scholarly journals Evaluation of Concrete Durability Based on Cloud Model and D-S Evidence Theory

2022 ◽  
Vol 2148 (1) ◽  
pp. 012054
Author(s):  
Sai Yang ◽  
Jinlong Huang ◽  
Yawei Qin ◽  
Xianguo Wu

Abstract The environment in alpine region is complex and harsh, and the durability of concrete is seriously affected by freeze-thaw and salt invasion. In this paper, the relative dynamic modulus of elasticity, chloride permeability coefficient, mass loss rate and carbonation depth are selected as the evaluation indexes of concrete durability in Northeast China. Based on prior knowledge and expert group decision-making, the durability grade is divided and the evaluation standard is established; The evaluation model of concrete durability based on cloud model and D-S evidence theory is established. According to the engineering experimental data, the membership degree of concrete durability evaluation index in different grades is obtained through the correlation measurement of cloud model. The normalized evidence is formed and fused by D-S evidence theory. The results show that the durability grade of concrete is grade I, which is consistent with the actual project. It shows that using cloud model and evidence theory evaluation model to evaluate the durability of concrete is a new and effective method.

The durability of concrete is generally evaluated by many NDT technique, among the different NDT technique RCPT is one of the popular NDT method used by many researchers & practicing Engineers for evaluation of concrete durability. However the RCPT technique has some limitation on field test of concrete, considering the limitation of the RCPT technique a new technique has been intr oduced called Electrical resistivity technique is used for evaluation of concrete durability in both field & lab test. Durability of concrete is mainly depends on the properties of concrete microstructure i.e. pore size distribution, shape & connectivity of the microstructural pores in concrete. In general smaller pore size, with lesser connectivity results lower permeability & shows more durability, while concrete with porous microstructure having larger pore size distribution along with larger degree of interconnections results in higher permeability and shows poor durability. In this paper an experimental studies were conducted for evaluation of concrete durability on different types of concrete samples by using electrical resistivity & RCPT technique. From the experimental results it has been observed that concrete with lower level of Chloride permeability shows higher Electrical resistivity. Thus Electrical resistivity of concrete is directly influencing the durability of concrete.


Processes ◽  
2021 ◽  
Vol 9 (12) ◽  
pp. 2273
Author(s):  
Zixue Guo ◽  
Yu Tian ◽  
Xinmei Guo ◽  
Zefang He

To solve the problem of fuzziness and randomness in regional logistics decarbonization evaluation and accurately assess regional logistics decarbonization development, an evaluation model of regional logistics decarbonization development is established. First, the evaluation index of regional logistics decarbonization development is constructed from three dimensions: low-carbon logistics environment support, low-carbon logistics strength and low-carbon logistics potential. Second, the evaluation indexes are used as cloud model variables, and the cloud numerical characteristic values and cloud affiliation degrees are determined according to the cloud model theory. The entropy weight method is used to determine the index weights, and the comprehensive determination degree of the research object affiliated to the logistics decarbonization level is calculated comprehensively. Finally, Beijing-Tianjin-Hebei region is used as an example for empirical evidence, analyzing the development logistics decarbonization and its and temporal variability in Beijing, Tianjin and Hebei provinces and cities. The results of the study show that the development logistics decarbonization in Beijing, Tianjin and Hebei Province has been improved to different degrees during 2013–2019, but the development is uneven. Developing to 2019, the three provinces and cities of Beijing, Tianjin and Hebei still have significant differences in terms of economic environment, logistics industry scale, logistics industry inputs and outputs, and technical support.


2020 ◽  
Vol 64 (1-4) ◽  
pp. 1365-1372
Author(s):  
Xiaohui Mao ◽  
Liping Fei ◽  
Xianping Shang ◽  
Jie Chen ◽  
Zhihao Zhao

The measurement performance of road vehicle automatic weighing instrument installed on highways is directly related to the safety of roads and bridges. The fuzzy number indicates that the uncertain quantization problem has obvious advantages. By analyzing the factors affecting the metrological performance of the road vehicle automatic weighing instrument, combined with the fuzzy mathematics theory, the weight evaluation model of the dynamic performance evaluation of the road vehicle automatic weighing instrument is proposed. The factors of measurement performance are summarized and calculated, and the comprehensive evaluation standard of the metering performance of the weighing equipment is obtained, so as to realize the quantifiable analysis and evaluation of the metering performance of the dynamic road vehicle automatic weighing instrument in use, and provide data reference for adopting a more scientific measurement supervision method.


2021 ◽  
Vol 11 (11) ◽  
pp. 5208
Author(s):  
Jianpo Liu ◽  
Hongxu Shi ◽  
Ren Wang ◽  
Yingtao Si ◽  
Dengcheng Wei ◽  
...  

The spatial and temporal distribution of tunnel failure is very complex due to geologic heterogeneity and variability in both mining processes and tunnel arrangement in deep metal mines. In this paper, the quantitative risk assessment for deep tunnel failure was performed using a normal cloud model at the Ashele copper mine, China. This was completed by considering the evaluation indexes of geological condition, mining process, and microseismic data. A weighted distribution of evaluation indexes was determined by implementation of an entropy weight method to reveal the primary parameters controlling tunnel failure. Additionally, the damage levels of the tunnel were quantitatively assigned by computing the degree of membership that different damage levels had, based on the expectation normalization method. The methods of maximum membership principle, comprehensive evaluation value, and fuzzy entropy were considered to determine the tunnel damage levels and risk of occurrence. The application of this method at the Ashele copper mine demonstrates that it meets the requirement of risk assessment for deep tunnel failure and can provide a basis for large-scale regional tunnel failure control in deep metal mines.


2013 ◽  
Vol 651 ◽  
pp. 245-250
Author(s):  
Tasi Lung Weng ◽  
Wei Ting Lin

The effect of penetrating sealer on the structure of surface pore, mechanical properties, and durability of cement-based composites was studied. Concrete specimens with various water/cement ratios (w/c=0.35, 0.45, 0.55) were cast and treated surfaced with various amounts of penetrating sealer at different ages. The effect of penetrating sealer on the mechanical properties of concrete was assessed by compressive strength. And, the rapid chloride permeability was also explored to test concrete durability. Test results indicate that the application of penetrating sealer significantly improves concrete compressive strength and chloride resistance. By using scanning electron microscopes observation, the penetrating depth of penetrating sealer can be determined and is about 2 cm. The penetrating sealer in this study may be categorized as deep penetrating sealer.


2014 ◽  
Vol 634 ◽  
pp. 517-526 ◽  
Author(s):  
Elsa Neto ◽  
Ana Souto ◽  
Aires Camões ◽  
Arlindo Begonha ◽  
Paulo Cachim

The heritage of fair-faced concrete, largely built in the twentieth century and nowadays recognized as heritage to be protected, is susceptible to attacks by graffiti, a form of vandalism that causes a major social and economic impact on society. Concrete is a porous material sometimes deteriorated over the years, and the interactions between the inks and the substrate and removal methods sometimes deteriorate or alter the concrete surface, especially if it is necessary to repeat the removal process. The anti-graffiti products are applied on the surface of the concrete, hindering the adhesion of paints or preventing its penetration into the pores of concrete, which in turn facilitates their removal. However, it appears that many of the existing protective products on the market may also alter the surface characteristics of the concrete irreversibly. Considering that the durability of concrete depends on the composition and characteristics of the surface, it is essential to know the effects of anti-graffiti protection systems on the durability of concrete and adopt the appropriate methodology to preserve this heritage. Thus, an experimental program was developed for analyzing changes in durability indicators and surface properties that protect concrete from deterioration (i) concrete without protection before and after application of spray paint, (ii) concrete with protection before and after application of spray paint and (iii) after paint removal were studied. Two anti-graffiti products were evaluated: a permanent and a sacrificial one. Effects of the anti-graffiti systems on the concrete durability are investigated and the tests performed include: water absorption by capillary and immersion at atmospheric pressure. The results of the water absorption tests show that the graffiti protection reduces the water absorption into the concrete and facilitates the removal of the graffiti without affecting negatively the characteristics of the surface and thus contributing to improve its durability.


2010 ◽  
Vol 163-167 ◽  
pp. 3110-3113
Author(s):  
Zheng Xi Gong ◽  
Jian Guo Yang

Reliability analysis is the premise for reinforcement and maintenance of an existing highway tunnel. In order to understand the structure reliability of an existing highway tunnel, a fuzzy mat-ter-element evaluation method was put forward based on entropy weight according to the fuzzy matter-element analysis method. Firstly, levels of inspection results were regarded as objects of matter-element and composite fuzzy matter-elements were constructed considering such factors and their evaluation indexes as cracks of concrete lining, lining thickness, concrete strength, cavities behind the lining and water leakage conditions. Secondly, reliability evaluation results of the existing tunnel structure were obtained by calculating the relevancy. Lastly, fuzzy matter-element evaluation model was effectively used to evaluate reliability of one highway tunnel structure.


2021 ◽  
Vol 2021 ◽  
pp. 1-7
Author(s):  
Lanchun Zhang ◽  
Zhongwei Zhu ◽  
Bin Huang ◽  
Tianbo Wang

In order to improve the transmission efficiency and carrying capacity of conventional single-belt continuously variable transmission (CVT), one new type of dual-belt CVT is proposed in this paper. Under the situation that this new dual-belt CVT should be switched between single- and dual-belt modes frequently according to driver’s intention and road conditions, so five objective evaluation indexes of mode switching quality for the dual-belt CVT are proposed, considering the aspects of vehicle power, comfort, and transmission durability comprehensively. Then, the objective evaluation model of mode switching quality is established by the BP neural network optimized by the genetic algorithm. It is found that the prediction results are consistent with the subjective evaluation. After analyzing the influence of the selected five evaluation indexes on the prediction results, it is obvious that these five evaluation indexes of mode switching quality for dual-belt CVT are reasonable.


2021 ◽  
Vol 2021 ◽  
pp. 1-17
Author(s):  
Fengwen Wu ◽  
Shiyu Qin ◽  
Chunyu Su ◽  
Mingyuan Chen ◽  
Qian Wang ◽  
...  

Historic districts represent an important characteristic of Beijing and are also a crucial carrier of Chinese historic culture. However, they are significantly affected by the rapid urban constructions. Thus, it is of great significance to maintain and promote the public space in historic districts. This paper uses a multisource data superposition method to select the evaluation index of public space. The AHP was also used to complete the single-level and total-level ranking and calculation of evaluation indexes. Finally, based on the DEA model, a vitality evaluation model of Beijing historic district public spaces was developed and its validity was verified through a case study of the Wanping historic district.


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