Revista de estructuras y construcción de acero

Iron has been used as construction material in human society for
long time. The first iron-chain suspended bridge, 106 m span Jihong
Bridge, was built in Southwest China in 1400s. In Europe, the first
cast iron bridge appeared in 1700s in Telford, England. Cast iron was
later replaced by more reliable wrought iron for construction of most
railway bridges in early 1800s. It was not until late 1800s / early 1900s
that steel structural systems appeared and took over iron in modern
construction industry. Based on the manufacturing procedure, steel
structures can be separated into two main categories: hot-rolled steel
and cold-formed steel. Accordingly, there are two independent design
and constructional systems.

Brilliant ideas are worth as much as a complete research. Steel
structures have followed a quite well-trodden and yet challenging path,
particularly with the advent of new materials in construction industries.
As a result, innovative and stimulating ideas played a significant part,
since both researchers involving in constructions and/or industries
drew comparisons among different materials to achieve most optimal
ideas. In different research and construction projects, the major
concern that whether sole material or a composition of two (or more)
materials outweigh, has always been raised among decision makers.
Notwithstanding, the significant role of steel as a crucial element in
construction has remained inarguable. Despite this, the need for new
ideas has been always vitally felt to come up with innovations in steel
comparable with concrete and other materials. To this end, Journal
of Steel Structure and Construction (JSSC) aims to provide an open
international forum for bright ideas on steel structures. This paper
outlines the significance of the ideas in steel elements and puts few
instances forward among the new advances.

LDG is an Excel macro to design for lateral wind and seismic loads
based on ASCE 7 and the IBC (International Building Code). The
objective of LDG is to provide numerical tables and optional graphs to
visualize lateral design data. The graphs reinforce important informed
intuition regarding force, shear and overturn moment distribution.
LDG requests user input of building size as well as wind and seismic
data. Building data includes x-width, y-length, number of stories, story
heights, and dead load. The data may be equal or variable for all
stories. LDG also requests wind and seismic importance factors, wind
speed, exposure- and gust-factors, etc. for wind design, R-factors, Sfactors,
etc. for seismic design. For clarity, seismic data is beige and
wind data green. Based on the user input LDG provides numeric table
and optional graphs defining for each level lateral force, shear and
overturn moment. For wind load LDG provides data in both X- and Ydirections.
The graphs may be displayed on the Excel input screen or
on a separate Excel screen. The attached screen includes seismic force
Fs, shear Vs, overturn moment Ms and wind graphs in X-direction,
force Fwx shear Vwx and overturn moment Mwx. The first column of
the wind table provides the wind pressure in psf. LDG includes a
separate tutorial to introduce the LDG features and use (Figures 1 and
2).

Traditionally, risk management is segmented and conducted in
separate business units or departments (i.e. silos) within a company.
Under silo-based risk management, silos deal with their own risks, and
none single group or person in the company has a grasp of the entire
exposure that the company faces. This is attributed to the way people
think about solving problems, the existing organizational structure,
and the evolution of risk management practice. In addition, this is due
to the fact that each silo within a company possesses the best expertise
to address the risks within its area of responsibility.

Construction practices involving the rehabilitating, retrofitting, and
reinforcing of concrete structures using fiber reinforced polymer (FRP)
fabrics have been well documented. Experimental efforts to
characterize the effectiveness of this technology, however, have
included many large scale FRP-concrete tests for strength/stiffness
evaluations which do not detect delamination effects; small-scale tests,
on the other hand, only provide average interface strength properties
that neither describe failure mechanisms nor provide fracture
toughness data. In this paper, the experimental fracture mechanics
specimen known as the single contoured-cantilever beam (SCCB) was
used to obtain important quantitative results of FRP-concrete
interfaces as subject to a host of conditions: dry, freezing-thawing,
wetting-drying, fatigue, and surface roughness effects on the integrity
of the interface bond. The findings of this research effort demonstrate
both the importance of surface preparation towards achieving an
optimal bond as well as offering a means of gaging rates of degradation
of the interface under a variety of commonly encountered construction
environments.