scholarly journals RFID-Based Crack Detection of Ultra High-Performance Concrete Retrofitted Beams

Sensors ◽  
2019 ◽  
Vol 19 (7) ◽  
pp. 1573 ◽  
Author(s):  
Benjamin Bruciati ◽  
Shinae Jang ◽  
Pierre Fils
Keyword(s):  
High Performance ◽  
Crack Detection ◽  
High Performance Concrete ◽  
Low Cost ◽  
Damage Index ◽  
Steel Beams ◽  
Ultra High Performance Concrete ◽  
Novel Material ◽  
New Material ◽  
The 1960S

Ultra-high-performance concrete (UHPC) is a novel material with multiple known uses and many still yet to be discovered. Recently, the use of encasing welded shear studs in UHPC on the web of corroded steel beams was developed. This creates a bearing force transfer mechanism to bypass the corroded web plate. This new material and its uses come with many uncertainties in the short and long term. Structural health monitoring (SHM) can be a tool to observe the development. Specifically, radio frequency technology (RFID) can be used. RFID has existed commercially since the 1960s and has been used as a crack sensor before, but never with UHPC. RFID-based crack sensing is being used to monitor the UHPC retrofit. A crack is simulated on the UHPC specimen and then a commercial, low cost tag is secured. Using backscatter power, the tag reads the crack existence and its increasing volume with every new damage stage. Using a damage index, comparing the uncracked and each cracked stage, this method is not restricted to the raw received signal strength indicator (RSSI), which could be different at each tag. With this sensor, the small cracks that occur in UHPC during its creation can be monitored to ensure the capacity of the retrofitting is maintained. The tested RFID-based crack sensor can be used on various other forms of UHPC.

SUSTAINABLE ULTRA-HIGH-PERFORMANCE GLASS CONCRETE FOR INFRASTRUCTURES

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Arezki Tagnit-Hamou ◽  
Nancy A. Soliman
Keyword(s):  
High Performance ◽  
Glass Powder ◽  
Mechanical Performance ◽  
High Performance Concrete ◽  
Low Cost ◽  
Research Work ◽  
High Strength ◽  
Quartz Powder ◽  
Ultra High Performance Concrete ◽  
Powder Particles

This paper presents research work on the development of a green type of ultra-high-performance concrete using ground glass powders with different degrees of fineness (UHPGC). This article presents the development of an innovative, low-cost, and sustainable UHPGC through the use of glass powder to replace cement, and quartz powder particles. An UHPGC with a compressive strength (fc) of up to 220 MPa was prepared and its fresh, and mechanical properties were investigated. The test results indicate that the fresh UHPGC properties were improved when the cement and quartz powder were replaced with non-absorptive glass powder particles. The strength improvement can be attributed to the glass powder’s pozzolanicity and to its mechanical performance (very high strength and elastic modulus of glass). A case study of using this UHPGC is presented through the design and construction of a footbridge. Erection of footbridge at University of Sherbrooke Campus using UHPGC is also presented as a full-scale application.

Comparison of Bond Behaviour between Reinforcement and UHPC and Ordinary Concrete in Extreme Conditions

2015 ◽  
Vol 1124 ◽  
pp. 319-324
Author(s):  
David Čítek ◽  
Tomáš Mandlík ◽  
Jiří Kolísko ◽  
Stanislav Řeháček
Keyword(s):  
High Performance ◽  
High Performance Concrete ◽  
High Strength ◽  
Ultra High Performance Concrete ◽  
Bond Behaviour ◽  
The Czech Republic ◽  
Prestressing Steel ◽  
Ordinary Concrete ◽  
New Material ◽  
Number Of Cycles

The UHPC (Ultra High Performance Concrete) is a promising material suitable for application in special structures. However, the knowledge on performance of this relatively new material is rather limited. The exceptional mechanical properties of UHPC allow for a modification of the design rules, which are applicable in ordinary or high strength concrete. The research executed already in the Czech Republic showed that the anchorage length of ordinary and prestressing steel may be significantly shorter than that which is usually required in code specifications. This paper deals in more detail with impact of thermal stress on bond of prestressing strands and UHPC. Samples were subjected to the cycling heat/frost device and effect of a number of cycles on final bond behaviour of both UHPC and ordinary concrete were investigated. The article describes differences between ordinary concrete and UHPC.

scholarly journals Development of Low-Cost Wireless Sensing System for Smart Ultra-High Performance Concrete

Sensors ◽  
2021 ◽  
Vol 21 (19) ◽  
pp. 6386
Author(s):  
Huy-Viet Le ◽  
Tae-Uk Kim ◽  
Suleman Khan ◽  
Jun-Young Park ◽  
Jong-Woong Park ◽  
...  
Keyword(s):  
Compressive Stress ◽  
Electrical Resistance ◽  
High Performance ◽  
High Performance Concrete ◽  
Low Cost ◽  
Wireless Sensing ◽  
Ultra High Performance Concrete ◽  
Maximum Compressive Stress ◽  
Sensing System ◽  
Wireless Sensing System

This study proposes the development of a wireless sensor system integrated with smart ultra-high performance concrete (UHPC) for sensing and transmitting changes in stress and damage occurrence in real-time. The smart UHPC, which has the self-sensing ability, comprises steel fibers, fine steel slag aggregates (FSSAs), and multiwall carbon nanotubes (MWCNTs) as functional fillers. The proposed wireless sensing system used a low-cost microcontroller unit (MCU) and two-probe resistance sensing circuit to capture change in electrical resistance of self-sensing UHPC due to external stress. For wireless transmission, the developed wireless sensing system used Bluetooth low energy (BLE) beacon for low-power and multi-channel data transmission. For experimental validation of the proposed smart UHPC, two types of specimens for tensile and compression tests were fabricated. In the laboratory test, using a universal testing machine, the change in electrical resistivity was measured and compared with a reference DC resistance meter. The proposed wireless sensing system showed decreased electrical resistance under compressive and tensile load. The fractional change in resistivity (FCR) was monitored at 39.2% under the maximum compressive stress and 12.35% per crack under the maximum compressive stress tension. The electrical resistance changes in both compression and tension showed similar behavior, measured by a DC meter and validated the developed integration of wireless sensing system and smart UHPC.

Numerical Analysis of Prestressed UHPC Lightened Member

2018 ◽  
Vol 272 ◽  
pp. 172-177
Author(s):  
Michaela Kopálová ◽  
Vladimír Pribramsky
Keyword(s):  
Web Application ◽  
High Performance ◽  
High Performance Concrete ◽  
Essential Elements ◽  
Bending Test ◽  
Steel Beams ◽  
Ultra High Performance Concrete ◽  
Four Point Bending ◽  
Entire Height ◽  
Beam Analysis

UHPC (ultra-high-performance concrete) is one of the essential elements in the development and research of new modern concrete structures. It is a material showing all the positive qualities in terms of the design efficiency and construction process. In this paper, we analyze the behavior of prestressed UHPC I-beam with lightened web that is loaded by four-point bending test. Two variants of I-beam were used for the analysis. The first variant is beam with a continuous thin web and the second variant is beam with lightened web, which is analogous to castellated steel I-profiles, commonly used types of steel beams with larger span. Although these are relatively small specimens, light beam analysis can be extrapolated for large span structures, especially bridges. In case of structures of larger magnitude with precast members of UHPC, a certain amount of discontinuous action cannot be avoided, which is the case of using a lightened beam with openings across the entire height of the web. Application of prestressed tendons ensures sufficient resistance for bending action; members are designed so failure occurs by shear response.

scholarly journals Elastic Restraint Effect of Concrete Circular Columns with Ultrahigh-Performance Concrete Jackets: An Analytical and Experimental Study

Materials ◽  
2021 ◽  
Vol 14 (12) ◽  
pp. 3278
Author(s):  
Mujahed Alsomiri ◽  
Xiaofang Jiang ◽  
Zhao Liu
Keyword(s):  
High Performance ◽  
Structural Engineering ◽  
High Performance Concrete ◽  
Limit State ◽  
Concrete Columns ◽  
Theory Of Elasticity ◽  
Ultra High Performance Concrete ◽  
Service Limit State ◽  
New Material ◽  
Superior Mechanical Properties

Concrete circular columns are among the most common vertical load-bearing members in structural engineering. Because of the change of service loads or environmental factors, the strengthening of deteriorated members is often demanded to restore and maintain their performance. In view of the limitations of the traditional strengthening methods and the superior mechanical properties of the new material, ultra-high-performance concrete (UHPC), this study analyzed the stress–strain state of concrete circular columns confined by UHPC jackets under axial compression in the elastic stage. Since elastic analysis is the basis for the service limit state design, the elastic stress solution was derived through the theory of elasticity, and experimental verification of the effectiveness of the UHPC jackets in circular concrete columns was performed. Theoretical bases and references for practical strengthening works are provided.

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