A new technique has been developed to prepare woodceramics with the raw material of wheat straws.The partial properties of woodceramics such as the remains of carbon, the density, the porosity, the bending strength, a...A new technique has been developed to prepare woodceramics with the raw material of wheat straws.The partial properties of woodceramics such as the remains of carbon, the density, the porosity, the bending strength, and resistivity are tested at the same time. Systematic analyses of the material properties, the forming mechanism, and the regularity of woodceramics are made. The effects of the formula of raw materials, the consistencies of phenol resin, and the temperature, on the technique and the properties of woodceramics are displayed. It is shown that wheat straws can be used to produce woodceramics with this technique. The presented work provides useful ideas for the study of the preparation of woodceramics.展开更多
There is the challenge to use materials in a more sustainable way.Even though cork has an interesting eco-profile as a material,other aspects contributing to an enhanced sustainable use of the resource are discussed:a...There is the challenge to use materials in a more sustainable way.Even though cork has an interesting eco-profile as a material,other aspects contributing to an enhanced sustainable use of the resource are discussed:addressing the life-span of products,materials substitution,and the trend of materials development identified.展开更多
Currently, in a context of sustainable development, the economic and environmental challenges incite, to valorize local materials such as clays and agro-industrial waste. It is in this approach that a new category of ...Currently, in a context of sustainable development, the economic and environmental challenges incite, to valorize local materials such as clays and agro-industrial waste. It is in this approach that a new category of compressed earth bricks (BTC) stabilized with shea meal (TK) and cement was proposed. The purpose of this paper is to investigate the effect of shea meal rate on the thermal conductivity properties of cement stabilized earth bricks. A lateritic clay (Lat) mainly composed of kaolinite (38.44%), quartz (24.94%), goethite (12.28%), hematite (4.44%) and illite (19.9%) was used to make bricks. Different mix designs made up of lateritic clay and 5% cement were studied. The shea meal is added as a partial lateritic clay replacement in different proportions. The thermal conductivity was determined by hot disk method and correlated to both porosity and density of elaborated materials. The results obtained show that the thermal conductivity and density of bricks decrease respectively from 0.72 W·m-1·K-1 to 0.52 W·m-1·K-1 and from 2.77 g·cm-3 to 2.52 g·cm-3. The presence of shea meal within the material generates pore formation, which may partly explain the improvement of the thermal insulation properties. A positive correlation was noted between density and thermal conductivity of these materials.展开更多
The approach that contributes to the development of eco-materials in construction is the use of mineral powders,which can improve mechanical properties and reduce cement consumption.This article aims to study th...The approach that contributes to the development of eco-materials in construction is the use of mineral powders,which can improve mechanical properties and reduce cement consumption.This article aims to study the effect of substitution by mass of cement with mineral powders on the physicomechanical properties and microstructure of sand concretes.The used mineral powders are A:the limestone,B:the natural pozzolan,C:the hydraulic lime,D:(1/3 limestone+1/3 natural pozzolan+1/3 hydraulic lime),and E:(1/2 natural pozzolan+1/2 hydraulic lime).The studied percentages are 5%,10%and 15%,in both separated and combined states.The studied properties are workability,compressive strength,the elasticity modulus in compression,shrinkage and microstructure analysis.The objective is to target the optimal percentage of the substitution of cement with mineral powders,which ensures the best compromise between the main properties of the studied sand concretes.The obtained results show that the optimal percentage is in favor of the substitution of cement by 10%D(1/3 limestone,1/3 natural pozzolan and 1/3 hydraulic lime).Even the 15%of mineral powder D,presented similar performances compared to the sand concrete(without mineral powders).Finally,in the context of the development of eco-materials,it should be noted that the 10%D and 15%D(1/3 limestone,1/3 natural pozzolan and 1/3 hydraulic lime)contribute to decrease the use of cement and consequently to reduce of CO2 emissions.展开更多
基金Supported by the item of innovating group of Hefei university of technology.
文摘A new technique has been developed to prepare woodceramics with the raw material of wheat straws.The partial properties of woodceramics such as the remains of carbon, the density, the porosity, the bending strength, and resistivity are tested at the same time. Systematic analyses of the material properties, the forming mechanism, and the regularity of woodceramics are made. The effects of the formula of raw materials, the consistencies of phenol resin, and the temperature, on the technique and the properties of woodceramics are displayed. It is shown that wheat straws can be used to produce woodceramics with this technique. The presented work provides useful ideas for the study of the preparation of woodceramics.
基金the Portuguese Foundation for Science and Technology (FCT reference:SFRH/BD/46646/2008)
文摘There is the challenge to use materials in a more sustainable way.Even though cork has an interesting eco-profile as a material,other aspects contributing to an enhanced sustainable use of the resource are discussed:addressing the life-span of products,materials substitution,and the trend of materials development identified.
文摘Currently, in a context of sustainable development, the economic and environmental challenges incite, to valorize local materials such as clays and agro-industrial waste. It is in this approach that a new category of compressed earth bricks (BTC) stabilized with shea meal (TK) and cement was proposed. The purpose of this paper is to investigate the effect of shea meal rate on the thermal conductivity properties of cement stabilized earth bricks. A lateritic clay (Lat) mainly composed of kaolinite (38.44%), quartz (24.94%), goethite (12.28%), hematite (4.44%) and illite (19.9%) was used to make bricks. Different mix designs made up of lateritic clay and 5% cement were studied. The shea meal is added as a partial lateritic clay replacement in different proportions. The thermal conductivity was determined by hot disk method and correlated to both porosity and density of elaborated materials. The results obtained show that the thermal conductivity and density of bricks decrease respectively from 0.72 W·m-1·K-1 to 0.52 W·m-1·K-1 and from 2.77 g·cm-3 to 2.52 g·cm-3. The presence of shea meal within the material generates pore formation, which may partly explain the improvement of the thermal insulation properties. A positive correlation was noted between density and thermal conductivity of these materials.
文摘The approach that contributes to the development of eco-materials in construction is the use of mineral powders,which can improve mechanical properties and reduce cement consumption.This article aims to study the effect of substitution by mass of cement with mineral powders on the physicomechanical properties and microstructure of sand concretes.The used mineral powders are A:the limestone,B:the natural pozzolan,C:the hydraulic lime,D:(1/3 limestone+1/3 natural pozzolan+1/3 hydraulic lime),and E:(1/2 natural pozzolan+1/2 hydraulic lime).The studied percentages are 5%,10%and 15%,in both separated and combined states.The studied properties are workability,compressive strength,the elasticity modulus in compression,shrinkage and microstructure analysis.The objective is to target the optimal percentage of the substitution of cement with mineral powders,which ensures the best compromise between the main properties of the studied sand concretes.The obtained results show that the optimal percentage is in favor of the substitution of cement by 10%D(1/3 limestone,1/3 natural pozzolan and 1/3 hydraulic lime).Even the 15%of mineral powder D,presented similar performances compared to the sand concrete(without mineral powders).Finally,in the context of the development of eco-materials,it should be noted that the 10%D and 15%D(1/3 limestone,1/3 natural pozzolan and 1/3 hydraulic lime)contribute to decrease the use of cement and consequently to reduce of CO2 emissions.
