Lixia Guo^1,2,3, Weikai Wang¹, Ling Zhong^1,2,3,*, Yuhang Guo¹

Journal of Renewable Materials, Vol.11, No.1, pp. 423-434, 2023, DOI:10.32604/jrm.2022.022942

Abstract Based on the high sulfur content in titanium gypsum, the concept of the calcium-silicon-sulfur (Ca/Si/S) ratio was proposed. The Ca/Si/S ratio of concrete was adjusted by changing the titanium gypsum, fly ash, and cement content. The effects of different Ca/Si/S ratios on the mechanical properties, hydration products, and concrete microstructure were investigated by nuclear magnetic resonance, uniaxial compression, and scanning electron microscopy. The result shows: (1) The compressive strength of concrete mixed with titanium gypsum increases first and then decreases with the Ca/Si/S ratio decrease. When the Ca/Si/S ratio is 1:0.85:0.10, the strength reaches the peak and is lower than… More > Graphic Abstract

Zida Liu¹, Danial Jahed Armaghani^2,*, Pouyan Fakharian³, Diyuan Li⁴, Dmitrii Vladimirovich Ulrikh⁵, Natalia Nikolaevna Orekhova⁶, Khaled Mohamed Khedher^7,8

CMES-Computer Modeling in Engineering & Sciences, Vol.133, No.3, pp. 799-824, 2022, DOI:10.32604/cmes.2022.021165

Abstract The uniaxial compressive strength (UCS) of rock is an essential property of rock material in different relevant applications, such as rock slope, tunnel construction, and foundation. It takes enormous time and effort to obtain the UCS values directly in the laboratory. Accordingly, an indirect determination of UCS through conducting several rock index tests that are easy and fast to carry out is of interest and importance. This study presents powerful boosting trees evaluation framework, i.e., adaptive boosting machine, extreme gradient boosting machine (XGBoost), and category gradient boosting machine, for estimating the UCS of sandstone. Schmidt hammer rebound number, P-wave velocity,… More >

Bo Zhang^1,2, Keqing Li^1,2, Siqi Zhang^1,2, Yafei Hu^1,2, Bin Han^1,2,*

Journal of Renewable Materials, Vol.10, No.12, pp. 3539-3558, 2022, DOI:10.32604/jrm.2022.021845

Abstract Cemented paste backfill (CPB) is a sustainable mining technology that is widely used in mines and helps to improve the mine environment. To investigate the relationship between aggregate grading and different affecting factors and the uniaxial compressive strength (UCS) of the cemented paste backfill (CPB), Talbol gradation theory and neural networks is used to evaluate aggregate gradation to determine the optimum aggregate ratio. The mixed aggregate ratio with the least amount of cement (waste stone content river sand content = 7:3) is obtained by using Talbol grading theory and pile compactness function and combined with experiments. In addition, the response… More > Graphic Abstract

Hualei Bai^1,2, Ying Li^1,2,*, Dahu Dai^1,2

Journal of Renewable Materials, Vol.10, No.11, pp. 3059-3078, 2022, DOI:10.32604/jrm.2022.020148

Abstract In order to make full use of waste recycled fine powder (RFP) in concrete and achieve the goal of carbon neutrality in the concrete industry, the durability of sulfate resistance is an important aspect of evaluating the performance of recycled powder concrete (RPC). Therefore, the durability of RPC under partial sulfate immersion was studied to provide theoretical guidance for understanding the erosion mechanism of RPC. The compressive strength, mass loss, and microstructure change patterns of RPC under partial immersion of 5% Na₂SO₄ and MgSO₄ solutions were analyzed by cubic compressive strength, mass loss rate, SEM-EDS, and XRD. The results showed… More >

Jiamao Li^1,2,*, Tao Si¹, Lin Li¹, Chuangang Fan^1,*, Zhaofang He³, Yuandi Qian³

Journal of Renewable Materials, Vol.10, No.11, pp. 3041-3058, 2022, DOI:10.32604/jrm.2022.020054

Abstract The purpose of this paper was using gold mine tailings and cemented materials with low alkalinity to fabricate baking-free bricks. The obtained baking-free brick samples were evaluated by unconfined compressive strength (UCS), water absorption percentage, freezing-thawing cycle, and drying-wetting cycle. The microstructures of the baking-free brick samples were analyzed using X-ray diffraction (XRD) and scanning electron microscope (SEM) techniques. The baking-free brick specimens cured for 28 days with the addition of 10% mixing water consumption and 1:6 cement/tailing ratio tended to obtain favorable comprehensive properties such as a high compressive strength of 15.15 MPa, a low water absorption percentage of… More > Graphic Abstract

Kai Zhang^1,2, Qunshan Wei^1,2,*, Shuai Jiang³, Zhemin Shen⁴, Yanxia Zhang^1,2, Rui Tang^1,2, Aiwu Yang^1,2, Christopher W. K. Chow⁵

Journal of Renewable Materials, Vol.10, No.11, pp. 2989-3008, 2022, DOI:10.32604/jrm.2022.019821

Abstract In this study, the dredged river sediment, soft texture and fine particles, is mixed with other materials and transformed into eco-friendly autoclaved aerated concrete (hereinafter referred to as AAC) blocks. The results indicated the bricks produced under the conditions of 30%–34% dredged river sediment, 24% cement, 10% quick lime, 30% fly ash, 2% gypsum and 0.09% aluminum powder with 0.5 water to material ratio, 2.2 MPa autoclave pressure and 6 h autoclave time, the average compressive strength of 4.5 MPa and average dry density of 716.56 kg/m³ were obtained, the two parameters (strength & density) both met the requirement of… More >

Bowen Liu¹, Yunxia Zhou¹, Hisham Essawy², Shang Feng¹, Xuehui Li¹, Jingjing Liao¹, Xiaojian Zhou^1,3,*, Jun Zhang^1,*, Sida Xie¹

Journal of Renewable Materials, Vol.10, No.11, pp. 3009-3024, 2022, DOI:10.32604/jrm.2022.019848

Abstract This study presents easily prepared free formaldehyde bio-based foam based on a prepared thermosetting resin comprising tannin–lignin–furfuryl alcohol-glyoxal (TLFG) via mechanical stirring in presence of ether as a foaming agent. The foam was developed through a co-polycondensation reaction of glyoxal and furfuryl alcohol with condensed tannin and lignin, which is a forest-derived product. Investigation using scanning electron microscopy (SEM) showed more closed-cell structure without cracks and collapse in the TLFG foam, with a higher apparent density with respect to tannin–furanic–formaldehyde (TFF) foam. Differential scanning calorimetry (DSC), dynamic thermomechanical analysis (DTMA), and thermogravimetric analysis (TGA) investigations revealed that the curing process… More >

Hongfei Yue¹, Aiguo Fang², Sudong Hua^1,*, Zenghuan Gu³, Yu Jia¹, Cheng Yang⁴

Journal of Renewable Materials, Vol.10, No.8, pp. 2247-2261, 2022, DOI:10.32604/jrm.2022.018901

Abstract A phosphogypsum-based subgrade stabilizer (PBSS) was formulated using industrial by-product phosphogypsum (PG), mixed with slag and calcium-silicon-rich active material (GSR). The active powder (AP) was used to modify PBSS, and PBSS-AP was obtained. PBSS and PBSS-AP were each mixed with 10% silty soil, and cement and lime (CAL: 5% lime + 2% cement) were used as the traditional material for comparative experiments. Samples were cured under standard conditions, and tested for unconfined compressive strength (UCS), water stability, volume expansion, and leachate, to explore the stabilization effect of the three solidified materials on silty soil. The results showed that the comprehensive… More >

Nikola Vavřínová^*, Kateřina Stejskalová, Jiří Teslík, Kateřina Kubenková, Jiří Majer

Journal of Renewable Materials, Vol.10, No.7, pp. 1859-1873, 2022, DOI:10.32604/jrm.2022.018908

Abstract This article is focused on the investigation of the mechanical and thermal properties of composite material that could be used for the production of plaster or plasterboards. This composite material is made of gypsum and reinforcing natural fibers. The article verifies whether this natural reinforcement can improve the investigated properties compared to conventional plasters and gypsum plasterboards made of pure gypsum. From this composite material, high-strength plasterboards could then be produced, which meet the higher demands of users than conventional gypsum plasterboards. For their production, natural waste materials would be used efficiently. As part of the development of new building… More >

Brya Aldawoodi^1,*, Salaheddin Sabri¹, Abdulmounem Alchekh Wis²

Journal of Renewable Materials, Vol.10, No.5, pp. 1269-1285, 2022, DOI:10.32604/jrm.2022.017445

Abstract This study aims to determine the most convenient calcination temperature and calcination duration of waste-stabilized Adobe (AB) to produce a new alkali-activated binder. Waste-stabilized Adobe mainly consists of soil, CaCO₃ as a stabilizer, and straw (for strengthening). The availability of raw materials for making Adobe presents the waste-stabilized Adobe as a potential product for a new alkali-activated binder. Waste-stabilized Adobe collected from an abandoned damaged building in the village of Inonu in Northern Cyprus, ground and calcined at the following temperatures: 450, 550, 650, 750, 850, and 950°C. The calcination at each temperature was held for different durations 1, 3,… More >