Corrosion Inhibition of Concrete Steel-Reinforcement in Saline/Marine Simulating-Environment by Rhizophora mangle L.

2015 ◽  
Vol 227 ◽  
pp. 185-189 ◽  
Author(s):  
Joshua Olusegun Okeniyi ◽  
Cleophas Akintoye Loto ◽  
Abimbola Patricia Idowu Popoola
Keyword(s):  
Corrosion Inhibition ◽  
Leaf Extract ◽  
Inhibition Efficiency ◽  
Rhizophora Mangle ◽  
Steel Reinforcement ◽  
Concrete Slabs ◽  
Test Results ◽  
Electrochemical Test ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs

Corrosion inhibition of concrete steel-reinforcement in 3.5% NaCl, simulating saline/marine environment, by the leaf extract ofRhizophora mangleL. was studied in this paper. For this, duplicated specimens of steel-reinforced concrete slabs, admixed with different concentrations of the leaf extract, were immersed in the corrosive test-medium. Analyses, as per ASTM G16-95 R04, of the electrochemical test-results identified 0.0833%Rhizophora mangleL., per weight of cement, with optimal inhibition efficiencyη= 95.73±0.15%. The study established a decrease in inhibition effectiveness as concentration ofRhizophora mangleL. increases.

scholarly journals RHIZOPHORA MANGLE L. LEAF BIOCHEMICAL CHARACTERIZATION: NATURAL-GREEN TOTAL-CORROSION INHIBITION PROSPECT ON CONCRETE STEEL-REINFORCEMENT IN 3.5% NaCl

2018 ◽  
Vol 81 (1) ◽  
Author(s):  
Joshua Olusegun Okeniyi ◽  
Esther Titilayo Akinlabi ◽  
Jacob Olumuyiwa Ikotun ◽  
Stephen Akinwale Akinlabi ◽  
Elizabeth Toyin Okeniyi ◽  
...  
Keyword(s):  
Leaf Extract ◽  
Biochemical Characterization ◽  
Rhizophora Mangle ◽  
Steel Reinforcement ◽  
Steel Reinforced Concrete ◽  
Organic Constituents ◽  
Ft Ir ◽  
Inorganic Constituents ◽  
Gaining Insight

Effective corrosion-protection by plant-extract on metals, in aggressive service-environment, is dependent on the biochemical constituents of which the natural plant is made-up. This paper investigates biochemical characterization of inorganic and organic constituents of Rhizophora mangle L. leaf for gaining insight on its steel-reinforcement corrosion mitigating prospect in NaCl-immersed concretes. For the study, atomic absorption spectroscopy (AAS), Fourier transform infrared spectroscopy (FT-IR) and phytochemical screening analyses were employed. Total-corrosion effect was also studied from steel-reinforced concrete samples, having different concentrations of the leaf-extract as admixture, and which were immersed in 3.5% NaCl (simulating saline/marine environment). Results, by AAS, showed that Rhizophora mangle L. leaf inorganic constituents were highest in iron, Fe = 10,316.17 μg/g and lowest in cadmium, Cd = 6.2019 μg/g but has neither lead (Pb) nor chromium (Cr). Also, organic constituents, by FT-IR, indicated extract from the leaf constitutes aromatic chained compounds rich in π-electrons as well as sulphur, nitrogen and oxygen-bearing ligands to which iron (steel-rebar) exhibits coordinate affinity. Phytochemical characterization showed that the leaf-extract contains alkaloids, tannins, phlobatannins, saponins, steroids and glycosides. Corrosion-inhibiting prospect testing, using the leaf-extract, indicated reduced steel-reinforcement total-corrosion effects that correlated with the extract admixture concentrations employed in the 3.5% NaCl-immersed steel-reinforced concretes.

Dimensioning the Flexural Strengthening of Concrete Slabs with Textile Reinforced Mortar - Litterature Data Evaluation

2018 ◽  
Author(s):  
Alex-Manuel Muresan ◽  
Daia Zwicky
Keyword(s):  
Concrete Slabs ◽  
Test Results ◽  
Structural Concrete ◽  
Bond Behaviour ◽  
Flexural Strengthening ◽  
The Third ◽  
Reinforced Concrete Slabs ◽  
Main Challenge ◽  
External Reinforcement ◽  
Textile Reinforced Mortar

When strengthening reinforced concrete slabs with textile reinforced mortars (TRM), the “correct” consideration of the global bond behaviour between textile and cementitious matrix is identified as the main challenge in determining the most appropriate global analytical model. The first model evaluated here is based on classical assumptions for structural concrete design. The second model, as another extreme assumption, is completely neglecting textile bond in the cracked zone, thus assuming it as unbonded, end-anchored, external reinforcement. The third model is based on the simplifying assumption of the textile reinforcement being only significantly activated when the internal steel reinforcement is yielding. Analytical results from these approaches are compared to a database containing more than 130 test results reported in literature, and are statistically evaluated.

Calculation of Ultimate Loads of Two-Way Reinforced Concrete Slabs

2012 ◽  
Vol 256-259 ◽  
pp. 850-854
Author(s):  
Yong Wang ◽  
Yu Li Dong
Keyword(s):  
Reinforced Concrete ◽  
Ultimate Load ◽  
Failure Criteria ◽  
Reinforcement Ratio ◽  
Concrete Slabs ◽  
Test Results ◽  
Simple Method ◽  
Simply Supported ◽  
Reinforced Concrete Slabs

This paper presents the latest developments of a simple method used to determine the ultimate load of two-way simply supported reinforced concrete slabs. Based on the reinforcement ratio, two failure criteria are proposed in the paper. The effectiveness of the developed model is validated through satisfactory comparison with from test results.

scholarly journals Punching shear behavior of thick reinforced concrete slabs according to Strut-and-Tie model

2014 ◽  
Vol 13 (3) ◽  
pp. 183-192
Author(s):  
Tadeusz Urban ◽  
Jakub Krakowski
Keyword(s):  
Reinforced Concrete ◽  
Experimental Test ◽  
Shear Behavior ◽  
Punching Shear ◽  
Concrete Slabs ◽  
Test Results ◽  
Strut And Tie ◽  
Reinforced Concrete Slabs ◽  
Symmetric Loading ◽  
Strut And Tie Model

The punching shear behavior of thick reinforced concrete slabs was analyzed in this paper by using strut-and-tie model (S-T). Calculating procedures were compared to our own experimental test results. The analyzed elements were subjected to symmetric loading and without shear reinforcement.

scholarly journals On the New "Manual on Design of Composite Steel and Concrete Structures (in Elaboration of Formulary SP 266.13330.2016 "Composite Steel and Concrete Structures. Design Rules")"

2019 ◽  
pp. 99-106
Author(s):  
Sergey B. Krylov ◽  
Vladimir A. Semenov ◽  
Denis V. Konin ◽  
Alexey S. Krylov ◽  
Lidiya S. Rozhkova
Keyword(s):  
Cross Sections ◽  
Concrete Structures ◽  
Concrete Slabs ◽  
Steel Beams ◽  
Deformation Model ◽  
Normative Documents ◽  
Beam Columns ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs ◽  
Composite Steel

The paper provides a brief overview of domestic and foreign guidelines (manuals) for the design of composite steel and concrete structures: steel-concrete slabs on profiled flooring, combined beams, and columns with rigid reinforcement. The necessity of creation of the actual manual corresponding to the modernlevel of development of construction science, normative documents and design practiceslinked to the new formulary SP 266.1325800.2016 is proved. It will facilitate the design, reduce labor expenditures and improve the reliability of composite steel and concrete structures. The new guidance provides general recommendations for the design of composite steel and concrete structures and the basic regulations for the calculations. The new guidance describes recommendations for modeling of composite steel and concrete structures and elements in the calculated complexes, the recommendations for calculation of combined beams fully concreting rectangular and T-section, partially concreting along with support slab on the lower flange of the beam, columns with rigid reinforcement, shear a connection of composite beams. Recommendations on the registration of creep, shrinkage and crack formation in the appointment of the modulus of elasticity are given. Recommendations on the use of diagrams of the state of concrete, reinforcement, and steel in the calculation of steel-concrete elements on a nonlinear deformation model are given. Recommendations on the use of the range of sheet flooring for steel-reinforced concrete slabs, as well as metal profiles as steel beams and rigid reinforcement in the cross sections of columns and combined beams, are presented. Recommendations on a design of units and details of composite steel and concrete structures are given, refined recommendations on buffer are presented. The examples of connection of steel beams with columns with rigid reinforcement are given. The examples of calculation of composite steel and concrete structures taking subject to the recommendations given in the Manual are presented.

scholarly journals Investigation on Structural Behavior of Bamboo Reinforced Concrete Slabs under Concentrated Load

2021 ◽  
Vol 50 (1) ◽  
pp. 227-238
Author(s):  
Yanuar Haryanto ◽  
Nanang Gunawan Wariyatno ◽  
Hsuan-Teh Hu ◽  
Ay Lie Han ◽  
Banu Ardi Hidayat
Keyword(s):  
Reinforced Concrete ◽  
Concrete Slab ◽  
Absorption Capacity ◽  
Concrete Slabs ◽  
Structural Behaviour ◽  
Reinforced Concrete Slab ◽  
Concentrated Load ◽  
Steel Reinforced Concrete ◽  
Reinforced Concrete Slabs ◽  
Cracking Pattern

Reinforced concrete is perhaps the most widely used building material in the world. However, the materials used for reinforcement of concrete i.e. steel is quite expensive and scarcely available in the developing world. As a result, bamboo is considered to be a cheaper replacement with high tensile strength. This research investigated the structural behaviour of bamboo-reinforced concrete slabs used for footplate foundation subjected to concentrated load. For this purpose, four different reinforced concrete slab panels were developed and analyzed. The influence of replacing steel with bamboo for the reinforcement of concrete slabs on their structural behaviour was assessed by determining the load-deflection characteristics, the ultimate load, the stiffness, the ductility, the cracking pattern, and the energy absorption capacity. The results showed that in comparison to steel reinforced concrete slabs, the strength of 82% can be acquired by the bamboo reinforced slabs. Furthermore, ductility demonstrated by the two types of specimens was almost equivalent i.e. up to 93%. Those indicated that the structural behaviour demonstrated by bamboo reinforced slabs is quite comparable to that of steel reinforced concrete slabs. Therefore, bamboo can prove to be a promising substitute for steel in concrete reinforcement. Future studies may further examine this opportunity.

Inhibition of Steel-Rebar Corrosion in Industrial/Microbial Simulating-Environment by Morinda lucida

2015 ◽  
Vol 227 ◽  
pp. 281-285 ◽  
Author(s):  
Joshua Olusegun Okeniyi ◽  
Cleophas Akintoye Loto ◽  
Abimbola Patricia Idowu Popoola
Keyword(s):  
Leaf Extract ◽  
Test System ◽  
Monitoring Methods ◽  
Test Environment ◽  
Steel Reinforced Concrete ◽  
Steel Rebar ◽  
Reinforced Concrete Slabs ◽  
Rebar Corrosion ◽  
Microbial Environment ◽  
Electrochemical Monitoring

This paper studies inhibition of steel-rebar corrosion in concrete immersed in 0.5 M H2SO4, simulating industrial/microbial environment by the leaf extract ofMorinda lucida. Electrochemical monitoring methods were employed for testing different concentrations of the leaf extract admixed in duplicated specimens of steel-reinforced concrete slabs immersed in the acidic test-system. Statistical analyses as per ASTM G16-95 R04 of the experimental results showed that effectiveness ofMorinda lucidaat inhibiting concrete steel-rebar corrosion increased with the concentration of the admixture. 0.4167%Morinda lucida, per weight of cement, was identified with optimum inhibition efficiencyη= 98.78±0.34% followed in effectiveness by 0.3333%Morinda lucidawithη= 93.20±1.76% at inhibiting steel-rebar corrosion in the corrosive test-environment.

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