This study tackles current environmental challenges by developing innovative and eco-friendly particle boards utilizing sorghum husk, combined with recycled expanded polystyrene (EPS). This dual eco-responsible approa...This study tackles current environmental challenges by developing innovative and eco-friendly particle boards utilizing sorghum husk, combined with recycled expanded polystyrene (EPS). This dual eco-responsible approach valorizes sorghum husk, often deemed agricultural waste, and repurposes EPS, a plastic waste, thus contributing to CO2 emission reduction and effective waste management. The manufacturing process involves dissolving recycled polystyrene within a solvent to create a binder, which is then mixed with sorghum husk and cold-pressed into composite boards. The study explores the impact of two particle sizes (fine and coarse) and two different concentrations of the recycled EPS binder. Results demonstrate significant variations in the boards’ mechanical properties, displaying a range of Modulus of Rupture (MOR) from 0.84 MPa to 3.85 MPa, and Modulus of Elasticity (MOE) spanning from 658.13 MPa to 1313.25 MPa, influenced by the binder concentration and particle size. These characteristics suggest that the boards can be effectively used in various construction applications, including interior decoration, false ceilings, and potentially for furniture and door manufacturing when combined with appropriate coatings. This study not only exemplifies the valorization of plastic and agricultural wastes but also offers a practical, localized solution to global climate change challenges by promoting sustainable construction materials.展开更多
Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are present...Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are presented,including the freeze-cut-drying method of preparing samples for scanning electronic microscopy (SEM),the SEM image processing technique and quantifying analysis method of the SEM images,and etc.The aggregates and pores in SEM images are identified using the different mathematics operators,and their effects are compared.The areas of aggregates and pores are obtained using the operator of morphology,and the influences of different thresholds in image segmentation are also discussed.The results show that the method,in which the variation of non-maximum grey-level gradient is limited,improves the effect of edge detections due to a weak distinction existing at the edge between the aggregates and pores in image.The determination of the threshold should combine the image characteristic with filling operation,so as to assure the precision of the image analysis,in which the contact-segmentation is the simplest and most effective method.The results also show that the pore areas in eco-materials are generally larger than those in the correlative soils,and their increment is large as soil fabric being fine.These differences are related to admixture of expansive perlitic.The operator of morphology provides a new method for the image analysis of other porous material microstructure such as soils and concretes.展开更多
The eco-material composition is not well-distributed in preparation. The eco-material samples were taken for computer image analysis, and its particle numbers and appearance parameters were measured. Based on the mech...The eco-material composition is not well-distributed in preparation. The eco-material samples were taken for computer image analysis, and its particle numbers and appearance parameters were measured. Based on the mechanism of connective mixing and diffusion, the particles distribution was simulated by a computer using the random walk with Levy flight. The results show that the eco-material microstructure simulated by a computer has an idealized porous structure. The particles distribution has a cluster characteristic that changes with the different size and number of particles in Levy flight trajectory. Each cluster consists of a collection of clusters and shows a structure of self-similar cluster,hence presents a well-defined fractal property. The results obtained from SEM observation are in good agreement with the numerical simulations, and show that the convective mixing presents in the Levy flight walk.展开更多
This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obt...This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obtained from geotechnical and mineralogical tests have shown that the clay samples Aga and Bak are fine soils moderately plastic class A soils consisting essentially of quartz with 73.13% and 74.56% respectively for Aga and Bak and clay minerals (kaolinite and illite) with 12.73% kaolinite and 8.55% illite for Aga against 8.31% kaolinite and 13.72% for Bak. Moreover, these samples do not contain swelling clays and contain a sufficient quantity of iron oxides which allows them to be valued in ceramics, in particular in compressed earth bricks (CEB).展开更多
In the Loess Plateau in Northern China,repeated freeze–thaw(FT)cycles deteriorate the strength and structure of loess as a foundation soil,resulting in the instability or failure of supporting structure.Lignosulfonat...In the Loess Plateau in Northern China,repeated freeze–thaw(FT)cycles deteriorate the strength and structure of loess as a foundation soil,resulting in the instability or failure of supporting structure.Lignosulfonate is an eco–material,utilized as an effective and nontraditional stabilizer to improve the engineering properties of metastable soils.A series of laboratory tests,including unconfined compression tests,cyclic loading–unloading tests and scanning electron microscopy,on calcium lignosulfonate(CL)-and sodium lignosulfonate(SL)-stabilized loess were performed to investigate the stabilization effect,deterioration mechanisms of the FT cycles,and the resistance to FT cycles.Two traditional stabilizers,quicklime(QL)and sodium silicate(SS),were selected,and the engineering properties of QL-and SS-stabilized loess were compared with those of CL-and SLstabilized loess.The results showed that the strength values of CL-and SL-stabilized loess specimens decreased by 34.2%and 50%respectively,after 20 FT cycles,whereas those of the traditionally SS-and QL-stabilized specimens decreased by 85.3%and 82.87%,respectively.The elastic moduli of SL-and QL-stabilized loess specimens decreased by 22.1%and 92.0%,respectively.The mean energy dissipations of nontraditionally treated specimens also decreased significantly less than those of traditionally treated specimens.Overall,the results showed CL and SL had better stabilization effects on engineering properties of loess than QL and SS,and their stabilized loess specimens exhibited stronger resistance to FT cycles.The study findings demonstrated the significant potential of lignosulfonate for extensive application in cold loess areas.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
文摘This study tackles current environmental challenges by developing innovative and eco-friendly particle boards utilizing sorghum husk, combined with recycled expanded polystyrene (EPS). This dual eco-responsible approach valorizes sorghum husk, often deemed agricultural waste, and repurposes EPS, a plastic waste, thus contributing to CO2 emission reduction and effective waste management. The manufacturing process involves dissolving recycled polystyrene within a solvent to create a binder, which is then mixed with sorghum husk and cold-pressed into composite boards. The study explores the impact of two particle sizes (fine and coarse) and two different concentrations of the recycled EPS binder. Results demonstrate significant variations in the boards’ mechanical properties, displaying a range of Modulus of Rupture (MOR) from 0.84 MPa to 3.85 MPa, and Modulus of Elasticity (MOE) spanning from 658.13 MPa to 1313.25 MPa, influenced by the binder concentration and particle size. These characteristics suggest that the boards can be effectively used in various construction applications, including interior decoration, false ceilings, and potentially for furniture and door manufacturing when combined with appropriate coatings. This study not only exemplifies the valorization of plastic and agricultural wastes but also offers a practical, localized solution to global climate change challenges by promoting sustainable construction materials.
文摘Microstructure of the eco-material combining vegetation recovery with slope protection is important for determining plant-growing properties.Several techniques for analyzing the eco-material microstructure are presented,including the freeze-cut-drying method of preparing samples for scanning electronic microscopy (SEM),the SEM image processing technique and quantifying analysis method of the SEM images,and etc.The aggregates and pores in SEM images are identified using the different mathematics operators,and their effects are compared.The areas of aggregates and pores are obtained using the operator of morphology,and the influences of different thresholds in image segmentation are also discussed.The results show that the method,in which the variation of non-maximum grey-level gradient is limited,improves the effect of edge detections due to a weak distinction existing at the edge between the aggregates and pores in image.The determination of the threshold should combine the image characteristic with filling operation,so as to assure the precision of the image analysis,in which the contact-segmentation is the simplest and most effective method.The results also show that the pore areas in eco-materials are generally larger than those in the correlative soils,and their increment is large as soil fabric being fine.These differences are related to admixture of expansive perlitic.The operator of morphology provides a new method for the image analysis of other porous material microstructure such as soils and concretes.
文摘The eco-material composition is not well-distributed in preparation. The eco-material samples were taken for computer image analysis, and its particle numbers and appearance parameters were measured. Based on the mechanism of connective mixing and diffusion, the particles distribution was simulated by a computer using the random walk with Levy flight. The results show that the eco-material microstructure simulated by a computer has an idealized porous structure. The particles distribution has a cluster characteristic that changes with the different size and number of particles in Levy flight trajectory. Each cluster consists of a collection of clusters and shows a structure of self-similar cluster,hence presents a well-defined fractal property. The results obtained from SEM observation are in good agreement with the numerical simulations, and show that the convective mixing presents in the Levy flight walk.
文摘This study was carried out with a view to appreciate the value of clay, raw materials in eco-construction. To achieve this, we sampled two clay raw materials denoted Aga and Bak and then characterized. The results obtained from geotechnical and mineralogical tests have shown that the clay samples Aga and Bak are fine soils moderately plastic class A soils consisting essentially of quartz with 73.13% and 74.56% respectively for Aga and Bak and clay minerals (kaolinite and illite) with 12.73% kaolinite and 8.55% illite for Aga against 8.31% kaolinite and 13.72% for Bak. Moreover, these samples do not contain swelling clays and contain a sufficient quantity of iron oxides which allows them to be valued in ceramics, in particular in compressed earth bricks (CEB).
基金funded by the China’s Second Tibetan Plateau Scientific Expedition and Research(2019QZKK0905)the National Natural Science Foundation of China(Nos.41672310 and U1703244)+1 种基金the Science and Technology Major Project of Gansu Province(143GKDA007)Research Project of the State Key Laboratory of Frozen Soils Engineering(SKLFSE-ZY-20)。
文摘In the Loess Plateau in Northern China,repeated freeze–thaw(FT)cycles deteriorate the strength and structure of loess as a foundation soil,resulting in the instability or failure of supporting structure.Lignosulfonate is an eco–material,utilized as an effective and nontraditional stabilizer to improve the engineering properties of metastable soils.A series of laboratory tests,including unconfined compression tests,cyclic loading–unloading tests and scanning electron microscopy,on calcium lignosulfonate(CL)-and sodium lignosulfonate(SL)-stabilized loess were performed to investigate the stabilization effect,deterioration mechanisms of the FT cycles,and the resistance to FT cycles.Two traditional stabilizers,quicklime(QL)and sodium silicate(SS),were selected,and the engineering properties of QL-and SS-stabilized loess were compared with those of CL-and SLstabilized loess.The results showed that the strength values of CL-and SL-stabilized loess specimens decreased by 34.2%and 50%respectively,after 20 FT cycles,whereas those of the traditionally SS-and QL-stabilized specimens decreased by 85.3%and 82.87%,respectively.The elastic moduli of SL-and QL-stabilized loess specimens decreased by 22.1%and 92.0%,respectively.The mean energy dissipations of nontraditionally treated specimens also decreased significantly less than those of traditionally treated specimens.Overall,the results showed CL and SL had better stabilization effects on engineering properties of loess than QL and SS,and their stabilized loess specimens exhibited stronger resistance to FT cycles.The study findings demonstrated the significant potential of lignosulfonate for extensive application in cold loess areas.
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.
