mechanical and physical properties of CEB stabilized with quicklime and filled with date palm fibers. The fibers have been chemically treated using an alkaline solution to enhance the fiber/matrix bonding consequently increases the mechanical strength. In this work, the effect of curing methods and curing time on mechanical strength of CEB was studied. The investigation results indicate that, although the strengths values of CEB filled with alkali treated fibers is slightly greater than that with untreated fibers, the fiber surface treatment did not result in an improvement in the fiber/matrix adhesion, leading to a decrease in strength of the Blocks. The research findings show that the use of date palm fibers lead to a reduction in thermal conductivity and bulk density and increases the capillary absorption of the Blocks. An adverse effect on thermal conductivity of CEB with alkali treated date palm fibers was observed.
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Mechanical Properties and Durability of Lime and Natural Pozzolana Stabilized Steam-Cured Compressed Earth Block Bricks
Geotechnical and Geological Engineering, 2015Co-Authors: Ouarda Izemmouren, Abdelhamid Guettala, Salim GuettalaAbstract:The paper outlines a study carried out to analyze the effects of mixed treatment (lime–natural pozzolana) on the mechanical properties and durability of Compressed Earth Blocks (CEB) undergone a steam curing. Effects of parameters such as conditions and the period of curing, lime and natural pozzolana content on the mechanical properties (dry tensile strength, dry and wet compressive strength, water strength coefficient) and tests of durability (capillary absorption, total absorption, wetting/drying and abrasion resistance) of CEB were investigated. The results obtained showed that steam curing of lime stabilized Blocks at 75 °C for about 24 h at atmospheric pressure leads to considerably higher strengths when compared with curing under plastic film at ambient temperatures. Therefore, the mechanical strengths of steam-cured at about 24 h are near to mechanical strengths of Blocks with moist-curing at 18 months. It has been shown that the addition of natural pozzolana (at contents of 10–30 %) with lime for steam-cured Compressed Blocks appears to produce the higher mechanical properties and sustainable than lime used alone.
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mechanical properties and hygroscopicity behavior of Compressed Earth Block filled by date palm fibers
Construction and Building Materials, 2014Co-Authors: Bachir Taallah, Abdelhamid Guettala, Salim Guettala, Abdelouahed KrikerAbstract:Abstract This paper investigates the mechanical properties and hygroscopicity behavior of Compressed Earth Block (CEB) filled by date palm fibers in order to valorize local building materials and the contribution to the cost reduction of housing especially in rural areas. In this framework, a series of Blocks were fabricated using a soil, stabilised with cement, the crushed sand and fibers, and compacted with a static loading by applying three compacting stresses (1.50, 5 and 10 MPa). Better result of the dry compressive strength was observed by CEB with 0.05% of fiber content, 8% cement content and compaction pressure of the 10 MPa. But for the remaining studied cases, the addition of fibers under compaction pressure has an adverse effect on the properties of CEB. Impact of palm fibers on the tensile strength was unfavorable because of their low tensile strength, very high water absorption, by heterogeneity or distribution and a low adhesion with the matrix. Could be said that by increasing cement content and decreasing palm fibers content there is a general decrease in total water absorption of the Blocks. The swelling of the Blocks increases with decreasing cement content and increasing palm fibers content.
Peter T Laursen - One of the best experts on this subject based on the ideXlab platform.
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analysis and seismic performance evaluation of flexure dominated interlocking Compressed Earth Block walls
Advances in Structural Engineering, 2015Co-Authors: Bing Qu, Bradley J Stirling, Peter T Laursen, Daniel C JansenAbstract:This paper presents development and validation of three analytical models for flexure-dominated Interlocking Compressed Earth Block (ICEB) walls, which are based on classic mechanics of materials, inelastic truss elements, and phenomenological hysteretic model, respectively. Based on the testing results from a prior experimental investigation, it is shown that the first two models provide reasonable estimates for the lateral load resistance of flexure-dominated ICEB walls and the third model captures the inelastic behavior of flexure-dominated ICEB walls under cyclic loading. Using the third model, incremental dynamic analyses were conducted and performances of two demonstration single-story buildings consisting of flexure-dominated ICEB walls were evaluated for three construction sites with different levels of seismicity. Computer simulation results show that both demonstration buildings are able to avoid Earthquake-induced collapse. It is also found that the current design and construction of flexure-do...
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testing of flexure dominated interlocking Compressed Earth Block walls
Construction and Building Materials, 2015Co-Authors: Bing Qu, Bradley J Stirling, Daniel C Jansen, David W Bland, Peter T LaursenAbstract:Abstract Interlocking Compressed Earth Blocks (ICEBs) are a form of dry stack masonry units made with indigenous soil and typically stabilized with cement. This paper presents testing results for seismic behavior of flexure-dominated ICEB walls. A total of four 1.8-m high ICEB wall specimens were constructed and tested. The specimen dimensions were varied to identify the effects of the following factors on performance of ICEB walls: height-to-width aspect ratio, presence of a flange at one end of the wall, and presence of an opening in the wall. Testing results show that flexure-dominated ICEB walls can exhibit stable hysteretic behavior until a ductile failure occurs. Additionally, wall ductility increases with increasing height-to-width aspect ratio when other design parameters remain the same. Furthermore, strength of an ICEB wall can be enhanced due to the presence of the flange at one end but reduced due to the presence of an opening.
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Out-of-plane structural response of interlocking Compressed Earth Block walls
Materials and Structures, 2015Co-Authors: Peter T Laursen, Daniel C Jansen, N. A. Herskedal, Bing QuAbstract:Stabilized Compressed Earth Block (CEB) structures are popular in developing countries because of their low cost, sustainable use of indigenous materials, and inherent simplicity. Interlocking CEB Blocks are dry stacked (no mortar in the joints), reinforced through flues and grouted. CEBs are typically used for single story homes and school houses. The current design practice for CEB structures in regions with severe natural hazards (typhoons and Earthquakes) is questionable in terms of structural integrity. This is accentuated by the complete lack of experimental out‐of‐plane load testing of CEB walls. Scientific evidence reported in this paper has the potential to improve the current design practice to make this a safer construction form. Five CEB walls were built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. Two walls were full-scale panels and the remaining three walls were 1.1 m tall. All tests showed flexure dominated behavior, except for one full scale wall in which shear dominated failure was observed in the stiffening element. Results from the experimentation showed that the CEB walls were relatively flexible, mainly due to slack in the dry-stack joints, and that the current US masonry design code procedures (MSJC-11, Building code requirements for masonry structures (TMS 402-11/ACI 530-11/ASCE 5-11) (2011)) adequately predict the wall flexural strength. A moment–curvature based model was proposed for prediction of the out-of-plane force–displacement response and validated by the experimental results.
Bachir Taallah - One of the best experts on this subject based on the ideXlab platform.
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the mechanical and physical properties of Compressed Earth Block stabilized with lime and filled with untreated and alkali treated date palm fibers
Construction and Building Materials, 2016Co-Authors: Bachir Taallah, Abdelhamid GuettalaAbstract:Abstract Most developing countries have an urgent need to construct and build houses that are more durable at a low cost. The Compressed Earth Block (CEB) has been identified as a low-cost material with the potential to redress the problem and reverse the shelter backlog. While its properties, using cement and lime, are well understood, the use of vegetal fibers with chemical stabilizers still raises a lot of questions. The principal objective of this research is to investigate the mechanical and physical properties of CEB stabilized with quicklime and filled with date palm fibers. The fibers have been chemically treated using an alkaline solution to enhance the fiber/matrix bonding consequently increases the mechanical strength. In this work, the effect of curing methods and curing time on mechanical strength of CEB was studied. The investigation results indicate that, although the strengths values of CEB filled with alkali treated fibers is slightly greater than that with untreated fibers, the fiber surface treatment did not result in an improvement in the fiber/matrix adhesion, leading to a decrease in strength of the Blocks. The research findings show that the use of date palm fibers lead to a reduction in thermal conductivity and bulk density and increases the capillary absorption of the Blocks. An adverse effect on thermal conductivity of CEB with alkali treated date palm fibers was observed.
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mechanical properties and hygroscopicity behavior of Compressed Earth Block filled by date palm fibers
Construction and Building Materials, 2014Co-Authors: Bachir Taallah, Abdelhamid Guettala, Salim Guettala, Abdelouahed KrikerAbstract:Abstract This paper investigates the mechanical properties and hygroscopicity behavior of Compressed Earth Block (CEB) filled by date palm fibers in order to valorize local building materials and the contribution to the cost reduction of housing especially in rural areas. In this framework, a series of Blocks were fabricated using a soil, stabilised with cement, the crushed sand and fibers, and compacted with a static loading by applying three compacting stresses (1.50, 5 and 10 MPa). Better result of the dry compressive strength was observed by CEB with 0.05% of fiber content, 8% cement content and compaction pressure of the 10 MPa. But for the remaining studied cases, the addition of fibers under compaction pressure has an adverse effect on the properties of CEB. Impact of palm fibers on the tensile strength was unfavorable because of their low tensile strength, very high water absorption, by heterogeneity or distribution and a low adhesion with the matrix. Could be said that by increasing cement content and decreasing palm fibers content there is a general decrease in total water absorption of the Blocks. The swelling of the Blocks increases with decreasing cement content and increasing palm fibers content.
Bing Qu - One of the best experts on this subject based on the ideXlab platform.
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analysis and seismic performance evaluation of flexure dominated interlocking Compressed Earth Block walls
Advances in Structural Engineering, 2015Co-Authors: Bing Qu, Bradley J Stirling, Peter T Laursen, Daniel C JansenAbstract:This paper presents development and validation of three analytical models for flexure-dominated Interlocking Compressed Earth Block (ICEB) walls, which are based on classic mechanics of materials, inelastic truss elements, and phenomenological hysteretic model, respectively. Based on the testing results from a prior experimental investigation, it is shown that the first two models provide reasonable estimates for the lateral load resistance of flexure-dominated ICEB walls and the third model captures the inelastic behavior of flexure-dominated ICEB walls under cyclic loading. Using the third model, incremental dynamic analyses were conducted and performances of two demonstration single-story buildings consisting of flexure-dominated ICEB walls were evaluated for three construction sites with different levels of seismicity. Computer simulation results show that both demonstration buildings are able to avoid Earthquake-induced collapse. It is also found that the current design and construction of flexure-do...
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testing of flexure dominated interlocking Compressed Earth Block walls
Construction and Building Materials, 2015Co-Authors: Bing Qu, Bradley J Stirling, Daniel C Jansen, David W Bland, Peter T LaursenAbstract:Abstract Interlocking Compressed Earth Blocks (ICEBs) are a form of dry stack masonry units made with indigenous soil and typically stabilized with cement. This paper presents testing results for seismic behavior of flexure-dominated ICEB walls. A total of four 1.8-m high ICEB wall specimens were constructed and tested. The specimen dimensions were varied to identify the effects of the following factors on performance of ICEB walls: height-to-width aspect ratio, presence of a flange at one end of the wall, and presence of an opening in the wall. Testing results show that flexure-dominated ICEB walls can exhibit stable hysteretic behavior until a ductile failure occurs. Additionally, wall ductility increases with increasing height-to-width aspect ratio when other design parameters remain the same. Furthermore, strength of an ICEB wall can be enhanced due to the presence of the flange at one end but reduced due to the presence of an opening.
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Out-of-plane structural response of interlocking Compressed Earth Block walls
Materials and Structures, 2015Co-Authors: Peter T Laursen, Daniel C Jansen, N. A. Herskedal, Bing QuAbstract:Stabilized Compressed Earth Block (CEB) structures are popular in developing countries because of their low cost, sustainable use of indigenous materials, and inherent simplicity. Interlocking CEB Blocks are dry stacked (no mortar in the joints), reinforced through flues and grouted. CEBs are typically used for single story homes and school houses. The current design practice for CEB structures in regions with severe natural hazards (typhoons and Earthquakes) is questionable in terms of structural integrity. This is accentuated by the complete lack of experimental out‐of‐plane load testing of CEB walls. Scientific evidence reported in this paper has the potential to improve the current design practice to make this a safer construction form. Five CEB walls were built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. Two walls were full-scale panels and the remaining three walls were 1.1 m tall. All tests showed flexure dominated behavior, except for one full scale wall in which shear dominated failure was observed in the stiffening element. Results from the experimentation showed that the CEB walls were relatively flexible, mainly due to slack in the dry-stack joints, and that the current US masonry design code procedures (MSJC-11, Building code requirements for masonry structures (TMS 402-11/ACI 530-11/ASCE 5-11) (2011)) adequately predict the wall flexural strength. A moment–curvature based model was proposed for prediction of the out-of-plane force–displacement response and validated by the experimental results.
Daniel C Jansen - One of the best experts on this subject based on the ideXlab platform.
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analysis and seismic performance evaluation of flexure dominated interlocking Compressed Earth Block walls
Advances in Structural Engineering, 2015Co-Authors: Bing Qu, Bradley J Stirling, Peter T Laursen, Daniel C JansenAbstract:This paper presents development and validation of three analytical models for flexure-dominated Interlocking Compressed Earth Block (ICEB) walls, which are based on classic mechanics of materials, inelastic truss elements, and phenomenological hysteretic model, respectively. Based on the testing results from a prior experimental investigation, it is shown that the first two models provide reasonable estimates for the lateral load resistance of flexure-dominated ICEB walls and the third model captures the inelastic behavior of flexure-dominated ICEB walls under cyclic loading. Using the third model, incremental dynamic analyses were conducted and performances of two demonstration single-story buildings consisting of flexure-dominated ICEB walls were evaluated for three construction sites with different levels of seismicity. Computer simulation results show that both demonstration buildings are able to avoid Earthquake-induced collapse. It is also found that the current design and construction of flexure-do...
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testing of flexure dominated interlocking Compressed Earth Block walls
Construction and Building Materials, 2015Co-Authors: Bing Qu, Bradley J Stirling, Daniel C Jansen, David W Bland, Peter T LaursenAbstract:Abstract Interlocking Compressed Earth Blocks (ICEBs) are a form of dry stack masonry units made with indigenous soil and typically stabilized with cement. This paper presents testing results for seismic behavior of flexure-dominated ICEB walls. A total of four 1.8-m high ICEB wall specimens were constructed and tested. The specimen dimensions were varied to identify the effects of the following factors on performance of ICEB walls: height-to-width aspect ratio, presence of a flange at one end of the wall, and presence of an opening in the wall. Testing results show that flexure-dominated ICEB walls can exhibit stable hysteretic behavior until a ductile failure occurs. Additionally, wall ductility increases with increasing height-to-width aspect ratio when other design parameters remain the same. Furthermore, strength of an ICEB wall can be enhanced due to the presence of the flange at one end but reduced due to the presence of an opening.
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Out-of-plane structural response of interlocking Compressed Earth Block walls
Materials and Structures, 2015Co-Authors: Peter T Laursen, Daniel C Jansen, N. A. Herskedal, Bing QuAbstract:Stabilized Compressed Earth Block (CEB) structures are popular in developing countries because of their low cost, sustainable use of indigenous materials, and inherent simplicity. Interlocking CEB Blocks are dry stacked (no mortar in the joints), reinforced through flues and grouted. CEBs are typically used for single story homes and school houses. The current design practice for CEB structures in regions with severe natural hazards (typhoons and Earthquakes) is questionable in terms of structural integrity. This is accentuated by the complete lack of experimental out‐of‐plane load testing of CEB walls. Scientific evidence reported in this paper has the potential to improve the current design practice to make this a safer construction form. Five CEB walls were built according to current design practice in Indonesia and Thailand, and subjected to out-of-plane loading. Two walls were full-scale panels and the remaining three walls were 1.1 m tall. All tests showed flexure dominated behavior, except for one full scale wall in which shear dominated failure was observed in the stiffening element. Results from the experimentation showed that the CEB walls were relatively flexible, mainly due to slack in the dry-stack joints, and that the current US masonry design code procedures (MSJC-11, Building code requirements for masonry structures (TMS 402-11/ACI 530-11/ASCE 5-11) (2011)) adequately predict the wall flexural strength. A moment–curvature based model was proposed for prediction of the out-of-plane force–displacement response and validated by the experimental results.