Effect of Fibres on Beam Column Joint Failure

2016 ◽  
Vol 857 ◽  
pp. 59-64 ◽  
Author(s):  
Jerison Scariah James ◽  
Margrette Mary James
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Structural Integrity ◽  
Fibre Reinforced Concrete ◽  
Structural Shape ◽  
Framed Structures ◽  
Water Storage Tank ◽  
High Rise ◽  
Column Joint ◽  
The Comparative Study

Concrete is one of the most resourceful and environmental friendly building materials. It can be cast to fit any structural shape from a cylindrical water storage tank to a rectangular beam, slabs and column in a high-rise building. In RC buildings, portions of columns that are common to beams at their intersections are called beam column joints. Beam-column joints have a crucial role in the structural integrity of the buildings. Review of literature indicates that numerous studies were conducted in the past to study the behaviour of beam-column joints with normal concrete. However, those recommendations are not intended for the fibre reinforced concrete. Some indicates that this material is an alternative to the confining reinforcement in the joint region. So the comparative study of the performance of different fibres in beam column joint has a greater importance and relevance in the field of RCC framed structures. This thesis aims to study the behaviour of beam column joint by evaluating the performance of fibre reinforced concrete. The incorporation of fibres in beam column joint is analysed in this study. The use of different types of fibres such as steel and polypropylene are evaluated.

Damage of Reinforced Concrete Structures due to Steel Corrosion

2015 ◽  
Vol 1111 ◽  
pp. 187-192
Author(s):  
Corina Sosdean ◽  
Liviu Marsavina ◽  
Geert de Schutter
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Structural Integrity ◽  
Colorimetric Method ◽  
Concrete Structures ◽  
Steel Corrosion ◽  
Degradation Process ◽  
Reinforced Concrete Structures ◽  
Chloride Ingress ◽  
Rc Structures

Reinforced concrete (RC) became one of the most widely used modern building materials. In the last decades a great interest has been shown in studying reinforcement corrosion as it became one of the main factors of degradation and loss of structural integrity of RC structures. The degradation process is accelerated in the case of RC structures situated in aggressive environments like marine environments or subjected to de-icing salts. In this paper it is shown how steel corrosion of the embedded rebars occurs and how this affects the service life of reinforced concrete structures. Also, an experimental study regarding the combined effect of carbonation and chloride ingress was realized. Samples with and without rebars were drilled from a RC slab which was stored in the laboratory for two years. Non-steady state migration tests were realized in order to determine the chloride profile, while the carbonation depth was measured using the colorimetric method based on phenolphthalein spraying. It was concluded that carbonation has a significant effect on chloride ingress, increasing it.

scholarly journals Experimental Investigation on Fibre Reinforced Concrete Pavement Slabs Subjected to Temperature Gradient

2021 ◽  
Vol 9 (9) ◽  
pp. 1967-1973
Author(s):  
Nandini Nair
Keyword(s):  
Reinforced Concrete ◽  
Temperature Gradient ◽  
Structural Integrity ◽  
Concrete Slab ◽  
Heavy Traffic ◽  
Ride Quality ◽  
Fibre Reinforced Concrete ◽  
Coir Fibre ◽  
Rigid Pavements ◽  
Improved Performance

Abstract: A long lasting, reliable and economical transportation system is a critical component for the continuous movement of heavy traffic. Rigid pavements are made of concrete are widely for land transportation used because of its increased life, strength and it provides efficient movement of heavy traffic. Concrete is a brittle material and its low tensile strength leads to the formation of cracks, which is one of the main reason of concrete failure. Addition of fibre prevents the crack formation because fibres are crack arresters. Fibre addition increases the structural integrity of the pavement. Concrete slab in pavement structure experiences daily temperature fluctuations and results in the formation of temperature gradients in the slab. The objective of this study is to investigate the material properties of the three different fibres used in pavement slabs subjected to temperature gradient and the fibres used is coir fibre. Reduced cracks ensure pavement durability, reduced maintenance, improved performance, improved performance and ride quality. Keywords: Rigid pavements, Fibre Reinforced Concrete (FRC), Coir Fibre, Temperature Gradient, Pavement Slab.

scholarly journals Behaviour of ultra-high performance fibre reinforced concrete beam-column joint under cyclic loading

2017 ◽  
Author(s):  
Charles K.S. Moy ◽  
Jun Xia ◽  
Chee Chin ◽  
Jianzhong Liu
Keyword(s):  
Reinforced Concrete ◽  
Cyclic Loading ◽  
High Performance ◽  
Fibre Reinforced Concrete ◽  
Normal Strength Concrete ◽  
Joint Region ◽  
Strength Concrete ◽  
Column Joint ◽  
Normal Strength ◽  
High Performance Fibre

Ultra-high performance fibre reinforced concrete (UHPFRC) has very high compressive strength up to 200 MPa and exhibits strain hardening effects under flexural loading. The bond strength between UHPFRC and steel reinforcement is much better than the normal strength concrete. Therefore, there is a potential to use UHPFRC material at the beam-column joint region to reduce the congestion of reinforcement as well as to improve the seismic resistance of the structure. In this pilot study, the beam column joints made of normal strength concrete and UHPFRC were tested under lateral cyclic loading up to failure using a 500 tonne capacity computer control servo hydraulic machine. The specimen with normal strength concrete failed at the joint region while the specimen with UHPFRC material failed due to yielding of the rebars in the beam sections near the column face and no obvious cracks were observed at the joint area. The specimens with UHPFRC as joint material exhibited higher initial lateral stiffness and achieved slightly higher ultimate load capacity than the specimen with normal strength concrete.

scholarly journals Development of a methodology for evaluating the structural integrity of reinforced concrete elements and other building materials

2016 ◽  
Author(s):  
Αναστάσιος Μπαλάσκας
Keyword(s):  
Reinforced Concrete ◽  
Building Materials ◽  
Structural Integrity ◽  
Pulse Velocity ◽  
Concrete Elements ◽  
Ultrasound Pulse

Οι κατασκευές από Σκυρόδεμα αποτελούν τη βάση του σύγχρονου τεχνικού πολιτισμού. Υποστηρίζουν τις συγκοινωνίες, την αποθήκευση πρώτων υλών και προϊόντων και προσφέρουν κατάλυμα σε ανθρώπους σε ευρεία κλίμακα. Η άποψη ότι οι κατασκευές από οπλισμένο σκυρόδεμα παρουσιάζουν υψηλή ανθεκτικότητα στο χρόνο έχει εγκαταλειφθεί προ πολλού. Είναι κατασκευές οι οποίες υπόκεινται σε συνθέτες καταπονήσεις λόγω: μακροχρόνιας φόρτισης από το ίδιο βάρος, δυναμικών σεναρίων φόρτισης συμπεριλαμβανομένων των σεισμών, καθώς και υποβάθμισης της δομικής ακεραιότητας λόγω περιβαλλοντικών συνθηκών. Οι κατασκευές από σκυρόδεμα πρέπει να υποβάλλονται σε επιθεώρηση και αξιολόγηση της κατάστασης της δομικής τους ακεραιότητας, ενώ θα πρέπει παράλληλα να προτείνονται κατάλληλες ενέργειες συντήρησης. Για να παραταθεί η ωφέλιμη διάρκεια ζωής τους, θα πρέπει να εφαρμόζεται μια αξιόπιστη μεθοδολογία παρακολούθησης της εναπομένουσας αντοχής και γενικότερα της δομικής ακεραιότητας των επιμέρους δομικών στοιχείων. Αρχικά βασικές πληροφορίες της μηχανικής τους απόδοσης εξάγονται από την οπτική επιθεώρηση, ωστόσο, αυτές αφορούν μόνο τις επιφανειακές ενδείξεις αποσάθρωσης και αστοχιών. Οι βλάβες μπορεί να ξεκινούν την εμφάνιση τους από το εσωτερικό του εκάστοτε δομικού στοιχείου για το λόγο αυτό και η αξιολόγηση της δομικής ακεραιότητας που βασίζεται μόνο στην οπτική επιθεώρηση είναι ατελής και πρόχειρη. Η ακουστική εκπομπή (ΑΕ) είναι εκείνη από τις μεθοδολογίες μη καταστρεπτικού ελέγχου που αξιολογούν τον πλήρη όγκο της δομής, η οποία έχει αρχίσει να εφαρμόζεται σε ευρεία βάση. Η (ΑΕ) είναι μια παθητική τεχνική μη καταστροφικής αξιολόγησης (NDE), που προσφέρει ιδιαίτερα πλεονεκτήματα, όπως η σε πραγματικό χρόνο παρακολούθηση της προόδου της βλάβης, η οποία είναι σε θέση να επιτρέπει τον χαρακτηρισμό του κρίσιμου χρόνου για την δομή σε σχέση με το εφαρμοζόμενο λειτουργικό φορτίο.Ο στόχος της παρούσας διατριβής είναι η ανάπτυξη και εφαρμογή μιας νέας μεθοδολογίας συνδυασμού τεχνικών NDE, ειδικότερα της ακουστικής εκπομπής (ΑΕ) και των υπερήχων (Ultrasound Pulse Velocity UPV), για την αξιολόγηση και την παρακολούθηση της βλάβης που προκαλείται στα στοιχεία της δομής. Η πρόβλεψη της υπολειπόμενης διάρκειας ζωής μιας δομής επικουρείται από τον χαρακτηρισμό του είδους θραύσης. Ανάλογα με τον τύπο θραύσης παρατηρείται διαφορετική κίνηση των πλευρών της ρωγμής κατά την δημιουργία της βλάβης, με συνέπεια η ελαστική ενέργεια που εκπέμπεται να παράγει κυματομορφές με διαφορετικά χαρακτηριστικά, οι οποίες καταγράφονται από τους αισθητήρες ακουστικής εκπομπής και αναλύονται ως προς την συχνότητά καθώς και άλλες παραμέτρους. Με αυτόν τον τρόπο επιτυγχάνεται ο προσδιορισμός του είδους θραύσης στα δομικά υλικά, χρησιμοποιώντας ελαστικές κυματικές μεθόδους. Τέλος, αναπτύσσεται μια καινοτόμος μεθοδολογία για τη διερεύνηση της βλάβης (τεχνητή και φυσική) σε δομικά στοιχεία με βάση το τσιμέντο, χρησιμοποιώντας ελαστικές κυματικές μη καταστρεπτικές μεθόδους .

scholarly journals APPLICATION OF ULTRA HIGH PERFORMANCE FIBRE REINFORCED CONCRETE ON EARTHQUAKE RESISTING STRUCTURE

2021 ◽  
Vol 6 (4) ◽  
Author(s):  
Dr. Ajay P. Shelorkar ◽  
Dr. Pradip D. Jadhao
Keyword(s):  
Reinforced Concrete ◽  
High Performance ◽  
Shear Failure ◽  
Reinforced Concrete Beam ◽  
Fibre Reinforced Concrete ◽  
Moment Resisting Frame ◽  
Moment Resisting ◽  
Column Joint ◽  
G 11 ◽  
High Performance Fibre

— Beam column joint is an important component of a reinforced concrete moment resisting frame and should be designed and detailed properly when the frame is subjected to earthquake loading. Failure of beam column joints during earthquake is governed by bond and shear failure mechanism which are brittle in nature. Modern codes provide for reduction of seismic forces through provision of special ductility requirements. A beam column joint has been moulded to the scale of 1:1.5 and the model has been subjected to cyclic loading to find its behavior during earthquake. The earthquake resisting structure is G+11 and has been analyzed using the Seismic Coefficient Method. This paper presents a synthesis of strengthening design of reinforced concrete beam and column by replacing it with Ultra High-Performance Fibre Reinforced Concrete.

scholarly journals The comparison of projectile impact resistance of ultra-high-performance fibre-reinforced concrete with various aggregates

2021 ◽  
Vol 250 ◽  
pp. 06007
Author(s):  
Martina Drdlová ◽  
Martin Šperl
Keyword(s):  
Reinforced Concrete ◽  
High Speed ◽  
High Performance ◽  
Structural Integrity ◽  
Impact Load ◽  
Impact Resistance ◽  
Fibre Reinforced Concrete ◽  
Projectile Impact ◽  
The Impact ◽  
High Performance Fibre

In order to apply the ultra-high-performance fibre-reinforced concrete (UHPFRC) in the constructions of ballistic protective structures, the impact resistance of UHPFRC has been investigated experimentally by conducting the high-speed projectile penetration tests. 5 mixtures with basalt and corundum aggregates with various grain size have been prepared and subjected to the quasi-static and 7.62 x 54R B32 API projectile impact load using the striking velocity of 850 m/s. The influence of the strength, size and material of the aggregate on the projectile impact resistance represented by differential efficiency factor (DEF), structural integrity and area and height of impact crater has been evaluated. The superior projectile resistance of UHPFRC with corundum has been observed. Regarding the size of the aggregates, the incorporation of coarser aggregates brings better projectile impact resistance.

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