scholarly journals KARAKTERISTIK MARSHALL KERAMIK SEBAGAI AGREGAT HALUS DAN FILLER PADA CAMPURAN HOT ROLLER SHEET (HRS)

2022 ◽  
Vol 5 (1) ◽  
pp. 104-109
Author(s):  
Ulwiyah Wahdah Mufassirin Liana ◽  
Santi Yatnikasari ◽  
Muhammad Noor Asnan
Keyword(s):  

Penelitian ini mengenai pemanfaatan bahan sisa keramik pada pemasangan lantai rumah sebagai agregat halus dan filler dalam pembuatan lapis perkerasan aspal. Sebagai bahan agregat halus dan filler, keramik dicampur dengan Semen Portland dengan komposisi tertentu. Hal ini dilakukan untuk meningkatkan daya ikat antar butiran keramik. Penelitian ini dilakukan untuk mengetahui penggunaan keramik sebagai dan agregat halus dan filler pada campuran HRS-WC terhadap karakteristik stabilitas, flow, density, VITM, VFWA, VMA, Marshall Quotient dan Immersion Test. Tahap pertama dimulai dari pemeriksaan bahan aspal dan agregat menggunakan spesifikasi Bina Marga. Tahap kedua membuat benda uji untuk mencari kadar aspal optimum dengan filler abu batu dengan kadar aspal 4%, 4,5%, 5%, 5,5%, dan 6%. Tahap ketiga dilakukan pengujian Marshall standar dan Immersion Test pada variasi agregat halus dan filler dengan kadar yaitu 0% keramik, 25% keramik, 50% keramik, 75% keramik dan 100% keramik dengan menggunakan kadar aspal optimum. Dari hasil penelitian dapat disimpulkan bahwa semakin banyak penambahan keramik akan menurunkan nilai stabilitas, Marshall Quotient, VITM dan VMA dan menaikkan nilai flow, density dan VFWA. Keramik dapat digunakan sebagai agregat halus dan filler dalam pembuatan lapis perkerasan HRS dengan variasi kadar 25% keramik.

Metals ◽  
2020 ◽  
Vol 11 (1) ◽  
pp. 3
Author(s):  
Huiling Zhou ◽  
Fanglian Fu ◽  
Zhixin Dai ◽  
Yanxin Qiao ◽  
Jian Chen ◽  
...  

The 6061-T6 aluminum alloy welding joints were fabricated using gas metal arc welding (GMAW) of various laser powers, and the effect of laser power on the microstructure evolution of the welding joints was investigated. The corrosion behaviors of 6061-T6 aluminum alloy welding joints were investigated in 3.5 wt% NaCl solution using scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDS). The results showed that the micro-galvanic corrosion initiation from Mg2Si or around the intermetallic particles (Al-Fe-Si) is observed after the immersion test due to the inhomogeneous nature of the microstructure. The preferential dissolution of the Mg2Si and Al-Fe-Si is believed to be the possible cause of pitting corrosion. When the laser power reached 5 kW, the microstructure of the welded joint mainly consisted of Al-Fe-Si rather than the Mg2Si at 2 kW. The relatively higher content of Al-Fe-Si with increasing in laser power would increase the volume of corrosion pits.


Coatings ◽  
2021 ◽  
Vol 11 (6) ◽  
pp. 667
Author(s):  
Zexin Wang ◽  
Fei Ye ◽  
Liangyu Chen ◽  
Weigang Lv ◽  
Zhengyi Zhang ◽  
...  

In this work, ZK60 magnesium alloy was employed as a substrate material to produce ceramic coatings, containing Ca and P, by micro-arc oxidation (MAO). Atmospheric plasma spraying (APS) was used to prepare the hydroxyapatite layer (HA) on the MAO coating to obtain a composite coating for better biological activity. The coatings were examined by various means including an X-ray diffractometer, a scanning electron microscope and an energy spectrometer. Meanwhile, an electrochemical examination, immersion test and tensile test were used to evaluate the in vitro performance of the composite coatings. The results showed that the composite coating has a better corrosion resistance. In addition, this work proposed a degradation model of the composite coating in the simulated body fluid immersion test. This model explains the degradation process of the MAO/APS coating in SBF.


Sensors ◽  
2021 ◽  
Vol 21 (2) ◽  
pp. 464
Author(s):  
Wei Ma ◽  
Sean Qian

Recent decades have witnessed the breakthrough of autonomous vehicles (AVs), and the sensing capabilities of AVs have been dramatically improved. Various sensors installed on AVs will be collecting massive data and perceiving the surrounding traffic continuously. In fact, a fleet of AVs can serve as floating (or probe) sensors, which can be utilized to infer traffic information while cruising around the roadway networks. Unlike conventional traffic sensing methods relying on fixed location sensors or moving sensors that acquire only the information of their carrying vehicle, this paper leverages data from AVs carrying sensors for not only the information of the AVs, but also the characteristics of the surrounding traffic. A high-resolution data-driven traffic sensing framework is proposed, which estimates the fundamental traffic state characteristics, namely, flow, density and speed in high spatio-temporal resolutions and of each lane on a general road, and it is developed under different levels of AV perception capabilities and for any AV market penetration rate. Experimental results show that the proposed method achieves high accuracy even with a low AV market penetration rate. This study would help policymakers and private sectors (e.g., Waymo) to understand the values of massive data collected by AVs in traffic operation and management.


2021 ◽  
Vol 11 (5) ◽  
pp. 2057
Author(s):  
Abdallah Namoun ◽  
Ali Tufail ◽  
Nikolay Mehandjiev ◽  
Ahmed Alrehaili ◽  
Javad Akhlaghinia ◽  
...  

The use and coordination of multiple modes of travel efficiently, although beneficial, remains an overarching challenge for urban cities. This paper implements a distributed architecture of an eco-friendly transport guidance system by employing the agent-based paradigm. The paradigm uses software agents to model and represent the complex transport infrastructure of urban environments, including roads, buses, trolleybuses, metros, trams, bicycles, and walking. The system exploits live traffic data (e.g., traffic flow, density, and CO2 emissions) collected from multiple data sources (e.g., road sensors and SCOOT) to provide multimodal route recommendations for travelers through a dedicated application. Moreover, the proposed system empowers the transport management authorities to monitor the traffic flow and conditions of a city in real-time through a dedicated web visualization. We exhibit the advantages of using different types of agents to represent the versatile nature of transport networks and realize the concept of smart transportation. Commuters are supplied with multimodal routes that endeavor to reduce travel times and transport carbon footprint. A technical simulation was executed using various parameters to demonstrate the scalability of our multimodal traffic management architecture. Subsequently, two real user trials were carried out in Nottingham (United Kingdom) and Sofia (Bulgaria) to show the practicality and ease of use of our multimodal travel information system in providing eco-friendly route guidance. Our validation results demonstrate the effectiveness of personalized multimodal route guidance in inducing a positive travel behavior change and the ability of the agent-based route planning system to scale to satisfy the requirements of traffic infrastructure in diverse urban environments.


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