Xue Xin^1,#, Yu Rong^1,#, Linping Su¹, Zhengmei Qiu¹, Chenjun Yang¹, Ming Liang^1,*, Ping Ji², Guoqiang Zhong³, Zhanyong Yao^1,*

Journal of Renewable Materials, Vol.10, No.4, pp. 1081-1095, 2022, DOI:10.32604/jrm.2022.018021

Abstract As the important matrix material, epoxy resin has been widely used in the composites for various fields. On account of the poor toughness of epoxy resin limiting their suitability for advanced applications, considerable interests have been conducted to modify the epoxy resin to meet the engineering requirements. In this study, the bio-based polyurethane (PU) modified resin was adopted to modify the pure bisphenol-A epoxy by blending method with various proportions. Aiming to illuminate the curing behavior, mechanical and thermal properties, the blended epoxy systems were characterized by viscosity-time analysis, dynamic mechanical analysis (DMA) at different frequencies and temperatures, mechanical tensile… More >

Daiyuan Zhang¹, Qian He², Baocong Du², Junbao Yu^2,3, Xudong Zhu³, Dingyi Yang², Shengcai Li², Tianyi Zhan¹, Liming Shen^1,*, Zhiqiang Wang^1,*, Xiaoning Lu¹

Journal of Renewable Materials, Vol.10, No.3, pp. 721-734, 2022, DOI:10.32604/jrm.2022.016793

Abstract Permeability of wood preservative is one of the most significant factors for protection of wood construction. Anisotropic flow permeability was involved in different directions of wood with higher flow resistance in the transverse and lower longitudinal directions. In this study, boron acid solution was brushed onto the tangential section of air-dried wood cubes and boron penetration along wood transverse direction was investigated under free diffusion, vacuum and HVEF treatments. Multi-scale boron distribution, FTIR measurement, leaching property, mechanical properties and fungistatic characteristic were investigated for free diffusion, vacuum and HVEF treated samples respectively. The results revealed that boron exhibited high permeability… More >

Yousef Y. Sewar¹, Zhancheng Zhang¹, Xinmiao Meng^1,*, Mohammed Y. Wahan¹, Hanxiao Qi^1,2, Qahtan M. Al-Shami^1,3, Shijiao Luo¹

Journal of Renewable Materials, Vol.10, No.1, pp. 219-235, 2022, DOI:10.32604/jrm.2021.016013

Abstract Engineered bamboo has recently received lots of attention of civil engineers and professional researchers due to its better mechanical performance than that of softwood timber. Parallel strand bamboo is one important part of engineered bamboo for its excellent durable performance compared to the laminated veneer bamboo. The required curing temperature in hot-pressing process is usually higher than 120°C to reduce the content of nutritional ingredients and hemy cellulose, and to avoid the decay from the environment and insects. Nonetheless, the appearance of engineered bamboo gets darker with the increase of temperature during the hot-pressing process. In order to minimize the… More > Graphic Abstract

Xi Chen^1,2, Ying Li^1,2,*, Hualei Bai^1,2, Liyuan Ma^1,2

Journal of Renewable Materials, Vol.9, No.12, pp. 2189-2208, 2021, DOI:10.32604/jrm.2021.015394

Abstract Recycled concrete powder (RCP) is used more and more in cement-based materials, but its influence on the hydration process is still unclear. Therefore, this paper studied the influence of recycled concrete powder (RCP) on the hydration process of cement and provides a theoretical basis for the hydration mechanism of cement composite materials. The hydration heat method was used to systematically analyze the thermal evolution process of cement paste with or without RCP. Hydration products were identified using X-ray diffraction (XRD) and thermal analysis (TG–DSC). The pore structure change of cement pastes was analyzed by mercury intrusion porosimetry (MIP) method. The… More > Graphic Abstract

Lei Guo^1,2,3,4, Pingping Chen¹, Lixia Guo^1,2,3,*, Zhilong Xue⁴, Zi Guan¹, Mingru Li¹

Journal of Renewable Materials, Vol.9, No.10, pp. 1805-1819, 2021, DOI:10.32604/jrm.2021.015140

Abstract In order to explore the relationship between the macroscopic properties and pore structure characteristics of baking-free slag-sludge bricks, the compressive strength and water absorption rate using aluminum industrial slag and sludge of different substitution rates were tested. Optical instruments and image analysis software were used to measure the parameters of the pore structure. Specifically, a fractal model was built based on the fractal theory, in which the fractal dimension was used as the characteristic index of the pore structure to analyze the correlation and interaction mechanism between the fractal dimension and the macroscopic mechanical properties. Based on this study, conclusions… More >

Yichen Lu¹, Zongning Chen¹, Enyu Guo^1,*, Xiangqing Kong², Huijun Kang¹, Yanjin Xu³, Rengeng Li⁴, Guohua Fan⁴, Tongmin Wang^1,*

CMES-Computer Modeling in Engineering & Sciences, Vol.127, No.2, pp. 705-720, 2021, DOI:10.32604/cmes.2021.015426

Abstract In this study, the real 3D model of the feather shaft that is composed of medulla and cortex is characterized by X-ray computer tomography, and the structural features are quantitatively analyzed. Compression and tensile tests are conducted to evaluate the mechanical performance of the feather shaft and cortex at different regions. The analysis of the 3D model shows that the medulla accounts for ∼70% of the shaft volume and exhibits a closed-cell foam-like structure, with a porosity of 59%. The cells in the medulla show dodecahedron and decahedron morphology and have an equivalent diameter of ∼30 μm. In axial compression,… More >

Man Yuan, Lu Hong, Zehui Ju, Wenli Gu, Biqing Shu, Jianxin Cui, Xiaoning Lu^*, Zhiqiang Wang^*

Journal of Renewable Materials, Vol.9, No.8, pp. 1433-1445, 2021, DOI:10.32604/jrm.2021.015040

Abstract In this study, the effects of three different particle sizes of wood wastes (A = –8 + 12 mesh; B = –12 + 20 mesh; C = –20 + 30 mesh) and factory shavings (D) on the properties of particleboard were investigated. According to the test results, three-layer particleboard was designed. Particleboard face layers made with mixture of A, B, and C. The core layer made with D. The ratio of core layer to face layers is 50:50. Three-layer particleboard were fabricated with 12% urea-formaldehyde (UF) resins and three different high voltage electrostatic field intensities (0 kv, 30 kv, 60… More >

Zhenhua Duan, Nv Han, Amardeep Singh, Jianzhuang Xiao^*

Journal of Renewable Materials, Vol.8, No.11, pp. 1375-1390, 2020, DOI:10.32604/jrm.2020.013044

Abstract Recycled aggregates (RA) are frequently obtained from various unknown sources, which caused variation in properties among recycled aggre- gates concrete (RAC). This paper investigated the macro and microscopic proper- ties of RAC prepared with RAs originated from different parent concretes with 90-day strength ranging from 30 MPa to 100 MPa. These parent concretes were prepared in advance and crushed to produce RA of distinct qualities. The attached mortar content can reach up to 69% in the concrete with highest strength grade. The microscopic investigation on different RAC was conducted with the X-ray Micro-Computed Tomography scanning technique and image process. Experi-… More >

Dan Li¹, Li Ding¹, Zhengang Liu², Qiang Li³, Kaiyun Guo¹, Hailin Cao^1,4,*

CMES-Computer Modeling in Engineering & Sciences, Vol.125, No.1, pp. 145-171, 2020, DOI:10.32604/cmes.2020.010822

Abstract Carbon nanotube (CNT)-reinforced composites have ultra-high elastic moduli, low densities, and fibrous structures. This paper presents the multi-scale finite element modeling of CNT-reinforced polymer composites from micro- to macro-scales. The nanocomposites were modeled using representative volume elements (RVEs), and finite element code was written to simulate the modeling and loading procedure and obtain equivalent mechanical properties of the RVEs with various volume fractions of CNTs, which can be used directly in the follow-up simulation studies on the macroscopic model of CNT-reinforced nanocomposites. When using the programming to simulate the deformation and fracture process of the CNT-reinforced epoxy composites, the mechanical… More >

Kang He¹, Yu Chen^1,*, Jian Wang²

Journal of Renewable Materials, Vol.8, No.8, pp. 969-992, 2020, DOI:10.32604/jrm.2020.09573

Abstract The behaviour of timber columns subjected to freeze-thaw cycles under axial compression is presented in this paper. A total of forty specimens, including twenty circular timber columns and twenty square timber columns, were tested under axial compression. The failure modes, ultimate bearing capacity, ductility coefficient, load-displacement curves and load-strain curves were obtained and analyzed. The number of freeze-thaw cycles (from 0 to 80) and the specimens’ height (from 225 mm to 360 mm) were considered as the main parameters. After freeze-thaw cycles, there was no obvious change on the surface of the timber columns. The test results showed that freeze-thaw… More >