This paper presents an analytical investigation on the peak lateral displacement demands of “hybrid” precast concrete panelized shear wall structures under seismic loading. The hybrid wall structure investigated uses a combination of mild [i.e., Grade 400 (U.S. Grade 60)] steel bars and highstrength unbonded post-tensioning (PT) strands for lateral resistance across horizontal joints. The analy...

This paper presents an ongoing research project on the behavior and design of “hybrid” precast concrete wall structures for use in seismic regions. Hybrid precast walls utilize a combination of mild (e.g., Grade 60) steel and high-strength unbonded post-tensioning (PT) steel for flexural resistance across horizontal joints. The mild steel reinforcement is designed to yield in tension and compre...

This paper presents the results of a fundamental study to expand the applicability of the current AASHTO LRFD Bridge Design Specifications for concrete strength up to 18 ksi for reinforced and prestressed concrete members in flexure and compression. A total of 321 specimens were tested to determine the material properties of three high-strength concrete mixtures having target compressive concre...

Fiber-reinforced polymer (FRP) products are used as an alternative to traditional methods for strengthening and retrofitting concrete and masonry structures to resist blast loads. The development and experimental validation of a methodology for modeling the response of blast loaded concrete and masonry structural components retrofitted with FRP, as well as corresponding response criteria, is im...

Multi-level shaking table tests were performed on a 1:3 reduced scale two-story reinforced concrete (RC) intermediate moment resisting frame (IMRF) conforming to the requirements given in ACI-318-19. The exterior joints lacked shear reinforcement assess viability of ACI model recommended for determining design strength beam–column joint panel. One horizontal components 1994 Northridge earthquak...

Fibre-reinforced polymer (FRP) rebars are being increasingly used to reinforce concrete structures that require long-term resistance a corrosive environment. This study presents structural performance of large scale two-way slabs reinforced with FRP rebars, and their performances were compared against conventional steel concrete. Both carbon (CFRP) basalt (BFRP) considered as replacement. Exper...

BACKGROUND Autologous chondrocyte implantation (ACI) involves the use of a periosteal patch (ACI-P) as a cover for transplanted chondrocytes. Theoretically, this periosteal patch provides mesenchymal stem cells and growth factors that encourage chondrocyte development/differentiation. However, there is a significant rate of graft hypertrophy with the use of periosteum compared with using a type...

This paper deals with the modeling of punching shear failure in reinforced concrete slabs using nonlinear finite element analysis. The 3D finite element analyses (FEA) were performed with the appropriate modeling of element size and mesh, and the constitutive modeling of concrete. The FE numerical models are validated by comparing with the experimental results obtained from tested specimens and...

The main aim of the present study is to achieve optimum design of reinforced concrete (RC) plane moment frames using bat algorithm (BA) which is a newly developed meta-heuristic optimization algorithm based on the echolocation behaviour of bats. The objective function is the total cost of the frame and the design constraints are checked during the optimization process based on ACI 318-08 code. ...