Requirements for the respect of the environment encourage to reduce the impact of human activity on the nature. Civil engineering answers these requirements by the development of ecological construction materials. Thi...Requirements for the respect of the environment encourage to reduce the impact of human activity on the nature. Civil engineering answers these requirements by the development of ecological construction materials. This paper deals with the transformation of clay raw materials which enable the processing of environmentally friendly construction materials: in addition to their biodegradability, the alveolar fired clay materials allow energy saving in home heating thanks to their thermal isolation properties. But their manufacturing is a high energy consumption process, in particular during compaction, drying and firing which contribute to the emission of greenhouse gases. The goal of this paper is to study the rheology of clay pastes in order to develop low energy in manufacturing processes. For this purpose, theoretical and experimental approaches were carried out on six clay varieties. In the theoretical approach, a finite element (FE) simulation model has been developed for pressing a non-rigid material predicting deformations and stresses occurring within the clay structure. Experiments have then been carried out to validate the finite element modelling. In this experimental approach, the clay pastes were transformed with water content respecting the Atterberg limits which determine the plasticity of clays. The samples compaction has been carried out under variable loadings in order to determine the suitable low energy consumption loading.展开更多
<div style="text-align:justify;"> <span style="font-family:Verdana;">The use of vegetable fibers composites in structures sometimes presents significant fires risks because of their hig...<div style="text-align:justify;"> <span style="font-family:Verdana;">The use of vegetable fibers composites in structures sometimes presents significant fires risks because of their high flammability. This work aims to study the impact of the addition of mineral filler (clay) on the fire behaviour of wood-polystyrene composites and their mechanical properties. Thus, composites containing 25% of expanded polystyrene binder have been produced. On this base material, proportions of clay ranging from 0% to 15% were gradually added. These samples were elaborated by compaction and for some them, submitted to thermoforming after drying. Both kinds of sample were subjected to flame persistence test;flexural strength and compressive strength test were also measured. The results show that composites without mineral filler ignite continuously until the total consumption and when the mineral filler content increases the combustion time decreases. The addition of the mineral filler allows these composites to pass from class M3 of moderately flammable combustible materials to class M2 of hardly flammable materials, according to the M classification of construction and furnishing materials. The measurement of the mechanical properties shows that the strengths increase when the filler content goes from 0% to 10% and then decrease. This leads to set the optimum content of mineral filler around 10%.</span> </div>展开更多
Natural rubber latex is </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">white liquid in the form of </span><span style="...Natural rubber latex is </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">white liquid in the form of </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> colloidal dispersion of rubber globules suspended in </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">aqueous liquid. Produced in large quantities in Ivory Coast, the local transformation of natural latex has so far remained insignificant, although some attempts have been made to use it in the manufacture of flexible facade briquettes for rounded walls. Thus, this study aims to incorporate clay as a filler in natural latex for use as an adhesive for tile installation. To do this, diffe</span><span style="font-family:Verdana;">rent proportions of clay paste were added to the natural latex and the resulting mixtures were used to make the sample and tile adhesive. From the analysis of the results obtained, it appears that the samples with a clay paste density of 0.8 and 1 absorb less water and show</span></span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> good pull-out strength. The mixtu</span><span style="font-family:""><span style="font-family:Verdana;">res of 30% and 35% latex and 0.8 </span><span><span style="font-family:Verdana;">and 1 clay paste density respectively have pullout stresses greater than 1 N/mm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">. According to</span></span><span style="font-family:Verdana;"> NF EN 1348, these adhesives can therefore be used as tile adhesive.展开更多
文摘Requirements for the respect of the environment encourage to reduce the impact of human activity on the nature. Civil engineering answers these requirements by the development of ecological construction materials. This paper deals with the transformation of clay raw materials which enable the processing of environmentally friendly construction materials: in addition to their biodegradability, the alveolar fired clay materials allow energy saving in home heating thanks to their thermal isolation properties. But their manufacturing is a high energy consumption process, in particular during compaction, drying and firing which contribute to the emission of greenhouse gases. The goal of this paper is to study the rheology of clay pastes in order to develop low energy in manufacturing processes. For this purpose, theoretical and experimental approaches were carried out on six clay varieties. In the theoretical approach, a finite element (FE) simulation model has been developed for pressing a non-rigid material predicting deformations and stresses occurring within the clay structure. Experiments have then been carried out to validate the finite element modelling. In this experimental approach, the clay pastes were transformed with water content respecting the Atterberg limits which determine the plasticity of clays. The samples compaction has been carried out under variable loadings in order to determine the suitable low energy consumption loading.
文摘<div style="text-align:justify;"> <span style="font-family:Verdana;">The use of vegetable fibers composites in structures sometimes presents significant fires risks because of their high flammability. This work aims to study the impact of the addition of mineral filler (clay) on the fire behaviour of wood-polystyrene composites and their mechanical properties. Thus, composites containing 25% of expanded polystyrene binder have been produced. On this base material, proportions of clay ranging from 0% to 15% were gradually added. These samples were elaborated by compaction and for some them, submitted to thermoforming after drying. Both kinds of sample were subjected to flame persistence test;flexural strength and compressive strength test were also measured. The results show that composites without mineral filler ignite continuously until the total consumption and when the mineral filler content increases the combustion time decreases. The addition of the mineral filler allows these composites to pass from class M3 of moderately flammable combustible materials to class M2 of hardly flammable materials, according to the M classification of construction and furnishing materials. The measurement of the mechanical properties shows that the strengths increase when the filler content goes from 0% to 10% and then decrease. This leads to set the optimum content of mineral filler around 10%.</span> </div>
文摘Natural rubber latex is </span><span style="font-family:Verdana;">the </span><span style="font-family:Verdana;">white liquid in the form of </span><span style="font-family:Verdana;">the</span><span style="font-family:Verdana;"> colloidal dispersion of rubber globules suspended in </span><span style="font-family:Verdana;">the </span><span style="font-family:""><span style="font-family:Verdana;">aqueous liquid. Produced in large quantities in Ivory Coast, the local transformation of natural latex has so far remained insignificant, although some attempts have been made to use it in the manufacture of flexible facade briquettes for rounded walls. Thus, this study aims to incorporate clay as a filler in natural latex for use as an adhesive for tile installation. To do this, diffe</span><span style="font-family:Verdana;">rent proportions of clay paste were added to the natural latex and the resulting mixtures were used to make the sample and tile adhesive. From the analysis of the results obtained, it appears that the samples with a clay paste density of 0.8 and 1 absorb less water and show</span></span><span style="font-family:Verdana;">s</span><span style="font-family:Verdana;"> good pull-out strength. The mixtu</span><span style="font-family:""><span style="font-family:Verdana;">res of 30% and 35% latex and 0.8 </span><span><span style="font-family:Verdana;">and 1 clay paste density respectively have pullout stresses greater than 1 N/mm</span><sup><span style="font-family:Verdana;">2</span></sup><span style="font-family:Verdana;">. According to</span></span><span style="font-family:Verdana;"> NF EN 1348, these adhesives can therefore be used as tile adhesive.
