scholarly journals Mechanical Connectors to Enhance the Interfacial Debonding of Concrete Overlays

2020 ◽  
Vol 10 (11) ◽  
pp. 3876
Author(s):  
Rubén-Daniel López-Carreño ◽  
Sergio Carrascón ◽  
Antonio Aguado ◽  
Pablo Pujadas

Concrete bonded whitetoppings and overlays usually fail due to a loss of bond between the layers as a consequence of direct actions (traffic loads) or indirect actions (temperature differences or shrinkage in the layers). These actions generate stresses in the interface that may exceed the strength capacity of the union between layers. This paper proposed an innovative solution for this problem that consisted of placing mechanical connectors in the overlay interfaces to provide them with post-cracking strength and maintaining the monolithic response of the pavement. Three experimental programs on real-scale pavements with two types of mechanical connectors were studied under heavy traffic in terms of structural performance. Findings reveal that this technique might be an excellent solution to the problem of interfacial debonding.

2011 ◽  
Vol 217-218 ◽  
pp. 181-186
Author(s):  
Shao Peng Wu ◽  
Jun Han ◽  
Xing Liu

Bitumen is widely used in road construction. Due to heavy traffic loads and environmental factors, bitumen properties will change during service life. Bitumen will age due to diffusion of oxygen and UV radiation. Repeated loading will result in decreasing strength because of fatigue. In this paper, one layer clay powder was used to modify base bitumen with different mass contents. Then the influences of ultraviolet radiation (UV) aging on the dynamic fatigue properties of the layered clay powder were evaluated by Dynamic Shear Rheomoter (DSR) and Universal Testing Machine (UTM). The ageing evaluation shows that the ageing resistance of bitumen is improved and this improvement is more notable in bitumen fatigue than mixture.


2012 ◽  
Vol 263-266 ◽  
pp. 2915-2919
Author(s):  
Gao Long Ma ◽  
Wen Tang

With the great increasing of high-speed networks,the traditional network intrusion detection system(NIDS) has a serious problem with handling heavy traffic loads in real-time ,which may result in packets loss and error detection . In this paper we will introduce the efficient load balancing scheme into NIDS and improve rule sets of the detection engine so as to make NIDS more suitable to high-speed networks environment.


1999 ◽  
Vol 13 (3) ◽  
pp. 251-273 ◽  
Author(s):  
Philip J. Fleming ◽  
Burton Simon

We consider an exponential queueing system with multiple stations, each of which has an infinite number of servers and a dedicated arrival stream of jobs. In addition, there is an arrival stream of jobs that choose a station based on the state of the system. In this paper we describe two heavy traffic approximations for the stationary joint probability mass function of the number of busy servers at each station. One of the approximations involves state-space collapse and is accurate for large traffic loads. The state-space in the second approximation does not collapse. It provides an accurate estimate of the stationary behavior of the system over a wide range of traffic loads.


UKaRsT ◽  
2018 ◽  
Vol 2 (2) ◽  
pp. 8
Author(s):  
Sugeng Dwi Hartantyo ◽  
Rasiyo Hepiyanto

Laston is a mixture of coarse aggregate, fine aggregate, and filler with a binder under the temperature of 145-155oC with the composition being studied and regulated by technical specifications. Laston is also known as AC (Asphalt Concrete).Laston itself is commonly used in Indonesia with continuous gradations used for heavy traffic loads. To get the addictive material is not easy and the material is expensive. Therefore, it is necessary to find alternatives to the cellulose fiber. Water hyacinth is a water weed that once grow and develop, it has high cellulose fiber content, which is about 60%.For that, done a research to add a hot asphalt mixture material that aims to improve the quality of mixed result. The selected material is natural water hyacinth. The method used is trial and error with reference of SNI 03-1737-1989. Variations used are 3%, 5%, and 7% of the asphalt weight, asphalt level used Is 5.61%.The result of this study is Marshall evaluation where the greatest score obtained for stability is 1325 kg,  Flow is 3.73 mm, Quotient Marshall is 401.02 kg/mm, VMA is 66.30%, VFWA is 19.25%, and VIM score is 54.35 %. With this result, the asphalt mixture can not be used because the results of VMA, VFWA, and VIM have not been suitable on specification of SNI 03-1737-1989.  Keywords: Laston, Asphalt Concrete, Water Hyacinth, SNI 03-1737-1989.


Author(s):  
Dong Woo Kim ◽  
Mohd Hairil Mohd ◽  
Byeong Joon Lee ◽  
Do Kyun Kim ◽  
Jung Kwan Seo ◽  
...  

Precisely evaluation of the reliability of aging structure is essential, particularly in the oil gas industry where inaccurate predictions of structural performance may have significant hazardous consequences. Related to this issue, it is important to predict the corrosion behavior of the gas pipeline structure used in the production of gas in subsea area. As corrosion is concerned, the effects of pipeline failure due to significant reduction of burst strength will make it hard for the pipeline operator to maintain the serviceability of pipelines. Therefore related to this problem, the resistance service of the pipeline is assessed by means of burst strength capacity. In this study, the critical part of the corrosion along 2.4 km pipeline is assessed using two approaches; empirical design codes formula and ANSYS numerical analysis. The future integrity of the pipeline is then assessed to predict the remaining year in service for the aging pipeline. The results and outcomes of the present study will be useful for evaluating the pipeline integrity as well as the prediction of the remaining life of in service aging pipeline structures.


2013 ◽  
Vol 634-638 ◽  
pp. 2746-2751 ◽  
Author(s):  
Noridah Mohamad ◽  
Najmuddin Hassan

The progressive research upon the issue on renewal technology that can improve the construction industry has initiated the study of Precast Lightweight Foam Concrete Sandwich Panel (PLFP) as an alternative to Industrialize Building System (IBS). This paper reports the analysis of structural behavior of PLFP with double shear connectors under axial load. The PLFP panel consists of two wythes which enclosed a layer of polystyrene layer. Six (6 mm) rebar was used as the vertical and horizontal reinforcement and 9 mm steel bar bent at 450 was used as the connector. Full scaled panel was tested under axial load till failure. It was found that PLFP panel with double shear truss connector has higher ultimate strength capacity compared to PLFP with single shear connectors ehen tested under axial load.


2020 ◽  
Vol 10 (22) ◽  
pp. 8186
Author(s):  
Sang-Sup Lee ◽  
Keum-Sung Park ◽  
Ju-Seong Jung ◽  
Kang-Seok Lee

The strength capacity of modular buildings is determined by the weakest part, and connections between modular units are often weaker than the modular units themselves. Thus, to verify the safety of modular structures, the structural performance of connections between modular units should be evaluated; the practical suitability of connection methods under a range of construction conditions should also be determined. In conventional modular building structures, modular units are generally connected using bolts between connector plates, interlocking devices, or steel plate welding. However, current methods are not technically or practically suitable for all types of modular buildings, such as high-rise modular buildings. Here, we describe a novel technology for connecting modular units to ensure the safety of modular structures. In this study, straight and cross-shaped metal connectors that use rectangular tubular columns and channel beams were proposed for connecting modules. Their structural performance was evaluated through cyclic loading tests by controlling the story drift angle in the width and longitudinal directions. The experimental results demonstrated that all specimens exhibited relatively stable behavior up to a drift angle of 0.04 rad, and there was a superior response in terms of energy absorption capability in the longitudinal direction results compared to the width direction. However, in comparison to the cross-shaped connector plate, the stiffness of the straight connector plate decreased as the drift angle of the column increased.


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