The development of advanced materials and technologies for
application to new and existing structures, infrastructures,
and equipment, aiming at improving their response to service
and extreme loads, represents an emerging issue both from
an academic and a professional viewpoint. Relevant performance
assessment procedures, based on effective experimental
verification methods [1] and refined numerical simulation
models [2], are quickly evolving as well.
New or improved building materials and innovative protection
technologies offer updated solutions to the constantly
increasing capacity requirements in structural, geotechnical,
plant, and mechanical engineering design and rehabilitation.
At the same time, they open novel and challenging research
and application perspectives.
The objective of this special issue was to provide readers
with a representative outlook of the latest achievements in
this field, including emerging aspects in modelling, testing,
manufacturing, and practical implementation studies. The
response of the scientific community was encouraging, with
over 100manuscripts submitted. The published papers offer a
selected and articulated overview of the examined topics.
Several papers are dedicated to concrete, reinforced
concrete (R/C) members, and cement composites. J. Zhang
and J. Li develop a semi-implicit constitutive integration
algorithm for elastoplastic damage models, specially implemented
for concrete. Literature mechanical tests of reinforced
concrete components are numerically simulated, showing the
effectiveness of the numerical method in history-dependent
energy estimation within this class of nonlinear problems. H.
Ding et al. examine the failure criteria and the constitutive
relation of early-age concrete,with the aimof providing a theoretical
basis for a novel strategy in early dismantling formwork
construction of floors, aimed at accelerating formwork
recycling as well as at reducing construction costs. Y. Shen
et al. propose a paper spool-inspired anchoring method and
a pretension procedure for carbon fiber reinforced polymer
(CFRP) sheets, for themanufacturing of prestressed concrete
flat slabs. Laboratory flexural tests confirm the feasibility of
this novel reinforcement technique, showing that uniformity
of the fiber stress during tensioning is a key aspect for the successful
application of prestress. Improved flexural calculation
models for R/C members built with ultrahigh performance
concrete (i.e., with cubic compressive strength exceeding
200MPa) are presented by B.-I. Bae et al., who revise the
normal stress distribution schemes adopted for standard concrete
classes. The models are verified and validated by means
Hindawi Publishing Corporation
Advances in Materials Science and Engineering
Volume 2016, Article ID 1854839, 3 pages
http://dx.doi.org/10.1155/2016/1854839
2 Advances in Materials Science and Engineering
of laboratory flexural tests on representative specimens in
this case too. High strength concrete materials, with cubic
compressive strength ranging fromabout 80MPa to 110MPa,
are examined in the paper of L. Zeng et al., as constituting
materials of R/C beam-to-column joints encasing I-shaped
hot-rolled steel profiles. An extensive campaign of cyclic
tests on half-scale weak-type joints allows evaluating the
beneficial influence of the adopted concrete classes in terms
of strength and at the same time a minimal decrease in
ductility, as compared to the cyclic performance of similar
joints cast with standard concretes. Composite concretesteel
tubular columns are the topic of the article by S.
Jayaganesh et al. An experimental programme is carried out
to evaluate the effects of the partial compression of square and
circular cross sections, highlighting a reduction in strength
in comparison to full compression, more accentuated in the
case of the square shape. The correlation of the test results
with the predictions of the analytical models proposed in the
literature to account for these effects seems rather satisfactory.
Another experimental activity is reported in the paper by J.
Deng et al., dedicated to a campaign of pseudostatic cyclic
tests of one-fifth scale prototype R/C bridge piers, damaged
and repaired by means of a steel-tube jacketing traditional
technique, or by wrapping interventions based on the use
of CFRP or basalt fiber reinforced polymer (BFRP) sheets.
The results attest satisfactory performance in all cases, with a
significant increase in lateral stiffness and strength provided
by jacketing as compared to the original response capacity,
and its complete restoration in the case of the two FRP-based
retrofitmeasures.The advantages of the lattermethod consist
in lower physical intrusion and quicker installation times.
The postprocessing study of an experimental programme
carried out by the pseudodynamic method on a set of 13 R/C
shear walls is presented in the article of F. J. Molina et al.,
where the results of the seismic tests are elaborated by an
innovative strategy that allows deriving a capacity-linemodel.
With this approach it is possible to understand better the
different safety margins that are observed in the experiments
depending on the assigned eigenfrequency in relation to the
earthquake response spectra. The effects of the amount of
reinforcement and normal load are also assessed. Enhanced
cement composite materials are investigated in the articles
by H. Choi et al. and J. Lai et al. The former deals with
the experimental characterization of an innovative Portland
cement mortar, prepared by incorporating multiwalled carbon
nanotubes in the mixture.The experimentally measured
compressive strength is greater than the one offered by
standard Portland mortars, as a consequence of the bridging
action of the nanotubes, which prevents the progression of
microcracks and helps reducing the space between the voids
in the hydration material. In J. Lay et al.’s paper, cement fly ash
gravel is examined as constituting material of pile composite
foundations, for their updated use in saturated tailing dams.
A finite element analysis of the settlements of this type
of foundation, calibrated on the experimental investigation
carried out by other authors, assesses a stable and rather
homogeneous response under the design embankment loads.
Three articles are dedicated to advanced seismic protection
technologies. In the paper byM. Ismail et al., a numerical
study of a base isolation system incorporating Roll-in-Cage
devices recently developed by the authors is carried out
by simulating its incorporation in a three-span prestressed
R/C box girder-type bridge. The results show a remarkable
global performance of the system, also in comparison with
other seismic isolation solutions, highlighting its benefits in
the potential application to bridge structures. The article of
F. Mazza and A. Vulcano reports a shaking table testing
programme developed on a one-third scale base-isolated steel
frame structure equipped with an in-parallel combination of
steel-PTFE sliders and elastomeric bearings (HDRBs). The
experimental response confirms the high level of protection
offered by the isolation technology and establishes a
database for a refined numericalmodelling of the constituting
devices. J. W. Hu and M.-H. Noh present a study on selfcentering
friction dissipative steel braces including special
components fabricated with shape-memory alloy wires and
friction-type dampers. A numerical investigation carried
out on single-degree-of-freedom models allows formulating
a design methodology aimed at mutually optimising the
recentering and energy dissipation capacities of the passive
protection system, with a view to its practical implementation.
Two more papers deal with the application of innovative
FRP composite materials in various fields of engineering.
N. B. Baba et al. examine the mechanical and physical
behaviour of a hybrid glass FRP (GFRP) fabricated with three
different types of glass fibers—3D, woven, and chopped—
combined with a mixture of polyester resin and hardener.
Fiber arrangement and volume are varied to evaluate the
combination capable of providing the best performance in
terms of tensile strength and water absorption, which is
identified by means of the characterisation test developed
in the study. In the article by M. E. Tas¸delen et al. the
torsional behaviour of novel braided sleeve composite shafts
consisting of carbon and glass fibers is investigated. Vacuum
assisted resin transfer molding and vacuum bagging
are adopted as manufacturing methods. The results of the
experimental programme and the relevant finite element
simulations underline that, for the same configuration of layup
sequences, the highest torque and tensile strengths are
obtained for test specimens manufactured with the former
method. Furthermore, hybrid carbon-glass solutions strike
the best balance between strength performance and costs.
Special issues are dealt with in the remaining three articles.
By considering the growing applications of piezoelectric
structures in innovative technical areas, L. M. Zhou et al.
implement a mixed cell-based smoothed/extended finite element
method for a careful electromechanical crack analysis of
the constituting material. The case study examples presented
in the paper show that this mixed method is more accurate
and quickly converging than a standard finite element
calculation, also bypassing the mapping process inherent to
the latter, which significantly increases the complexity of the
calculation. J.Chen et al. report an on-site experimental study
of the cooling effect of crushed rock-based embankments on
slope wetlands situated along a railway line. A monitoring
system installed in an embankment of notable dimensions
allows reconstructing the temperature fields and the freezing
Advances in Materials Science and Engineering 3
history with time. The surveyed data show that only the
embankment shady side can be effectively cooled down
in a warm permafrost region, and the crushed rock-based
embankment can cool the entire embankment in a cold
permafrost region. Finally, in the paper by Y. Ou et al.
an innovative self-propagating high-temperature synthesis
(SHS) process to prepare amorphous boron powder, which
is an attractive material in several enhanced engineering
applications, is discussed. The new technique proposed
in this study consists in combining the SHS process and
the traditional magnesium thermal reduction method. The
effectiveness of the resulting technique suggests its possible
industrial application and adoption as a common approach
to prepare various inorganic materials.
SORACE Stefano;
BLOCKEN Bert;
BORRI Claudio;
CARACOGLIA Luca;
MOLINA RUIZ Francisco Javier;
MÜLLER Gerhardt;
2016-08-01
HINDAWI PUBLISHING CORP
JRC102050
1687-8434,
http://www.hindawi.com/journals/amse/2016/1854839/,
https://publications.jrc.ec.europa.eu/repository/handle/JRC102050,
10.1155/2016/1854839,
