Analysis of Weighting Coefficients of Post-Assessment Indexes for Cold Recycling Engineering of Asphalt Pavement Based on Hierarchy Analytic Procedure

2012 ◽  
Vol 204-208 ◽  
pp. 1857-1863
Author(s):  
Min Jiang Zhang ◽  
Wen Bo Zhang ◽  
Bao Yang Yu

Based on the theory of hierarchy analysis, the post-assessment indexes system of cold recycling technology project have been established, and the hierarchy analytic procedure have been used to determine the weighing coefficients for post-assessment indexes of cold recycling engineering of asphalt pavement, and the weighing values for various levels factors were given for the cold recycling base layer project of highway of Shenyang-Yingkou. Considering the road performance and economic benefit, societal and environmental benefit, the analytic hierarchy procedure (AHP) method can effectively avoid making wrong decisions subjectively and made it more scientific and reasonable to determine the weighing values of post-assessment indexes, and it is an effective method to determine the weighing values for post-assessment indexes of the cold recycling technology project.

2016 ◽  
Vol 11 (4) ◽  
pp. 291-301 ◽  
Author(s):  
Marek Iwański ◽  
Anna Chomicz-Kowalska

This paper presents findings of a study concerning the influence of binder type on the mechanical properties of road base in the cold recycling technology. The principal aim of this investigation was to evaluate the mixes in scope of susceptibility to moisture and low-temperatures. In the comparative research foamed bitumen and bitumen emulsion were used in four different concentrations (2.0%, 2.5%, 3.0%, 3.5%). The materials used in the study were reclaimed from an existing road construction layers: reclaimed aggregate from the road base and reclaimed asphalt pavement obtained by milling the surface and binder course. Portland cement in 2.0% concentration was used as a hydraulic binder. The evaluated parameters were: indirect tensile strengths, tensile strength retained and indirect tensile stiffness modulus at 25 °C. These tests were complemented by an evaluation of susceptibility to moisture and frost according to modified procedures implemented by American researchers: Tunnicliff, Root and Lottman. Moreover, tests for low-temperature cracking were conducted according to Finnish standard. The investigations showed that the use of foamed bitumen for road base layer produced in the cold recycling technology results in better mechanical properties and resistance to moisture and frost compared to using bitumen emulsion. The use of 2.5% of foamed bitumen and 2.0% of Portland cement in the recycled road base allowed to meet the established criteria.


2013 ◽  
Vol 368-370 ◽  
pp. 1973-1978
Author(s):  
Bao Yang Yu ◽  
Hong Yu Ding ◽  
Jia Yu Tian

Based on analytic hierarchy procedure, established the post-assessment indexes system of graded crushed stone base project. Considering the road performance and economic benefit, societal and environmental benefit, the weighing values for various layers factors group of the graded crushed stone base project of Heng-Gai line are calculated. Analytic hierarchy procedure (AHP) method can effectively avoid making decisions subjectively and more scientific and reasonable to determine the weighing values of post-assessment indexes and it is an effective method to determine the weighing values for post-assessment indexes of the graded crushed stone base project.


2012 ◽  
Vol 238 ◽  
pp. 497-502
Author(s):  
Zhi Dong Guo ◽  
Jia Liu ◽  
Cang Bo Li

Cold recycling technology of old asphalt pavement is a relatively new technology which has important application in the road surface treatment. Combining with the application of the cold recycling technology in rural old asphalt pavement, this paper analyzes and elaborates its construction technology and experience approach. The existing old asphalt pavement material is used in accordance with the new design requirements to form a special pavement structure surface. On rolling forming sections, the test is conducted for compaction, smoothness, bending and sinking and drill-core sampling for compressive strength. The results show that this process meets the general requirements of pavement base, and the quality is good with the advantages of saving costs and reducing waste damaging the environment.


2021 ◽  
Vol 4 (6) ◽  
Author(s):  
Zecheng Ni ◽  
Shijing Chen ◽  
Yihuan Li ◽  
Hongxi Peng ◽  
Jiawen Liang ◽  
...  

The early asphalt pavement in our country severely reduced the road performance due to various external factors during the use process. According to incomplete statistics, there are more asphalt pavements that need to be renovated and repaired every year in China, and the amount of construction waste such as asphalt concrete and other construction waste reaches 1,000. About ten thousand tons. If such a huge amount of construction waste is not used, it will inevitably cause great pollution to the environment. If it can be reused, not only will it be environmentally friendly and energy-saving, it will also save more than one billion yuan in costs. In view of the above problems, this article conducts related Research and Analysis on the Principle in Plant Cold Recycling for Foamed Bitumen and Mixture Performance to provide reference for future projects.


2012 ◽  
Vol 594-597 ◽  
pp. 1402-1406 ◽  
Author(s):  
Yue Zhang ◽  
Yun Long Zhao ◽  
Bao Yang Yu

In order to overcome the weakness of semi-rigidity base layer,the road performance of the SRX(Solution Road RomixSoilfix) stabilized base material and the mechanics response of asphalt pavement with the base layer stabilized by SRX have been studied in this paper. The CBR value and resilient modulus of SRX stabilized base material were given by indoor test. Based on the multiple layer elastic theory, both the mechanical responses of asphalt pavement structure with the SRX stabilized base and semi-rigid base were given, and according to the calculation results, the two kinds of pavement structure fatigue life were analyzed. The results have shown that the CBR value of SRX flexible material is greater than that of graded crushed stone; the SRX stable material can be used as pavement base layer, but the fatigue performance of SRX flexible base materials should be paid much attention.


2021 ◽  
Author(s):  
Kateryna Krayushkina ◽  
Tetiana Khymeryck ◽  
Kyrylo Fedorenko

Until recently, the most common way for recovering of damaged and worn asphalt pavements on Ukrainian roads remains the provision of additional reinforced layers over the old pavement with patching. However, such measures give only a short-term effect because after one or two years, the existing deformations and fractures beneath reinforced layers occur, especially in conditions of insufficient strength of the foundations. But nowadays, recycling technology of different variations became the main method of existing pavement renovation. The economic attractiveness of cold recycling technology is primarily in the reuse of existing road material for arrangement of new pavement layers, so there is no need to arrange special areas for storage and disposal of old asphalt. In addition, the use of such technology helps to minimize the harmful impacts on the environment during road repair works. The essence of cold recycling technology, which is the most widely used in Ukraine for the arrangement of a road foundation layer, is in the fact that the defective and destroyed pavement layers are strengthened directly by complex admixtures of organic (hot bitumen, bituminous emulsion, foamed bitumen) and mineral suspensions, lime) binders. Cold recycling, according to the complications of the work, is divided into several types, depending of the depth of cutting. The choice of a particular type of recovery depends mainly on the condition of the entire pavement structure, which is determined prior to the start of repair works. Optimal mis design of the organic and mineral mixture for the arrangement of the road foundation layer by cold recycling technology is also executed before the beginning of the works. Actually, the main direction of cold recycling technology research in Ukraine is the usage of new materials such as fiber - basalt or polymer, stabilizing additives (ionic or polymeric), industrial waste - slags of various types of production or other by-products. Performed studies have shown that the use of organic and mineral mixtures of optimal design with the insertion of basalt fiber increases crack resistance and durability of the arranged road foundation layer.


2012 ◽  
Vol 204-208 ◽  
pp. 1909-1913 ◽  
Author(s):  
Ming Hui Liu

Abstract. Cold recycling technology is applied to road rehabilitation in the recent years, and it has the advantages of mixture without heating, high RAP availability, low cost, quick speed of construction etc. Cold in-place recycling technology in this paper has been summarized including applied scope, cold recycling layer type, additives and new aggregates. We gives a detailed comparison and analysis to cold recycled mixture design method, and points out important design indexes. Combined with practical engineer of the technology in China, it analyzes application prospect and development trend on cold recycling technology.


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