dr. Concrete - an article

 
Rapid changes in the profile of social needs generated by development of industry affected also construction industry. Last 50 years brought to constructions new calculation methods, new safety standards and the need of fast and reliable structure adaptation to new situations. Developing industry connected with lack of care caused significant deterioration of existing infrastructure. All of those aspects caused sudden need of repairing or strengthening significant number of buildings and adjusting the others to new purposes, loads and safety standards. This need was realized by researchers in 1960s, and since that time many systems of strengthening repairs were invented. One of most effective proposals of strengthening bases on Carbon Fibers. While flexural behaviour of CFRP strengthened RC members is well recognised, torsional behaviour of such elements is almost unverified. Although prepared in 2001 fib Bulletin 14 treats briefly about torsion, basing on published in Swedish, researches of Täljsten dated 1998, but this area seemed to be generally neglected. That is why, in 1999, team of researchers from Silesian University of Technology, PL, decided to undertake the investigation program concerned on complex state of stresses with torsion influence included. Practice shows that problem of torsion in strengthened elements is essential in repaired bridges, edge beams, elements supporting overhead cranes and many others.

Keywords: CFRP, concrete, strengthening, torsion