This paper presents experimental results of three continuously supported concreteslabsreinforced with basalt-fibre-reinforced polymer (BFRP) bars. Three different BFRP reinforcement combinations of over and under reinforcement ratios were applied at the top and bottom layers of continuousconcreteslabs tested. One additional concretecontinuous slab reinforced with steel bars and two simply supported slabsreinforced with under and over BFRP reinforcements were also tested for comparison purposes. All slabs sections tested had the same width and depth but different amounts of BFRP reinforcement. The experimental results were used to validate the existing design guidance for the predictions of moment and shear capacities, and deflections of continuousconcrete elements reinforced with BFRP bars. The continuously supported BFRP reinforcedconcreteslabs illustrated wider cracks and larger deflections than the control steel reinforcedconcrete slab. All continuous BFRP reinforcedconcreteslabs exhibited a combined shear–flexure failure mode. ACI 440-1R-15 equations give reasonable predictions for the deflections of continuousslabs (after first cracking) but stiffer behaviour for the simply supported slabs, whereas CNR DT203 reasonably predicted the deflections of all BFRP slabs tested. On the other hand, ISIS-M03-07 provided the most accurate shear capacity prediction for continuously supported BFRP reinforcedconcreteslabs among the current shear design equations.
The Basalt and Carbon FRP bars used in this investigation are manufactured and funded by Magmetech Ltd. (UK), which are formed by the pultrusion technique. The surface of these bars is coated with a coarse silica sand to improve bond and force transfer between reinforcing bars and concrete increase bonding with the concrete matrix. The mechanical characteristics of these reinforcing bars were obtained by carrying out tensile tests on a number of specimens of each diameter. Anchorage systems have been proposed to avoid premature failure of FRP bars during tensile tests at the steel jaws of the testing machine. Referring to previous successful systems for applying tensile loading of FRP bars, it was decided to explore the system developed by researchers at West Virginia University. In this technique, the length of the two anchorages was 300 mm each based on previous research (Micelli and Nanni 2001) as shown in Figures 3–3 and 3–4. In addition, a free length of 400 mm was provided as recommended by unpublished ACI provisions. The specimens were initially prepared by embedding the ends of bar into steel pipes filled with expansive grout in vertical position by using wooden formwork (see Figures 3–5a and 3–5b). All prepared specimens were tested
86 earlier in specimens of group [B] than in those of group [D]. This occurred possibly because specimens of group [D] had hybrid reinforcement having a higher axial stiffness than that of their counterparts from group [B]. Varying the hogging-to- sagging nominal capacity ratio had an almost no effect on the cracking load for specimens of group [B]. Increasing the hogging-to-sagging nominal capacity ratio increased the cracking load in the hogging region of specimens of group [D]. The load capacity of all specimens increased with an increase in the hogging-to-sagging nominal capacity ratio. Although specimens of groups [B] and [D] were designed to have similar sectional moment strength, the load capacity of specimens of group [D] was on average 18% higher that of group [B]. This could be attributed to the presence of the steel reinforcement that allowed specimen D1 to be intact after the occurrence of local BFRP rupture in the hogging region which allowed for a greater moment to be transferred from the hogging to the sagging regions, and hence increased the load capacity. The higher load capacities exhibited by specimens of group [D] compared with those of their counterpart specimens from group [B] can be attributed to a variation in the actual mechanical properties of BFRP and/or steel bars compared to those obtained from tensile tests.
perimeter dimensions of the punching shear failures (Dulude et al. 2013; Hassan et al. 2013a; Hassan et al. 2013b). Moreover, effects of different reinforcement diameters with constant reinforcement ratio which was included in this project weren’t addressed previously in the past research work. More test specimens are needed to cover a wider range of data, especially in this part of the mentioned parametric study to enable a more precise prediction of the punching shear stress. On the other hand, the accuracy of current equations in the FRP design codes and guidelines CSA S806 (2012), ACI 440(2015), and JSCE (JSCE et al. 1997) and other design approaches from the literature are assessed. This research also develops a new database of results from concentric punching shear tests of GFRP reinforcedconcrete flat slabs. Hence, this work aims to provide useful information to researchers and practising engineers. While FRP bar properties have been commercially improved, a review study of punching shear behaviour is required.
repercussions requiring costly repair and maintenance operations. To overcome this issue, various measures and procedures have been developed and tested, yet none of these seemed to provide a practical and cost-effective solution. It was found that these remedies rather than permanently solve the corrosion problems; they were merely slowing down the process (Song & Saraswahty, 2007). In the last decade, the use of fibrereinforced polymer (FRP) bars as reinforcement material has emerged as a practical alternative solution (Barris et al., 2012). FRP is a composite material made of continuous fibres consisting of high strength carbon, aramid or glass fibres embedded in a polymeric matrix (i.e. thermosetting resins) where the fibres primarily carry the load. Due to their inherent non-corrosive nature, utilisation of FRP reinforcement in new structures can increase service life and decrease maintenance and rehabilitation costs whereas in existing structures, the versatile nature of FRP, can allow retrofitting in an efficient manner which can provide significant savings in both construction costs as well as environmental benefits. FRP materials have a combination of physical and mechanical characteristics such as lightweight, high tensile strength, high stiffness, excellent durability and high fatigue strength.
aggregate, or by external factors, such as connections to walls and columns. Although initially shallow, plastic shrinkage cracks can grow to full-depth over time . The cracks are not only unsightly, but they allow the penetration of deleterious substances, and consequently, can lead to the rapid deterioration of a structure. Most notable is the penetration of water and chlorides enabling the corrosion of embedded steel reinforcement. Shrinkage cracking is often attributed to severely reducing the serviceability of concrete structures, particularly those with a large surface area to volume ratio, including: slabs-on-grade, tunnel linings and repair overlays. Perhaps most detrimental is the reduced serviceability of bridge decks due to early age cracking. A number of reports published from various state departments of transportation (DOTs) in the United States of America, suggest that shrinkage is a major contributing factor to early age cracking [8-11]. In these reports, shrinkage refers to the strain that develops at both an early-age (plastic shrinkage), and over a longer duration after the concrete has hardened (drying shrinkage). However, according to the Transportation Research Board , the mechanisms that lead to plastic shrinkage cracks do not explain full depth cracks, and therefore, it is probable drying shrinkage can propagate plastic shrinkage cracks. Since cracks in concrete can propagate at a stress lower than that required to initiate them , the control of plastic shrinkage cracking should be a key design consideration in regards to preventing or reducing cracking, and in-turn, minimizing life- cycle costs.
BFRP bars with a diameter of 8mm and 10mm used in this study (Figure-1) were provided by Arrow Technical Textiles Pvt. Ltd, Mumbai. All the BFRP bars supplied by these industries were manufactured by pultrusion process. BFRP bars had fibre content of 80.1% and 80.3% for 8mm and 10mm- diameters, respectively. The density of the BFRP bars was 2044kg/m 3 and 2065kg/m 3 for 8mm and 10mm-diameters, respectively. The tensile properties of these BFRP bars were determined by testing of five specimens as per ASTM D7205 guidelines. The tensile test setup, stress-strain relationship and failure pattern of tested BFRP bars as shown in Figure-2. It was observed that the ultimate tensile strength of BFRP bars of 8mm and 10mm-diameters were 1378MPa and 1475Mpa respectively. The scanning electron microscopy (SEM) images of tensile fractured BFRP specimens are presented in Figure-3.
Experimental results on beam tests, performed by Gustafsson and Karlsson (2006), were used for comparison with design results obtained when designed according to, the FIB model code, RILEM TC-162-TDF (2003) and the Spanish EHE-08 in order to determine the accuracy of the design methods. The comparison showed that the different methods had little variation in the design results. When compared to the experimental results, underestimations, up to 12.5%, in ultimate moment resistances and both under- and overestimations in shear resistances, depending on the diameter of the ordinary reinforcement bars, were revealed. These over- underestimations might be caused by the use of the simplified linear post cracking behaviours, presented by the design codes and guidelines. It should also be mentioned that mean values of the experimental results were used due to the large variation in the material behaviour of the beam specimen. This variation in the ultimate moment resistance was up to 9.5% for beams with the same material properties and could also be a cause for the underestimations obtained.
being exposed to accelerated conditioning environments. Cory High et al. (2015) investigated the use of basalt fiber bars as flexural reinforcement for concrete members and the use of chopped basalt fibers as an additive to enhance the mechanical properties of concrete. Chaohua Jiang et al. (2014) studied the effects of the volume fraction and length of basalt fiber (BF) on the mechanical properties of FRC. Coupling with the scanning electron microscope (SEM) and mercury intrusion porosimeter (MIP), the microstructure of BF concrete was also studied. Fathima Irine et al. (2014) investigated the mechanical properties of Basalt fiber concrete and compare the compressive, flexural and splitting tensile strength of basalt fiber reinforcedconcrete with plain M30 grade concrete. Jon sung Sim et al. (2005) investigated the applicability of the basalt fiber as a strengthening material for structural concrete members through various experimental work for durability, mechanical properties and flexural strengthening. Kunal Singha (2012) presented a short review on basalt fiber. Mehmet Emin Arslan (2016) investigated the fracture behaviour of basalt fiber reinforcedconcrete (BFRC) and glass fibrereinforcedconcrete (GFRC). In the experimental study three-point bending tests were carried out on notched beams produced using BFRC and GFRC.Gore Ketan et al. (2013) evaluated the performance of high strength concrete (HSC) containing supplementary cementations materials. Concrete had a good future and is unlikely to get replaced by any other material on account of its ease to produce, infinite variability, uniformity, durability and economy with using of basalt fiber in high strength concrete. Nasir Shafiq et al. (2016) presentenced the flexural test results of 21 fiber reinforcedconcrete (FRC) beams containing Poly vinyl alchol (PVA) and basalt fibers (1-3% by volume) Fiber reinforcedconcrete was made of three different binders. Experimental results showed that the addition of PVA fibers significantly improved the post-cracking flexural response compared to that of the basalt fibers. Amuthakkannan et al. (2013) focused on the effect of fibre length and fibre content of basalt fiber on mechanical properties of the fabricated composites. TianyuXie and Togay Ozbakkaloglu (2016) conducted experimental study on the axial compressive behavior of concrete filled FRP tubes (CFFTs), prepared using different amounts of recycled concrete aggregate (RCA).
Abstract— Concrete is the most widely used building material in the construction industry. It consists of a rationally chosen mixture of binding material such as cement, well graded fine and coarse aggregates, water and admixtures. Conventional concrete is modified by random dispersion of short discrete fine fibres to improve its mechanical properties. The improvement in structural performance depends on the strength characteristics, volume, spacing, dispersion and orientation, shape and the aspect ratio of the fibres. For fibres to be more effective, each fibre needs to be fully embedded in the matrix, thus cement paste requirement is more. It is relatively strong in compression but weak in tension and tends to be brittle. These two weaknesses have limited its use. Another fundamental weakness of concrete is that cracks start to form as soon as concrete is placed and before it has properly hardened. Glass, fibre, carbon fibres are commonly used in manufacturing of reinforcing bars for concrete applications. This study present the art of knowledge of basaltfibre, it is relatively new material. Basalt is an igneous rock, It is a single material fibre manufactured by melting of basalt and extruding the molten basalt through small nozzles to produce continuous filaments of basaltfibre. It is a high performance non-metallic fibre made from basalt rock melted at high temperature. In the last decade, basalt has emerged as a contender in the fibre reinforcement of composites. In this report Evaluation of mechanical properties in basaltfibrereinforcedconcrete were investigated. The volume fractions of basaltfibre of (0.1, 0.2, 0.3, and 0.5% by total mix volume) were used. Properties such as compressive and splitting tensile strengths were examined. Results indicated that the strength increases with increase the fibre content till 0.3% then there is a slight reduction when 0.5% fibre used. The modulus of elasticity shows the trend of the strengths results. Many applications of basaltfibre are residential, industrial, highway and bridges etc.
crete structures and composite materials in infrastructure, increases the demand of design of high strength and durable reinforcedconcrete structure subjected to static and impact loads. The structural design deals with various types of loads such as earthquake load, and impact occurs from various reasons such as vehicle collision, rock fall, military exercise, missile attacks etc. Construction industry is heading towards a new era with (HPC). High performance concrete overcomes the limitations of conventional concrete. The use of HPC is not only limited to infrastructural projects but also in high rise structures, nuclear reactor, defense structure etc. Now-a-days fibers are the most used materials to improve the ductile property of concrete. The properties of carbon fibers, such as high stiffness, high tensile strength, low weight, high chemical resistance, high temperature tolerance and romising fiber materials to be used in the Fiber Reinforcedconcrete (FRC). Use of polypropylene fibers reduces cracks during plastic and hardened state particularly when it is use in structural elements such as beam, column, slabs etc. which quality of concrete constructions. Hence, addition of carbon fibers and polypropylene fiber to HPC increases toughness, energy absorption capacity of High Performance Fiber Reinforced The present experimental investigation has been focused to develop a comprehensive understanding of test slab specimen under impact loading. HPC of M60 grade of concrete integrated with carbon fibers and polypropylene fibers. Series of twelve slab test specimens 0mm) with varying thickness of 60, 50 and 40 mm with and without carbon fibres (0.5% by volume),polypropylene fibres (900 gm/m 3 ), and combination of both. Impact tests on the slab test specimens were carried out on a low velocity repeated impact ne using instrumented drop weight hammer of 10.2 kg attached with Load Cell and was designed, fabricated and installed at Civil Engineering Department, UVCE, Bangalore University, 56. Accelerometer, LVDT’s was used to record the Time-histories and Load, Deflection, and Acceleration. The experimental result shows a significant increase in the energy absorption, peak loads same number of impact blows for the carbon and polypropylene fibrereinforcedconcrete test
The County of Essex and MEDA Engineering, along with the University of Windsor worked together to identify a local concrete structure to apply the basaltfibrereinforced polymer (BFRP) composite to. After considering other structures, including a culvert, and looking for local contractors willing to work with the new product, a suitable bridge and local contractor willing to work with the new product were identified. The Merrick Creek Bridge, located on Country Road 8, west of Country Road 9 in Windsor, Ontario (Figure 5.2) was selected as an ideal candidate structure. The Merrick Creek Bridge is estimated to have been constructed in the 1970s. It is made with eleven precast prestressed T-beam girders topped with a concrete deck and spans 12.9 m. Figure 5.3 shows the section view of the bridge. Figure 5.4 shows the plan view of the bridge. In each figure, the girders are labelled A-K from north to south. The plan view in Figure 5.4 shows how
The replacement of steel bars with fiber-reinforced polymer (FRP) bars as internal reinforcement to RC structures is now an accepted practice to enhance the durability and prolong the serv- iceability of these structures. In addition to ultra-high tensile strength and lightweight properties, the FRP composite materials are corrosion resistant, durable, and nonmagnetic (Gangarao et al. 2007). In comparison with steel, FRP materials have relatively lower ductility, lower bonding strength, and anisotropic properties. In effect, new and compatible design framework is necessary to ensure the safety and serviceability of concrete structures rein- forced with FRP bars. Fico (2008) presented several FRP rein- forced RC structures that were successfully built in Japan (e.g., floating marine structures, pontoon bridge, and magnetic levitation railway) and in other countries. Research and develop- ment on FRP reinforced RC structures had become tantamount that several countries developed their own design guidelines such as the Japan Society of Civil Engineers in Japan, ISIS and CSA-S806 [Canadian Standards Association (CSA) 2010] in Canada, and ACI 440.1R [American Concrete Institute (ACI) 2006] in the United States. Although the initial costs of using FRP are higher compared with those of steel, they will even up in the long run because the costly repair and maintenance from steel corrosion (Mazaheripour et al. 2013; Achillides and Pilakoutas 2004) will be avoided. The use of FRP materials is particularly relevant in cases where the design of RC structures is controlled by durability requirements (Tastani and Pantazopolou 2006) and long-term sus- tainable performance.
Fibrereinforcedconcrete (FRC) is a concrete containing fibres other than cement, sand and aggregates which increases the compressive strength, tensile strength and workability of concrete. So we can define fibrereinforcedconcrete as a composite material of cement concrete or mortar and discontinuous discrete and uniformly dispersed fibre.
ABSTRACT: The behaviour of reinforcedconcrete structures is influenced by the interaction between the concrete and reinforcement. The bond between steel and concrete is very important and essential so that they can act together without any slip in a loaded structure. Hence bond has been, and still is a topic of fundamental and applied research. Here a Study on the effect of steel and recron 3S fibre on the bond strength and bond stress- slip response of deformed steel bars embedded in fibrereinforcedconcrete was carried out both experimentally and analytically. Experimental study was carried out by doing pullout tests using Universal Testing Machine (UTM) on cubes of size 150x150x150mm. A total of 24 pullout specimens were cast and tested. The variables considered were, the volume fraction of hooked steel fibres, the volume fraction of recron 3S fibres and the diameter of reinforcement bars. The analytical study was carried out using ANSYS software by modeling a cubical specimen similar to experimental work. It was seen that steel fibres showed higher bond strength than recron 3S fibres and that of control specimen. The results obtained from analytical tests showed the same trend as that of experimental ones.
A series of the elements tested by Swamy and Ali  were selected to gain a better understanding of the predicted effect of the steel ﬁbre volume on the punching shear strength of slab– column connections. The selected test elements had identical geometrical dimensions and ﬁbre type and the concrete compres- sive strength was similar for all batches. The failure criteria and the estimated load rotation relationships for the elements selected are presented in Fig. 9 a. As is shown in Fig. 9 b, the proposed model predicts well the increase of the punching shear strength with the increase of the ﬁbre volume. Furthermore, an increase in the quantity of similar ﬁbres provides for an increase in the deforma- tional capacity. As the concrete contribution to the punching strength decreases with the increase of the slab rotation, the weight of the ﬁbre contribution becomes more relevant to the resistance mechanism. The predicted concrete and ﬁbres contribu- tions to the punching shear strength for elements tested by Swamy and Ali (  are shown in Fig. 9 b, with an excellent correlation ob- served between the model predictions and the test results. 5. Code-like formulation
The technical advantages of using SFRC in this typology of structures have been extensively studied [3-5], among them are the increased toughness and ductility, the cracking control or the enhanced performance in case of dynamic effects or impacts. Besides these, other advantages related with the construction should be considered when analysing the possibility of using SFRC. Given that fibres are added in the concrete plant when the concrete mix is manufactured, the amount of work on site decreases significantly. The operations of preparing, handling and placing the traditional reinforcement are reduced to localized areas where the traditional reinforcement might be necessary. As a result, the execution time of the structure is also reduced. Furthermore, the use of SFRC makes the vibration of the concrete unnecessary and the occupational safety is improved due to the lack of risks associated to the handling of the traditional reinforcement.
The steel reinforcedconcrete beams consisted of 2no. 8 mm diameter high tensile steel rebars as main tension reinforcement. The first vertical flexural crack in the beams occurred at a relatively small load of between 20 - 35%, i.e. 15 – 21 kN of their ultimate load, in the constant bending moment region. With further load increase, additional flexural cracks developed along the span of the beam length. The cracks propagated outside the flexural zone and started to take a diagonal shape towards the compression fibres of the beam. However, the width of these flexural cracks did not change significantly, suggesting that they were all secondary flexural cracks. Secondary cracks are those that are widely spaced and occur under low loads without influencing other cracks to arise. These cracks develop during the initial stages of the cracking due to internal expansion and contraction of the concrete constituents as well as low flexural stresses accumulating from the self-weight of the beam. Hassoun and Al-Manaseer (2008) stated that, when steel bars are subjected to low tensile stresses, the widths of the cracks remain small, but the numbers of cracks increase. As the tensile stresses progress further, an equilibrium stage is reached. When the tensile stresses are further increased to a point, that between the steel and the concrete there is a difference in strain, then the second stage of the cracking starts to occur, where the widths of the cracks increase without any significant increase in the number of cracks. These cracks are known as the main cracks. Usually, one or two cracks start to widen more than the others, forming critical cracks. This was observed during the experiment from 36 – 45 kN loads for the specimens until failure. The cracks started to widen and extend towards the top compression fibres of the beams without any additional cracks forming. The beams continued to sustain
2.1 Venu Malagavell and Neelakanteswara Rao Patura,(2011), “Strength Characteristics of Concrete Using Solid Waste an Experimental Investigation” They concluded concrete is a mixture of cement, fine aggregate, coarse aggregate and water. Concrete plays a vital role in the development of infrastructure, buildings, industrial structures, bridges and highways etc. leading to utilization of large quantity of concrete. Solid waste disposal i.e. water bottles, polythene bags, cement bags, cold drink bottles etc. was creating lot of environmental problems. An attempt has been made in this study by using solid waste (non-biodegradable) material in the concrete. FibreReinforcedConcrete (FRC) is an emerging field in the area of Concrete Technology. This study mainly focused on the use of cement bags waste (High Density Polyethylene (HDPE)) in concrete. Concrete having compressive strength of 30 N/mm2 was used for this study. Cubes, cylinders and beams are casted with 0 to 6% of fibre with 0.5% increment. Samples were tested for the compressive strength, split tensile strength and Flexural strength and comparison analysis was made for the conventional concrete and modified concrete. It has been found that, increase in the compressive strength, split tensile strength and flexural strength of concrete by using the fibres up to some extent.