Replacement Of Steel Reinforcement Research Articles

Parametric Study of Concrete Members with GFRP Reinforcement Subjected to Bending and Axial Force

The paper deals with the possible replacement of steel reinforcement by GFRP reinforcement for concrete elements subjected to bending moment and compressive axial force. For the last 15 years, Fibre Reinforced Polymer (FRP) bars became more popular and commercially available as reinforcement for concrete elements. Composite FRP materials are still new in construction and many engineers are not familiar with their properties and behaviour. FRP has certain advantages over steel reinforcement. It is a durable material that is not subject to corrosion, does not conduct heat, is an electrical insulator and conducts electrical current, and is non-magnetic. In contrast, FRP also has certain deficiencies such as sensitivity to higher temperatures, alkaline environments, and reduction of mechanical properties at high levels of long-term stress. In the case of FRP reinforcements, the plastic branch is missing in the σ-ε diagrams, what leads to a sudden failure of the reinforced concrete element, either by tensile rupture of the reinforcement or by crushing the concrete. The most used FRP reinforcement is made of glass fibres - GFRP reinforcement. The paper deals with the possible replacement of steel reinforcement by GFRP reinforcement for slab and beam elements. The text describes a parametric study for different reinforcement ratio with GFRP reinforcement and steel reinforcement. The study is performed for a cross-section of 500x500 mm for a column element and a cross-section of 1000x250 mm for a slab element. The effect of longitudinal GFRP reinforcement in elements under compression was investigated. The study contains a comparison of interaction P-M diagrams of concrete elements with steel and GFRP reinforcement. For design of GFRP reinforced concrete elements, it is necessary to consider different material characteristics such as tensile strength and modulus of elasticity. The contribution of the GFRP reinforcement in compression was neglected due to the anisotropic nature of the GFRP reinforcement and the low modulus of elasticity. The main reference basis for the elaboration of a parametric study is the fib Bulletin No. 40.

Tensile characterisation of bamboo strips for potential use in reinforced concrete members: experimental and numerical study

The usage of bamboo as a replacement for steel reinforcement in concrete is in the early stages of development as bamboo reinforced concrete (BRC) members involve a lot more uncertainties than steel-reinforced concrete members. The properties of bamboo vary inter- and intra-species. A prerequisite to developing a rational design of BRC members, therefore, requires two stages—(i) a statistical characterisation of the mechanical properties of bamboo, and (ii) identifying the variables contributing significantly towards the stress-strain/load-displacement behaviour. This paper first experimentally characterizes the longitudinal tensile properties of Bambusa balcoa, a commonly found bamboo species in India. Statistical analysis of the experimental results suggests that most of the mechanical properties follow a lognormal distribution. The elastic modulus is found to have a dominant contribution towards the stress-strain behaviour. A high fidelity finite element model, the results of which are validated with experiments, indicates that only the variation of elastic modulus can capture 92% of the variability in the experimental results. We also create a low-fidelity finite element model using equivalent tensile modulus, which can capture 82% of the variability in the experimental results. Lastly, a finite element model of a BRC beam is created using the low-fidelity finite element model of bamboo. A comparison with the experimental results suggests a good agreement between them.

Performance of Bamboo and Steel Reinforced Concrete under Flexural Strength

As well known, concrete and steel are widely used in construction industry due to its strength and durability. The usage of these materials is threatening the environment as steel and concrete are non-renewable sources and the productions were consuming largest energy in construction industry. In order to overcome this problem some studies were conducted by different researchers in replacing steel with bamboo in structural components such as beam, column, slab and others. Therefore, in this study, the usage of bamboo as the replacement for steel reinforcement in concrete covering slab is tested. The flexural strength of bamboo reinforced concrete covering slab for 100 mm x 50 mm and 100 mm x 100 mm meshing were tested under four-point load. The result of comparison of flexural strength between steel reinforcement and bamboo meshing shows that the steel reinforcements have more flexural strength than bamboo meshing with percentage difference of 40.95% for 100 mm by 100 mm meshing opening and 62.37% for the 100 mm x 50 mm meshing opening size. From the experiment, it shows that slab cover with steel reinforcement has higher bending strength that the bamboo reinforced. The brittle behaviour of bamboo cannot compete with steel with higher elasticity.

Influence of profile deck sheet in composite slab system

Composite structures play a vital role in construction sector due to rapid completion of the projects. In composite structures, Plates are mostly used as a structural element for effective replacement of steel reinforcement. Normally the composite floor deck system involves a profile deck sheet as a bottom layer of slab system to take care of the tensile strength of the element. Concrete is poured over a deck sheet and with minimum reinforcement to take care of shrinkage stresses. Profile deck sheet plays a dual role as tensile reinforcement when concrete hardens and act as a temporary shuttering during fresh concreting. The main objective of this paper is to determine the vibration characteristics of profile deck sheet for various shapes of profile as composite slab system. Modal analysis is a technique in which vibration studies can be determined for various profile shapes by involving parameters such as mode shape, natural frequency, plate stresses and deformation by using finite element analysis.

Variasi Rajutan Bambu Petung Sebagai Pengganti Tulangan Baja Dari Kuat Lentur FS 4,7 MPA

In this globalization era, almost all buildings use concrete with steel reinforcement as the main component of building frames. it is known that the basic material for steel is iron ore, and iron ore is a non-renewable natural resource, while its supply in nature is increasingly limited. Therefore, the price of steel reinforcement also increased. therefore, there needs to be an alternative replacement of steel reinforcement in concrete. Bamboo has a fairly high tensile strength, between 100-400 MPa, almost equal to the tensile strength of steel reinforcement equivalent to ½ to ¼ of the ultimate stress of steel reinforcement shows the same results and tensile strength of bamboo can reach 1280 kg / cm2. Bamboo is used as reinforcement in concrete with knitted shapes and patterns. In this research, the flexural strength test of 15 concrete blocks measuring 15 X 15 X 60 Cm was carried out when the concrete age was 28 days with 3 different variables. The results showed that bamboo reinforced concrete beams had an average maximum flexural strength value of 7.20 MPa. So that the use of petung bamboo reinforcement has a positive effect and deserves to be used as an alternative to steel reinforcement.

Investigation of non-autoclaved foamconcrete beams reinforced with bamboo

Purpose: of this paper presents the experimental results of a study of strength and flexural behaviour of non-autoclaved foam-concrete beams reinforced with bamboo Design/methodology/approach: Six experimental samples of reinforced lightweight foamed concrete beams with hardened density D800 and D1200 with the same bamboo reinforcement were tested on lateral bending. Findings: A low level of anchoring of bamboo reinforcement in foam-concrete beams can provide their premature destruction. Research limitations/implications: Next experiments should be provided for improving the anchoring of bamboo reinforcement such as the bad adhesion between the bamboo and foam-concrete caused premature destruction of experimental samples. Practical implications: Replacement of steel reinforcement on the bamboo one in foam- concrete structures can be economical benefit. Originality/value: Increasing of experimental base leads to developing and creating new building standards in the nearest future.

Axial Tensile Strength Analysis of Naturally Treated Bamboo As Possible Replacement of Steel Reinforcement in the Concrete Beam

This paper was undertaken to evaluate Giant bamboo (Dendrocalamus Asper) which is abundant natural resource that can be considered as an alternative for construction materials for reinforcement to compensate the low tensile property of the concrete. Considering the cost, even though steel reinforcement is a very suitable material for complementing concrete’s low tensile strength, bamboo products as it enter the diverse worldwide markets, the value of these natural resource stands to grow. Bamboo and steel are structural materials with different engineering qualities used for the construction of buildings and other engineering construction related purposes. To overcome these problems, full socio-economic potential of bamboo is yet to be realized as alternative materials to substitute the reinforcing bar in concrete for less important structures by investigating the tensile properties of this type of natural reinforcement. To evaluate these properties, 5 for each bamboo were tested in natural preservation submerged in fresh-water and salt-water for 7 days and 28 days cycles for internode and node section in which tension test was conducted on bamboo specimen following the ASTM standards. From this test, average ultimate tensile strength is approximately 211.18 MPa in the specimens without node for 7 days soaked in salt-water and 138.97 MPa in the specimens with node soaked in fresh water for 28 days. Finally, 7 cycles of wetting and drying in solution of salt-water treated did not increase the bamboo tensile strength neither the Young’s Modulus, therefore, the study concludes that due to the minimal breaking force (FB) of bamboo, it cannot be employed as a main structural member in buildings and other heavy engineering works but can be used for partition walls, ceilings, roofs and other areas of lightweight engineering construction that is not heavy loadbearing capacity.

Time-Variant Reliability Analysis and Flexural Design of GFRP-Reinforced Bridge Decks

AbstractGlass-fiber reinforced polymer (GFRP) reinforcement is being used in bridge decks as a replacement for steel reinforcement. It is thought that since the GFRP reinforcement does not corrode, it could be a more sustainable material for reinforced concrete structures. However, it is widely reported that GFRP bars do deteriorate when embedded in concrete or when immersed in concrete pore solutions. The American Concrete Institute (ACI) and AASHTO use environmental exposure factors to reduce the design strength due to this loss of capacity. However, these exposure factors have not been calibrated. In addition, limited research has been performed to quantify the time-variant flexural moment capacity of GFRP-reinforced flexural members. Recently, a Bayesian approach was used to develop a time-variant probabilistic capacity model based on capacity data of GFRP reinforcement embedded in concrete for a period of up to seven years. This model is used herein to assess the time-variant flexural moment capacity...

Strength and deflection behavior of spun concrete poles with CFRP reinforcement

Prestressed spun concrete poles are used primarily for supporting electric power transmission lines and distribution and for area lighting. In many applications they are placed directly in brackish water or saltwater, resulting in deterioration of the concrete pole due to steel corrosion. A new type of reinforcement that can provide the desired structural characteristics and at the same time address the issue of corrosion is needed. Carbon fiber-reinforced polymer (CFRP) composites show potential as a replacement for steel reinforcement because of their corrosion resistance, high strength, and light weight that enables easier handling and reduces the self-weight of structures. The main objective of the research was to study the strength and deflection behavior of spun concrete poles with CFRP reinforcing bars. The study showed that the performance of the poles reinforced with CFRP bars was satisfactory under bending loads, which are the primary governing loads in most applications.