scholarly journals STRESS-STRAINSTATE OF THE FLEXIBLE ELEMENT WITH COMPOSITE UNREMOVABLE FORMWORK

Author(s):  
N Shalobyta ◽  
T Shalobyta

The article deals with the work under load of a bent reinforced concrete girder element with a fixed formwork made of cement-bonded particleboard reinforced with. The main strength and deformation parameters of a multi component structure are determined, the main pre-purpose of which is to use overlap for monolithic structures with the inclusion of non-removable formwork of cement-bonded wood board in collaboration.

2011 ◽  
Vol 243-249 ◽  
pp. 1072-1084 ◽  
Author(s):  
Qiong Yu ◽  
Zhou Dao Lu ◽  
Jiang Tao Yu ◽  
Xing Zhuang Zhao ◽  
Jin Dai

Test of two specimens (four different joints) of steel secondary beam embedded in reinforced concrete girder in frame structure and one specimen with steel cantilever beam embedded in reinforced concrete girder under static load were conducted. The steel beam up-flange was pulled out because of the concrete cracks caused by the moment, shear and torsion at the upper zone of the concrete beam near the steel beam end. Shear failure of the concrete beam and the top flange pullout failure are the most hazardous failure modes. Lacking restraint of concrete and the reinforcement of steel bar in the concrete slab and catenary action of restraint steel beam, the capacity of steel cantilever beam is much smaller than other beams. Load-slip curve of top flange of steel beam, load-rotation curve of the steel beam end are obtained through experiment. Primary calculation method of joints flexural capacity related to section size of composite steel beam, embedded depth of steel beam, flange width of steel beam embedded end, height of frame girder, is put up with. Analytical results of ABAQUS are shown as follows. Top flange pullout failure of steel beam is caused by the detachment of concrete and steel beam end, and the warp of the concrete slab near the support plays an unfavorable action on the performance of the steel beam. The end rotational angle of the steel beam with anchor bar is smaller than that without. The steel beam with shear connectors develops a smaller rotational angle and a higher load capacity.


2017 ◽  
Vol 20 (11) ◽  
pp. 1658-1670 ◽  
Author(s):  
Shizhu Tian ◽  
Hongxing Jia ◽  
Yuanzheng Lin

The behaviour of bridge columns strengthened using carbon fibre–reinforced polymer composites has been studied extensively. However, few investigations have been conducted regarding the influence of carbon fibre–reinforced polymer-strengthened columns on the seismic behaviour of reinforced concrete continuous girder bridges. This article details the hybrid simulations of a continuous reinforced concrete girder bridge whose columns are strengthened by carbon fibre–reinforced polymer jackets. In the hybrid simulations, one ductile column is selected as the experimental element, which is represented by a 1/2.5-scale specimen, and the remaining bridge parts are simultaneously modelled in OpenSees (the Open System for Earthquake Engineering Simulation). After combining the experimental element and the numerical substructure, the hybrid analysis model is developed with the established hybrid simulation system. The displacements of the bridge and the lateral force–displacement response of the experimental element in hybrid simulation are obtained. Compared with the results of numerical simulation, the stability and accuracy of the established hybrid simulation system are demonstrated. Meanwhile, the comparative hybrid simulation results of the as-built bridge and the carbon fibre–reinforced polymer-strengthened bridge also prove the effectiveness of the carbon fibre–reinforced polymer jackets’ confinement in the continuous reinforced concrete girder bridge.


Author(s):  
M.Ya. Kvashnin ◽  
◽  
I.S. Bondar ◽  
S.S. Khasenov ◽  
G.S. Bikhozhaeva ◽  
...  

This paper presents some results of instrumental measurements of dynamic coefficients and fiber stresses of reinforced concrete girder spans of railway overpasses under mobile load. The results obtained can be used for further monitoring of similar structures on the main railway lines of the Republic of Kazakhstan, to identify damage in the structures of bridges.


2019 ◽  
Vol 97 ◽  
pp. 02034
Author(s):  
Evgenij Borisyuk

Rebar fixators of various types (plastic and concrete) became widespread with manufacturing of building structures of precast and monolithic reinforced concrete in order to fix steel reinforcement cage in strictly design position and to exclude the probability of its displacement during concreting. Such sufficiently rigid fixing is necessary for the following reliable operation of the structure in the building, as well as for the preservation of steel reinforcement which protected by a necessary layer of concrete from corrosion. Information available in the literature does not allow us to judge about the effects that different types of fixators apply to exploitative properties (such as strength and crack resistance) of reinforced concrete. The experiments, according to the accepted method, showed that these characteristics are slightly worse for the samples with plastic fixators and fixators made of low grade concrete than for the samples without fixators or fixators made of high grade concrete. On the base on the research results it becomes possible to substantiate the distinction between the areas of application of plastic and concrete fixatives


2018 ◽  
Vol 20 (1) ◽  
pp. 318-329 ◽  
Author(s):  
Divyashree Yadav ◽  
Naveen Kwatra ◽  
Pankaj Agarwal

2019 ◽  
Vol 91 ◽  
pp. 02043
Author(s):  
Andrew Varlamov ◽  
Sergey Tverskoi ◽  
Vadim Gavrilov

The article analyzes the sizes of concrete samples. We revealed a possibility to reduce sizes of samples. We simultaneously carried out tests of standard and small (25x25x100 mm) concrete samples. Small samples were obtained by cutting standard samples. In the course of study, the density, strength, and deformation of standard and small specimens were measured. The results are presented in tables and graphs. The strength of small samples was lower than the strength of reference samples. We identified loss of strength of the samples when cutting concrete. The average characteristics of deformation of concrete remained. Small samples are recommended for use in assessing the stress-strain state of reinforced concrete structures.


2019 ◽  
Vol 968 ◽  
pp. 234-239
Author(s):  
Talyat Azizov ◽  
Oleksii Melnik ◽  
Oleksandr Myza

The results of experimental studies of combined beams consisting of a stone part, reinforced with side reinforced concrete plates are given. Experimentally shown the viability of the proposed structures. The conditions for ensuring the combined action of a stone beam and a reinforced concrete plate are given. Cases are shown when one-sided plates can be used and when double-sided reinforced concrete plates can be used. A comparison of experimental data with the data calculated by the authors developed methods is given. A good agreement between theoretical and calculated data is shown.


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