Diyala Journal of Engineering Sciences (Mar 2021)
Experimental Study of the Structural Behaviour of Reinforced Concrete Box Girder with the Using of Steel Plates Strengthening and Different Shapes of Cells
Abstract
The aim of this research is to study the effect of corrugated steel plate strengthening on the structural behavior of reinforced concrete box girder using corrugated steel plates with vertical and horizontal corrugation and studying the effect of the shape of cells using rectangular and circular shape with the same web width and strengthening the circular cell with flat plate. Five simply supported reinforced concrete box girders are casted using Self-compacting concrete and experimentally tested under four-point load. The box girder specimens are divided into two groups according to the steel strengthening and the shape of cells. The experimental results showed that in the first group, the using of the vertical and horizontal corrugated steel plates strengthening increased the ultimate load by (7.14% and 11.03%) respectively compared with the control box girder, and decreased the crack width, the results also showed that in the second group, the using of circular cell and circular strengthened cell increased the ultimate load by (17.85% and 29.22%) respectively compared with the control box girder with rectangular cell and decreased the crack width. All the box girders in the first and second group failed with diagonal shear. Conclusions • The ultimate load of the box girder strengthened by vertical and horizontal corrugated steel plate increased by (7.14% and 11.03%) respectively compared with the control box girder, also, the ultimate load of box girder with rectangular cell with horizontal corrugated steel plate is more than in box girder with rectangular cell with vertical corrugated steel plate by (3.63%), which indicates that the horizontal corrugated steel plates is more efficient. • The ultimate load of the box girder with circular cell and the box girder with circular cell with steel plate strengthening increased by (17.85% and 29.22%) respectively compared with the control box girder with rectangular cell, which gives the indication that using circular cell lead to increase the load capacity of the box girder for the same web thickness, also, the ultimate load of the box girder with circular cell with steel plate strengthening is more than in box girder with circular cell without strengthening by (9.64%). • The crack width of the box girder with corrugated steel plate strengthening decreased compared with the control box girder. • The crack width decreased in the box girder with circular cells with and without steel strengthening compared with the control box girder with rectangular shape. • The deflection of the box girder with corrugated steel plate strengthening is less than the control box girder for the same load. • The ultimate deflection of the box girder strengthened by vertical and horizontal corrugated steel plate increased by (10.916% and 2.6%) respectively compared with the control box girder. • The deflection of the box girder with circular cell and the box girder with circular cell with steel plate strengthening is more than in the control box girder with rectangular cell for the same load, also, the ultimate deflection of these box girders increased by (63.5% and 33.7%) respectively compared with the control box girder with rectangular cell. • The steel tensile strain and concrete compressive strain in the box girders with vertical and horizontal corrugated steel plates are less than in the control box girder for the same load. • The steel tensile strain and concrete compressive strain in the box girder with circular cells with and without steel strengthening are less than in the control box girder with rectangular shape at the same load.
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