Isamar Rosa¹, Henning Roedel¹, Maria I. Allende¹, Michael D. Lepech^1,*, David J. Loftus²

Journal of Renewable Materials, Vol.8, No.8, pp. 845-861, 2020, DOI:10.32604/jrm.2020.09844 - 10 July 2020

Abstract Biopolymer-bound Soil Composites (BSC), are a novel bio-based construction material class, produced through the mixture and desiccation of biopolymers with inorganic aggregates with applications in soil stabilization, brick creation and in situ construction on Earth and space. This paper introduces a mixture design methodology to produce maximum strength for a given soil-biopolymer combination. Twenty protein and sand mix designs were investigated, with varying amounts of biopolymer solution and compaction regimes during manufacture. The ultimate compressive strength, density, and shrinkage of BSC samples are reported. It is observed that the compressive strength of BSC materials increases proportional More >

Peishuai Chen^1,2,3,*, Junjie Cao⁴, Weizhong Chen³, Weisheng Rao²

Structural Durability & Health Monitoring, Vol.14, No.2, pp. 147-163, 2020, DOI:10.32604/sdhm.2020.07619 - 23 June 2020

Abstract Existing studies on the durability of subsea tunnel mainly focus on the concrete deterioration and steel corrosion, while there are few on the influence of mechanical properties deterioration of surrounding rock on the durability of subsea tunnel. To improve the accuracy of long-term stability prediction, seawater corrosion tests of intensely weathered surrounding rock of subsea tunnel are carried out. In this study, the strength characteristics of remolded samples of intensely weathered granite under different seawater concentrations are investigated, the strength attenuation equation under seawater corrosion is established, and the chemical damage evolution equation and model More >

Hongtao Wang^1,2,*, Ping Liu^1,2, Lige Wang^3,4,*, Chi Liu⁵, Xin Zhang^1,2, Luyao Liu^1,2

CMES-Computer Modeling in Engineering & Sciences, Vol.124, No.1, pp. 375-391, 2020, DOI:10.32604/cmes.2020.08270 - 19 June 2020

Abstract Layered rock strata are observed to be common during the excavation of tunnels or cavities, and may significantly affect the deformation and failure characteristics of surrounding rock masses due to various complex forms and mechanical properties. In this paper, we propose a three-dimensional axisymmetric velocity field for roof collapse of shallow cavities in multi rock layers, by considering the influences of roof cross-section shapes, supporting pressure, ground overload, etc. The internal energy dissipation rate and work rates of external forces corresponding to the velocity field are computed by employing the Hoek-Brown strength criterion and its… More >

Amer Ibrahim Al-Omari^{1, *}, Ibrahim M. Almanjahie², Amal S. Hassan³, Heba F. Nagy⁴

CMC-Computers, Materials & Continua, Vol.64, No.2, pp. 835-857, 2020, DOI:10.32604/cmc.2020.10944 - 10 June 2020

Abstract In reliability analysis, the stress-strength model is often used to describe the life of a component which has a random strength (X) and is subjected to a random stress (Y). In this paper, we considered the problem of estimating the reliability R=P [Y<X] when the distributions of both stress and strength are independent and follow exponentiated Pareto distribution. The maximum likelihood estimator of the stress strength reliability is calculated under simple random sample, ranked set sampling and median ranked set sampling methods. Four different reliability estimators under median ranked set sampling are derived. Two estimators are obtained… More >

A. A. Mazlan¹, M. T. H. Sultan^1,2,3,*, S. N. A. Safri², N. Saba², A. U. M. Shah², M. Jawaid²

Journal of Renewable Materials, Vol.8, No.7, pp. 833-843, 2020, DOI:10.32604/jrm.2020.08724 - 01 June 2020

Abstract The present paper deals with the effect of loading different pineapple leaf fibre (PALF) length (short, mixed and long fibres) and their reinforcement for the fabrication of vinyl ester (VE) composites. Performance of PALF/VE composites was investigated through three-point bending flexural testing and viscoelastic (dynamic) mechanical properties through dynamic mechanical analysis (DMA). DMA results revealed that the long PALF/VE composites displayed better mechanical, damping factor and dynamic properties as compared to the short and mixed PALF/VE composites. The flexural strength and modulus of long PALF/VE composites were 113.5 MPa and 14.3 GPa, respectively. The storage More >

Haikuan Wu^1,2, Changwu Liu^1,2,*, Song Shi^1,2, Kangliang Chen^1,2

Journal of Renewable Materials, Vol.8, No.7, pp. 727-738, 2020, DOI:10.32604/jrm.2020.09589 - 01 June 2020

Abstract In order to study the effect of recycled plastic particles on the physical and mechanical properties of concrete, recycled plastic concrete with 0, 3%, 5% and 7% content (by weight) was designed. The compressive strength, splitting tensile strength and the change of mass caused by water absorption during curing were measured. The results show that the strength of concrete is increased by adding recycled plastic into concrete. Among them, the compressive strength and the splitting tensile strength of concrete is the best when the plastic content is 5%. With the increase of plastic content, the… More >

Xueliang Wang¹, Qiangang Xu¹, Xiuxin Wang¹, Junhui Guo², Wancheng Cao¹, Chun Xiao^3,*

Journal of Renewable Materials, Vol.8, No.5, pp. 565-577, 2020, DOI:10.32604/jrm.2020.09020 - 29 April 2020

Abstract An accelerated decay test and a natural decay test were conducted synchronically to explore the strength degradation of decaying wood members under long-term exposure to natural environment. A natural decay test was carried out to measure the bending strength, compressive strength parallel to grain and modulus of elasticity of the wood members, with 6 groups of specimens decayed in natural environment for 3 to 18 months respectively. To compare with corresponding decay test, in which 6 other groups of specimens were measured under accelerated conditions. The experimental data collected were evaluated by Pearson productmoment for… More >

Xin Gu², Lin Wang^{1, 2, 3}, Fuyong Chen², Hongrui Li², Wengang Zhang^{1, 2, 3, ∗}

CMC-Computers, Materials & Continua, Vol.63, No.1, pp. 263-281, 2020, DOI:10.32604/cmc.2020.07535 - 30 March 2020

Abstract Temporal variation of rock mass properties, especially the strength degradation due to drying-wetting cycles as well as the acidic wetting fluid (rainfall or reservoir water) is crucial to stability of reservoir rock slopes. Based on a series of drying-wetting cycling and experiments considering the influences of pH values, the degradation degree models of the reduced cohesion c′, friction angle φ′ are developed. 2D stability analysis of the slope is subsequently carried out to calculate the factor of safety (Fs) via limit equilibrium method (LEM) and a predictive model of Fs is built using multivariate adaptive regression… More >

Paul Chege^1,2, Andrea Palágyi², Csaba Lantos², Erzsébet Kiss¹, János Pauk^2,*

Phyton-International Journal of Experimental Botany, Vol.89, No.1, pp. 111-119, 2020, DOI:10.32604/phyton.2020.07554 - 01 March 2020

Abstract Many attempts on optimization of sorghum [Sorghum bicolor (L.) Moench] tissue culture induction media have been made, but the culture system remains with some bottlenecks compared to that of other crops. This study aimed at assessing the suitability of various induction media to produce embryogenic callus (yellow and friable) with high induction rates and reduced phenolic exudation. The six culture medium modifications: 3 based on Murashige and Skoog (MS) medium and one each based on Chu N6, Gamborg B5 and 190-2 media respectively were applied in the culture of mature embryos from 10 sorghum genotypes. Although… More >

R. VENKATESAN^*, S. R. DARSON IMMANUEL JOHN, N. RAJESWARI

Journal of Polymer Materials, Vol.36, No.3, pp. 261-273, 2019, DOI:10.32381/JPM.2019.36.03.6

Abstract Nanocomposite films of chitosan (CH) incorporated with different wt. % of the polyoligomericsilsesquioxane (POSS) were prepared by solution casting. The thermal, mechanical, morphological and antimicrobial properties of the nanocomposites were examined. TGA analyses of the nanocomposites indicate that the filler enables the enhancement of thermal stability of chitosan. The tensile strength of the nanocomposite films is enhanced (10.9 MPa for neat chitosan to 24.0MPa for 5wt. % filled chitosan) by the addition of POSS while the elongation at break is reduced. The nanocomposite films exhibited excellent antimicrobial activity against both gram positive and gram negative More >