Concrete International November 2014 No. 11 Complete Issue
Click on the cover image for the flip book version.
Bagby Street Reconstruction in Houston Recognized for Sustainable Design and Construction
The Bagby Street Reconstruction Project in Houston, TX,
was the first project to achieve Greenroads® Certification
in the State of Texas, receiving a Silver Rating for its
design and construction sustainability efforts from the
Cement Industry Honors 2014 Leaders in Environmental Excellence
Plants commended for benefiting local communities, global environment
A Red Road in Jamaica
Jamaica has excellent mineral resources including bauxite for alumina production. Red mud is a waste produced from bauxite processing. Four out of five bauxite mines in Jamaica have closed for production leaving red mud impoundments. The article presents research on developing a low-cost repair material containing red mud for filling potholes and service trenches in the secondary roads in Jamaica. The authors discuss laboratory and field trials, propose suitable construction methods, and encourage commercial application for the preblended cementitious material.
Field Application of Composite Post-Tensioning System
Adjacent precast prestressed concrete box beams are used for bridge superstructures. Joints between these box beams are often grouted and transverse post-tensioning is applied. The authors of the article developed design standards for transverse post-tensioning of box beams using unbonded carbon-fiber composite cables (CFCC) for the Michigan Department of Transportation. They also assisted in construction of two box beam bridges with transverse ties comprising large-diameter CFCC. The article presents details of these projects.
ACI Documents on Formwork Maintain the Legacy
Over the past year, ACI published three new or updated documents related to formwork. ACI 347.3R-13, "Guide to Formed Concrete Surfaces," is an entirely new publication that describes formed surfaces, basics of layout and design, specification, construction, and evaluation of formed surfaces. ACI 347R-14, "Guide to Formwork for Concrete," is a revised version of the 2004 edition of the guide, with updated provisions for wind loads on formwork and the latest design information for materials used in formwork construction. The eighth edition of ACI SP-4, Formwork for Concrete, is a complete update of this staple in the formwork community, originally authored by Mary K. Hurd.
AIA 2014 Educational Facility Design Excellence Awards
The American Institute of Architects (AIA) Committee
on Architecture for Education (CAE) has selected
11 educational and cultural facilities for this year's
CAE Educational Facility Design Awards.
Durability of Reinforced Concrete Beams Strengthened with CFRP Sheets
Externally bonded carbon fiber reinforced polymer (CFRP) reinforcement is used to rehabilitate deteriorated concrete infrastructure. Due to the lack of field performance data, the long-term durability of CFRPs is typically predicted using accelerated aging tests in the laboratory. The authors believe that CFRPs would be more widely accepted if reliable data were available regarding the long-term durability of the CFRP systems, especially the potential for debonding under severe loading and environmental exposures. The article presents research on CFRP retrofits exposed for 7 years to a combination of sustained loading and wetting-and-drying cycles.
Products & Practice Spotlight: Sharing Constructible Models Reduces Liability
Building information modeling (BIM) has been introduced into the design and construction industry over the last decade. BIM users benefit from completing even the most complex projects on time and within budget. Yet, many structural engineering firms hesitate to maximize the potential of BIM due to fear of increased liability and risk related to sharing models. In this article, the author explains why this fear is unfounded and how using constructible BIM can help
Concrete Q&A: Water Tanks and ASTM C1157 Cements
Q. I am the construction administrator for a water
storage tank being built in the Bahamas. The
construction documents for the project reference
ACI 350.5-12.1 The contractor has told me that all concrete
suppliers in the Bahamas have switched from ASTM C150
cements to ASTM C1157 cements. Although ACI 318-112 lists
ASTM C1157 hydraulic cement as an acceptable cementitious
material, I’ve noted that ACI 350.5-12 does not. Can I use
ASTM C1157 cement in a potable water storage structure even
though it is not specified in ACI 350.