The Influence of Porous Asphalt Pavement Based on DEMATEL

2012 ◽  
Vol 178-181 ◽  
pp. 1333-1337 ◽  
Author(s):  
Ching Tsung Hung ◽  
Shih Huang Chen ◽  
Chia Chen Wu

Taiwan position is in the subtropics, the climate is high temperature and much rains of year. Freeway mostly uses traditional dense grade in pavement construction, so the pavement could not remove water quickly in rainy day. It will deteriorate by rutting and aging, due to increasing maintenance frequency and cost. Porous asphalt pavement has high performance on road user safe and amenity in many countries. But the prescription in porous asphalt is Variable, for example, the fiber has miner and wood. Base on multiple conditions, the best performance can choice by multiple criteria decision method. This methodology needs the criteria under independent, but the real world is not. The study use Decision-Making Trial and Evaluation Laboratory method to establish the relationship in criteria. With result, the drainage capacity was the important factor in porous asphalt pavement.

Geofluids ◽  
2021 ◽  
Vol 2021 ◽  
pp. 1-13
Author(s):  
Zhanqi Wang ◽  
Jianguang Xie ◽  
Lei Gao ◽  
Yanping Liu ◽  
Kuan Li

The appearance of porous asphalt (PA) pavement is to solve the problem of road ponding in rainy days. The internal air voids in PA pavement are the main functional structure that determines its drainage performance. It is of great practical significance to find out the relationship between void drainage capacity and air voids. This paper is aimed at researching the relationship between three-dimensional (3D) pore structures and drainage performance of PA concrete. Four samples were formed and scanned by CT equipment to obtain the internal cross-sectional CT images. Image dodging algorithm and OTSU method were conducted to deal with these CT images for segmenting them into three subimages (void image, asphalt mortar image, and aggregate image) according to the three components of PA concrete. The voids on void images were identified and classified into three groups according to the three kind of pores (interconnected pore, semi-interconnected pore, and closed pore) and reshaped them into 3D pore structures according to the overlapping principle. Then, the volume and size distribution of the pores was analyzed. Besides, this research mainly focused on the influence of several parameters obtained from interconnected pores on the drainage performance of PA concrete at last. The permeability coefficient of PA concrete samples was tested, and equations between permeability coefficient and void content were fitted linearly. The distribution of hydraulic radius and cross-sectional area ratio was calculated and researched by statistical methods. A new parameter, perimeter variation coefficient, is proposed to study the influence of boundary wall roughness on the drainage performance. At last, equivalent drainage channel was drawn to reflect the drainage capacity of PA concrete.


2020 ◽  
Vol 2020 ◽  
pp. 1-9 ◽  
Author(s):  
Yaolu Ma ◽  
Xianhua Chen ◽  
Yanfen Geng ◽  
Xinlan Zhang

The purpose of this paper is to report on the drainage of porous asphalt pavement evaluation method suited for use in analyzing clogging effect. To preliminarily reveal the decrease in permeability caused by clogging of permeable asphalt pavement, an innovative device was proposed to evaluate the anisotropy of permeability influenced by clogging, and the maximum drainage capacity without surface ponding can be obtained when the supplied water was controlled. Then, finite element models for asphalt pavements with hydromechanical coupling were proposed based on porous media theory and Biot’s theory. The variation in pore water pressure was simulated by considering the decrease in voids and the increase in clogging grains. The results indicate that the internally retained water should not be ignored because the semiconnected voids were filled with water rapidly at the beginning of permeability tests. To avoid surface ponding, the drainage capacity coefficient (DCC) can be used to evaluate the maximum drainage capacity (MDC) influenced by clogging. Moreover, the pore water pressure increased due to the reduction in voids and a high level of clogging. In addition, the peak value of pore water pressure is also affected by the upper-layer height of the pavement. Under the action of clogging and driving load, a reasonable thickness of the upper layer and a drainage evaluation should be considered to improve road safety.


2018 ◽  
Vol 45 ◽  
pp. 00114
Author(s):  
Lesław Bichajło ◽  
Krzysztof Kołodziej

The paper characterizes the porous asphalt mixture used in pavement construction. This kind of pavement can reduce traffic noise and reduce the slipperiness of the road pavement. The effectiveness of the porous asphalt depends on many design and technological aspects, but especially on the air-void clearance in the pavement layer. The paper includes the results of water permeability research based on laboratory tests of specimens from actual road pavement. The research shows the differences between the contamination of the road pavement sections located inside and outside the city. The paper includes recommendations for using porous asphalt based on experiences under Polish conditions.


2010 ◽  
Vol 163-167 ◽  
pp. 4492-4500
Author(s):  
Yong Li Ren

The segregation of gradation is believed to be one of the main causes of the premature pavement deteriorations. Much of unqualified aggregates used in asphalt pavement construction result in the segregation of gradation. The traditional aggregate handling method has the defects of poor quality in processing and low rate of qualified aggregate in result in highway construction in china. The beginning of the study is from more than 30 sections of the asphalt pavement construction, in which the sieve sizes for aggregate processing and the variation of aggregate gradation is under investigation. Found and used a set of standardized screens for aggregate processing on a large scale processing. The key of the gradation segregation control in asphalt pavement construction is the quality control of the aggregate processing, is pointed out. The relationship between the sieve sizes for aggregate handling and the standard sieve sizes which should be controlled; the relationship between the aggregate specifications and the screens for aggregate processing; and the relationship between the sort of mix and the aggregate specifications, is put forward. With application of the new aggregate processing method, almost all variation factor percent passing key controlled sieves is smaller than 2.6%. The mean surface texture depth measured from 229 inspection sites is 1.03 mm and the maximum variation factor of the texture depth is only 2.7%. The authors believe that the standardized aggregate processing technique reported in this paper is the most effective means to reduce asphalt pavement segregation and may open a new era in the realm of aggregate processing for highway constructions in China.


1997 ◽  
Vol 36 (8-9) ◽  
pp. 397-402
Author(s):  
Yasuhiko Wada ◽  
Hiroyuki Miura ◽  
Rituo Tada ◽  
Yasuo Kodaka

We examined the possibility of improved runoff control in a porous asphalt pavement by installing beneath it an infiltration pipe with a numerical simulation model that can simulate rainfall infiltration and runoff at the porous asphalt pavement. From the results of simulations about runoff and infiltration at the porous asphalt pavement, it became clear that putting a pipe under the porous asphalt pavement had considerable effect, especially during the latter part of the rainfall.


Author(s):  
Mohammad Nadeem Akhtar ◽  
Mohammed Jameel ◽  
Abdullah M. Al-Shamrani ◽  
Nadeem A. Khan ◽  
Zainah Ibrahim ◽  
...  

2021 ◽  
Vol 13 (6) ◽  
pp. 3341
Author(s):  
Jesús Maya ◽  
Juan F. Luesia ◽  
Javier Pérez-Padilla

Universities strive to ensure quality education focused on the diversity of the student body. According to experiential learning theory, students display different learning preferences. This study has a three-fold objective: to compare learning styles based on personal and educational variables, to analyze the association between learning styles, the level of academic performance, and consistency of performance in four assessment methods, and to examine the influence of learning dimensions in students with medium-high performance in the assessment methods. An interdisciplinary approach was designed involving 289 psychology, early childhood education and primary education students at two universities in Spain. The Learning Style Inventory was used to assess learning styles and dimensions. The assessment methods used in the developmental psychology course included the following question formats: multiple-choice, short answer, creation-elaboration and an elaboration question on the relationship between theory and practice. Univariate analysis, multivariate analysis, and binomial logistic models were computed. The results reveal Psychology students to be more assimilative (theoretical and abstract), while early childhood and primary education students were evenly distributed among styles and were more divergent and convergent (practical) in absolute terms. In addition, high scores in perception (abstract conceptualization) were associated with a high level of performance on the multiple-choice tests and the elaboration question on the relationship between theory and practice. Abstract conceptualization was also associated with medium-high performance in all assessment methods and this variable predicted consistent high performance, independent of the assessment method. This study highlights the importance of promoting abstract conceptualization. Recommendations for enhancing this learning dimension are presented.


2021 ◽  
pp. 1-12
Author(s):  
Jia Zhou ◽  
Dingkun Wang ◽  
Bingong Li ◽  
Xuelian Li ◽  
Xingjun Lai ◽  
...  

<b><i>Introduction:</i></b> Trimethylamine N-oxide (TMAO) is a metabolite produced by gut bacteria. Although increased TMAO levels have been linked to hypertension (HTN) and chronic kidney disease (CKD) with poor prognosis, no clinical studies have directly addressed the relationship between them. In this study, we investigated the relationship between TMAO and renal dysfunction in hypertensive patients. <b><i>Methods:</i></b> We included healthy controls (<i>n</i> = 50), hypertensive patients (<i>n</i> = 46), and hypertensive patients with renal dysfunction (<i>n</i> = 143). Their blood pressure values were taken as the highest measured blood pressure. Renal function was evaluated using the estimated glomerular filtration rate. Plasma TMAO levels were measured using high-performance liquid chromatography tandem mass spectrometry. <b><i>Results:</i></b> We found significant differences in plasma TMAO levels among the 3 groups (<i>p</i> &#x3c; 0.01). The plasma TMAO of patients with HTN was significantly higher than that of healthy people, and the plasma TMAO of patients with HTN complicated by renal dysfunction was significantly higher than either of the other groups. Patients in the highest TMAO quartile were at a higher risk of developing CKD stage 5 than those in the lowest quartile. In the receiver operating characteristic curve, the area under the curve of TMAO combined with β 2-macroglobulin for predicting renal dysfunction in patients with HTN was 0.85 (95% confidence interval 0.80–0.90). <b><i>Conclusion:</i></b> An elevated TMAO level reflects higher levels of HTN and more severe renal dysfunction. TMAO, combined with β 2-macroglobulin levels, may assist in diagnosing CKD in hypertensive patients. Plasma TMAO has predictive value for early kidney disease in hypertensive patients.


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