Concrete Construction
Cement & Concrete
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Focus on
Floors (Click
here or on individual topics.)  The
following sections will help you through the various issues relating
to concrete slabs and floors (click on topic). You will find that
there is much more than you imagined to that hard surface you walk
on every day.
Building Tips for Trouble-Free Concrete Slabs
Concrete is the material of choice for driveways,
sidewalks, patios, steps, and for garages, basements, and industrial
floors. It is relatively inexpensive to install and provides an
attractive, durable surface that is easy to maintain. Proper attention
to the standard practices and procedures for constructing exterior
or interior concrete can yield a concrete surface that will provide
long-lasting, superior performance. Click
here for some building tips that will aid in the construction
of quality concrete projects.
Safety Measures for Concrete
Construction
 Concrete
construction is no exception to the importance of construction safety.
Although claiming one of the lower jobsite-injury rates, dangers
associated with both the material aspects and construction practices
of concrete construction must be addressed to continue the industry’s
focus on safety. Heightened awareness, improved safety training
programs, and diligent enforcement are the keys to improving safety
on the jobsite. More.
Bugholes: Causes and Prevention of a Pesky Problem
 One
of the primary influences affecting the surface quality of concrete
is bugholes. Bugholes, pinholes, blowholes, surface voids –
they are recognized by various names, but all refer to a common
problem that contractors want to avoid. Bugholes, are small, regular
or irregular cavities (usually not exceeding 15 mm [9/16 in.]) resulting
from entrapment of air bubbles on the surface of vertically formed
concrete structures during placement and consolidation. More.
Conductive Concrete for Bridge Deck Deicing
 Heated
deck of Roca Spur Bridge in Nebraska is the world's first implementation
using conductive concrete for deicing. To read full article by Christopher
Y. Tuan, Ph.D., P.E., Associate Professor of Civil Engineering,
University of Nebraska click
here.
First Use of Ultra-High Performance Concrete
for an Innovative Train Station Canopy
 The
Shawnessy Light Rail Transit (LRT) Station, constructed during fall
2003 and winter 2004, forms part of a southern expansion to Calgary's
LRT system and is the world's first LRT system to be constructed
with ultra-high performance concrete (UHPC). To read the full article
by V. H. Perry and D. Zakariasen, Lafarge Canada Inc., click
here.
Pervious Concrete and Freeze-Thaw
 Pervious
pavements have been used for years throughout the warmer climates
of the United States with excellent results. However, in climates
prone to severe freeze-thaw cycles, some are hesitant to use these
pavements until it has been proven that pervious concrete can be
made to resist freeze-thaw damage. Research on this topic is currently
underway. More.
"Bendable Concrete" Replaces Bridge
Expansion Joints
 University
researchers have collaborated with a state Department of Transportation
to apply bendable concrete in a local bridge project. Engineered
Cementitious Composites (ECC) have been shown to have all of the
characteristics sought by highway designers and structural engineers
for a highly durable concrete material. The distinctive property
of ECC is the ability to bend while maintaining its compressive
strength. These properties make the material a good fit for use
in place of bridge expansion joints as demonstrated in this innovative
project. More.
Concrete Shines as Solar Reflectance Material
Concrete does a very good job of reflecting solar
energy. That is the finding from a recent PCA study which measured
the solar reflectance of 135 concrete specimens from 45 mixes representing
exterior concrete flatwork. In fact, all concretes tested in this
study would qualify for LEED® credits for Heat Island Effect.
Solar reflectance index (SRI), a calculated
value based on solar reflectance, SR, is one way to determine how
much light energy a material reflects: stated another way, comparing
SRI or SR of different materials tells which ones absorb less solar
radiation. This is useful because darker materials absorb more heat,
which is generally considered undesirable for its effect on the
environment. This may have an immediate, local effect, like heat
gain in urban areas (heat island).
More.
Read the complete report describing test procedures,
concrete mixes, materials, and other aspects of this study, Solar
Reflectance of Concretes for LEED Sustainable Sites Credit: Heat
Island Effect (SN2982).
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