Corrosion Stress Strain Behavior Of Small Size Plain Concrete

As the human body ages, it becomes more fragile. America’s infrastructure is nearly the same. With the everyday use of many large structures, such as bridges, buildings, and other large structures made of concrete and/or steel, many are beginning to wither away while the average American is unaware of these changes. In many projects around the world, there is a material that is being commonly used to strengthen structures known as Carbon Fibre Reinforced Polymer (CFRP). The types of structures that this material can help to strengthen includes, but is not limited to, reinforced concrete columns, bridge girders, steel structures, and cable

Introduction : To determine the strength, maximum load can be applied and workability of concrete mixture.

This is the most recent type of concrete formwork. It’s an emerging tech for RCC construction as well as architectural design work. This materials’ flexibility creates the ability to make concrete of any shape.

Abstract: Advancement in recent years on the efficiency of glass fiber-reinforced polymer (GFRP) in production and cost benefits have increased their use as alternative means to steel rebar in bridge deck bases. The purpose in applying rebar is to increase the tensile strength of concrete. Considering the versatility of bridges there are many factors that need to be analyzed when choosing whether to use steel rebar or GFRP material such as: cost, tensile strength, and weather resistance. Stress-strain graphs were calculated, graphed, and analyzed to determine the yield tensile strength and stiffness of steel rebar and GFRP. Data collected from alkaline bath tests were graphed and analyzed to determine the thermal and corrosion resistance of each material. Costs per square inch of each material were also compared as well as each materials quality and life expectancy. The results of the conducted test analysis found the GFRP to have greater thermal resistance, lower cost, and higher life expectancy than the steel rebar, however the steel rebar’s stiffness was found to be about six times larger than the GFRP’s. These results suggest that the advancements in GFRP can provide longer lasting bridge structures and will change the future of construction and restoration of bridges.

Pre-cast pre-stressed double-tee girders are considered as an essential element of modern infrastructure used to construct civil project worldwide. These girders can be found in under-strengthlevel because of the local damages and developed cracks as the result of collision due to transportation and mishandling. Therefore, it is very important to find out an efficient retrofitting technique in order to restore the lost capacity and/or even outperform it. The current paper presentsa field tests up to collapse forthree actual-size pre-cast pre-tensioned double-tee (DT) girders having different levels of damage retrofitted using Externally Bonded Carbon Fiber Reinforced Polymer (EB-CFRP) technique. The girder stems for two of them were strengthened in flexure using uni-directional U–shaped CFRP sheets, while all girders were shear-strengthened at the dapped-ends. Each girder was loaded incrementally up to collapse using concrete Jersey Barriers, at the meantime, the deflections of the girder and developed strains on both concrete surface and the CFRP sheets were recorded at each increment. Test results assured the adequacy of the adopted strengthening configurations from both ultimate capacity and ductility viewpoints. It addition, the flexural resistance showed reasonable results compared to the analytical design resistance recommended by ACI 440.2R-08.

Shear walls are structural members used to elongate the strength of R.C.C. structures. These shear walls will be construct in each level of the structure, to form an effective box structure. Equal length shear walls are placed symmetrically on opposite sides of outer walls of the building. Shear walls are added to the building interior to provide more strength and stiffness to the building when the exterior walls cannot provide sufficient strength and stiffness. It is necessary to provide these shear walls when the tolerable span-width ratio for the floor or roof diaphragm is exceeded. The present work deals with a study on the improvement location of shear walls in symmetrical high rise building. Position of shear walls in symmetrical buildings has due considerations. In symmetrical buildings, the center of gravity and center of rigidity coincide, so that the shear walls are placed symmetrically over the outer edges or inner edges (like box shape). So, it is very necessary to find the efficient and ideal location of shear walls in

Nipun Verma et.al 2014, presented the Self-compacting concrete is gaining attention worldwide owing to its ability to compact without the need for either internal or external vibration even in areas of highly congested reinforcement such as beam-column joints. Since last two decades, several researches have been conducted on Self-compacting concrete and now application of SCC has gained momentum. In the present study, bond stress corresponding to the maximum pull-out load that can be regarded as the bond strength or ultimate bond strength was conducted. The slow development of compressive strength and bond strength in SCC at early age is generally due to

Over the past quarter century, the number of both experimental and analytical studies have increased dramatically on the monotonic axial behavior of FRP-confined concrete columns, and as a result, many uniaxial stress-strain models have been generally developed; however, most of these studies have focused largely on FRP-confined circular plain (unreinforced) concrete cylinders numerous authors tested (e.g., Mirmiran and Shahawy 1997;Mirmiran et al.1998; Xiao and Wu 2000; Lam and Teng 2002,2003;Berthet et al.2005;Almusallam 2007; Benzaid et al.2008;Eid and Paultre 2007,2008;Teng et al. 2009;Smith et al. 2010;Cui et al.2010). Relatively few of which have included small or medium scale noncircular unreinforced specimens

The steel tube in a concrete filled tubular (CFT) column acts as both lateral and longitudinal reinforcement, and is thus subjected to hoop tension and biaxial stresses of longitudinal compression. At the same time, concrete is tri-axially stressed. Concrete filled tubular (CFT) column has become popular as structural-member in buildings due to their excellent performance for structural characteristics, which include high ductility, stiffness, and high strength. The advantages of the Concrete filled tubular (CFT) column over other composite members are that the filled-in concrete prolongs local buckling of the steel tube wall, the steel tube provides formwork for the concrete, the tube prevents excessive concrete spalling and composite columns add more stiffness to a frame compared to old-style steel frame construction. According to past study on the concentric compression behavior of Concrete filled tubular (CFT) columns, the ultimate axial strength of Concrete filled tubular (CFT) columns is largely affected by the thickness of the steel tube and the shape of its cross section Although confining effect in square columns show a small increase in axial strength due to triaxial-effects, although it has large wall thicknesses. On the other hand, the axial load and deformation behavior of columns is remarkably affected by the cross sectional shape, diameter/width-to thickness ratio (D/t) of the steel tube, and the strength of the filled concrete.

The experimental results depend on a combination of test parameters, structural parameters and materials parameters. For the complete stress-strain curve, the test parameters are difficult to be separated from the material and structural parameters. The softening behavior of concrete, as found in laboratory tests, depends strongly on structural aspects such as specimen dimensions, boundary conditions and feed-back signal. And it also depends on test parameters such as testing machine characteristics, friction restraint between loading plates, allowable rotations of loading plates before and during the test and loading rates as well as on the concrete composition. Uniaxial compression tests on cubes and cylinders, with different heights, have shown that a stress-strain curve of concrete is not a material property but a mix of structural and material behavior.

Abstract: This study aimed to compare the seismic behaviour of different bracing systems in 10th time smaller real prototype steel building model. The uniaxial shake table experiment was carried out to assess the structural performance on different bracing systems in same storey height building (model type-I) and different storey height building (model type- II). Three structural configurations were used: bare frames (BFs), X- braced frames (XBFs) and Diagonal braced frames (DBFs). The effects of some parameters influencing the seismic performance, including the type of the bracing system, the storey height of the were investigated. The results show that the different braced frames performed well in terms of joint displacement and performance point when compared to the simple bare frame frame in steel buildings. It can be concluded with a comparative account of the obtained results, that use of XBF and DBF enhances structural performances. DBF shows highly effective and economical because of it consume lesser material and give effective result.

* In this test, standard cylinders and cubes will be subjected to uniaxial compressive loading and the load will be applied gradually

amount of mix needed to achieve the desired result is an iterative process. This is

The response of structural systems depends on the rigidity of the connections and this knowledge becomes very important to understand the influence of connections on the load path under both lateral and vertical loads. Precast buildings with skeletal frames system may have different forms based on the types of joint and their position as indicated in the Table 1-1. The structural joints can be idealized as either hinged or fixed and be either precast or formed at site. The performance of the precast frame systems identified as type 3, 6, 7 and 8 in Table 1-1, and subjected to lateral and gravity loads are compared with the cast in-situ frame systems. The performance of building is evaluated in terms of displacements, bending moment, storey drifts and storey shear for different load cases analysis for the following frame configurations.

Abstract 1: A slowly growing number of studies have concentrated too much on investigating, but less on modelling the cyclic axial stress-strain response of concrete columns (RC) confined with fiber-reinforced polymer FRP sheets. Since the early 1990s, the largest amount of research, including both experimental and analytical studies, has been rising continuously, in contrast, on the monotonic axial stress-strain behavior of concrete columns externally jacketed with FRP composite wraps. However, most of the available literature on the behavior of FRP-confined RC columns has focused extensively on square and circular concrete columns that can be classified as small or medium-size. Also recently, a few experimental studies have been devoted to investigating the cyclic axial compression behavior of small-scale unreinforced (plain) rectangular concrete columns with smaller-cross sections. Therefore, a deep review indicates that there is a distinct lack of research on the axial stress-strain behavior of FRP-confined RC columns subjected to a cyclic axial compression loading. This is owing to the fact that the majority of the structural buildings columns (RC) are noncircular ,and it has been clearly demonstrated that the behavior of these columns mainly depends on several factors such as aspect ratio of cross-section,