scholarly journals Performance Assessment of a Renovated Precast Concrete Bridge Using Static and Dynamic Tests

2020 ◽  
Vol 10 (17) ◽  
pp. 5904
Author(s):  
Milan Sokol ◽  
Michal Venglár ◽  
Katarína Lamperová ◽  
Monika Márföldi
Keyword(s):  
Precast Concrete ◽  
Measuring System ◽  
Data Logger ◽  
Global Response ◽  
Traffic Loads ◽  
Dynamic Analyses ◽  
Time Histories ◽  
Load Tests ◽  
Method Model ◽  
Complex Measuring

The article presents the development of a SHM (Structural Health Monitoring) strategy intended to confirm the improvement of the load-bearing capacity of a bridge over the Ružín Dam using static and dynamic load tests, as well as numerical simulations. The paper comprises measurements of the global response of the bridge to prepare a verified and validated FEM (Finite Element Method) model. A complex measuring system used for the tests consisted of two main parts: an interferometric IBIS-S (Image by Interferometric Survey-Structures) radar and a multichannel vibration and strain data logger. Next, structure–vehicle interactions were modelled, and non-linear numerical dynamic analyses were performed. As a result, the time histories of displacements of the structure from traffic effects were obtained. Their comparison with IBIS-S radar records proves that this method can be effectively used for assessing bridges subjected to common traffic loads. The results (measured accelerations) obtained by local tests in external pre-stressed cables are presented and a convenient method for acquiring the axial force in the cables is proposed.

Investigation of Grouted Coupler Connection Details for Accelerated Bridge Construction

2021 ◽  
pp. 036119812199939
Author(s):  
Brent Phares ◽  
Yoon-Si Lee ◽  
Travis K. Hosteng ◽  
Jim Nelson
Keyword(s):  
Crack Width ◽  
High Performance ◽  
Static Load ◽  
High Performance Concrete ◽  
Precast Concrete ◽  
Chloride Penetration ◽  
Load Testing ◽  
Test And Evaluation ◽  
Load Tests ◽  
Precast Elements

This paper presents a laboratory investigation on the performance of grouted rebar couplers with the connection details similar to those utilized on the precast concrete elements of the Keg Creek Bridge on US 6 in Iowa. The testing program consisted of a series of static load tests, a fatigue test, and evaluation of the chloride penetration resistance of laboratory specimens. The goal of this testing was to evaluate the ability of the grouted rebar couplers to develop flexural capacity at the joint between the precast elements as well as the durability of the connection. For structural load testing, seven full-scale specimens, each with #14 epoxy-coated rebars spliced by epoxy-coated grouted couplers, were fabricated and tested in three different loading cases: four-point bending, axial tension plus bending, and a cyclic test of the system in bending. The static load testing demonstrated that the applied axial load had a minimal effect on the formation of cracks and overall performance of the connection. When ultra-high performance concrete was used as a bedding grout, the initiation of crack was slightly delayed but no considerable improvement was observed in the magnitude of the crack width during loading or the crack closure on unloading. The results of the seventh specimen, tested in fatigue to 1 million cycles, showed little global displacement and crack width throughout the test, neither of which expanded measurably. No evidence of moisture or chloride penetration was detected at the grouted joint during the 6-month monitoring.

scholarly journals Modified mortar pad behavior in the transfer of compressive stresses

2016 ◽  
Vol 9 (3) ◽  
pp. 414-434
Author(s):  
J. D. Ditz ◽  
M. K. EL Debs ◽  
G. H. Siqueira
Keyword(s):  
Precast Concrete ◽  
Concrete Strength ◽  
Compressive Load ◽  
Stress Transfer ◽  
Compressive Stresses ◽  
Bonded Phase ◽  
Concrete Blocks ◽  
Load Tests ◽  
Styrene Butadiene ◽  
Concrete Elements

ABSTRACT This research aims to analyze the compressive stress transfer between precast concrete elements using cement mortar pads modified with polypropylene fibers, styrene-butadiene latex and heat-expanded vermiculite. The stress transfer analyses are performed interleaving a cementbearing pad between two concrete blocks, subjecting the entire specimen to different compressive load tests. The parameters analyzed in the tests are: surface roughness (using bosses on the bonded phase of different thicknesses), compressive strength with monotonic and cyclic loadings. The main results obtained in this study are: a) the presence of pad increased the strength in 24% for thicknesses of imperfections of 0.5 mm and approximately 12% for smooth faces blocks; b) gain of effectiveness of the bearing pad when the concrete strength was reduced; c) for cyclic loading, the bearing pad increased in 48% the connections strength.

scholarly journals Limitations of the Danish driving formula for short piles

2021 ◽  
Vol 44 (2) ◽  
pp. 1-6
Author(s):  
Silvio Heleno de Abreu Vieira ◽  
Francisco R. Lopes
Keyword(s):  
Load Capacity ◽  
Precast Concrete ◽  
Free Fall ◽  
Technical Note ◽  
Driven Piles ◽  
Concrete Piles ◽  
Load Tests ◽  
Semi Empirical ◽  
The City ◽  
Pile Length

Dynamic formulae are a widely used expedient for the control of driven piles to ensure load capacity. These formulae have considerable limitations when used in the prediction of the load capacity on their own, but are very useful in the control of a piling when combined with other tests. This technical note presents an evaluation of the Danish Formula for 54 precast concrete piles, comparing its results with High Strain Dynamic Tests (HSDTs), Static Load Tests (SLTs) and predictions by a semi-empirical static method (Aoki & Velloso, 1975). The data used in the comparison come from three works in the city of Rio de Janeiro, Brazil. All piles were driven with free-fall hammers and in one particular work the piles were relatively short. The predictions of the Danish Formula were evaluated in relation to the pile length/diameter ratio. It was concluded that for short piles - with lengths less than 30 times the diameter - this formula indicates bearing capacities higher than the actual ones. A correction for a safe use of the Danish Formula for short piles is suggested.

Circular precast concrete manholes: experimental investigation

2011 ◽  
Vol 38 (3) ◽  
pp. 319-330 ◽  
Author(s):  
Reem Sabouni ◽  
M.H. El Naggar
Keyword(s):  
Large Scale ◽  
Precast Concrete ◽  
Technical Information ◽  
Experimental Program ◽  
Traffic Loading ◽  
Sanitary Sewer ◽  
Testing Facility ◽  
Load Tests ◽  
Geotechnical Testing ◽  
The University

Circular precast concrete manholes are widely used in sanitary sewer and storm water systems. The lack of detailed technical information on them and the conservatism of their governing codes and standards call for a detailed investigation on them. The main objectives of this paper are to evaluate the state of strains in the precast concrete manhole and state of stresses in the soil beneath the base to be used in developing enhanced guidelines for the design of their bases. Three full-scale circular precast concrete manholes, two 1200 mm in diameter and one 1500 mm in diameter, were tested in the large-scale geotechnical testing facility (LSGTF) at the University of Western Ontario. Only one 1200 mm manhole base was reinforced. Twenty seven load tests were performed on the manholes, which involved loads representing the Ontario truck loads incorporated in the Canadian Highway Bridge Code. None of the manhole sections tested in the experimental program experienced any cracks. The test results showed that traffic loading had a small effect on the pressure under the manhole base. All three specimens could withstand the critical Ontario truck loads, even the non-reinforced ones.

scholarly journals Personal rapid transit vehicle with polyurethane wheels – modelling and simulation issues

2013 ◽  
Vol 27-28 (3-4) ◽  
pp. 71-79 ◽  
Author(s):  
Włodzimierz Choromański ◽  
Jerzy Kowara
Keyword(s):  
Simulation Model ◽  
Contact Model ◽  
Tire Model ◽  
Rapid Transit ◽  
Simulation Environment ◽  
Personal Rapid Transit ◽  
Adams Simulation ◽  
University Of Arizona ◽  
Dynamic Analyses ◽  
Load Tests

The article focuses special attention to the dynamic response of wheels – track interaction in Personal Rapid Transit (PRT) vehicle’s application. The main issue is the wheels/ track contact model for polyurethane treaded wheels. The contact model has been defined using the available UA-Tire analytical model (University of Arizona Tire Model) initially worked out in the paper [1], The model is available in ADAMS simulation environment. To obtain the necessary parameters a simulation model in FEM environment as well as the polyurethane treaded wheels have been constructed. The model has undergone quasistatic load tests in order to find indispensable characteristics. The paper includes the description of simulation model of the PRT vehicle and presents selected outcomes of kinematic and dynamic analyses.

scholarly journals Design of an earthquake resisting building using precast concrete cross-braced panels and incorporating energy absorbing devices

1979 ◽  
Vol 12 (4) ◽  
pp. 340-345
Author(s):  
C. D. Matthewson ◽  
R. A. Davey
Keyword(s):  
Precast Concrete ◽  
Office Building ◽  
Cost Estimates ◽  
Braced Frame ◽  
System A ◽  
Steel Members ◽  
Dynamic Analyses ◽  
Inherent Strength ◽  
Strength And Stiffness ◽  
Energy Absorbing

The design and the analysis of an irregular six storey office building are described. The building has an unconventional earthquake resisting system: a precast concrete cross-braced perimeter frame incorporating force-limiting devices (termed "inserts") in the form of enclosed axially yielding short steel members. A series of inelastic dynamic analyses indicates that the system very effectively combines the inherent strength and stiffness of the cross-braced frame with the energy-dissipating function of the yielding inserts. Cost estimates indicate that the system is a particularly economic one.

The automated laser comparator for calibration of digital equipment leveling

2018 ◽  
Vol 933 (3) ◽  
pp. 17-22 ◽  
Author(s):  
A.N. Prusakov ◽  
A.I. Spiridonov ◽  
A.A. Prusakov
Keyword(s):  
Measurement Errors ◽  
Measuring System ◽  
Electronic Components ◽  
Calibration Laboratory ◽  
Linear Coefficient ◽  
Bar Code ◽  
Verification Process ◽  
Vertical Positioning ◽  
Complex Measuring ◽  
Digital Equipment

Describes a device and methods for automated laser comparator for calibration of digital leveling equipment. The comparator created by the technology of the Finnish Geodetic Institute and placed in the building of the geodetic calibration laboratory of geodetic polygon of FSBE “Centre of geodesy, cartography and SDI”. Shows the main technical characteristics, modes of operation and basic procedures in the calibration of bar-code leveling rods. It is noted that the comparator is a complex measuring system in the form of high-precision optical-electronic stand, consisting of individual mechanical, optical and electronic components and assemblies. One of the features of the design of the comparator is the vertical positioning of its component parts, which allows to determine the error of position of the strokes of the scale of the rod in a working position. Based on the results of verification receive corrections to readings on a rod scale and a linear coefficient of expansion of the material from which rod is made. Lists the possible measurement errors in the verification process and the peculiarities of metrological assurance of operation of the comparator. Formulated one of the immediate tasks in the testing of the comparator

Performance Evaluation of a Solar TUNNEL Dryer for Paddy Drying at Prathum Tani, Thailand

2015 ◽  
Vol 799-800 ◽  
pp. 1455-1458 ◽  
Author(s):  
Krissadang Sookramoon
Keyword(s):  
Moisture Content ◽  
Air Temperature ◽  
Data Logger ◽  
Air Velocity ◽  
Tunnel Dryer ◽  
Chamber Volume ◽  
Load Tests ◽  
Velocity Measuring ◽  
Flat Plate Collector ◽  
Drying Chamber

A paddy solar tunnel dryer was designed, constructed and fabricated with a 2.112 m2flat plate collector with drying chamber volume of 0.113 m3, this design was improved to satisfy the drying desires of small farmers. The collector-dryer system has been equipped with data acquisition system to evaluate the performance, such as a data logger, K-type thermocouples, and air velocity measuring equipment. No load tests on the dryer; with 1000 cfm (DC) driven fans have been conducted. The performance of the dryer during drying of paddy has also been analyzed for the two configurations. The results, shown by plotting the variation of air temperature, moisture content indicated that the dryer performs better with DC driven fans, as they considerably reduce the fluctuations in the drying air temperature with fluctuating solar radiation. The moisture content reduced from 49.96 to 17.64 MC (% w.b.) in 6 hours. The average drying temperature was 67.75 °C. The heated air was approximately 344.47 W, with the incoming heat in the solar tunnel dryer of 1738.34 W. The thermal efficiency of a solar tunnel dryer was on the average of 22.72%.

Load Tests Results on Friction Piles in Sand

1971 ◽  
Vol 8 (1) ◽  
pp. 7-22 ◽  
Author(s):  
François A. Tavenas
Keyword(s):  
Bearing Capacity ◽  
Skin Friction ◽  
Pile Foundation ◽  
Precast Concrete ◽  
Loading Test ◽  
Testing Program ◽  
Total Length ◽  
Concrete Pile ◽  
Load Tests ◽  
Timber Piles

As part of the design of an important pile foundation, an extensive testing program has been carried out in order to determine the type and the necessary characteristics of the pile best suited to the site and the structure to be designed. Three types of piles have been tested, i.e. timber piles, a steel H-pile, and a Herkules precast concrete pile. The Herkules and H-piles were equipped with deformation gauges and driven in 10-ft (3-m) increments to a total length of 70 ft (21 m), a loading test being carried out at the end of each increment. Thus, it was possible to determine the variations of the bearing capacity, the point–resistance, and the skin-friction as functions of the embedded pile length.The aim of this paper is to present the technique used and the results obtained.

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