Jinfa Jiang¹, Long Xiong², Ming Bao², Zihan Zhou^2,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.8, pp. 1983-1995, 2023, DOI:10.32604/fdmp.2023.026023

Abstract Reasonable treatment and utilization of waste residuals discharged during the production of ready-mixed concrete is an important problem in the cement industry. In this study, a composite admixture was prepared by using ready-mixed concrete waste residuals, furnace slag, and water granulated slag. The grinding characteristics of such material were investigated. Moreover, the effect of such admixture on cement hydration and pore structure was analyzed by X-ray diffraction, thermogravimetric-differential scanning calorimetry, scanning electron microcopy and mercury intrusion porosimetry. As shown by the results: The grinding characteristics of the waste residuals can be improved significantly by mixing them with furnace slag and… More > Graphic Abstract

Yonggan Yang^1,2,3,4, Zihao Kang¹, Binggen Zhan^1,3,*, Peng Gao^1,3,*, Qijun Yu¹, Yanlai Xiong⁴, Jingfeng Wang^1,3, Yunsheng Zhang⁵

Journal of Renewable Materials, Vol.11, No.4, pp. 1895-1910, 2023, DOI:10.32604/jrm.2023.025059

Abstract In this paper, the effects of different mineral admixtures and sulfate solution types on the appearance, mass change rate, relative dynamic elastic modulus, and corrosion resistance coefficient of concrete were systematically studied. X-ray Diffraction (XRD), Mercury Intrusion Porosimetry (MIP), Scanning Electron Microscopy (SEM), and X-ray Computed Tomography (X-CT) were used to explore and analyze the changes in the microstructure and the corrosion products of concrete in the sulfate solution. The results show that the existence of magnesium ions accelerates concrete deterioration. There is a critical dosage of fly ash for magnesium sulfate resistance of concrete. The magnesium sulfate resistance of… More > Graphic Abstract

Zhihai He^1,2, Menglu Shen¹, Jinyan Shi^3,*, Jingyu Chang¹, Víctor Revilla-Cuesta⁴, Osman Gencel⁵

Journal of Renewable Materials, Vol.11, No.4, pp. 1835-1852, 2023, DOI:10.32604/jrm.2023.024887

Abstract Recycling solid waste in cement-based materials cannot only ease its load on the natural environment but also reduce the carbon emissions of building materials. This study aims to investigate the effect of recycled glass powder (RGP) on the early-age mechanical properties and autogenous shrinkage of cement pastes, where cement is replaced by 10%, 20% and 30% of RGP. In addition, the microstructure and nano-mechanical properties of cement paste with different RGP content and water to binder (W/B) ratio were also evaluated using SEM, MIP and nanoindentation techniques. The results indicate that the early-age autogenous shrinkage decreases with the increase of… More > Graphic Abstract

Mengqi Cong^*, Yang Zhang, Yunlong Zhang, Xiao Liu, Yalin Lu, Xiaoping Li

Journal of Renewable Materials, Vol.11, No.4, pp. 1977-1989, 2023, DOI:10.32604/jrm.2023.023849

Abstract Magnesium alloy has been considered as one of the third-generation biomaterials for the regeneration and support of functional bone tissue. As a regeneration implant material with great potential applications, in-situ Mg₂Si phase reinforced Mg-6Zn cast alloy was comprehensively studied and expected to possess excellent mechanical properties via the refining and modifying of Mg₂Si reinforcements. The present study demonstrates that the primary and eutectic Mg₂Si phase can be greatly modified by the yttrium (Y) addition. The size of the primary Mg₂Si phases can be reduced to ~20 μm with an addition of 0.5 wt.% Y. This phenomenon is mainly attributed to… More > Graphic Abstract

Wei Chen^1,*, Weijie Shan¹, Yue Liang¹, Frederic Skoczylas²

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.3, pp. 679-696, 2023, DOI:10.32604/fdmp.2022.021249

Abstract This study deals with the analysis of the detrimental effects of a “sulfate attack” on cement mortar for different dry-wet cycles. The mass loss, tensile strength, and gas permeability coefficient were determined and analyzed under different exposure conditions. At the same time, nitrogen adsorption (NAD), scanning electron microscopy (SEM), and X-ray diffraction (XRD) techniques were used to analyze the corresponding variations in the microstructure and the corrosion products. The results show that certain properties of the cement mortar evolve differently according to the durations of the dry-wet cycles and that some damage is caused to the mortars in aqueous solution.… More >

Zhiqiang Wu^1,2, Yi Wu², Renjun Xie², Jin Yang¹, Shujie Liu³, Qiao Deng^4,*

FDMP-Fluid Dynamics & Materials Processing, Vol.19, No.2, pp. 399-406, 2023, DOI:10.32604/fdmp.2022.020402

Abstract One of the main obstacles hindering the exploitation of high-temperature and high-pressure oil and gas is the sealing integrity of the cement sheath. Analyzing the microstructure of the cement sheath is therefore an important task. In this study, the microstructure of the cement sheath is determined using a CT scanner under different temperature and pressure conditions. The results suggest that the major cause of micro-cracks in the cement is the increase in the casing pressure. When the micro-cracks accumulate to a certain extent, the overall structure of the cement sheath is weakened, resulting in gas channeling, which poses a direct… More >

Xinli Zhang¹, Jiayu Zhang¹, Zuhua Zhang^2,*, Yiqiang Wu^1,*, Yingfeng Zuo¹

Journal of Renewable Materials, Vol.11, No.1, pp. 27-40, 2023, DOI:10.32604/jrm.2023.023400

Abstract Geopolymer is a new alternative cement binder to produce concrete. In the present study, a novel geopolymer composites containing bamboo shaving (0–2 wt.%) were fabricated and exposed to the temperatures of 200°C, 400°C, 600°C and 800°C. Physical properties, micro-structure, and mechanical strengths of the geopolymer composites were evaluated before and after heating in order to understand their thermal properties, which are essential for the use as building materials. As the temperature rises, the drying shrinkage and apparent porosity of the composites increase, while the compressive and bending strengths decrease. At the temperature range of 200°C–800°C, the residual compressive strength rates of… More >

Yubo Zhang, Ping Lei, Lina Wang, Jiqing Yang^*

Journal of Renewable Materials, Vol.11, No.1, pp. 393-410, 2023, DOI:10.32604/jrm.2022.022659

Abstract In this paper, a split Hopkinson pressure bar (SHPB) was used to investigate the dynamic impact mechanical behavior of sisal fiber-reinforced cement-based composites (SFRCCs), and the microscopic damage evolution of the composites was analyzed by scanning electron microscopy (SEM) and energy-dispersive X-ray spectrometry (EDS). The results show that the addition of sisal fibers improves the impact resistance of cement-based composite materials. Compared with ordinary cement-based composites (OCCs), the SFRCCs demonstrate higher post-peak strength, ductility, and energy absorption capacity with higher fiber content. Moreover, the SFRCCs are strain rate sensitive materials, and their peak stress, ultimate strain, and energy integrals all… More >

Jundong Yin¹, Lei Wang¹, Baoyin Zhu², Guodong Zhang², Dongfeng Li^1,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-3, 2022, DOI:10.32604/icces.2022.08750

Abstract High performance martensitic heat resistant steels are widely used in fossil fuel power plant industry due to because of their good creep resistance at high temperatures. In-depth understanding of the high temperature inelastic deformation mechanism of such steels is crucial to ensure the reliable, safe and efficient operation of the power plant [1]. The martensitic steels have a complex microstructure with a hierarchical arrangement, including a collection of packets in the prior austenite grain, blocks in the packet and laths along with dispersed nanoscale strengthening phases (e.g., MX precipitates and carbides). The purpose of this paper is to study the… More >

Daniel Varadaradjou^1,*, Hocine Kebir¹, Jérôme Mespoulet², David Tingaud³, Salima Bouvier¹, Paul Deconick², Kei Ameyama⁴, Guy Dirras^3,*

The International Conference on Computational & Experimental Engineering and Sciences, Vol.24, No.1, pp. 1-3, 2022, DOI:10.32604/icces.2022.08673

Abstract The development of new architecture metallic alloys with controlled microstructures is one of the strategic ways for designing materials with high innovation potential and, particularly with improved mechanical properties as required for structural materials [1]. Indeed, unlike conventional counterparts, metallic materials having so-called harmonic structure displays strength and ductility synergy. The latter occurs due to a unique microstructure design: a coarse grain structure surrounded by a 3D continuous network of ultra-fine grain known as “core” and “shell”, respectively. In the present study, pure harmonic-structured (HS) Nickel samples were processed via controlled mechanical milling and followed by spark plasma sintering (SPS),… More >