Concrete International March 2015 No. 3 Complete Issue
Click on the cover image for the flip book version.
2014 APA Awards for Excellence Winners
Each year, the Architectural Precast Association (APA) hosts its Awards for Excellence program, which recognizes excellence in design, manufacturing, and craftsmanship of architectural precast concrete structures and individual components.
Decorative Concrete Council Award Winners for 2015
The Decorative Concrete Council, a council of the American Society of Concrete Contractors (ASCC), St. Louis, MO, has announced the winners of its seventh annual Decorative Concrete Awards competition.
Le Corbusier’s Love for Concrete
One of the pioneers of modern architecture, Le Corbusier’s love affair with concrete, evident in a number of his nearly 75 projects, began early.
Novel Ultra-High Performance Glass Concrete
Ultra-high-performance glass concrete (UHPGC) developed at the University of Sherbrooke, Sherbrooke, QC, Canada, was used in the construction of two new pedestrian bridges on the university campus. The bridges were designed to meet the university’s architectural and structural requirements for pedestrian use and its regulation on sustainable development. The mold for the bridges was built at the Bétons Génial Inc. plant and transported to the university’s laboratory where the UHPGC was produced and placed. The article contains details on the bridge design, formwork and fabrication, and installation as well as information on the UHPGC mixture and its properties.
Reinforcing Steel in Pervious Concrete
While pervious concrete has received much attention as a pavement material, it has been also used in the past to construct walls like the ones at Rosehill Cemetery, in Chicago, IL. Over the past 18 years, the author made periodic observations of the condition of these walls. Although increasing incidences of visible distress have been noted, predominantly above the interface of the pervious concrete wall and the mortar-coated porous concrete foundation, the walls have performed well. The article provides a discussion on condition of the walls by examining the potential corrosion mechanisms for steel embedded in pervious concrete.
Products & Practice Spotlight: Graphic Concrete Rejuvenates Semba Center Building in Osaka
The Semba Center Building in Osaka, Japan, was an unsightly, bazaar-like complex of 10 buildings in the city center housing textile companies. It had reached such an age that city officials demanded its renovation to reinforce the brick façade against the possibility of earthquakes and to prevent the bricks from cracking and falling. Selecting the materials and agreeing to the renovation solution proved to be a lengthy process. Finally, graphic concrete with seven kimono patterns was chosen for the new façade of the Semba Center Building.
ACI Names 37 New Fellows
Members to be awarded at The ACI Concrete Convention and Exposition.
ACI Concrete Sustainability Forum VII
The ACI Concrete Sustainability Forum VII took place in Washington, DC, on October 29, 2014, at the ACI Fall Convention. The forum comprised four parts: presentations on Concrete Sustainability Forum history and lessons, a panel discussion, a luncheon lecture, and a tour of the U.S. National Building Museum. Speakers discussed the preparation of ACI 130R, “Guideline to Concrete Sustainability”; sustainability requirements in fib’s Model Code for Concrete Structures 2010; innovative cements; concrete production using CO2; sustainable pavements program, and resilient buildings and communities.
Controlling Early-Age Cracking in Mass Concrete
Mass concrete placements are conducted using thermal control plans that provide limits on maximum concrete temperature as well as maximum temperature differential. While the maximum temperature is limited to avoid damage due to delayed ettringite formation, temperature differential is limited to avoid or minimize cracking due to internal restraint. In the latter case, strategies generally include insulating placed concrete. This article summarizes existing guidelines that allow near-surface reinforcing steel to be included in strategies for minimizing thermal cracking. Construction teams are cautioned that reinforcement will not eliminate requirements to limit maximum temperature or to consider the effects of maximum temperature differential on cracking. Cost analyses and consultation with the owner are recommended.
Concrete Q&A: Withdrawn ASTM Standard and Code and Cement Type
Q. We are currently in the process of developing
a prequalified mixture design to meet the requirements
of ACI 349-13. 1 Section 188.8.131.52
of ACI 349-13 requires testing perASTM E204-98(2007),
“Standard Practices for Identification of Material by Infrared
Absorption Spectroscopy, Using the ASTM Coded Band and
Chemical Classification Index.” In the process of checking the
ASTM International website, we discovered that the standard
has been withdrawn. Is this specification still valid?