Response of thin lightly-reinforced concrete walls under cyclic loading

Seismic performance of slender RC U-shaped walls with a single-layer of reinforcement

“…It is emphasized here that the ductility values for TUE and TUF (in Table 4) should be interpreted with some caution, as these walls were subjected to limited drifts in the directions that would typically produce large compression strains at the ends of the flanges; if loading had not been limited in these directions, it is likely that a non-ductile, crushing-type failure would have been observed for both wall specimens and at lower ductility capacities than those indicated in Table 4. The ductile reinforcing bars used in the boundary ends (previously discussed in Section 2.2) also allowed the walls tested here to achieve high ductilities, whereas low-ductility welded wire mesh has been used in Colombian construction practice (Blandón et al, 2018;Blandón and Bonett, 2020). Thus, a wall detailed with low-ductility steel could result in a brittle failure due to fracturing of the bars, which can also be exacerbated with the phenomenon of low-cycle fatigue (Tripathi et al, 2018).…”

“…Due to some loopholes in the current material standards in some countries (e.g. Colombia), it is anticipated that many of the RC walls embedded in these buildings are slender (80 -100 mm), unconfined, and detailed with a single-layer of vertical reinforcement (Carrillo and Alcocer, 2012;Rosso et al, 2018;Blandón et al, 2018;Blandón and Bonett, 2020;Hube et al, 2020). For example, no special transverse reinforcement to confine the boundary ends of RC walls is required by some building codes in Latin American (Massone et al, 2012).…”

“…Furthermore, a minimum longitudinal reinforcement ratio (ρwv) of just 0.25% is required by the building codes in Colombia for RC walls (Arteta et al, 2017), which is low considering the amount typically required to cause secondary cracking and ensure that a ductile response of the wall is achieved in the event of an earthquake (Hoult et al, 2018a;Hoult et al, 2018b;Lu and Henry, 2018). However, concentrating reinforcement in the boundary ends of the wall is also practiced in Latin America if higher flexural demands are required (Blandón et al, 2018). RC walls (or cores) are often non-rectangular due to architectural and structural requirements (Belletti et al, 2013;Smyrou et al, 2013.…”

“…Many of these buildings contain slender and unconfined RC walls with a single layer of longitudinal reinforcement, as discussed above. The seismic performance of these types of structural elements is largely unknown and hard to quantify due to the paucity of experimental research in this area; to the authors' knowledge, there are only relatively few experimental programs that have focused on RC walls with a single layer of reinforcement: Albidah (2016) and Altheeb (2016) tested (in total) three unconfined rectangular RC walls detailed with a single layer of horizontal and vertical reinforcement, typical of the construction practice in Australia; Puranam and Pujol (2017) tested four rectangular RC walls with a single layer of conventional-strength and high-strength longitudinal reinforcing bars to investigate the minimum amount required to ensure that fracturing of the bars did not limit the displacement capacity of the walls; Almeida et al (2017) tested two RC T-shaped walls with a single-layer of reinforcement, corresponding to the current design practices in Colombia; four slender RC T-shaped specimens designed to current Colombian practice were tested by Blandón et al (2018); more recently, Blandón and Bonett (2020) tested two unconfined rectangular RC walls with a single layer of reinforcement, the specimens of which were designed to typical construction practice in moderate seismic regions in South America. In comparison to experimental tests on rectangular RC walls, there is a paucity of experimental research on the seismic performance of U-shaped walls (Beyer et al, 2017).…”

Seismic performance of squat thin reinforced concrete walls for low-rise constructions

“…Housing demand in Latin America has increased considerably in recent years. To supply this demand, houses and buildings with thin reinforced concrete (RC) walls have been constructed in seismic prone countries like Colombia, Mexico, Peru, Venezuela, and Chile (Blandon et al, 2018; Carrillo et al, 2009; Gonzales and López-Almansa, 2012; Mejía et al, 2014; Muñoz et al, 2006; Santa María et al, 2017). The advantage of using RC walls relies on its strength, low cost, and fast speed of construction.…”