Girgin ZC, Girgin K, "Predictions on ultimate
strengths and strains of carbon, glass, basalt, PEN, PET, and natural FRP
confined circular columns", Structural Concrete, Early View, Dec 2025.
DOI: 10.1002/suco.70396
Tuncer, HM ; Girgin, ZC, “Hemp fiber reinforced
lightweight concrete (HRLWC) with coarse pumice aggregate and mitigation of
degradation”, Materials and Structures (2023) 56:59, https://doi.org/10.1617/s11527-023-02142-8
Akyürek, ME; Girgin, ZC, "Selection of appropriate solid wood species for bending-active structures", JOURNAL OF THE FACULTY OF ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY, Vol 38, Issue 4, (2023). https://doi.org/10.17341/gazimmfd.1104075.
Tuncer, HM ; Girgin, ZC, “Comparison of hemp fibres with macro synthetic fibres in lime-metakaolin matrix incorporating pumice as coarse aggregates", Megaron, Vol. 18, No. 1, pp. 88–97, March 2023, DOI: https://doi.org/10.14744/MEGARON.2023.00868
LinkGunes, ME; Pekmezci, BY, Girgin, ZC, “Durability of natural hydraulic lime (NHL) based TRM composites through hot water immersion method”, Materials and Structures (2021) 54:24,https://doi.org/10.1617/s11527-020-01608-3
Aygul, Ceylan, Girgin, ZC, "Comparisons on withdrawal resistance of resin and phosphate coated annular ring nails in CLT specimens", Construction and Building Materials, 238 (2020) 117742.
Girgin, ZC, “Effect of slag, nano clay and metakaolin on mechanical performance of basalt fibre cementitious composites”, Construction and Building Materials, Vol. 192, Dec 2018, pp.70-84.
Link | Scopus | Google
Girgin,
ZC, Tak,Yıldırım, M.,
“Usability of Basalt Fibres in Fibre Reinforced Cement
Composites”, Materials and Structures, Vol. 49, Issue 8, 2016, pp.3309-3319.
Link | Scopus | Google
Link | Scopus | Google
Girgin,
ZC, Girgin, K., “Design-Oriented
Combined Model (7 MPa to 190 MPa) for FRP-Confined Circular Short Columns”, Polymers, Oct. 2015,
pp.1915-1917.
Link | Scopus | Google
Link | Scopus | Google
Girgin,
ZC, “Modified
Johnston Failure Criterion from Rock Mechanics to Predict the Ultimate Strength
of Fiber Reinforced Polymer (FRP) Confined Columns”, Polymers, Jan. 2014,
pp.59-75.
Link | Scopus | Google
Link | Scopus | Google
Girgin,
K., Girgin, ZC, Aksoylu, M.G, “Research on the normality of the
plastic strain vector to the yield surface in RC sections”, Materials and
Structures, 47(7), pp.1115-1130, 2014.
Link
Link
Girgin,
ZC, "A
Modified Failure Criterion to Predict Ultimate Strength of Circular Columns
Confined by Different Materials", ACI Structural Journal, Vol.106
(6), Nov-Dec 2009, pp. 800-809.
Link | Scopus | Google
Link | Scopus | Google
Girgin,
ZC, Arıoğlu,
N., Arıoğlu, E. “Evaluation of Strength Criteria for
Very-High-Strength-Concretes under Triaxial Compression”, ACI
Structural Journal, Vol.104 (3), May-June 2007, pp. 278-284.
Link | Scopus | Google
Link | Scopus | Google
Arıoğlu,
N., Girgin, ZC, Arıoğlu, E., “Evaluation of the Ratio Between
Splitting Tensile Strength and Compressive Strength for Concretes up to 120 MPa
and its Application in Strength Criterion”, ACI Materials Journal, Vol.103 (1),
Jan. 2006, pp. 18-24.
Link | Scopus | Google
Link | Scopus | Google
Girgin,
ZC,
Girgin, K., “A Numerical Method for Static and Free-Vibration analysis of
Non-Uniform Timoshenko Beam-Columns”, Canadian Journal of Civil Engineers, 33,
March 2006, pp.278-293.
Link | Scopus | Google
Link | Scopus | Google
Girgin,
ZC, Girgin, K., “A Numerical
Model for Static or Dynamic Stiffness Matrix of Non-Uniform Members Resting on
Variable Elastic Foundations”, Engineering Structures, 27,
2005, pp. 1373-1384.
Link | Scopus | Google
Link | Scopus | Google
Discussions
Pann,
K.S., Yen T., Tang, C.W., Lin, T.D. “New Strength Model on Water-Cement Ratio
and Capillary Porosity”, ACI Materials Journal, July-August 2003, Discussion by
Arioglu, N., Girgin, Z.C., Arioglu, E., May-June 2004,Vol.101(3),
p.250-252.
Qasrawi,
H.Y. “Concrete Strength by Combined Nondestructive Methods Simply and Reliably
Predicted”, Cement and Concrete Research, 30, 2000, Discussion by
Arioğlu, E., Arioglu, N., Girgin, Z.C., 31, 2001, p. 1239-1240.
Carpinteri,
A., Ferro, G., Monetto, I. “Scale Effects in Uniaxially Compressed Concrete
Specimens”, Magazine of Concrete Research, 51(3), 1999, Discussion by Arioglu,
E., Arioglu, N., Girgin, Z.C., 52(5), 2000, p.395-398.
Articles in Other Indexed Journals
Kuruscu, A.O, Girgin, Z.C., "Efficiency of Structural Materials in Sustainable Design", Journal of Civil Engineering and Architecture, Vol.8, No.10, October 2014, pp. 1260-1265, ISSN 1934-7359.
Girgin, Z.C., "Statistical Evaluation of Worldwide Sustainable Energy Production (2000-2010)", Journal of Energy and Power Engineering, Vol.6 (10), October 2012, pp. 1575-1581.
Details of Articles in SCI-Expanded
Title: Effect of slag, nano clay and metakaolin on mechanical performance of basalt fibre cementitious composites
Title: Predictions
on ultimate strengths and strains of carbon, glass, basalt, PEN, PET, and
natural FRP confined circular columns
By: Girgin, ZC; Girgin, K
Source: STRUCTURAL CONCRETE
Volume: - Issue: -
Article Number: -
Abstract: In
this study, the ultimate strength and strain models, originally developed for
carbon and glass fiber-reinforced polymer (CFRP and GFRP) confined circular columns,
have been adapted to other recent fiber composite types of basalt, polyethylene
naphthalate, polyethylene terephthalate, and natural fibers. The Hoek-Brown
strength criterion from rock mechanics, which was extended for the first time
to CFRP and GFRP confined concrete, has been applied to almost all fiber types
to predict the ultimate strengths through a unified approach. Regression
relationships for ultimate strains are also proposed based on a compiled
database. The presented models encompass a wide range from low- to
high-strength concrete and partially include ultra-high-performance concrete,
with very low error rates. The strength and strain models in this study, when
compared to the well-known models in the current literature, indicate that especially
reported strain models deviate significantly from experimental results. The
evaluations of the proposed models reveal a high level of accuracy for every
type of fiber.
Author Keywords: BFRP, CFRP, GFRP,
Hoek-Brown criterion, NFRP, PEN, PET, ultimate
strain, ultimate strength
Title: Hemp fiber reinforced lightweight concrete (HRLWC) with
coarse pumice aggregate and mitigation of degradation
By: Tuncer, HM; Girgin, ZC
Source: MATERIALS AND STRUCTURES
Volume: 56, Issue: 3
Article Number: 59
Abstract: Concrete
with cellulosic fibers should preserve the microstructural and functional
properties with less degradation and without micro-organisms for several years.
This study focuses on the usability of hemp fibers in a mixture combined with
lightweight aggregates (LWA) and cementitious materials. Unlike mostly mortar
based current literature, this study addresses the hemp fiber reinforced
lightweight concrete (HRLWC) in which coarse aggregates are also used, and
these aggregates are volcanic pumice aggregates (VPA). In order to mitigate
fiber degradation induced by alkali attack, supplementary cementitious
materials (SCM) e.g. metakaolin, blast furnace slag and fly ash were used.
Total binding materials and water to binder ratio were taken constant, and the
hemp fiber ratio was chosen as V-f = 1.0%. In this scope, compressive strength,
flexural behavior, energy absorption, crack width, density, and water
absorption were experimentally investigated. Herein, two important exposures on
samples are under consideration, one is the natural moisture curing due to LWAs
which resemble water reservoir gradually releasing water, the first time for
cellulosic fibers in the current literature. The second one is the accelerated
aging test to provoke alkali release by immersing in hot water for 10 days. The
findings from test results and micro photographs reveal that the pumice
aggregates combined with proper SCMs are suitable to contribute sustainable
HRLWC design
Author Keywords: Hemp, Cellulosic
fibers, Pumice, LWA, SCM, HRLWC
Title: Selection of appropriate solid
wood species for bending-active structures
By: Akyürek, ME; Girgin, ZC
Source: JOURNAL OF THE FACULTY OF
ENGINEERING AND ARCHITECTURE OF GAZI UNIVERSITY
Volume: 38, Issue: 4
Pages: 2421-2423
Abstract: The
general purpose of this study is to define the bendability criteria of grid
shell. In particular, it is aimed to determine the suitability of woods in
Turkey for grid shell with analytical methods. Theory and Methods: In this
study, bending capacity of grid shells were examined according to tree type,
sizing and detailing. Design radius of curvature (Rt) was defined for 20mm
thick laths regarding Turkiye woods simply in terms of allowable bending
strength (o -em) and elastic modulus (E). Rt values were compared with USFPL's
experimental radius of curvature (Rd) to verify the relationship between design
and experimental method, relationship was confirmed with very high correlation
coefficient t (r=0.97). Proper woods were determined through regression
analyses among Rt, E, rho, production amount and cost. Bendability and
mechanical characteristics of some woods were also compared with the case
studies and Europe. Finally, wood species in Turkiye were classified through
the criteria of usability and ordering to the importance in the grid shell.
Results: In the structures examined, the ratio of height to length of the laths
is 0.23-0.30, and the ratio to span is 0.33-0.41. In terms of lightness and
bendability, the material should have a thin section, straight fibers, few
knots, high bending strength, low elastic modulus and low density. In terms of
lightness and bendability, larch from softwoods and maple and linden from
hardwoods are the most efficient examples Yet, production of maple and linden
are insufficient. Generally, the cost increases as the radius of curvature
decreases. Oak is relatively expensive due to its durability (Figure A). The
bending ability of larch, oak and beech is higher than its European
counterparts with its low elastic modulus and high bending strength. The
European Spruce, on the other hand, is more qualified than its example in
Turkey. Conclusion: Among all Turkish woods examined, Oak, beech and larch in
Turkiye are the most suitable woods in terms of supply, mechanical properties
and bendability for grid shell construction.
Author Keywords: Elastic structures, Timber
grid shell, Turkiye woods, Material selection, Radius of
curvature
Title: Comparison of hemp fibres with macro synthetic fibres
in lime-metakaolin matrix incorporating pumice as coarse aggregates
By: Tuncer, HM; Girgin, ZC
Source: MEGARON
Volume: 18, Issue: 1
Pages: 88-97
Abstract: Significant developments are observed in the
design of composite building materials nowadays, especially on environmental
and sustainability issues. For structural usage, nowadays researchers reveal
lime, which is the traditional binding material known since ancient times. Lime
known for its sustainable feature is often used with supplementary cementitious
materials (SCM) such as metakaolin, fly ash, ground granulated blast furnace
slag, and silica fume due to unfavourable properties regarding durability,
strength, and slow hydration rate. On the other hand, cellulosic fibres with
the advantages such as low density, high tensile strength, and moderate elastic
modulus have cost competitiveness and eco-efficiency for fibrereinforced
composites. The structural use of cellulosic fibres may be possible if the
degradation of hemp fibres in an alkali environment is mitigated. In this
study, the experimental studies on hemp fibres were carried out by comparing
with two types of macro synthetic fibres in a lime+metakaolin (L+MK)-based
matrix. Durability as well as compressive and flexural characteristics were
addressed in those fibrous matrices. First time in the current literature,
macro synthetic fibres were included in the lime-based mixture. Besides, as a
new contribution, coarse lightweight aggregates (LWA) were incorporated into
this type of matrix with those fibres. The experimental findings indicate that
the degradation of hemp fibres can be mitigated successfully, and three types
of fibrous mixtures provide proper mechanical characteristics in their
categories.
Author Keywords: Hemp,lime, macro synthetic fibre, metakaolin, pumice
Title: Durability
of natural hydraulic lime (NHL) based TRM composites through hot water
immersion method
By: Gunes, ME; Pekmezci,
BY; Girgin, ZC
Source: MATERIALS AND STRUCTURES
Volume: 54, Issue: 1
Abstract: The textile reinforced mortar (TRM) composites are widely utilized for
the seismic strengthening of masonry walls subjected to in-plane and
out-of-plane actions. The probability of out-of-plane failure via snap-through
mechanism is dominated by the flexural characteristics of relatively slender
masonry wall. In this study, a rapid and early decisive procedure is proposed
to direct the design of TRM composite through the bending tests combining
accelerated ageing. The durability of natural hydraulic lime based TRM
composites, which is unknown in the current literature, is addressed for glass,
basalt and carbon textiles. The interaction between fiber mesh and matrix is
discussed regarding fiber type, the influence of impregnation, flexural
performance and failure modes. For total five types of fabrics, the flexural
capacities are compared at ambient conditions and then through hot water ageing
test (immersion at 50 degrees C during 10 days). The experimental findings
indicate to the importance of the interaction between fiber and matrix about
the durability and ductility of TRM composites.
Author Keywords: Textile reinforced mortar
(TRM), Natural hydraulic lime (NHL), Bending tests, Durability,
Accelerated ageing, Hot water immersion
Title: Comparisons
on withdrawal resistance of resin and phosphate coated annular ring nails in
CLT specimens
By: Ceylan, A; Girgin, ZC
Source: CONSTRUCTION AND BUILDING
MATERIALS
Volume: 238
Article Number: 117742
Published: MAR 30 2020
Abstract: As a fastener type, the galvanized annular ring
nails are common in timber engineering. Nowadays, partially resin or fully
phosphate coated annular nails are used as well. In this study, the withdrawal
resistance of those nails, whose holding capacities have not been involved in the
current literature, is investigated comparing with other nail types (galvanized
annular and helical nails) and wood screw via experimental test results on
cross-laminated timber (CLT) specimens. Each single fastener was driven
perpendicularly into the surface (side face) of CLT specimen as in the
wall-floor angle bracket connections. Not only the numerical values of holding
capacity but also the load-displacement curves are focused in the experimental
tests. Furthermore, the withdrawal energy during the pull-out of single
fastener, which is not investigated so far but may have highly significant
implications for metallic connections of CLT panels, was evaluated graphically.
The validity of the current withdrawal models in the literature is verified by
the experimental results for the nail types under consideration. Moreover, the
effects of the parameters such as grain pattern, manual/gun-drive conditions
are addressed in this study as well.
Author Keywords: CLT,
Withdrawal strength, Withdrawal energy, Annular ring nail,
Resin-coated, Phosphate-coated, Galvanized, Helical nails,
Wood screw
Title: Experimental
investigation of Structural Behavior for Cross Laminated Timber (CLT) Wall-to-Floor
Connection
By: Ceylan, A; Girgin, ZC
Source: MEGARON
Volume: 14
Abstract: Cross-Laminated Timber (CLT) is an innovative industrial wood product, especially as a structural wall in order to meet the rigidity and strength requirements in multi-storey timber buildings. CLT members are assembled with metal connectors (angle bracket, joining plates, etc.) via nails, screws, dowels, etc. For energy-absorbing structural CLT connections, many experimental studies have been conducted on the effectiveness of the connections, especially for the earthquake prone regions. There is no scientific study in this context in Turkey yet. For this purpose; the performance of a full-scale CLT wall-to-floor specimen assembled with metal connection was experimentally investigated under axial tensile force due to bending moments of seismic loads. Domestic angle bracket, plates, and phosphate coated annular ring nails were used. All the displacements and strains were measured and collected during the test of the specimen, behavior of connection and the failure mode was observed. As a result, the back side deformation of CLT wall member was prevented with the plates for a longer period compared with no-plate case and the withdrawal resistance of from CLT floor increased through phosphate coated annular ring nails and extra three nails in the corner of angle bracket on the front side. Domestic metal connectors were used in the experiments to support the metal industry and the production with low cost. This study is a pioneering study in Turkiye on the experimental performance of CLT connections for the structural utilization. The results are promising, and the further experimental researches will continue for the most effective connection type.
Author Keywords: CLT wall-to-floor connection, CLT shear wall, cross laminated timber, earthquake resistant building design, phosphate coated annular ring nail, structural behavior
Title: Effect of slag, nano clay and metakaolin on mechanical performance of basalt fibre cementitious composites
By: Girgin, ZC (Girgin, Zehra Canan)
Source: Construction
and Building Materials
Volume: 192
Abstract: In
this study, the effects of pozzolanic admixtures (ground granulated blast
furnace slag, nano-clay, metakaolin) are investigated in chopped basalt fibre
cementitious composites (BRC). First, the variations in compressive
strengths and flexural characteristics during 3,
7, 28, 56, 90 and 120-day curing periods are addressed. Afterwards, most
importantly, the degradation in the flexural performance during
aging tests (freeze-thaw test, heat-rain test) are focused. The main aim
is considerably to save the pull-out behaviour
of BRC, even when exposed to harsh atmospheric conditions. All the test results
are compared with
control specimens (100% cement). The results arising from the experiments
including metakaolin are
promising to enhance the durability performance of BRC. The implications in
this experimental study are valid for basalt fibre reinforced concrete (BFRC)
subjected to those atmospheric conditions as well.
Author Keywords : Basalt fibres, BRC, BFRC, Aging
tests, Strain capacity, Pull-out
Title: Usability of basalt fibres
in fibre reinforced cement composites
By: Girgin, ZC (Girgin, Zehra Canan); Yildirim,
MT (Yildirim, Mehtap Tak)
Source: MATERIALS AND STRUCTURES
Volume: 49
Issue: 8
Pages: 3309-3319
DOI: https://doi.org/10.1617/s11527-015-0721-4
Published: AUG 2016
Published: AUG 2016
Abstract: In the recent years, the
basalt fibre (BF) reinforced polymer composites were introduced to retrofit the
structural elements. However, on the contrary, the studies on the use of BF in
concrete are very limited. This study addresses experimentally to find out the
performance of BF as an alternative to glass fibres for the usability in fibre
reinforced cement composites (e.g. fac, ade panels). BF have some advantages
such as fire resistance and alkaline resistance higher than those of glass
fibres. The research was especially carried out to achieve the variation of the
flexural strength in the extreme conditions that only cement was used as binder
material. The heatrain test was conducted to observe durability of BF as well.
The experimental results indicated that the flexural strain capacity of BF is
sensitive to stress accumulation due to the cement hydration products in the
matrix-fibre interface. This sensitivity especially increased during heat-rain
durability test, however any sign of chemical attack in the alkaline
environment was not observed in SEM images.
ISSN: 1359-5997
Accession
Number: WOS:000379590300022
Title: A Design-Oriented Combined Model (7 MPa to 190 MPa) for
FRP-Confined Circular Short Columns
By: Girgin, ZC (Girgin, Zehra Canan); Girgin, K (Girgin,
Konuralp)
Source: POLYMERS
Volume: 7
Issue: 10
Pages: 1905-1917
Pages: 1905-1917
DOI: https://doi.org/10.3390/polym7101489
Published: OCT 2015
Accession Number: WOS:000364289200001
Published: OCT 2015
Abstract: This study addresses a design
oriented combined model to predict the ultimate strengths and ultimate strains
in an extensive range of unconfined strength (7 to 190 MPa) for the axially
loaded fiber-reinforced polymer (FRP)-wrapped circular short columns. Modified
Hoek-Brown strength criterion, which was previously extended to FRP-confined
concrete from 7 to 108 MPa, is revisited and verified. An empirical strength
model beyond 108 MPa encompassing ultra-high strength concrete (UHSC) and
ultra-high performance concrete (UHPC) data, as well as empirical strain
models, are defined to accomplish the design oriented combined model. This
article especially focuses on the verification of the proposed strain models.
The assessment performances of those models for carbon FRP (CFRP) and glass FRP
(GFRP) confinement are compared with specific models in the current literature.
Strength and strain predictions for UHSC and UHPC are integrated into the design
oriented combined model as well. The assessments on this model agree with the
experimental results in high accuracy.
ISSN: 2073-4360Accession Number: WOS:000364289200001
Title: Research on the normality of the plastic strain vector to
the yield surface in RC sections
By: Girgin, K (Girgin,
Konuralp); Girgin, ZC (Girgin, Z. Canan); Aksoylu, MG (Aksoylu, M. Gunhan)
Source: MATERIALS AND STRUCTURES
Source: MATERIALS AND STRUCTURES
Volume: 47
Issue: 7
DOI: https://doi.org/10.1617/s11527-013-0116-3
Published: JUL 2014
Published: JUL 2014
Abstract: In this study, the
normality condition of the plastic strain vector to the yield surface utilized
for elastic-perfectly plastic materials is investigated for reinforced concrete
(RC) sections. If the plastic strain vector can be assumed outward normal to
the yield surface in RC sections under combined biaxial bending and axial load,
the components of the vector can be expressed by a single parameter. Thus, the
material nonlinearity can be simplified through the extended plastic hinge
concept based on the normality condition. In this study the normality of the
plastic strain vector is verified via numerical examples in symmetrically
reinforced rectangular and circular RC sections subjected to biaxial bending
and axial load for various configurations of longitudinal reinforcement.
ISSN: 1359-5997eISSN: 1871-6873
Accession Number: WOS:000336021300002
Title: Modified Johnston Failure Criterion from Rock Mechanics to Predict the Ultimate Strength of Fiber Reinforced Polymer (FRP) Confined Columns
By: Girgin, ZC (Girgin, Zehra Canan)
Source: POLYMERS
Volume: 6
Issue: 1
Pages: 59-75
DOI: https://doi.org/10.3390/polym6010059
Published: JAN 2014
Accession Number: WOS:000336091800004
Title: Modified Failure Criterion to Predict Ultimate Strength of Circular Columns Confined by Different Materials
By: Girgin, ZC (Girgin, Z. Canan)
Issue: 1
Pages: 59-75
DOI: https://doi.org/10.3390/polym6010059
Published: JAN 2014
Abstract: The
failure criteria from rock mechanics, Hoek-Brown and Johnston failure criteria,
may be extended and modified to assess the ultimate compressive strength of
axially loaded circular fiber reinforced polymer (FRP)-confined concrete
columns. In addition to the previously modified Hoek-Brown criterion, in this
study, the Johnston failure criterion is extended to scope of FRP-confined
concrete, verified with the experimental data and compared with the significant
relationships from the current literature. Wide-range compressive strengths
from 7 to 108 MPa and high confinement ratios up to 2.0 are used to
verify the ultimate strengths in short columns. The results are in good
agreement with experimental data for all confinement levels and concrete
strengths.
ISSN: 2073-4360Accession Number: WOS:000336091800004
Title: Modified Failure Criterion to Predict Ultimate Strength of Circular Columns Confined by Different Materials
By: Girgin, ZC (Girgin, Z. Canan)
Source: ACI STRUCTURAL
JOURNAL
Volume: 106
Issue: 6
Pages: 800-809
Published: NOV-DEC 2009
Accession Number: WOS:000271202100006
Volume: 106
Issue: 6
Pages: 800-809
Published: NOV-DEC 2009
Abstract: This study addresses
the extension of a failure criterion developed for rock data to small or near
full-size circular concrete columns confined by different materials. Initially,
a wide range database on small-scale specimens confined by fiber-reinforced
polymer (FRP) sheets or tubes and analytical studies were evaluated to predict
the ultimate compressive strength. Then, the reinforced concrete (RC)
short-columns retrofitted with FRP jacket were examined through available data.
The research further covers middle- or near full-scale columns confined by FRP
composites and steel reinforcement. All of these estimations were conducted
within a unified approach to the failure criterion. Thus, the ultimate
compressive strength for different confining materials can be predicted easily
and systematically.
ISSN: 0889-3241Accession Number: WOS:000271202100006
Title: Evaluation of strength criteria for very-high-strength concretes under triaxial compression
By: Girgin, ZC (Girgin, Z. Canan); Arioglu, N (Arioglu, Nihal); Arioglu, E (Arioglu, Ergin)
Source: ACI STRUCTURAL JOURNAL
Volume: 104
Issue: 3
Pages: 278-284
Published: MAY-JUN 2007
Abstract: In this study, the
empirical relationships proposed in the current literature were verified to
assess their validity for compressive strengths between 66 and 132 MPa (8700 to
19,145 psi). A relationship was suggested to predict the ultimate strength 4
very high-strength concrete under triaxial compression. Furthermore, strength
criteria essentially developed to estimate the ultimate strength of intact rock
were applied to the concrete. The results of triaxial tests were employed to
verify the applicability of these strength criteria for high-strength concrete.
It is interesting to note that the strength criteria developed for intact rocks
can also be applied to the assessment of ultimate strength and failure curve in
high-strength concretes. Knowing only the cylinder compressive strength and the
ratio of tensile-to-compressive strength, the failure envelope can be
successfully evaluated by means of these criteria without performing triaxial
tests in high-strength concretes.
ISSN: 0889-3241Accession Number: WOS:000246510900003
Title: A numerical method for static and
free-vibration analysis of non-uniform Timoshenko beam-columns
By: Girgin, ZC (Girgin,
ZC); Girgin, K (Girgin, K)Source: CANADIAN JOURNAL OF CIVIL ENGINEERING
Volume: 33
Issue: 3
Pages: 278-293
DOI: https://doi.org/10.1139/L05-109
Published: MAR 2006
Abstract: A generalized
numerical method is proposed to derive the static and dynamic stiffness
matrices and to handle the nodal load vector for static analysis of non-uniform
Timoshenko beam-columns under several effects. T his method presents a unified
approach based,on effective utilization of the Mohr method and focuses on the
following arbitrarily variable characteristics: geometrical properties, bending
and shear deformations, transverse and rotatory inertia of mass, distributed
and (or) concentrated axial and (or) transverse loads, and Winkler foundation
modulus and shear foundation modulus. A successive iterative algorithm is
developed to comprise-all these characteristics systematically. The algorithm
enables a non-uniform Timoshenko beam-column to be regarded as a substructure.
This provides an important advantage to incorporate all the variable
characteristics based on the substructure. The buckling load and fundamental
natural frequency of a substructure subjected to the cited effects are also
assessed. Numerical examples confirm the efficiency of the numerical method.
ISSN: 0315-1468Accession Number: WOS:000238258600008
Title: Evaluation of ratio between splitting tensile strength and compressive strength for concretes up to 120 MPa and its application in strength criterion
By: Arioglu, N (Arioglu,
N); Girgin, ZC (Girgin, ZC); Arioglu, E (Arioglu, E)
Source: ACI MATERIALS JOURNAL
Volume: 103
Issue: 1
Pages: 18-24
Published: JAN-FEB 2006
Abstract: A large-scale regression analysis was carried out using experimental data gathered from various sources to evaluate the ratio of splitting tensile strength to cylinder compressive strength as a function of compressive strength of concrete. The reliability of the proposed equation based on experimental data for compressive strength ranging between 4 and 120 MPa (580 to 17,400 psi) was assessed by means of the integral absolute error (IAE). It is also shown that, by only knowing compressive strength and the ratio of tensile to compressive strength, the failure envelope for very high-strength concrete can be established using Johnston's strength criterion without performing triaxial compression tests. A numerical example demonstrates the application of Johnston's strength criterion.
ISSN: 0889-325X
Accession Number: WOS:000237129000003
Source: ACI MATERIALS JOURNAL
Volume: 103
Issue: 1
Pages: 18-24
Published: JAN-FEB 2006
Abstract: A large-scale regression analysis was carried out using experimental data gathered from various sources to evaluate the ratio of splitting tensile strength to cylinder compressive strength as a function of compressive strength of concrete. The reliability of the proposed equation based on experimental data for compressive strength ranging between 4 and 120 MPa (580 to 17,400 psi) was assessed by means of the integral absolute error (IAE). It is also shown that, by only knowing compressive strength and the ratio of tensile to compressive strength, the failure envelope for very high-strength concrete can be established using Johnston's strength criterion without performing triaxial compression tests. A numerical example demonstrates the application of Johnston's strength criterion.
ISSN: 0889-325X
Accession Number: WOS:000237129000003
Title: A numerical method for static or dynamic stiffness matrix of non-uniform members resting on variable elastic foundations
By: Girgin, ZC (Girgin, ZC); Girgin, K (Girgin, K)
Source: ENGINEERING STRUCTURES
Volume: 27
Issue: 9
Pages: 1373-1384
DOI: https://doi.org/10.1016/j.engstruct.2005.04.005
Published: AUG 2005
Abstract: This paper presents a generalized numerical method which
is based on the well-known Mohr method. Static or dynamic stiffness matrices,
as well as nodal load vectors for the static case, of non-uniform members are
derived for several effects. The method focuses on the effects of resting on
variable one- or two-parameter elastic foundations or supported by no
foundation; a variable iterative algorithm is developed for computer
application of the method. The algorithm enables the non-uniform member to be
regarded as a sub-structure. This provides an important advantage to encompass
all the variable effects in the stiffness matrix of this sub-structure.
Stability and free-vibration analyses of the sub-structure can also be carried
out through this method. Parametric and numerical examples are given to verify
the accuracy and efficiency of the submitted method.
ISSN: 0141-0296Accession Number: WOS:000230383300007
