Strengthening of RC Buildings with Steel Elements

13.14: Seismic assessment and strengthening of existing steel moment‐resisting frame buildings: the European EC8‐3 and current challenges

“…admissible storey drifts for serviceability limit states or control of P-Δ effects). Although the requirements defined in part 1 of Eurocode 8 could be used to account for this issue, as discussed by Castro et al [9], such an assumption could lead to over-strengthened structures and would clash with the issues regarding the expected probabilities of collapse of existing buildings discussed above. According to Annex B of EC8-3, beams should develop their full plastic moment without buckling in the flange or in the web at the DL and the SD limit sate, and limited local buckling should occur at the NC limit state.…”

“…Naturally, the reliability of such a condition will depend on the quality of the information collected from the members framing into that same joint and such level of uncertainty should be conveniently dealt with by confidence factors. At last, and as discussed by Castro et al [9], EC8-3 provides very limited guidance, particularly in its Annex A, on the detailing and design of the connections of steel members to other existing members (e.g. reinforced concrete members).…”

“…Furthermore, a discussion on how EC8-3 treats uncertainty, by means of the so-called Confidence Factors, and on the adequacy of such factors to steel members is also provided based on the findings reported in [7]. Finally, the current limitations of EC8-3 regarding the retrofitting and strengthening of existing structures using steel members will be highlighted [9]. In brief, this work intends to present to the scientific and structural engineering community the current limitations of EC8-3, with the goal of identifying topics in need of future research, as well as to report the recent findings achieved by the authors.…”

Performance evaluation of structures with reinforced concrete columns retrofitted with steel jacketing

“…Currently, there are few codes devoted to seismic strengthening of buildings. In consequence, engineering discernment is commonly based on assessment methods that are conceptually appropriate to the design of new structures, rather than assessing existing ones [11].…”

Strengthening of pre-damaged concrete cylinders using post-tensioned steel straps

“…This in turn requires readily available fast strengthening techniques that use simple tools, widely available materials and relatively low-skilled labour. Previous research has investigated the use of steel cages to strengthen RC columns (Sahoo and Rai 2009, Nagaprasad et al 2009, Castro et al 2018, although in general such cages only provide passive confinement. Recent research has verified the effectiveness of an innovative "active confining" technique at enhancing the capacity and deformability of concrete components (Ma et al 2014;Garcia et al 2015, Helal et al 2016, Ma et al 2016).…”