Mohammad Akhtar¹, Abdulsamee Halahla², Amin Almasri^3,*

Structural Durability & Health Monitoring, Vol.15, No.4, pp. 335-348, 2021, DOI:10.32604/sdhm.2021.015988

Abstract This research aims to study the effect of elevated temperature on the compressive strength evolution of concrete made with recycled aggregate. Demolished building concrete samples were collected from four different sites in Saudi Arabia, namely from Tabuk, Madina, Yanbu, and Riyadh. These concretes were crushed and recycled into aggregates to be used to make new concrete samples. These samples were tested for axial compressive strength at ages 3, 7, 14, and 28 days at ambient temperature. Samples of the same concrete mixes were subjected to the elevated temperature of 300°C and tested for compressive strength again. The experimental result reveals… More >

Zhongnan Gao^1,2,#, Xiumei Zhong^1,2,#, Qian Wang^1,2,*, Yongqi Su³, Jun Wang^1,2

Journal of Renewable Materials, Vol.10, No.4, pp. 1063-1080, 2022, DOI:10.32604/jrm.2022.017374

Abstract In the seasonal permafrost region with loess distribution, the influence of freeze-thaw cycles on the engineering performance of reinforced loess must be paid attention to. Many studies have shown that the use of fiber materials can improve the engineering performance of soil and its ability to resist freeze-thaw cycles. At the same time, as eco-environmental protection has become the focus, which has been paid more and more attention to, it has become a trend to find new environmentally friendly improved materials that can replace traditional chemical additives. The purpose of this paper uses new environmental-friendly improved materials to reinforce the… More >

Yingchun Yang^1,*, Liqing Chen¹, Xingdong Sun¹, Yuguang Mao²

Journal of Renewable Materials, Vol.10, No.4, pp. 1007-1023, 2022, DOI:10.32604/jrm.2022.017372

Abstract Herein, micro iron ore tailings (micro-IOTs) were prepared by wet-grinding and applied to improve sulphoaluminate cement (SAC) performance. The physicochemical properties of micro-IOTs were investigated by particle size analysis, XRD, and XPS. The hydrates trait and the hydration mechanism of micro-IOTs-SAC composite were studied by XRD, TGA, MIP, and SEM. The results demonstrated that micro-IOTs with an average grain diameter of 517 nm could be obtained by wet-grinding. The setting time of SAC gradually decreased with increasing micro-IOTs content. By adding 2% micro-IOTs, the compressive strengths of SAC pastes were enhanced about 22% and 10% at 4 h and 28… More >

Xiang Deng¹, Sudong Hua^1,*, Fan Xia², Yanfang Zhang², Dapeng Guo³, Xinxing Zhu³, Defei Zhu³

Journal of Renewable Materials, Vol.10, No.4, pp. 939-953, 2022, DOI:10.32604/jrm.2022.016874

Abstract Recycled powder (RP) is produced as a by-product during the process of recycling construction and demolition (C&D) wastes, presenting a low additional value. Using RP-based solidifying material can not only improve its utilization efficiency, but also reduce the cost of commercial solidifying materials. To date, this is the best solidifying material utilized to dispose the original waterworks sludge (OWS) with high moisture contents (60%), and the product could be used to fabricate non-fired bricks. This has become a new environment-friendly technology of “using waste to treat waste”. In this paper, the influence of different particle sizes and dosages of RP… More >

Jianbing Zhang¹, Rongjin Liu^1,2,3,*, Siyuan Fu¹, Tianyu Gao¹, Zhongfei Zhang¹

Journal of Renewable Materials, Vol.9, No.11, pp. 2001-2013, 2021, DOI:10.32604/jrm.2021.015812

Abstract Based on aluminum sulfate, a fluorine-free and alkali-free liquid accelerator (FF-AF-A) was prepared in this study. The setting time and compressive strength of three cement types with different FF-AF-A dosages were fully investigated. The compatibility of the FF-AF-A with the superplasticizers were also investigated, and the early hydration behavior and morphology of the hydration products of reference cement paste with the FF-AF-A were explored by hydration heat, X-ray diffractometry (XRD), and scanning electron microscopy (SEM). Test results indicated that adding the FF-AF-A at 8 wt% of the cement weight resulted in 2 min 35 s initial setting time and 6… More >

Mario Bonagura, Lucio Nobile^*

Structural Durability & Health Monitoring, Vol.15, No.2, pp. 125-137, 2021, DOI:10.32604/sdhm.2021.015644

Abstract The compressive strength of concrete is one of most important mechanical parameters in the performance assessment of existing reinforced concrete structures. According to various international codes, core samples are drilled and tested to obtain the concrete compressive strengths. Non-destructive testing is an important alternative when destructive testing is not feasible without damaging the structure. The commonly used non-destructive testing (NDT) methods to estimate the in-situ values include the Rebound hammer test and the Ultrasonic Pulse Velocity test. The poor reliability of these tests due to different aspects could be partially contrasted by using both methods together, as proposed.in the SonReb… More >

Zhiyu Weng¹, Lina Wang^1,2,*, Qiang Liu², Xuemin Pan¹, Yonghao Xu³, Jing Li¹

Journal of Renewable Materials, Vol.9, No.8, pp. 1503-1517, 2021, DOI:10.32604/jrm.2021.015003

Abstract To explore an environmentally friendly improvement measure for red clay, the function and mechanism of xanthan gum biopolymer and polypropylene fibers on the strength properties of red clay were investigated by unconfined compressive strength and scanning electron microscopy tests. The test results demonstrated that the contents and curing ages of xanthan gum had significant influences on the unconfined compressive strength of red clay. Compared with untreated soil, 1.5% xanthan gum content was the optimal ratio in which the strength increment was between 41.52 kPa and 64.73 kPa. On the other hand, the strength of xanthan gum-treated red clay increased, whereas… More >

Zenghuan Gu¹, Aiguo Fang², Sudong Hua^1,*, Qingzhou Zhao², Lidong Sun², Fan Xia², Liying Qian³, Xiaojian Ren³

Journal of Renewable Materials, Vol.9, No.2, pp. 253-268, 2021, DOI:10.32604/jrm.2021.011912

Abstract The research used industrial by-products original phosphogypsum (PG) as the main raw material, slag (SG) and Portland cement (PC) as auxiliary materials, and the optimal additive amount was determined according to the compressive strength value of the sample. Comprehensively evaluate the water resistance and volume stability of the samples, and determine the best formula for new roadbed stabilized materials. The results showed that when the weight ratio of PG, slag and cement was OPG:SG:PC = 6:3:1, and mixed with 5% micro silica fume (MSF) and 3‰ hydroxypropyl methyl cellulose (HPMC), the sample’s comprehensive performance was the best, specifically, the sample’s… More >

R. A. Rahman¹, A. Fazlizan^1,*, N. Asim¹, A. Thongtha²

Journal of Renewable Materials, Vol.9, No.1, pp. 61-72, 2021, DOI:10.32604/jrm.2021.013296

Abstract Autoclaved aerated concrete (AAC) has become more attractive due to its excellent and environmental-friendly properties in building construction. AAC is relatively lightweight, possesses lower thermal conductivity, higher heat resistance, lower shrinkage, and fasten construction than normal concrete. AAC is a combination of silica sand, cement, gypsum, lime, water, and an expansion agent. To improve its physical and mechanical properties and reduce its production cost, tremendous innovations where waste materials were utilized as partial replacement of AAC materials were done. This paper is intended to present the literature on the utilization of waste materials as a means of a partial replacement… More >

Yang Ming^1,2,3, Ping Chen^1,2,3,*, Yuanhao Wang^1,2,3,*, Ling Li^1,2,3, Xuandong Chen^1,2,3, Pengliang Sun^1,2,3,4

Journal of Renewable Materials, Vol.8, No.12, pp. 1647-1655, 2020, DOI:10.32604/jrm.2020.011929

Abstract In order to increase use ratio of steel slag solid waste, the concrete containing steel slag powder and zeolite powder as admixtures was prepared by using the orthogonal test method. The effects of water-binder ratio, sand ratio, steel slag powder content and zeolite powder on working properties, mechanical strength and chloride ion permeability of the concrete was studied. It was found that the early strength of the concrete had a decrease with the mixing of steel slag and zeolite powders, but its later strength approached to pure concrete. Moreover, the physical filling and pozzolanic activity of the admixtures increased the… More >