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Dynamic And Static Behavior Of Hollow-Core Frp-Concrete-Steel And Reinforced Concrete Bridge Columns Under Vehicle Collision, Omar I. Abdelkarim, Mohamed Elgawady

Civil, Architectural and Environmental Engineering Faculty Research & Creative Works

This paper presents the difference in behavior between hollow-core fiber reinforced polymer-concrete-steel (HC-FCS) columns and conventional reinforced concrete (RC) columns under vehicle collision in terms of dynamic and static forces. The HC-FCS column consisted of an outer FRP tube, an inner steel tube, and a concrete shell sandwiched between the two tubes. The steel tube was hollow inside and embedded into the concrete footing with a length of 1.5 times the tube diameter while the FRP tube stopped at the top of footing. The RC column had a solid cross-section. The study was conducted through extensive finite element impact analyses …

Behavior Of Fire-Exposed Rc Frames Before And After Jacketing, M. Monir M. Ajan Alhadid

Electronic Thesis and Dissertation Repository

Analysis and design of fire-exposed Reinforced Concrete (RC) frames before and after jacketing with concrete layers are commonly performed using prescriptive methods that rely on the concept of fire rating. These methods were developed based on empirical results on individual RC members subjected to certain fire conditions. In typical fire scenarios, the residual capacity, stiffness and thermal deformations affects not only the local performance of each fire-exposed member, but also the load redistribution and global behavior of the entire frame. In terms of fire safety, the philosophy of the new building codes considers objective-based design as an alternative of the …

Strength Of Reinforced Concrete Beams With High-Strength Steel, Brian C. Rogers, Aishwarya Puranam, Santiago Pujol

The Summer Undergraduate Research Fellowship (SURF) Symposium

Structures are commonly made of reinforced concrete, which is a composite material made of concrete and steel reinforcement. Using high-strength steel, with yield stress larger than 100 ksi, could help reduce the quantity of steel required in structural members, thus reducing costs and improving constructability. The hypothesis being tested is that smaller quantities of high-strength steel reinforcement (HSSR) can be used in place of conventional steel in reinforced concrete beams while maintaining similar strength and deformation at failure. Two reinforced concrete beams with two different types of longitudinal steel reinforcement were constructed. The beams were 18 in. wide, 30 in. …

High Strength Steel In The Reinforced Concrete Structures: Serviceability, Alan Kanybek, Aishwarya Puranam, Santiago Pujol

The Summer Undergraduate Research Fellowship (SURF) Symposium

The use of high-strength steel (yield stress larger than 100 ksi) in reinforced concrete structures can provide an effective alternative to using conventional steel (yield stress up to 80 ksi). The goal of this study is to investigate if slabs with reduced quantities of high-strength steel reinforcement meet the serviceability criteria. Instantaneous and long-term deflections in slab specimens with conventional steel and reduced amounts of high-strength steel (as compared with conventional steel) were studied. Two sets of two reinforced concrete slabs, each 14 ft. long, 30 in. wide, were built. The depth, quantity, and type of longitudinal reinforcement were varied …

Response Of High-Strength Steel Reinforced Concrete Structures To Simulated Earthquakes, Lucas Laughery

Open Access Dissertations

In reinforced concrete (RC) structures expected to resist earthquake demands, substituting smaller amounts of high-strength steel for conventional steel reinforcement can help reduce reinforcement congestion and placement costs while keeping strength unchanged.

Provided cross-sectional dimensions remain unchanged, reducing the amount of longitudinal steel in a member will result in a member with similar initial stiffness but lower post-cracking stiffness. Nominal strength can be kept nearly the same if this reduction in the amount of steel is accompanied by a corresponding increase in the strength of the steel. The topic of this investigation is whether two frames with the same initial …

Investigation Of A Novel 3d Non-Destructive Evaluation For Corrosion Process In Reinforced Concrete, Guohao Fang, Biqin Dong, Ningxu Han, Feng Xing

International Conference on Durability of Concrete Structures

X-ray computed microtomography (X-ray μCT) method is proposed to trace the corrosion features of steel bar in cementitious materials. Three-dimensional corrosion morphology (including morphology of steel corrosion, corrosion products and cracks formation) are characterized and reconstructed. Experimental results demonstrate that X-ray μCT can track time-dependent development of corrosion products and the subsequent initiation and propagation of corrosion-induced cracks. In addition, scanning electron microscope (SEM) and energy dispersive spectrometer (EDS) are used to morphologically and chemically analyze the corrosion result. The microscopic analysis result is found to be in a very good agreement with the image analysis measured by X-ray μCT. …

An Experimental Study On Effect Of Steel Corrosion On The Bond–Slip Performance Of Reinforced Concrete, Xiaolin Zhang, Xuebing Liang, Hancheng Huang, Haijun Zhou

International Conference on Durability of Concrete Structures

This paper studied the effects of reinforcement corrosion on bond performance between rebar and concrete. Tests were carried out to evaluate the degradation of bond between reinforcing steel and concrete for different corrosion levels of reinforcing steel. A series of 20 specimens of different concrete strength with various reinforcing steel corrosion levels were designed and manufactured. Each specimen was casted as a 200-mm concrete cube, and a steel rebar was centrally embedded with two stirrups around it. The steel rebar were corroded using an electrochemical accelerated corrosion technique. The corrosion crack opening width and length were recorded after the corrosion …

Durability-Based Optimal Design Methodology For Rc Members In Corrosive Environment, Saeid A. Alghamdi, Shamsad Ahmad, Adamu Lawan

International Conference on Durability of Concrete Structures

No abstract provided.

Research On Concrete Durability Improving For Existing Island-Building And Its Application, Mao Jianghong, Zhu Yaofeng, Xu Fangyuan, Jin Weiliang, Xu Yidong, Chen Xu

International Conference on Durability of Concrete Structures

China’s coastal cities contain a large number of islands with abundant human activities, in which buildings are in a typical marine corrosion environment and the corrosion of reinforced concrete structures is very prominent. This paper makes research work on two aspects: (1) the durability assessment and durability improvement after a thorough investigation of the architecture of Xiangtan County, Ningbo city, on an island and (2) the application research of the bidirectional electromigration rehabilitation (BIEM) technology to enhance the durability of existing island building life. This paper designs a set of BIEM equipment based on solar power supply and develops a …

Corrosion Of Steel In Concrete And Its Prevention In Aggressive Chloride-Bearing Environments, Luca Bertolini, Maddalena Carsana, Matteo Gastaldi, Federica Lollini, Elena Redaelli

International Conference on Durability of Concrete Structures

This keynote paper deals with the durability of reinforced concrete (RC) structures exposed to aggressive environments characterized by high concentration of chloride ions, namely, marine environments or the use of de-icing salts. The mechanism of chloride-induced corrosion of steel in concrete is introduced, and its influence on the service life of RC structures is analyzed. Factors affecting the time to corrosion initiation are described with regard to both concrete properties and environmental exposure conditions. Design approaches available for achieving durability targets associated with the design service life are analyzed, focusing on studies carried out by the authors in recent years …

Effects Of Vertical Ground Motion On Seismic Performance Of Reinforced Concrete Flat-Plate Buildings, Sara Jean George

UNLV Theses, Dissertations, Professional Papers, and Capstones

Reinforced concrete flat plate is a type of structural system widely used for office and residential buildings in many areas including those with high seismic risk. In the regions of high seismicity, moment frames or shear walls are employed to resist lateral loading while the flat-plate system is designed to primarily resist gravity loading. Flat-plate structures must maintain lateral deformation capacity as well as resist gravity loading under seismic loads. The deformation capacity of a slab-column connection is a function of vertical shear transferred from slab to column. The effects of vertical loading become even more exaggerated when the flat-plate …

Behaviour Of Reinforced Concrete And Composite Conical Tanks Under Hydrostatic And Seismic Loadings, Ahmed Elansary

Electronic Thesis and Dissertation Repository

Conical liquid storage tanks are widely used to store different liquids and to provide water supply at cities and municipalities. However, no comprehensive guidelines currently exist in the codes of practice for the structural analysis and design of such tanks. The walls of a conical tank can be made of steel, reinforced concrete, or a combination of the two materials in a composite type of construction in which steel and concrete walls are connected using steel studs. The research conducted in this thesis provides a comprehensive understanding of the structural behaviour of reinforced concrete and composite conical tanks under hydrostatic …

Circular Rc Columns Partially Confined With Frp, Sahar Y. Ghanem

Theses and Dissertations--Civil Engineering

Wrapping reinforced concrete (RC) columns with Fiber Reinforced Polymer (FRP) composites is effective in increasing their capacity. The current state of art concentrates primarily on fully wrapped RC columns and few studies dealt with partially wrapped columns. The majority of the studies did not account for the influence of the existing steel reinforcement on the column’s behavior. Other studies estimated the total confinement pressure as the sum of the confinement pressure due to the external FRP jacketing and due to the internal transverse steel reinforcement. Few models dealt with the coupled effect of the confinement from steel and partial FRP …

Shear Behavior Of Reinforced Fly Ash-Based Geopolymer Concrete, Noor S. Yacob

Masters Theses

"The geopolymerisation of aluminosilicate materials such as fly ash has been a radical change in construction material's chemistry and composition, compared to the portland cement-based concrete calcium silicate-hydrate chemistry. The adoption of fly ash in concrete industry is a good use of by-product ashes to reduce emissions of the greenhouse gas implicitly. However, in this research, the replacement of portland cement by fly ash is 100%, which makes it a zero-cement concrete with no proprietary chemical additives.

Geopolymer concrete (GC) is a revolutionary synthetic material that combines sustainability and high engineering properties, and it is relatively cost-effective compared to portland …