Strengthening of flat slabs with transverse reinforcement by introduction of steel bolts using different anchorage approaches

• Published in: Engineering structures 2012-11, Vol.44, p.63-77
• Main Authors: Inácio, Micael M.G., Pinho Ramos, A., Faria, Duarte M.V.
• Format: Article
• Language: English
• Subjects: Anchorage; Anchorages; Applied sciences; Bolts; Building structure; Buildings. Public works; Construction (buildings and works); Durability. Pathology. Repairing. Maintenance; Exact sciences and technology; Flat slab; Punching; Reinforced concrete; Reinforced concrete structure; Reinforcement; Repair (reinforcement, strenthening); Shear; Slabs; Strengthening; Structural steels
• ISSN: 0141-0296; 1873-7323
• DOI: 10.1016/j.engstruct.2012.05.043

► Eight specimens were strengthened with the introduction of prestressed vertical bolts. ► Large and small anchorages on surface and small embedded anchorages were used. ► The use of embedded anchorages led to a slightly decrease of punching load capacity. ► EC2 and MC2010 provided a good agreement with experimental punching loads. The present work reports the experimental research carried out to study a strengthening method for flat slabs under punching by introduction of new shear reinforcement. Eight specimens were strengthened with the introduction of prestressed vertical bolts, using different anchorage approaches: large anchorage on surface, small anchorage on surface and small embedded anchorage. A reference specimen, unstrengthened, was also tested. The experimental punching loads, failure modes and shear reinforcement contribution are compared with the provisions of EC2, ACI 318-11 and MC2010. The tests results show that using small embedded anchorage plates is viable and efficient method for punching capacity improvement. Additionally is a method also with advantages of better aesthetics for the final strengthened structure.