Jian Yang, Xiaoli Li^*, Hui Wang, Kaiqiang Geng

Journal of Renewable Materials, Vol.9, No.12, pp. 2241-2260, 2021, DOI:10.32604/jrm.2021.015565

Abstract In the present study, in order to investigate the effects of fly ash on the structural evolution and strength damage mechanism of Pisha-sandstone cement soil, unconfined compressive strength tests of Pisha-sandstone cement soil with different fly ash content levels and various ages were carried out. The apparent morphology, microstructures, and chemical compositions of the samples were observed and analyzed using ultra-depth three-dimensional microscopy, scanning electron microscopy, and XRD methods. The results revealed that the unconfined compressive strength levels of Pisha-sandstone cement soil samples displayed increasing trends with the increases in fly ash content and age. For example, when the fly… 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

Shengquan Zhou¹, Minjie Shi^1,*, Wei Chen¹, Yongfei Zhang¹, Weijian Wang¹, Haojin Zhang¹, Dongwei Li²

Journal of Renewable Materials, Vol.9, No.11, pp. 1941-1957, 2021, DOI:10.32604/jrm.2021.015693

Abstract The characteristics of soil treated with cationic polyacrylamide (CPAM) mass content of 0%, 0.2%, 0.4%, 0.6%, 0.8%, and 1% were investigated through a series of laboratory tests to explore the practical engineering effect of an expansive soil amended with environmental protection material CPAM. The results indicate that with the increasing CPAM content, the liquid limit and plasticity index of soil decrease, the plastic limit increases, and the free swelling ratio and loaded swelling ratio decrease. Besides, the improved soil has less disintegrating property and better water stability. The shear strength increases as the content increases, and the optimal content is… More > Graphic Abstract

Jiongzhi Yang, Srivatsa Harish, Candy Li, Hengduo Zhao, Brittney Antous, Pinar Acar^*

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 1285-1302, 2021, DOI:10.32604/cmc.2021.016829

Abstract This paper presents a de-novo computational design method driven by deep reinforcement learning to achieve reliable predictions and optimum properties for periodic microstructures. With recent developments in 3-D printing, microstructures can have complex geometries and material phases fabricated to achieve targeted mechanical performance. These material property enhancements are promising in improving the mechanical, thermal, and dynamic performance in multiple engineering systems, ranging from energy harvesting applications to spacecraft components. The study investigates a novel and efficient computational framework that integrates deep reinforcement learning algorithms into finite element-based material simulations to quantitatively model and design 3-D printed periodic microstructures. These algorithms… More >

Anh Tuan Hoang¹, Xuan Phuong Nguyen², Osamah Ibrahim Khalaf³, Thi Xuan Tran⁴, Minh Quang Chau⁵, Thi Minh Hao Dong², Duong Nam Nguyen^6,*

CMC-Computers, Materials & Continua, Vol.68, No.1, pp. 1129-1145, 2021, DOI:10.32604/cmc.2021.015349

Abstract The type of technology used to strengthen the surface structure of machine parts, typically by carbon-permeation, has made a great contribution to the mechanical engineering industry because of its outstanding advantages in corrosion resistance and enhanced mechanical and physical properties. Furthermore, carbon permeation is considered as an optimal method of heat treatment through the diffusion of carbon atoms into the surface of alloy steel. This study presented research results on the thermodynamic calculation and simulation of the carbon permeability process. Applying Fick’s law, the paper calculated the distribution of carbon concentration in the alloy steel after it is absorbed from… More >

Zhihang Wang^1,*, Jinyu Xu^1,2, Xin Meng¹, Conigjin Zhu¹

Journal of Renewable Materials, Vol.9, No.6, pp. 1157-1168, 2021, DOI:10.32604/jrm.2021.014878

Abstract In this paper, the specimens of polymer-cement composites after 1 d, 7 d, 15 d, and 30 d aging without aging and UV aging are subjected to fixed extension test and tensile test. By observing the mode of the composite in the fixed-elongation test, and measuring the elastic recovery rate, tensile strength, elongation at break, peak tensile strain, tensile toughness and pre-peak tensile toughness of the composite, the effects of UV aging on the bonding and the tensile properties of the composite were studied. And combining with scanning electron microscopy experiments, the micro-mechanism of the effect of ultraviolet aging on… More >

Thi Xuan Tran¹, Xuan Phuong Nguyen², Duong Nam Nguyen³, Dinh Toai Vu¹, Minh Quang Chau⁴, Osamah Ibrahim Khalaf⁵, Anh Tuan Hoang^6,*

CMC-Computers, Materials & Continua, Vol.67, No.3, pp. 3249-3264, 2021, DOI:10.32604/cmc.2021.015411

Abstract Currently, the 65Mn steel is quenched mainly by oil media. Even though the lower cooling rate of oil compared to water reduces the hardness of steel post quenching, the deforming and cracking of parts are often minimized. On the other hand, the oil media also has the disadvantage of being flammable, creating smoke that adversely affects the media. The poly alkylene glycol (PAG) polymer quenchant is commonly used for quenching a variety of steels based on its advantages such as non-flammability and flexible cooling rate subjected to varying concentration and stirring speed. This article examines the effect of PAG polymer… More >

Mateusz Barczewski^1,*, Jacek Andrzejewski^1,*, Radomir Majchrowski², Kamil Dobrzycki¹, Krzysztof Formela³

Journal of Renewable Materials, Vol.9, No.5, pp. 841-853, 2021, DOI:10.32604/jrm.2021.014490

Abstract Agricultural waste is a still untapped source of materials that can, in case of proper utilization, significantly improve the sustainability of polymers and their composites. In this work, polymer composites based on isotactic polypropylene were produced incorporating ground sunflower husk in the amount of 10 wt% and 20 wt%. The work’s main objective is to evaluate how preliminary fractioning of this agricultural waste filler affects the thermomechanical properties, microstructure and surface topology of polypropylene-based injection molded composites. The composites were analyzed for mechanical properties (tensile, impact strength and hardness), thermomechanical properties (Vicat softening point VST, heat deflection temperature HDT, and… More >

Huazhe Jiao^1,2, Yachuang Wu¹, Wei Wang^2,*, Xinming Chen¹, Yunfei Wang¹, Juanhong Liu³, Wentao Feng⁴

Journal of Renewable Materials, Vol.9, No.4, pp. 637-650, 2021, DOI:10.32604/jrm.2021.014310

Abstract Higher concentration is beneficial for the Paste and Thickened Tailings (PTT) operation in metal mine. Partial paste thickeners are produced lower density underflow. Flocculated tailings are intended to form a water entrapped network structure in thickener, which is detrimental to underflow concentration. In this study, the continuous thickening experiment was carried out for ultra-fine tungsten tailings to study the influence of rake shearing on underflow. The micro pores structure and seepage flow in tailings bed before and after shearing are studied by CT and simulation approach to reveal the shearing enhancement mechanism of thickening process. The results shown that, the… More >

Kai Long^1,*, Xiaoyu Yang¹, Nouman Saeed¹, Zhuo Chen¹, Yi Min Xie²

CMES-Computer Modeling in Engineering & Sciences, Vol.126, No.1, pp. 293-310, 2021, DOI:10.32604/cmes.2021.012734

Abstract A methodology for achieving the maximum bulk or shear modulus in an elastic composite composed of two isotropic phases with distinct Poisson’s ratios is proposed. A topology optimization algorithm is developed which is capable of nding microstructures with extreme properties very close to theoretical upper bounds. The effective mechanical properties of the designed composite are determined by a numerical homogenization technique. The sensitivities with respect to design variables are derived by simultaneously interpolating Young’s modulus and Poisson’s ratio using different parameters. The so-called solid isotropic material with penalization method is developed to establish the optimization formulation. Maximum bulk or shear… More >