Concrete International December 2013 No.12 Complete Issue
Click on the cover image for the flip book version.
Concrete Product Guide
2014 ACI Honors and Awards Program
Nominations are open for the annual awards of the Institute
Pankow Celebrates 50th Anniversary
On May 17, 1963, design-build innovator Charles Pankow launched his new company in a garage,determined to excel in concrete construction while he developed and refined the design-build method.
OSHA Revises Hazardous Materials Pictograms
Symbols designed to help workers handle chemicals safely
The International Parking Institute 2013 Awards of Excellence
The International Parking Institute (IPI) honored seven parking facilities with 2013 Awards of Excellence in seven different categories.
A Simple Means for Reducing the Risk of Progressive Collapse
In general, the negative bending moment capacity of beam end sections is larger than the positive bending moment capacity. Under a column loss scenario, the bottom reinforcing bars are thus likely to fracture before the top reinforcing bars. Research presented in this article investigates the effectiveness of a technique for enhancing the ductility at the beam end sections. The research shows that debonding of the reinforcing bars from the surrounding concrete delays the fracture of bars and enhances ductile behavior. The proposed approach therefore shows promise as a method for enhancing the resistance of reinforced concrete frames to disproportionate collapse.
Equivalent Durability Performance of Portland Limestone Cement
This article, the third in a series on portland limestone cement (PLC), reports on the mechanisms that allow PLC mixtures to maintain the same levels of durability performance as portland cement (PC) mixtures. It discusses results of alkali-silica reactivity, sulfate resistance, freezing-and-thawing, scale resistance, and carbonation testing. PC and PLC used in presented studies came from the same mill circuit. The target limestone content of the PLC was 12%, the limestone was interground with the cement clinker, and the fineness of the PLC was increased to achieve the same 28-day (mortar) strength as the PC.
Two-Way Slab Parking Structures in Canada
Over the years, there have been changes to codes governing the design of two-way slab parking structures in Canada. These changes include improvements to the general design provisions for two-way slab structures, as well as the introduction of special provisions for parking structures. In this article, factors affecting the structural safety of existing two-way slab parking structures in Canada are reviewed, including inadequacies in older codes, construction defects, and deterioration due to exposure to de-icing chemicals.
Best Practices in Decorative Concrete
Many traditional curing methods, such as water application by sprinkling, ponding, or absorbent materials, shouldn’t be used on decorative concrete flatwork because they will discolor the concrete.
Concrete Q & A: Popouts or Popoffs?
My concrete driveway was placed last year in the fall. This summer, I noticed that small concrete fragments have broken off the driveway surface exposing large pieces of aggregate. Can you tell me what might have caused this issue? Should I worry about further deterioration?