Assessment and Evaluation of Blended Cement Using Bamboo Leaf Ash BLASH Against Corrosion

Concrete provides a high degree of protection against corrosion of embedded steel reinforcement. Owing to the harsh environmental conditions and the presence of aggressive elements from the marine environment, deteriorating corrosion affects the durability of reinforced concrete structures. This study evaluated the effectiveness of bamboo leaf ash BLASH as a supplementary cementing material or admixture with Portland cement to improve the durability of reinforced concrete structures. Specimens of 0, 10, 15, and 20% BLASH mixtures were prepared using 16, 20, and 25 mm steel reinforcements. A total of 100 cylindrical specimens were cast and used in this study. The specimens were accelerated by corrosion using impressed current techniques and a galvanostatic method in a simulated environment. The results show that specimens with a BLASH content of 10% exhibited superior performance and exhibited longer corrosion initiation and propagation times. It has a higher resistance to acid penetration and lower corrosion rates. The crack parameters of the specimen with BLASH admixtures, such as the crack width and crack frequency, were negligible. The use of BLASH as an admixture strengthens its durability and improves its residual strength and serviceability. Doi: 10.28991/cej-2021-03091707 Full Text: PDF

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Monitoring carbon steel behavior under biotic and abiotic conditions

MRS Proceedings ◽

10.1557/opl.2015.318 ◽

2015 ◽

Vol 1768 ◽

Author(s):

E.J. León ◽

D.A. Koleva ◽

H.M. Jonkers ◽

J.M.C. Mol ◽

H. Terryn ◽

...

Keyword(s):

Reinforced Concrete ◽

Carbon Steel ◽

Common Knowledge ◽

Concrete Structures ◽

Steel Corrosion ◽

Engineering Practice ◽

Reinforced Concrete Structures ◽

Initial Surface ◽

Abiotic Conditions ◽

Simulated Environment

ABSTRACTDeterioration of concrete structures, together with corrosion of reinforcing steel due to the action of microorganisms, is known as Microbiologically Induced Corrosion of Concrete (MICC). The activity of microorganisms can initiate and further accelerate both steel corrosion and cement-based matrix degradation in reinforced concrete structures. The mechanism is related to initial surface colonization and further bio-products (and aggressive substance respectively) penetration into the bulk concrete matrix, reaching the reinforcement level. Common knowledge is that bio-deterioration-related infrastructure degradation, maintenance and repair have a significant economic impact worldwide. However, due to the complexity of all related mechanisms, a durable and feasible solution is still to be achieved for the engineering practice. This paper briefly points out main bio-degradation related mechanisms for concrete, steel and reinforced concrete structures and presents results on the electrochemical response of carbon steel in simulated environment under biotic and abiotic conditions.

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Case study: influence of performance levels of ABNT NBR 15575 without consumption of materials used in reinforced concrete structures

Revista IBRACON de Estruturas e Materiais ◽

10.1590/s1983-41952019000400013 ◽

2019 ◽

Vol 12 (4) ◽

pp. 956-971

Author(s):

F. S. CUNHA ◽

K. A. L. COLLA ◽

H. EHRENBRING ◽

F. L. BOLINA ◽

B. TUTIKIAN

Keyword(s):

Reinforced Concrete ◽

Residential Buildings ◽

Concrete Structures ◽

Performance Level ◽

Superior Performance ◽

Performance Standard ◽

Reinforced Concrete Structures ◽

Performance Levels ◽

The Impact ◽

Minimum Performance

Abstract The Brazilian construction industry still discusses the consequence of the Performance Standard on housing developments. According to ABNT NBR 15575 [1], the systems that compose residential buildings need to meet minimum performance requirements. Among the systems, the structural must reach a minimum Service Life (SL) of 50 years, or intermediate or higher that corresponds to 63 and 75 years, respectively. The industry also debates the impact and viability of increasing the SL of reinforced concrete structures. Therefore, this article aimed to analyze a single reinforced concrete building designed for the 3 SL specified by ABNT NBR 15575 [1]. The study focused on the total consumption of steel and concrete. The structure’s designed conditions of exposure were varied for each performance level, based on the 4 environmental exposure classes (EEC) of ABNT NBR 6118 [3] and ABNT NBR 12655 [11], totalizing 12 situations. It was noted that the increased performance level increases consumption of materials, and the designs made for EEC IV consumed 12.3% and 16.2% more steel and concrete at the intermediate and superior performance levels respectively, when compared to the minimum performance level.

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Corrosion vulnerability of reinforced concrete structures with different blended cement due to chloride ingress

Materials Today Proceedings ◽

10.1016/j.matpr.2020.07.668 ◽

2020 ◽

Author(s):

Bayezid Baten ◽

Tafannum Torsha ◽

Tanvir Manzur

Keyword(s):

Reinforced Concrete ◽

Concrete Structures ◽

Blended Cement ◽

Reinforced Concrete Structures ◽

Chloride Ingress

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Study on Technical Standards of Reinforced Concrete Structures with Long Service Life when Using Blended Cement and Finishing Materials

10.23967/dbmc.2020.133 ◽

2020 ◽

Author(s):

T. Kage ◽

H. Tanano ◽

N. Tsuchiya ◽

H. Jinnai

Keyword(s):

Reinforced Concrete ◽

Service Life ◽

Concrete Structures ◽

Blended Cement ◽

Reinforced Concrete Structures ◽

Technical Standards

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Design of precast reinforced concrete structures of frame buildings: a new set of rules

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.04.04-09 ◽

2019 ◽

pp. 4-9 ◽

Cited By ~ 1

Keyword(s):

Reinforced Concrete ◽

Concrete Structures ◽

Reinforced Concrete Structures ◽

Building Frames ◽

Fine Grained ◽

Rigid Frame ◽

Floor Slabs ◽

Frame Buildings ◽

Spatial System ◽

Precast Elements

Currently, prefabricated reinforced concrete structures are widely used for the construction of buildings of various functional purposes. In this regard, has been developed SP 356.1325800.2017 "Frame Reinforced Concrete Prefabricated Structures of Multi-Storey Buildings. Design Rules", which establishes requirements for the calculation and design of precast reinforced concrete structures of frame buildings of heavy, fine-grained and lightweight structural concrete for buildings with a height of not more than 75 m. The structure of the set of rules consists of eight sections and one annex. The document reviewed covers the design of multi-story framed beam structural systems, the elements of which are connected in a spatial system with rigid (partially compliant) or hinged joints and concreting of the joints between the surfaces of the abutting precast elements. The classification of structural schemes of building frames, which according to the method of accommodation of horizontal loads are divided into bracing, rigid frame bracing and framework, is presented. The list of structural elements, such as foundations, columns, crossbars, ribbed and hollow floor slabs and coatings, stiffness elements and external enclosing structures is given; detailed instructions for their design are provided. The scope of the developed set of rules includes all natural and climatic zones of the Russian Federation, except seismic areas with 7 or more points, as well as permafrost zones.

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Improvement Of Curvilinear Diagrams Of Concrete Deformation

Promyshlennoe i Grazhdanskoe Stroitel stvo ◽

10.33622/0869-7019.2019.08.99-104 ◽

2019 ◽

pp. 99-104

Keyword(s):

Reinforced Concrete ◽

Peak Load ◽

Experimental Studies ◽

Concrete Structures ◽

Deformation Model ◽

Reinforced Concrete Structures ◽

Significant Difference ◽

Deformation Diagrams

Problems when calculating reinforced concrete structures based on the concrete deformation under compression diagram, which is presented both in Russian and foreign regulatory documents on the design of concrete and reinforced concrete structures are considered. The correctness of their compliance for all classes of concrete remains very approximate, especially a significant difference occurs when using Euronorm due to the different shape and sizes of the samples. At present, there are no methodical recommendations for determining the ultimate relative deformations of concrete under axial compression and the construction of curvilinear deformation diagrams, which leads to limited experimental data and, as a result, does not make it possible to enter more detailed ultimate strain values into domestic standards. The results of experimental studies to determine the ultimate relative deformations of concrete under compression for different classes of concrete, which allowed to make analytical dependences for the evaluation of the ultimate relative deformations and description of curvilinear deformation diagrams, are presented. The article discusses various options for using the deformation model to assess the stress-strain state of the structure, it is concluded that it is necessary to use not only the finite values of the ultimate deformations, but also their intermediate values. This requires reliable diagrams "s–e” for all classes of concrete. The difficulties of measuring deformations in concrete subjected to peak load, corresponding to the prismatic strength, as well as main cracks that appeared under conditions of long-term step loading are highlighted. Variants of more accurate measurements are proposed. Development and implementation of the new standard GOST "Concretes. Methods for determination of complete diagrams" on the basis of the developed method for obtaining complete diagrams of concrete deformation under compression for the evaluation of ultimate deformability of concrete under compression are necessary.

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