Browsing by Author "Xiong, Haocheng"

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    Effect of Curing on Mechanical Properties of Cement-Stabilized Coral Sand in Marine Environment
    Chen, Mingyuan; Geng, Jiuguang; Xiong, Haocheng; Shang, Tao; Xue, Cheng; Abbas, Montasir M. (Hindawi, 2020-07-22)
    The use of coral sand prepared from cement-stabilized materials can significantly reduce the cost, construction period, and damage to the environment caused by stone mining. The choice of water in mixing and curing the cement-stabilized materials on islands should be considered. Cement-stabilized coral sand was tested in three different preparation and maintenance systems in the marine environment. The compressive strength, weight change, and chloride ion concentration change in cement-stabilized coral sand with different cement content were measured after 7 d, 28 d, 60 d, and 90 d, respectively. The microstructure of specimens was observed by XRD and SEM. Results show that the compressive strength of specimens in the seawater mixing and seawater curing system developed 0.9 MPa faster than that in the fresh water mixing and curing system at an early stage. But the compressive strength of specimens in seawater mixing and seawater curing shrank later, being 0.5 MPa lower than that in fresh water mixing and curing. The cement content was positively correlated with the free chloride ion reaction and mass growth rate. For road construction on islands, the mixing and curing of cement-stabilized coral sand with seawater should be given priority in the early stage.
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    Feasibility Study for Using Piezoelectric-Based Weigh-In-Motion (WIM) System on Public Roadway
    Xiong, Haocheng; Zhang, Yinning (MDPI, 2019-07-31)
    Weigh-in-Motion system has been the primary selection of U.S. government agencies as the weighing enforcement for decades to protect the road pavement. In recent years, the number of trucks has increased by about 40% and in 2017, they travel 25% more annually than in 2016. The lack of the budget has slowed down the expansion of weighing enforcement to catch up with the growing workload of vehicle weighing. Unsupervised pavement section suffers more pavement damage and increased repairing cost. In this work, a piezoelectric material based WIM system (P-WIM) is developed. Such a system consists of several piezoelectric material disks that are capable of generating characteristic voltage output from passing vehicles. The axle loading of the vehicle can be determined by analyzing the voltage generated from the P-WIM. Compared to traditional WIM system, P-WIM requires nearly zero maintenance and costs 80% less on capital investment and less labor and effort to integrate. To evaluate the feasibility of this technology to serve as weighing enforcement on public roadways, prototype P-WIMs are fabricated and installed at a weigh station. The vehicle loading information provided by the weigh station is used to determine the force transmission percentage of the installed P-WIMs, which is an important parameter to determine the vehicles’ axle loading by generated voltage.
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    Piezoelectric Energy Harvesting for Roadways
    Xiong, Haocheng (Virginia Tech, 2015-02-11)
    Energy harvesting technologies have drawn much attention as an alternative power source of roadway accessories in different scales. Piezoelectric energy harvesting consisting of PZT piezoceramic disks sealed in a protective package is developed in this work to harness the deformation energy of pavement induced by traveling vehicles and generate electrical energy. Six energy harvesters are fabricated and installed at the weigh station on I-81 at Troutville, VA to perform on-site evaluation. The electrical performance of the installed harvesters is evaluated by measuring the output voltage and current generated under real traffic. Instant and average power outputs are calculated from the measured waveforms of output voltage and current. The analysis of the testing results shows that the electrical productivity of the energy harvesters are highly relevant to the axle configuration and magnitude of passing vehicles. The energy transmission efficiency of the energy harvester is also assessed.