scholarly journals Application of Conductive Materials to Asphalt Pavement

2017 ◽  
Vol 2017 ◽  
pp. 1-7 ◽  
Author(s):  
Hai Viet Vo ◽  
Dae-Wook Park

Snow-melting pavement technique is an advanced preservation method, which can prevent the forming of snow or ice on the pavement surface by increasing the temperature using an embedded heating system. The main scope of this study is to evaluate the impact of conductive additives on the heating efficiency. The electrical resistivity and thermal conductivity were considered to investigate effects of conductive additives, graphite, and carbon fibers on the snow-melting ability of asphalt mixtures. Also, the distribution of the conductive additives within the asphalt concrete body was investigated by microstructural imaging. An actual test was applied to simulate realistic heating for an asphalt concrete mixture. Thermal testing indicated that graphite and carbon fibers improve the snow-melting ability of asphalt mixes and their combination is more effective than when used alone. As observed in the microstructural image, carbon fibers show a long-range connecting effect among graphite conductive clusters and gather in bundles when added excessively. According to the actual test, adding the conductive additives helps improve snow-melting efficiency by shortening processing time and raising the surface temperature.

In systems of external reinforcement on the basis of carbon fibers used for strengthening concrete structures, special attention should be paid to the anchoring of carbon reinforcement elements. Taking into account their installation in the external reinforcement system in the reinforced structure, the anchoring elements can work on the shear. At the same time, the nature of such operatioj as a whole is insufficiently studied, which raises many questions both about their calculation and their design. In order to improve calculation and design methods of carbon anchors, special experimental studies of the parameters of anchors and their impact on the bearing capacity of the anchor fastening were carried out. These studies relate to the length of the anchorage in the concrete body, maximum shear forces, ultimate deformations of the anchor etc. According to the results of the experiments conducted, the analysis of results obtained was performed, in particular, various schemes of destruction of anchors were analyzed and the impact of the depth of the anchor, its diameter of the anchor, as well as the type of binder on the degree of theirdestruction were studied.


2019 ◽  
Vol 2019 ◽  
pp. 1-10 ◽  
Author(s):  
Hechuan Li ◽  
Jianying Yu ◽  
Quantao Liu ◽  
Yuanyuan Li ◽  
Yaqi Wu ◽  
...  

It is consensual that the self-healing property of asphalt concrete can repair the damage inside it during high temperature and rest period. In order to not affect the traffic, the rest period of asphalt pavement is very short and uncontrollable; so, it is necessary to obtain enough high temperature in a limited time to achieve higher healing efficiency of asphalt concrete. The purpose of this paper is to study the induction heating efficiency and healing behaviors of asphalt concretes doped with different conductive additives. Steel fiber, steel grit, and steel slag were added to asphalt mixtures as conductive additives to prepare induction healing asphalt concretes. The steel grit and steel slag were added to replace the aggregates of corresponding particle size by equal volume to ensure the consistency of asphalt concrete volume, which can avoid degrading the performance of asphalt concrete due to the change of porosity. The induction heating efficiency and healing rate of asphalt concrete were quantified by infrared camera and three-point bending-healing experiment, respectively. The results showed that the thermal properties of asphalt concrete changed with the addition of different conductive additives. The asphalt concrete with steel fiber had the best induction heating property. While steel slag had extremely weak induction heating speed, the better thermal insulation property of the asphalt concrete with steel slag resulted in a higher induction healing rate. It was suggested to add steel slag to induction healing asphalt concrete to improve the healing rate.


Author(s):  
Stéphanie Harchambois ◽  
Vincent Le Toux ◽  
Geoffrey Guindeuil ◽  
Romain Vivet ◽  
François-Xavier Pasquet ◽  
...  

Abstract The Electrically Trace Heated Blanket (ETH-Blanket) is a new offshore intervention/remediation system currently in development by TechnipFMC for the efficient remediation of plugs due to hydrates or wax in subsea production and injection flowlines. The ETH-Blanket consists of a network of heating cables placed underneath an insulation layer which is laid onto the seabed above the plugged flowline. By applying electrical power to the cables, heat is generated by Joule effect which warms up the flowline content until hydrate dissociation or wax plug remediation through softening or complete melting. As part of a Joint Industry Project (JIP) between TechnipFMC, Shell and Total, full-scale thermal testing of an ETH-Blanket prototype was carried out in Artelia facilities (in Grenoble, France). This testing was performed to verify the capability of the ETH-Blanket system to increase the temperature of the fluid inside a pipe sample above a target temperature (hydrate dissociation temperature or wax disappearance temperature) for various conditions. The impact of lateral misalignment of the ETH-blanket on the pipe and of the pipe burial depth were studied. Moreover, the tests were carried out on two pipe samples, with different designs and insulation properties. In parallel, CFD models of the test set-up were built to replicate the thermal behaviour of the ETH-Blanket. The combination of these models with the measured heating efficiency of the prototype allowed characterising the performances of the system in real subsea conditions. This paper presents the description of the full scale thermal testing conditions. Results of the different tests are detailed and the impact of the different parameters on the ETH-Blanket thermal performances are assessed, focusing on natural convection effects, thermal losses and the overall data gathering process.


Reliable anchoring of carbon reinforcement elements into the body of the structure is one of the most important aspects when designing the strengthening of reinforced concrete structures with the system of external reinforcement based on composite materials. The use of carbon fiber anchoring elements in this case is confirmed by numerous tests, but there are no methodological provisions for the calculation and design of these anchors at the moment. Special experimental studies of the parameters of anchors and their effect on the bearing capacity of the anchorage have been conducted for this purpose. The tests were carried out in two stages, during the experiments the breaking load, the size of the concrete pull-out cone, as well as the nature of the destruction of the anchor were recorded. In addition, the length of the anchorage in the concrete body, the pull-out forces, the maximum deformations of the anchor and the length of the anchorage when introducing the anchor fibers in the external reinforcement system have been defined. According to the results of the experiments, the analysis of the results, in particular, various schemes of destruction of anchors and the impact of the depth of the anchor on them, its diameter, as well as the type of binders was carried out.


2019 ◽  
Vol 24 (2) ◽  
pp. 166
Author(s):  
Kusdiyono Kusdiyono ◽  
Supriyadi Supriyadi ◽  
Tedjo Mulyono ◽  
Sukoyo Sukoyo

At present, plastic is a material that is needed by the community at large, where the impact is also very extraordinary after the plastic is used in everyday life which can cause serious problems if the management is not done properly. The problem of plastic waste does not only occur in the city of Semarang, but also in other cities, so that the Ministry of Environment and Forestry has implemented a paid plastic bag program in the short term. But this is only to deal with problems in the short term. In the long run, it will not solve the problem of "plastic waste", because the policy actually encourages people to buy plastic which, of course, will add a new burden for the community to buy it. Based on the above problems, it is necessary to utilize this plastic waste to be made into road pavement materials such as in the manufacture of Asphal Concrette Wearing Course, by making 5 mixed variations ranging from (2 to 10)% of the weight of the aggregate . This research was initiated through a survey process, material procurement, testing of stacking materials, making test specimens, testing specimens. The results of the research can show that the type of Thermosetting plastic waste has a significant influence on the Asphalt Concrete mixture AC-WC heat mixture, including: Density, Marshall Stability, Flow, VIM, VMA, MQ and the remaining Marshall Stability tend to show an increase, moderate VFA and VIMrefusal Density values tend to show a decrease. Thus the plastic waste from the Thermosetting type can be used as a partial replacement of the aggregate for the Asphalt Concrete mixture AC-WC heat mixture with a plastic waste content is limited to a maximum of 10% and at an optimum asphalt content of 5.55%. Thus this research is expected to be of benefit to the industry and the people of Semarang in relation to the use of plastic waste for road pavement.


Mathematics ◽  
2022 ◽  
Vol 10 (2) ◽  
pp. 178
Author(s):  
Mohammed Alghaseb ◽  
Walid Hassen ◽  
Abdelhakim Mesloub ◽  
Lioua Kolsi

In this study, a 3D numerical study of free ventilated room equipped with a discrete heat source was performed using the Finite Volume Method (FVM). To ensure good ventilation, two parallel openings were created in the room. A suction opening was located at the bottom of the left wall and another opening was located at the top of the opposite wall; the heat source was placed at various positions in order to compare the heating efficiency. The effects of Rayleigh number (103 ≤ Ra ≤ 106) for six heater positions was studied. The results focus on the impact of these parameters on the particle trajectories, temperature fields and on the heat transfer inside the room. It was found that the position of the heater has a dramatic effect on the behavior and topography of the flow in the room. When the heat source was placed on the wall with the suction opening, two antagonistic behaviors were recorded: an improvement in heat transfer of about 31.6%, compared to the other positions, and a low Rayleigh number against 22% attenuation for high Ra values was noted.


BioResources ◽  
2020 ◽  
Vol 15 (4) ◽  
pp. 7671-7686
Author(s):  
Young-Rok Seo ◽  
Sang-U Bae ◽  
Birm-June Kim ◽  
Min Lee ◽  
Qinglin Wu

Waste wood-plastic composite (WPC) was used in this work as a raw material to produce recycled WPCs reinforced with carbon fiber and nanoclay. To evaluate the synergistic effects of carbon fiber and nanoclay, various performances (i.e., microstrucural, mechanical, thermal, water absorption, and electrical properties) were investigated. Scanning electron micrographs and X-ray diffraction analysis of the fillers (carbon fiber and nanoclay) present in the recycled WPCs showed that the nanoclays were properly intercalated when filled with carbon fibers. According to mechanical property analysis, hybrid incorporation of carbon fibers and nanoclays improved impact strength, tensile strength, and flexural strength. However, further incorporation of nanoclays reduced the impact strength and did not improve the tensile modulus or the flexural modulus. The carbon fibers present in the recycled WPCs improved the electrical conductivity of the composites, despite the various fillers that interfered with their electrical conduction. In addition, carbon fibers and nanoclays were mixed into the recycled WPCs to improve the thermal stability of the composites. Finally, the presence of nanoclays in recycled WPCs led to increased water uptake of the composites.


2018 ◽  
Vol 774 ◽  
pp. 410-415 ◽  
Author(s):  
Kazuto Tanaka ◽  
Ken Uzumasa ◽  
Tsutao Katayama

Carbon fiber reinforced thermoplastics (CFRTP) are expected to be used as a structural material for aircraft and automobiles not only for their mechanical properties such as high specific strength and high specific rigidity but also for their high recyclability and short molding time. Generally, in a composite material having a laminated structure, interlaminar delamination is often caused by an out-of-plane impact, so the interlayer property plays an important role in the mechanical properties. It has been reported that the fiber/matrix interfacial strength increases by grafting carbon nanotubes (CNT) on the carbon fiber surface. In this study, CNT grafted carbon fibers were used for reinforcement of CFRTP laminate for the improvement of impact properties of CFRTP laminates. The impact absorbed energy of the CFRTP laminate using CNT grafted carbon fibers as reinforcing fiber was higher than that using untreated CF.


2011 ◽  
Vol 12 (2) ◽  
pp. 101-109 ◽  
Author(s):  
Tamer M. Breakah ◽  
Jason P. Bausano ◽  
R. Christopher Williams ◽  
Stan Vitton

2003 ◽  
Vol 1823 (1) ◽  
pp. 111-120 ◽  
Author(s):  
Nasir G. Gharaibeh ◽  
Michael I. Darter

The Illinois Department of Transportation has periodically conducted pavement longevity studies to assess the longevities and the traffic loadcarrying capacities of these new and rehabilitated pavements so that any needed improvements to design, construction, or rehabilitation could be identified and implemented in a timely manner. The results of the latest round of pavement longevity studies in Illinois provide performance data updated through 2000 for new hot-mix asphalt concrete (HMAC), jointed reinforced concrete pavement (JRCP), and continuously reinforced concrete pavement (CRCP) construction as well as the asphalt concrete (AC) overlays (first, second, and third overlays) of these original pavements. These studies were conducted on more than 2,000 centerline miles of Interstate and other freeways that were constructed beginning in the 1950s in Illinois. Significant findings on the performance of the original pavements and overlays were obtained, and these findings will be of value to designers and managers to improve pavement cost-effectiveness and life. Survival curves have an economic impact on the agency. Key findings show the impact of pavement type (HMAC, JRCP, or CRCP), slab thickness, geographic location (north or south), durability cracking (D-cracking), and AC overlay thickness (coupled with preoverlay condition) on longevity and load-carrying capacity. The results of the probabilistic analysis illustrate the wide variation in pavement life and traffic carried. The study also provides models for predicting the probability of survival for various designs of original pavements and AC overlays in Illinois for use in pavement management.


Sign in / Sign up

Export Citation Format

Share Document