A Design Method to Induce Ductile Failure of Flexural Strengthened One-Way RC Slabs

Abstract

Strengthening existing reinforced concrete (RC) slabs using externally bonded materials is increasingly popular due to its adaptability and versatility. Nevertheless, ductility reduction of the rehabilitated flexural members with these materials can lead to brittle shear failure. Therefore, a new approach for strengthening is necessary. This paper presents a methodology to induce ductile failure of flexural strengthened one-way RC slabs. Ultimate failure loads can be considered to develop the proposed design methodology. Different failure modes corresponding to ultimate failure loads for RC slabs are addressed. Flexural and shear failure regions of RC slabs can be established by considering the failure modes. The end span of the concrete slab is shown for a case study, and numerical examples are solved to prove the essentiality of this methodology.

An Efficient Method for Optimizing HPC-FRP Retrofit Systems of Flexural Strengthened One-Way Continuous Slabs Based on ACI 440.2R

“…In this study, the prediction of flexural and shear carrying capacities of strengthening slabs with retrofit systems is shown to be in good agreement with the previous literature [ 28 , 29 , 30 , 31 ]. Additionally, civil engineers, especially the authors mentioned in this topic, have also long been interested in optimizing the strength of materials for more efficient workability of structures, resulting in cutting construction costs.…”

“…According to previous works [ 30 , 31 ], the failure limits of one-way continuous slabs in frames subjected to uniformly distributed loads are defined. The slab’s shear and moment carrying capacities are used to predict the failure mode and ultimate failure load.…”

“…For post-strengthened slabs, additional strength should be limited to avoid sudden failure, which could result from an excessive enhancement in flexural strength over shear strength. Thus, previous studies have developed novel failure mode classification and failure limits for continuous RC slabs based on their shear- and moment-carrying capacities [ 30 , 31 ]. A calculation method for retrofitted slabs to prevent brittle failure and induce ductile failure was also recommended.…”

“…Limit equations to divide specific regions corresponding to failure modes for continuous RC slabs were derived according to the recommendations of the ACI committee [ 7 , 40 ]. The basis for establishing these equations is based on appropriate mechanistic analyses detailed in the available literature [ 30 , 31 ] and validated by experimental works [ 21 , 28 , 29 ]. For the end span, limit equations in each region are determined from the expressions.…”

The Effects of Bond–Slip Laws on the Debonding Failure and Behavior of Flexural Strengthened RC Slabs in Hybrid FRP Retrofit Systems

“…Strengthening structures with external bonded materials has become one of the popular choices for rehabilitation and upgrading existing reinforced concrete (RC) structures [ 1 , 2 ]. Researchers and engineers are particularly interested in restoring and strengthening partially damaged RC structures to minimize the impact on environmental deterioration and cost savings [ 3 , 4 , 5 ]. Fiber-reinforced polymer (FRP) materials have been widely used in the field of external reinforcement in recent decades because of their lightweight, high tensile strength, and non-corrosion resistance [ 6 , 7 , 8 , 9 , 10 , 11 , 12 ].…”