Papers by Keyword: Adobe

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Authors: M.A.P. Rezende, R.C. Alves, E.V.M. Carrasco, J.N.R. Mantilla, M.A. Smits, V.D. Pizzol, P.V. Krüger
Abstract: This article presents and discusses an adobe production with shows a clay/silt/sand proportion that is completely different from that recommended by most authors and construction associations. The main objective was to improve comprehension of earth behaviors as building material by studying these two atypical cases of adobe production. The soil was analyzed by different tests as the grain size distribution test and Atterberg limits. Adobe resistance was tested using a methodology proposed by Proterra network which was created by a group of researchers from different Iberian American laboratories. This methodology was used in Ph.D. thesis, too. The results show a soil with 1% clay and 65.1 silte and an average of resistance of 2.11 MPa for the adobes. These results show the importance of the clay mineral structure and the complexity of the soil behavior, indicating the need for additional studies.
346
Authors: Mohammad Najinassajfar, Ali Vahidi
Abstract: Adobe (khesht) is the most common traditional material which is used in Persian structures because of compatibility with environment, being economic, ease and rapidity of use. In different eras of Persian history using adobe had been common. Its archaism refers to sixth millennium B.C. Attendance to these kinds of structures is important for two reasons. First, most residential structures and old regions of cities are made by adobe. Second reason is the cultural and antiquarian aspect of monuments. This article introduces features of adobe as a traditional material. Besides, process of building adobe structure and its reaction to earthquake.
818
Authors: Tiago Martins, Humberto Varum
Abstract: Adobe is commonly found in Aveiro's ancient constructions. Preservation and rehabilitation of those constructions, some of them with architectural and historical interest, has been forgotten for many years. As a result, in Aveiro region, the majority of existing constructions in adobe is structurally weak, and, in several cases, they are in the threshold of ruin. Rehabilitation and/or strengthening urge. Despite some efforts has been made, a great difficulty for technicians working on the rehabilitation of these constructions relies on the lack of knowledge on adobe's mechanical behaviour. In fact, in order to properly describe the structural behaviour of those constructions, there is a need to investigate the mechanical behaviour of adobe. Hence, this paper is based on a study intended to characterise the behaviour of adobe brick units. Specimens were prepared from selected representative constructions of the Aveiro region. The prepared specimens were tested in order to evaluate their mechanical behaviour in compression and tension.
1571
Authors: Andréa A.R. Corrêa, Lina Bufalino, Thiago de Paula Protásio, Marcelo X. Ribeiro, Danilo Wisky, Lourival Marin Mendes
Abstract: The raw mud brick (adobe) is a millenary technology that awakens a wide interest in ecologic and non-conventional constructions. Some advantages are low cost, thermal comfort and minimum environmental impact. For better use, it is important to improve their mechanical properties. Dynasolo DS-328® is a chemical stabilizer used in soil compression for road paving and it is similar to termite saliva. This composition is based on vegetal oils. It is a high-concentrated liquid product, water soluble, non-toxic, non-corrosive, and non-flammable. The cohesive properties promote the investigation about the incorporation of this product in adobe composition. Therefore, this work aimed to evaluate synthetic termite saliva" incorporation to adobes at four different concentrations: 1:2000; 1:1500; 1:1000 and 1:500. The reagent is an aluminum sulfate at 1:5000 for all treatments. The soil is a Red Latosol cambisol corrected to 50% fine sand fraction. Soil bulk density, particle density and total pore volume were: Ds = 1.42 kg/dm3, Dp = 2.62 kg/dm3 and VTP = 45.8%. The soil Atterberg limits were: LL (liquid limit) 55.44%; PL (plastic limit) 34.58%; SL (shrinkage limit) 21.67%; and PI (plasticity index) 20.86%. The ideal moisture content was variable, ranging from 50% to 40% according synthetic termite saliva" increase. Adobes were submitted to compression and bending resistance tests. This research confirmed that synthetic termite saliva" incorporation improved the adobe compressive resistance and chose the treatment 1:1500 because it increased 20% this property.
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Authors: Andréa A.R. Corrêa, Bárbara Maria Ribeiro Guimarães, Mario Vanoli Scatolino, Moisés G. Duarte, Thamirys A. Lopes, Lourival Marin Mendes
Abstract: Adobe (raw mud brick) is a non-conventional technology that awakens a wide interest in sustainability constructions. However is important to improve the physical properties to reduction its water absorption and capillarity. The stabilization of adobe with products that don`t harm the environment and improve these physical properties must be goal for studies. Then Dynasolo DS328® known as synthetic termite saliva" is a chemical stabilizer produced in Brazil that can be a good option. This composition with vegetal oils is non-toxic, hydrophobic and has cohesive properties. The product is a high-concentrated liquid, water soluble and non-flammable. Therefore, this research aimed to compared the synthetic termite saliva" incorporation at four different concentrations: 1:2000; 1:1500; 1:1000 and 1:500 with adobes without stabilization. The reagent chosen was an aluminum sulfate at 1:5000 for all treatments. The adobe soil is a Red Latosol cambisol in natura and corrected to 50% fine sand fraction. The ideal moisture content is variable, ranging from 50% to 40% according DS328® increase. Adobes were submitted to water absorption, capillarity and linear contraction field tests science-based. This research confirmed the cohesive properties of chemical stabilization with synthetic termite saliva". It improved density and reduced the water absorption, capillarity, mass loss and linear shrinkage. The better treatment was 1:500 concentration.
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Authors: Liang Bin Qin, Wei Chen, Xue Wei Li
Abstract: Compressive strength of adobe ,which were produced by Traditional methods in rural areas,was from 0.8MPa to 2.0MPa. Adding cement and controling the proportion of water increased compressive strength of adobe in this experiment. The level of compressive strength can been increased by 4 to 10 times. The influence which cement affect compressive strength of adobe and the optimal ratio of cement and water are obtained by statistical methods.And the data provide evidence for production of adobe in vast rural areas.
217
Authors: Zhong Tao, Liang Bin Qin, Wen Pan, Xiao Dong Yang, Yu Bai
Abstract: Experimental study on the behavior of Single Adobe, Rammed Earth Wall, Single modified adobe block, modified adobe wall and Reinforcement of Bamboo Rammed-earth Wall is put forward in this paper. The experiments include compression, shear and bending test of single adobe, and uniaxial lateral loading test of rammed earth and modified adobe wall and reinforcement of bamboo rammed-earth wall. The mechanical properties of the specimens are obtained through test. The test and research will offer a technological support for the Chinese Government started the Rural House Earthquake Safety Project(RHESP)and formulation of the code for seismic design of rural buildings.
1338
Authors: Hana Mori Böttger, Claudia Ostertag
Abstract: This paper investigates an inexpensive but potentially very effective reinforcement method for adobe block wall systems. Reinforcing fabric materials were embedded in the mortar between each layer of blocks to provide a barrier against the propagation of the dominant diagonal cracks which are commonly observed in adobe walls after a seismic event, and are largely responsible for the collapse of adobe structures. The effectiveness of the reinforcing materials in resisting and arresting cracks was investigated in splitting tension tests. Reinforced and unreinforced adobe walls were fabricated and tested in diagonal compression to simulate the transfer of shear due to lateral forces. Felt fabric reinforcement was found to provide the greatest physical deformation of the wall sample and greatest dissipation of energy while maintaining acceptable load-bearing capacity. The final displacement of the reinforced sample was found to be nearly three times that of the unreinforced control specimen. A secondary motivation for this investigation was to address the need for such engineering solutions to be highly affordable to those most likely to build with adobe block. Earthquakes have ravaged many regions of the world, and while advancements in engineering and life-safety codes have resulted in significant improvements in performance of modern structures, we must also seek out methods by which traditional building systems, which continue to house large numbers of people, can withstand the scrutiny of modern safety criteria. Further investigations are encouraged to determine location-specific solutions with this goal in mind.
156
Authors: Christopher J. Whitman
Abstract: According to the latest official census of 2002, earth construction represented 5.5% of the Chilean building stock. These buildings of traditional construction techniques of unfired earth and straw blocks (adobe), rammed earth (tapial) or wattle and daub (quincha) form a large proportion of Chile’s National Monuments and heritage buildings. In addition to their heritage value, these buildings with their high thermal mass, respond well to the climate conditions of both the altiplano of northern Chile and the Central Valley, zones with high diurnal temperature oscillations, with typical daily temperature differences of up to 20°C. However following the 2005 earthquake in Tarapacá, northern Chile and that of the 27th February 2010 in Central Chile a serious rethink has been required as to the retention and restoration of adobe buildings. Public opinion has labelled earth construction as unsafe and most reconstruction to date has taken place with prefabricated timber solutions which lack the necessary thermal mass to respond well to the climatic conditions. At the same time research into the structural integrity, seismic resistance, maintenance and the living conditions provided by earth construction has been undertaken. In this wider context this paper presents the compilation of international and Chilean research into the hygrothermal properties of adobe construction, in addition to the authors insitu measurements of the temperature and relative humidity in two surviving adobe dwellings in the earthquake hit village of Chépica located in Chile´s Central valley. These measurements are compared with those of a dwelling rebuilt with straw bales and earth render in the same location. Based on this information the paper studies the challenge of rebuilding and restoring heritage buildings whilst providing occupants with the necessary levels of environmental comfort.
186
Authors: Andréa Aparecida Ribeiro Corrêa, Thiago de Paula Protásio, José Tarcísio de Lima, Gustavo Denzin Tonoli, Lourival Marin Mendes
Abstract: Among non-conventional materials available in Brazil for construction, sugar cane bagasse lignocellulosic particles and “synthetic termite saliva” are included. The utilization of such particles as reinforcement and the “synthetic termite saliva” for soil chemical stabilization in adobe production were not investigated in the literature yet. Therefore, this research aimed to evaluate the mechanical properties of adobes produced with those materials. The soil used was Red Latosol Cambisol type with clayey texture with kaolinite presence, and particle size correction for 50% sand. Bagasse sliver particles were washed with residual water of the distillation process at 45°C and air dried. Their density and chemical composition were determined. The adobes were produced with 30x15x8cm-size wood molds. The following samples were analyzed: adobes without particles (control); and adobes with bagasse incorporation at 2%, 4% and 6% based on dry mass and “synthetic termite saliva” at 1:1500 and 1:500 proportions. Aluminum sulfate solvent was applied at 1:5,000. The adobes were stored in a covered warehouse until complete drying. Compression and static bending strength were evaluated. The results showed a positive interaction between adobe components and compression strength, which was improved up to 60%. The best composition tested was 6% sugar cane bagasse and “synthetic termite saliva” at 1:500.
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