Finite Element Analysis of Beam – Column Joints Reinforced with GFRP Reinforcements

Glass Fibre Reinforcement Polymer (GFRP) reinforcements are currently used as internal reinforcements for all flexural members due to their resistance to corrosion, high strength to weight ratios, the ability to handle easily and better fatigue performance under repeated loading conditions. Further, these GFRP reinforcements prove to be the better alternative to conventional reinforcements. The design methodology for flexural components has already come in the form of codal specifications. But the design code has not been specified for beam-column joints reinforced internally with GFRP reinforcements. The present study is aimed to assess the behaviour of exterior beam-column joint reinforced internally with GFRP reinforcements numerically using the ABAQUS software for different properties of materials, loading and support conditions. The mechanical properties of these reinforcements are well documented and are utilized for modelling analysis. Although plenty of literature is available for predicting the joint shear strength of beam-column joints reinforced with conventional reinforcements numerically, but no such study is carried for GFRP reinforced beam-columns joints. As an attempt, modelling of beam-column joint with steel and with GFRP rebars is carried out using ABAQUS software. The behaviour of joints under monotonically increasing static and cyclic load conditions. Interpretation of all analytical findings with results obtained from experiments. The analysis and design of beam-column joints reinforced with GFRP reinforcements are carried out by strut and tie model. Strut and Tie models are based on the models for the steel reinforced beam-column joints.  The resulting strut and tie model developed for the GFRP reinforced beam-column joints predicts joint shear strength. Joint shear strength values obtained from the experiments are compared with the analytical results for both the beam-column joints reinforced with steel and GFRP reinforcements. The joint shear strength predicted by the analytical tool ABAQUS is also validated with experimental results.

Study on Bond Strength of Alccofine Based Normal and High Strength Concrete

Plenty of research works in India and abroad focusing on the reuse or recycling of waste materials from many industries. Among that finding out suitable cementitious material for the replacement of cement is significant. Many waste materials such as fly ash, silica fume, GGBS, metakaoline, micro materials, quartz power, etc. are tried out for replacing partially or full of cement in concrete. A new ultrafine material called Alccofine is tried out for replacing partially in this research. M20 and M60 grade of concrete is intended to study the performance of normal and high strength concrete by replacing the cement with alccofine of different dosages.  Previous researches showed that the replacement of alccofine increases the strength. Design mix made for M20 and M60 grade and cubes casted with various percentage of alccofine with cement. Hence the study is aimed to assess the bond behavior of M20 and M60 grade of concrete structures as an alternate to the conventional materials. The cubes are prepared initially for the design mix and determined the strength of concrete. Then specimens are prepared for the bond test and tested using pullout test methods. The results are analyzed and observed that the bond strength is increased with increase of alccofine replacement to certain dosage.

Effect of Alccofine and GGBS Addition on the Durability of Concrete

Portland cement is the most important ingredient of concrete.  A large scale production of cement plant consume large amount of energy and produce a number of undesirable products (  which negatively affect the environmental and depletion of natural resources. This treat to ecology has to lead to researchers to use industrial by-products as supplementary cementitious material in making concrete. In view this silica fume (SF), ground granulated blast furnace slag (GGBS), rice husk ash, fly ash (FL), metakolin, alccofine (AL), micro fine material, etc.; are tried out for replacing cement partially or fully in concrete, without compromising on its strength, also reduce greenhouse gases and sustainable way of management of waste. A new ultra-fine material emerged in market is called alccofine. This is available as a cementious material for replacing cement. Since this a new material, a study is tried out with the combination of Alccofine and GGBS. Ordinary Portland Cement 53 grade was used throughout the study and the grade of concrete is M20.  Totally 108 cubes and 27 cylinder were cast and tested in the laboratory with nine different percentage combination of alccofine (A), GGBS (G) and cement (C) (C100, C70A0G30, C90A10G0, C60A10G30, C30A10G30, C40A0G60, C85A15G0, C55A15G30, C25A15G60). Each case 3 nos. of specimen were used for repeatability. It is intended to study the compressive strength, and its durability properties like acid attack test, sulphate attack test and rapid chloride permeability test (RCPT). Among the nine different combination the maximum compressive strength of concrete is achieved by using AL10% and GGBS 30% is 38.08 N/mm2. C60A10G30 is 28.76% higher than the control mix. Result shows that concrete incorporating alccofine and GGBS have higher compressive strength and alccofine enhanced the durability of concrete also

Comparative Study on Two Storey Car Showroom Using Pre-engineered Building (PEB) Concept Based on British Standards and Euro Code

Majority of steel structures are used for low-rise single storey buildings mainly for industrial purpose. Steel structures are preferred for industrial buildings due to its higher strength to weight ratio as compare to RCC structures and steel structures also gives more free internal space by allowing long clear span between columns. Pre-engineered building (PEB) is a modern age concept of utilizing structural steel and optimizing the design by ensuring the economical integrity of the structure. The structural members are designed and fabricated in the factory under controlled environment to produce optimum sections by varying the thickness of the sections along the length of the member as per the bending moment requirement. The aim of the research paper is to analyses and design a PEB car showroom of two storey (G+1) using STAAD Pro in accordance to British standards (BS 5950-1:2000) and Euro codes (EC3 EN-1993-1) with wind and seismic analysis. In order to achieve the above aim of the project, two models of the car showroom were created namely British Standard (BS) model and Euro code (EC) model using STAAD Pro. The member property for BS model is assigned with tapered frame sections while the EC model is assigned with universal standard section frames. The load cases were assigned to the models for analysis include dead load, live load, wind load and seismic load. Wind load and seismic load being the critical dynamic loads that will be analyzed for the stability of the structure against lateral forces. The results from the analysis and design of the two models were within the allowable limits for ultimate and serviceability limit state since the internal stresses in all the members satisfies the unity check ratio requirements for both design codes. The dynamic analysis results suggest that EC model has higher resistance to seismic loading as compare to BS model since the maximum displacement with time in X-direction for EC model is 8.83 mm and for BS model is 10.5 mm. The total weight of the structure for BS model is 1125.431 kN and for EC model is 1214.315 kN, which makes EC model 7.9% heavier than BS model. Moreover, the total weight of all the portal frames for BS model is 457.26 kN and for EC model is 574.725 kN, which makes tapered frame sections to utilize and reduce the amount of steel by 25.7%. Therefore, BS model proved to be an economical model when compared to Euro code. 

Study on Retrofitting of RC Column Using Ferrocement Full and Strip Wrapping

Ferrocement is one of the cement-based composites used for retrofitting and rehabilitation among many applications. Ferrocement is one of the reinforced concrete form with lightweight and thin composite with durability and environmental resistant that strengthen the conventional RC columns to increase its strength and serviceability. This paper examines the performance of the ferrocement wrapping in RC columns experimentally with numerical simulation using ANSYS19. Totally sixteen number of RC column of size 150 mm × 150 mm in cross section and 450 mm in length were cast and tested in laboratory. Twelve are retrofitted columns with respect to volume fraction and wrapping technique. Six columns were retrofitted by full wrapping technique and six columns of strip wrapping technique. The remaining four columns are control columns in virgin condition to compare with the retrofitted columns. Concerning the volume fraction of each specimen, the number of pre-woven mesh layers were single layer, double layer and three layers. C30 concrete grade adopted in all specimens as per ACI Committee 211-1.91 with 4H8 longitudinal reinforcement and H6 of 75mm c/c ties. As the previous researchers examined the ferrocement and proved its efficiency. This study aims to examine the ferrocement in full and strip wrapping technique to compare their efficiency to increase the strength. Finite element analysis using ANSYS19 adopted to compare the experimental data with the numerical simulation. The results are analyzed and observed that the ferrocement has increased the confinement and strength of the RC columns.

biological mediated ag nanoparticles from barleria longiflora for antimicrobial activity and photocatalytic degradation using methylene blue

AbstractThe present study focuses on extraction of green synthesized silver nanoparticles (Ag-NPs) from Barleria longiflora L. leaves for antibacterial and photocatalytic activities. The extracted Ag-NPs have been characterized by XRD, FTIR, FE-SEM with EDX, HR-TEM accompanied SAED pattern and UV-Visible absorption spectroscopic techniques. Spectral studies confirmed the UV-Visible absorption spectrum of the Ag-NPs at a wavelength of 443 nm and a good crystalline nature with a face-centered cubic crystal structure using XRD spectrum. Surface topography and the presence of Ag in the prepared sample have been confirmed from SEM and EDX measurements. Various functional groups present in the sample have been examined using FT-IR spectroscopic analysis. A homogeneous dispersion of spherical form nanoparticles with a usual size of 2.4 nm was confirmed by visualization using FE-SEM and HR-TEM. Moreover, Ag-NPs stimulate a strong inhibition of Enterococcus sp., Streptococcus sp, Bacillus megaterium, Pseudomonas p..

Seismic Upgradation of RC Beams Strengthened with Externally Bonded Spent Catalyst Based Ferrocement Laminates

Globally, since there are more systems of civil infrastructure, there are also more degraded buildings and structures. If upgrading or strengthening is a practical option, complete replacement is likely to be an escalating financial burden and may be a waste of natural resources. It is necessary to repair or strengthen a number of reinforced concrete buildings and structures in order to boost their load-bearing capabilities or improve their ductility under seismic stress. Additionally, due to changes in service circumstances, a structure might need to be modified to reduce deflections or manage cracking. Strengthening may be preferable to limiting usage, capping applied loads, and regularly inspecting the structure rather than removing the existing structure or part and building a new one. This study aims to examine the flexural, shear, and combined effect of flexural and shear behavior of reinforced concrete (RC) beams strengthened with externally bonded spent catalyst-based ferrocement laminates and compare them to the control beams (unstrengthened) under two-point loading conditions. This study involves researching laminates with various spent catalyst doses, such as 3, 6, 9, and 12%, in an effort to determine the best amounts that will improve the structural performance of ferrocement laminates. Twelve spent catalyst-based ferrocement laminates measuring 500(L) × 125(B) × 20 mm (thickness) with 3% volume fraction of meshes each were cast and tested in the lab as part of the preliminary investigation. For repeatability, three laminates per case were employed. Eight numbers of under-reinforced RC beams measuring 75(L) × 100(B) × 150(D) mm were cast for the main study; six numbers were strengthened with optimized spent catalyst-based ferrocement laminates bonded with flexible epoxy systems at the tension zone, shear zone, and combination of tension and shear zone. Two of the beams were cast as control specimens. The beams were then evaluated using a Universal Testing Machine (UTM) with a 1000 kN capacity under two-point loading conditions. As a result, the strength, yield load, ultimate load, stiffness, ductility, and related failure modes of all tested beams' flexural and shear performances were examined. According to a preliminary analysis of laminates made of spent catalyst, the dosage of 9% provides good flexural strength in comparison to other doses. In comparison to the strengthened beam, the control beam's initial cracks appeared earlier. In comparison to the control beam, the strengthened beam has an increase in load-carrying capacity of 18% for flexure, 16% for shear, and 30% for the combined impact of flexure and shear. In comparison to the control beam, the deflection of the strengthened beam was decreased by close to 20 to 40% for flexure, 10 to 30% for shear, and 15 to 20% for the combined effects of flexure and shear at the same load level. In relation to control beams, the ductility also improved up to 30% for flexure, 25% for shear, and 25% for the combined impact of flexure and shear. Similar to this, the retrofitted beam is stiffer than the control beam by approximately 40% for flexure, 48% for shear, and 30% for the combined effect of flexure and shear. Theoretical formulation by section analysis is also derived and it gives close agreement with control and strengthened beams. The flexural and shear strengthening of the RC beam retrofitting system is effectively increased by using spent catalyst-based ferrocement laminates. No beam showed signs of premature and brittle failure. According to the test findings, it can be said that spent catalyst-based ferrocement reinforced beams perform better in every way than control beams. Doi: 10.28991/HIJ-2023-04-01-013 Full Text: PD