In the present study, a new method for retrofitting reinforced concrete beam is introduced in which steel-concrete composite jackets containing steel fiber is used. For this purpose, 75% of the peripheral surface of reinforced concrete beams was initially reinforced using steel plates and bolts, and steel fiber reinforced concrete was used between the steel plates and the peripheral surfaces of...

in order to investigate the flexural behaviors of rc beams after freeze-thaw cycles, compressive strength test of concrete cubes after 0, 50, 100, 125 freeze-thaw cycles were made, and static flexural experiment of 48 rc beams after 0, 50, 100, 125 freeze-thaw cycles were made. the relationships of relative compressive strength, mass loss rate, relative dynamic elastic modulus and numbers of fr...

realistic prediction of concrete shrinkage and creep requires the calculation of the distributions of relative humidity at various times. although the distributions of the relative humidity can be computed by numerical methods from the differential equation for diffusion, simple prediction formulas can facilitate structural analysis. the purpose of this paper is to present a simple formula for ...

concrete filled steel tube columns (cfst) are a kind of composite columns according to advantages of cfst relative to reinforced concrete and steel columns. use of these materials is common in recent years especially in high building, unnecessary of molding, high ductility, proportionate resistance with low volume, economical, low deformation relative to steel columns are among advantages. in t...

this paper describes a methodology in designing high-performance concrete for simply supported beams, using a hybrid optimization strategy based on a variable neighborhood search threshold acceptance algorithm. three strategies have been applied to discrete optimization of reinforced concrete beams: variable neighborhood descent (vnd), reduced neighborhood search (rns) and basic variable neighb...

The effect of humidity on the morphological and thermomechanical properties of electrospun poly(vinyl alcohol) (PVA) fiber mats reinforced with cellulose nanocrystals (CNs) was investigated. Scanning electron microscopy (SEM) images revealed that the incorporation of CNs improved the morphological stability of the composite fibers even in high humidity environments. Thermal and mechanical prope...

In the article, compressive strength, tensile and residual strength of fiber-reinforced concrete reinforced with basalt fibers were studied based on experiment. Basalt 10 mm 30 in length 0.017 thick added at 0.0%, 0.1%, 0.2%, 0.3%. The samples stored room temperature relative humidity above 75%, tested days 7 28. addition increased changed its brittle behavior to a more ductile one. When amount...

Ultra-high performance concrete (UHPC) is a developing concrete and today is increasing to interest using it in structures due to its advantages such as high-compressive strength, modulus of elasticity, highly durability and low-permeability. Therefore, it is necessary to provide models for prediction of nonlinear behavior of this material. This study is aimed to investigate the tension-stiffen...