Cracking of Beams Strengthened with Externally Bonded SRP Tapes

World Multidisciplinary Civil Engineering-Architecture-Urban Planning Symposium - WMCAUS

土木建筑工程

Krzywo, Rafal^1

Silesian University of Technology, Akademicka 5, Gliwice

44-100, Poland^1

关键词: Advanced treatment;    Calculation procedure;    Cold drawn steel;    Externally bonded;    High-strength steel wires;    Linear stress strain relationship;    Perfect plasticity;    Ultra high strength steel;   

Others  :  https://iopscience.iop.org/article/10.1088/1757-899X/245/3/032095/pdf
DOI  :  10.1088/1757-899X/245/3/032095

学科分类：土木及结构工程学

来源: IOP

【 摘 要 】

Paper discusses strengthening efficiency of relatively new kind of SRP composite based on high strength steel wires. They are made of ultra-high strength steel primarily used in cords of car tires. Through advanced treatment, the mechanical properties of SRP steel are similar to other high carbon cold drawn steels used in construction industry. Strength significantly exceed 2000 MPa, there is no perfect plasticity at yield stress level. Almost linear stress-strain relationship makes SRP steel mechanical properties similar to carbon fibers. Also flexibility and weight ratio of the composite overlay is slightly worse than CFRP strip. Despite these advantages SRP is not as popular as other composites reinforced with fibers of high strength. This is due to the small number of studies of SRP behavior and applicability. Paper shows selected results of the laboratory test of beams strengthened with use of SRP and CFRP externally bonded overlays. Attention has been focused primarily on the phenomenon of cracking. Comparison include the cracking moment, crack width and spacing, coverage of crack zone. Despite the somewhat lower rigidity of SRP tapes, they have a much better adhesion to concrete, so that the crack width is comparable in almost the whole load range. The paper also includes an assessment of the common methods of checking the condition of cracking in relation to the tested SRP strengthening. The paper presents actual calculation procedures to determine the crack spacing and crack width. The discussed formulas are verified with results of provided laboratory tests.