An analytical model is proposed to construct a stress‐strain relationship for confined concrete. The consists of parabolic ascending branch, followed by linear descending segment. It based on calculation lateral confinement pressure generated circular and rectilinear reinforcement, the resulting improvements in strength ductility A large volume test data, including poorly well‐confined concrete was evaluated establish parameters model. Confined corresponding strain are expressed terms...

A mathematical model is developed to express the stress-strain relationship of high-strength concrete confined by transverse reinforcement. The applicable both normal-strength and concretes, covering a strength range between 30 130 MPa. It incorporates all relevant parameters confinement that have been observed play important roles in column tests. These include type, volumetric ratio, spacing, yield strength, arrangement reinforcement as well section geometry. Therefore, it can be used for...

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The use of high-strength concrete (HSC) in seismically active regions poses a major concern because the brittle nature material. confinement requirements for HSC columns may be prohibitively stringent when ordinary grade transverse steel reinforcement is used. An alternative to conventional fiber-reinforced polymer (FRP) tubes form stay-in-place formwork which can fulfill multiple functions of: (1) formwork; (2) reinforcement; and (3) protective shell against corrosion, weathering chemical...

An analytical procedure is proposed for the force‐deformation relationship of a reinforcing bar anchored in concrete. The leads to computation deformations two parts, as extension and slippage. reinforcement determined by establishing inelastic strain distribution along embedment length bar. Constant average bond elastic frictional over plastic are assumed. rigid body slippage computed when stressed far end. increase stress considered develop force with available anchorage length. at end...

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The use of high-strength concrete (HSC) in seismically active regions poses a major concern because the brittle nature material. confinement requirements for HSC columns may be prohibitively stringent since they require proportionately greater than normal-strength concrete. An alternative to conventional reinforcement is fiber reinforced polymer (FRP) casings, form stay-in-place formwork. This paper investigates FRP formwork as with square cross sections. Large scale building columns,...

A hysteretic model is proposed for shear response of reinforced concrete members subjected to force and bending moment reversals. The consists a primary force‐shear displacement curve unloading reloading branches under cyclic loading. the envelope relationship, can be considered same as relationship monotonic loading up onset strength decay. established by any acceptable procedure, with well‐defined cracking yield points, used in constructing model. rules were obtained from large number test...

Strengthening of concrete structures using fiber-reinforced polymer (FRP) systems has become a widely accepted technology in the construction industry over past decade. Externally bonded FRP sheets are proven to be feasible alternative traditional methods for strengthening and stiffening deficient reinforced or prestressed members. However, delamination from surface poses major concerns, as it usually leads brittle member failure. This paper reports on development anchors overcome problems...

This paper describes the proposed changes to 2005 edition of National Building Code Canada related force modification factors. A description ductility- and overstrength-related factors is given. The selection values for these two various seismic resistance systems given in light design detailing provisions that are specified Canadian Standards Association standards steel, concrete, timber, masonry building structures.Key words: buildings, ductility, earthquakes, factors, overstrength, seismic.

Observations on damage to concrete structures, due the 1994 Northridge earthquake, are reported from a Canadian code perspective. Most of damaged structures were older, nonductile, that do not conform current design and detailing requirements. Concern is expressed about seismic hazard older having similar deficiencies. A significant number parking suffered extensive precast collapsed. Deficiencies in these include lack proper diaphragm connections, mix gravity load columns with ductile...

The 1975 Turkish code provisions are first reviewed to provide the background for design and detailing of structures prior earthquake. performance reinforced concrete masonry is described indicating many deficiencies in design, detailing, construction execution. behaviour precast structures, steel industrial facilities also presented. 1997 building summarized a description new provides evidence both excellent poor practice. Some examples retrofitting damaged soon after earthquake...

Experimental research was conducted to investigate the behavior of square high-strength concrete columns confined by rectilinear reinforcement. Large-scale with strengths between 60 MPa and 124 were tested under monotonically increasing concentric compression. The test parameters included volumetric ratio spacing transverse reinforcement, distribution longitudinal reinforcement resulting tie arrangement, yield strength compressive strength. results indicate that can be achieve inelastic...

Four concrete block masonry and two reinforced walls were designed to simulate low-rise nonductile built decades ago, before the enactment of earthquake-resistant design provisions. Two unreinforced partially reinforced. The had minimum reinforcement. One wall from each pair was retrofitted using a steel strip system consisting diagonal vertical strips that attached through-thickness bolts. Stiff angles anchor bolts used connect foundation top loading beam. All tested under combined constant...

A reconnaissance was conducted in Indonesia to investigate the effects of 26 December 2004 earthquake and tsunami on buildings, bridges, other physical infrastructure. The infrastructure coastal regions Banda Aceh completely devastated by both wave pressures seismic ground excitations. damaging were most pronounced unreinforced masonry walls, nonengineered reinforced concrete low-rise timber-framed buildings. Engineered structures survived pressure, but many suffered extensive damage due...

Seismic resiliency of new buildings has improved over the years due to seismic codes and design practices. However, vulnerability seismically deficient older buildings, designed built on basis practices, poses a significant threat life safety survivability buildings. It is economically not feasible retrofit entire inventory Therefore, there need for comprehensive plan identify critical prioritize their upgrading requirements. A risk-based evaluation technique proposed in this paper quantify...

The purpose of this paper is to provide a summary the evolution seismic design in Canada. This presents significant changes approach taken determining hazards and hazard maps, describes provisions National building code introduction important parameters base shear such as period vibration structure, influence type soil, concepts ductility energy dissipation capacity elements structures are presented. levels shears, determined from different versions Building Code Canada, compared for...

A reliable building vulnerability assessment is required for developing a risk-based and retrofit prioritization. Tesfamariam Saatcioglu (2008) proposed simple module where the performance modifiers are in congruence with FEMA 154. This paper an extension of that include detailed modifier 310 represented heuristic based hierarchical structure. Some input parameters obtained through walk down survey subject to vagueness uncertainty modelled fuzzy set theory. knowledge base rule modeling...

Research has shown that the addition of steel fibers to concrete results in improved postcracking tensile capacity leading enhanced toughness, ductility, and damage tolerance. These performance enhancements make fiber-reinforced (SFRC) an ideal material for use blast-resistant design structures. literature is conflicting on SFRC at high strain rates. There also very limited research structural components under blast loads. This paper presents a program investigating reinforced columns. In...

Lateral prestressing of concrete columns was investigated as a method seismic retrofit. Experimental research conducted to develop design procedure for shear deficient columns. The technology consists external in transverse direction by means individual hoops that consist strands and specially designed anchors. Seven full-scale were tested under constant axial compression incrementally increasing lateral deformation reversals. results, presented discussed this paper, indicate the retrofit...

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Large‐scale reinforced concrete columns were tested to investigate hysteretic behavior of anchorage slip in structures. The subjected constant axial compression and unidirectional bidirectional lateral‐deformation reversals. results indicate a significant increase column rotation due slip. Penetration yielding into the footing was observed tension reinforcement, while localized at column‐footing interface. Axial resulted early closure crack associated with slip, reducing related...