Service life of concrete structures is limited by the susceptibility reinforcement to corrosion. Oxidation iron leads formulation various products (such as ferrous and ferric oxides), some which occupy much greater volume than original that gets consumed corrosion process. As progresses, these accumulate, thereby generating expansive pressures on surrounding concrete. The pressure builds up levels cause internal cracking around bar eventually through cover spalling. Loss marks end service...

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Corrosion of reinforcement in bridge piers is encouraged by chloride contamination from exposure to marine environment and deicing salts used bridges during winter. Because corrosion products generally occupy greater volume than the original material, expansive forces are generated concrete leading spalling cover further acceleration disintegration. Jacketing such structures fiber-reinforced composite sheets an effective remedy, not only as a means slowing down rate reaction, but also...

Using the experimental background of 130 triaxial tests conducted on cylindrical specimens, a plasticity-based constitutive model concrete behavior is developed. Parameters reference database include water:cement ratio (i.e., f′c), degree saturation at testing, and load path used in tests. In model, damage quantified by volumetric expansion that builds up progressively material as it approaches failure caused propagation microcracks. This behavioral index calibrated with to available...

An experimental study on the simulation of corrosion in large-scale reinforced concrete columns and their repair using carbon fibre polymer (CFRP) sheets is presented. Seven were subjected to an accelerated regime, wrapped CFRP sheets, then tested structural failure (or) further post-repair corrosion, monitoring, testing. Accelerated was achieved by adding sodium chloride mixing water, applying a current reinforcement cage, subjecting specimens cyclic wetting drying. Results showed that...

Instability of reinforcement in adequately detailed reinforced concrete (RC) structural elements is a symptom excessive deformation compression, and it typically marks the limit usable ductility member. Because supply (deformability) measure effectiveness confining reinforcement, detailing necessary for stability intimately related to that required confinement. Existing design models consider two problems independently, associate initiation bar buckling with occurrence critical milestone...

Results from 50 bond tests conducted using the so-called direct tension pullout specimen type are presented. Anchorages of steel bars with machined deformations were tested so as to enable a targeted study effect rib height and related area on behavior; or without combined presence external confinement over embedded length. The novel form presented in paper was designed simulate state stress arising usual bar anchorages zones flexural members (where both cover concrete stressed tension)....

The efficacy of fiber-reinforced polymer (FRP) confinement as a means repairing/strengthening reinforced concrete members with nonductile details is explored in this paper particular emphasis on the interaction between jacket and embedded longitudinal compression reinforcement at onset bar buckling. To end, total 27 short prismatic specimens were tested to failure under concentric subsequent application FRP jackets; four additional controls. Specimens had square cross section most detailed...

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The local bond mechanics of glass-fiber reinforced polymer (GFRP) bars in normal strength concrete was investigated through experimental testing and analytical modeling. program comprised 30 direct tension pullout specimens with short anchorages. A novel test setup, specially designed so as to minimize the spurious influence conditions on measured properties adopted study. Parameters considered were bar roughness diameter, size effect expressed by constant cover diameter ratio, external...

Purpose Important differentiating attributes in the procedures used, characteristic mineral composition of binders, and implications these have on final long term stability physico-mechanical performance concretes produced are identified discussed, with intent to improve transparency clarity field geopolymer concrete technologies. Design/methodology/approach This state-of-the-art review covers area concrete, a class sustainable construction materials that use variety alternative powders lieu...

In this article a solution to the pole assignment problem with output feedback is proposed. Necessary and sufficient conditions are derived which related controllability or observability of initial system. These arise from state-feedback using input matrix For open loop system new calculated such that under closed has desired poles. proposed approach, multilineal algebra, algebraic geometry theory generalized inverse matrices employed. An illustrative example method also given. The main...

The composite flexural action of prismatic reinforced concrete (RC) members repaired/strengthened by RC jacketing was modeled with a dual-section approach. model considers the relative slip at interface between existing member and jacket establishes mechanisms that are mobilized to resist this action, thereby supporting behavior. An iterative step-by-step incremental algorithm developed for calculating overall response curve. Consideration frictional interlock dowel associated sliding...