Shixue Liang¹, Zhongshu Xie¹, Tiancan Huang^{2, *}

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.3, pp. 1079-1103, 2020, DOI:10.32604/cmes.2020.09200 - 28 May 2020

Abstract Concrete is intrinsically endowed with randomness on meso-scale due to the random distribution of aggregates, mortar, etc. In this paper, two random medium models of concrete mesostructure are developed and comparative studies are provided based on random field representation approach. In the first place, concrete is considered as a kind of one-phase random field, where stochastic harmonic function is adopted as the approach to simulate the random field. Secondly, in order to represent the stochastic distribution of the multi-phase of concrete such as aggregates and mortar, two-phase random field based on the Nataf transformation and More >

Xingguo Feng^1,2,3, Yiji Zhang¹, Xiangyu Lu^1,*, Yiwen Xu¹, Leyuan Zhang¹, Chao Zhu¹, Tong Wu¹, Yashi Yang⁴, Xuhui Zhao⁵

Journal of Renewable Materials, Vol.8, No.5, pp. 513-534, 2020, DOI:10.32604/jrm.2020.09549 - 29 April 2020

Abstract Durability and ecological effects of the stainless steel reinforced coral waste concrete were compared with those of the carbon steel reinforced ordinary concrete. The results showed that the corrosion current densities of the stainless steel in the coral waste concrete were less than one-tenth of those of the carbon steel in the same grade ordinary concrete. The stainless steel in the seawater coral waste concrete maintained passivation even after more than two years of immersion in 3.5% NaCl solution, while the carbon steel counterparts in the ordinary concrete were seriously corroded under the same condition. More >

Tiancan Huang¹, Hao Zhou^2,*, Hamid Beiraghi³

CMES-Computer Modeling in Engineering & Sciences, Vol.123, No.2, pp. 691-715, 2020, DOI:10.32604/cmes.2020.09046 - 01 May 2020

Abstract Large cooling towers in thermal power plants and nuclear power plants are likely to suffer from strong earthquakes during service periods. The resulting destructions of the cooling towers would endanger the power plants and threaten the security of the related areas. It is important to use effective means to evaluate the safety status of the cooling towers and guide further precautions as well as retrofitting efforts. This paper is therefore focused on an elaborate numerical investigation to the earthquake-induced collapses of a large cooling tower structure. A complete numerical work for simulation of material failure,… More >

Shixue Liang^{1, *}, Hankun Liu²

CMES-Computer Modeling in Engineering & Sciences, Vol.122, No.3, pp. 1015-1038, 2020, DOI:10.32604/cmes.2020.07799 - 01 March 2020

Abstract A multi-scale damage model of concrete is proposed based on the concept of energy equivalent strain for generic two- or three-dimensional applications. Continuum damage mechanics serves as the framework to describe the basic damage variables, namely the tensile and compressive damage. The homogenized Helmholtz free energy is introduced as the bridge to link the micro-cell and macroscopic material. The crack propagation in micro-cells is modeled, and the Helmholtz free energy in the cracked micro-structure is calculated and employed to extract the damage evolution functions in the macroscopic material. Based on the damage energy release rates More >

Lei Tian, Liuchao Qiu^*, Jingjun Li, Yongsen Yang

Journal of Renewable Materials, Vol.8, No.2, pp. 154-170, 2020, DOI:10.32604/jrm.2020.08701 - 01 February 2020

Abstract In recent decades, the utilization of waste tires, plastic and artificial shale ceramsite as alternative fine aggregate to make self-compacting concrete (SCC) has been recognized as an eco-friendly and sustainable method to manufacture renewable construction materials. In this study, three kinds of recycled aggregates: recycled tire rubber particles, wood-plastic particles, artificial shale ceramsite were used to replace the sand by different volume (5%, 10%, 20% and 30%), and their effects on the fresh and hardened properties of SCC were investigated. The slump flow and V-funnel tests were conducted to evaluate the fresh properties of modified-SCC… More >

Yunfa Zhang¹, Xiaozhou Xia^{1, *}, Zhenjie Wu¹, Qing Zhang¹

CMC-Computers, Materials & Continua, Vol.62, No.1, pp. 413-442, 2020, DOI:10.32604/cmc.2020.04660

Abstract Considering the fact that the initial defects, like the imperfect interfacial transition zones (ITZ) and the micro voids in mortar matrix, weaken the mechanical properties of concrete, this study develops corresponding constitutive models for ITZ and matrix, and simulates the concrete failure with finite element methods. Specifically, an elastic-damage traction-separation model for ITZ is constructed, and an anisotropic plastic-damage model distinguishing the strength-difference under tension and compression for mortar matrix is proposed as well. In this anisotropic plastic-damage model, the weakening effect of micro voids is reflected by introducing initial isotropic damage, the distinct characteristic More >

Gao Xiaolong¹, Li Chunguang², Qiao Yunhong³

Intelligent Automation & Soft Computing, Vol.25, No.4, pp. 775-783, 2019, DOI:10.31209/2019.100000081

Abstract Plagued by consistent temperature cracks caused by hydration heat of mass concrete construction, a lot of research on concrete DAMS and other large hydraulic concrete, the theory also more deeply, and for large span bridge foundation pile caps, corresponding much smaller size of mass concrete, the related research is less. This article obtains from the cooling water pipes "embedded" scheme optimization, based on the new Tianjin Haihe river bridge project as the engineering background, construction of the concrete hydration heat temperature rise theory model was set up, with the help of theory formula, the numerical More >

Hyun Kyu Shin¹, Yong Han Ahn², Sang Hyo Lee³, Ha Young Kim^4,*

CMC-Computers, Materials & Continua, Vol.61, No.3, pp. 911-928, 2019, DOI:10.32604/cmc.2019.08269

Abstract Compressive strength of concrete is a significant factor to assess building structure health and safety. Therefore, various methods have been developed to evaluate the compressive strength of concrete structures. However, previous methods have several challenges in costly, time-consuming, and unsafety. To address these drawbacks, this paper proposed a digital vision based concrete compressive strength evaluating model using deep convolutional neural network (DCNN). The proposed model presented an alternative approach to evaluating the concrete strength and contributed to improving efficiency and accuracy. The model was developed with 4,000 digital images and 61,996 images extracted from video More >

Jintao He, Dong Lei^*, Xuwei Cui, Pengxiang Bai, Feipeng Zhu

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 78-78, 2019, DOI:10.32604/icces.2019.05228

Abstract With the combination of scanning electron microscope (SEM) and digital image correlation (DIC), the mechanical properties of interfacial transition zone (ITZ) in concrete are experimentally studied. The experimental compression tests are performed on cuboid samples whose half part is aggregate and the other part is mortar. The morphology of the ITZ is captured by SEM under compressive load, and from the recorded images the deformation of the ITZ is analyzed. After that, the distribution of the nominal compressive elastic modulus of the ITZ is obtained along the distance from the aggregate to the mortar, which… More >

Xianglong Su^*, Wenxiang Xu, Wen Chen

The International Conference on Computational & Experimental Engineering and Sciences, Vol.21, No.4, pp. 77-77, 2019, DOI:10.32604/icces.2019.05090

Abstract Creep of concrete can last for decades, which displays the ultra-slow rheological phenomena. As an empirical formula, the logarithmic law is usually used to describe the ultra-slow creep. However, the logarithmic law does not always work well especially for the long-term creep. And its corresponding relaxation response cannot be obtained analytically. It is known that the Mittag-Leffler and the inverse Mittag-Leffler functions are generalized from the exponential and the logarithmic functions, respectively. And the inverse Mittag-Leffler function is much slower and generalized than the logarithmic function. In this paper, we use the non-local structural derivative… More >