Hydrologic Design of Pervious Concrete

Pervious concrete has been used in some regions for decades; however, recent interest in sustainable development and recognition of pervious pavements by the U.S. Environmental Protection Agency (EPA) as a best management practice for storm water management has heightened interest in its use. Pervious concrete applications support national programs such as EPA’s Heat Island Reduction Initiative and Low Impact Development and provide a potential for credit in the LEED^® (Leadership in Energy and Environmental Design) rating system for sustainable building construction.

Pervious concrete can be used to improve water quality by capturing the “first flush” of surface runoff, reducing temperature rise in receiving waters, increasing base flow, and reducing flooding potential by creating short term storage detention of rainfall. In order to fully utilize these benefits, the hydrological behavior of the pervious concrete system must be assessed. The hydrological performance is a key parameter in decisions to use this material as a best management practice for storm water management and is usually the characteristic of most interest to permit-granting agencies. More.

Hydrologic Design of Pervious Concrete (EB303)
This new publication provides an overview and discussion of techniques which can be used for hydrological design, considering the inter-relationship between runoff characteristics, material characteristics, and site geometry. It also presents guidelines for the preliminary selection of appropriate pervious concrete characteristics for specific applications and environments. More.

Pervious Concrete Workshops
This workshop offers detailed instruction on pervious concrete pavement as a solution to reducing storm water runoff from building sites and other paved areas. Attendees will learn the details of pervious concrete pavement systems, engineering properties and construction techniques. More.

ACI Pervious Concrete Specification—Comments Invited
The American Concrete Institute announces that ACI Committee 522 plans to publish Specification for Pervious Concrete Pavement, ACI 522X-XX. The draft document is currently available as a download from the ACI website. ACI invites the public to review and comment on the proposed document during a public discussion period. All comments received by September 15 will be considered by the committee.

Save on PCA Pervious Resources
Purchase Pervious Concrete: Hydrological Design and Resources CD (CD063), and Pervious Concrete Pavements (EB302), and the new Hydrologic Design of Pervious Concrete (EB303) for a special combination price and save 25%. Purchase the special offer.

Q: What are the different forms of sulfate in portland cement and how can I analyze cement for SO₃?

Sulfates in portland cement can be broadly categorized as (1) added sulfates— gypsum, hemihydrate, anhydrite, several synthetic forms of sulfates (typically by-products like flue gas desulfurization materials), and (2) clinker sulfates—including arcanite, aphthitalite, calcium langbeinite, and thenardite. Although normally reported as SO₃ (% by mass) for consistency, sulfur can be found in any combination of these forms. Elemental sulfur is almost never found in portland cement as it is normally produced in an oxidizing environment. Since every cement is unique, chemical analyses are the best method of determining the SO₃ content of cements. More.

Click here for more cement and concrete FAQs.

The Panels Are Gone—But Don't Forget Them

In 1938 and then again the early 1960s, PCA placed decorative concrete panels in an outdoor display to demonstrate developing methods for creating architectural finishes on concrete. A second goal of the project was to assess durability in a long-term, natural weathering exposure.

Sixty years after the initial installation, however, the land was sold and the display had to be removed. The excellent performance of architectural concrete is documented in this research bulletin. Get a free copy of this report for your library. More.

Click here for more about architectural and decorative concrete.

Cement Specs Now Consistent

The new 2007 editions of the standard specifications for portland cement, AASHTO M 85 and ASTM C 150, now have consistent provisions for fineness, Type II C₃S requirements (including Type II heat of hydration–related criteria), and the use of up to 5% limestone in portland cement.

ASTM C 150-07 was approved in May and is available online as a single standard. AASHTO M 85-07 is contained in the recently printed AASHTO Standard Specifications for Transportation Materials and Methods of Sampling and Testing, 27th Edition and Provisional Standards, 2007 Edition, and can also be purchased online as a single standard.

More at www.ASTM.org and the AASHTO online book store

"Must Have" Resources

Do you have the key cement and concrete references on your bookshelf?

There is a lot of literature to select from. In fact, it’s overwhelming! To help you zero in on the most critical references, PCA has compiled a list of what it considers the top 10 resources for both the concrete practitioner and cement specialist. Check them out!

Top 10 Concrete References.
Top 10 Cement References.

Revision of Test Methods and Specifications for Controlling Heat of Hydration in Hydraulic Cement (SN3007)

This research report reviews current practice for determining heat of hydration of hydraulic cement (ASTM C 186) for purposes of acceptance testing.The research concludes that isothermal conduction calorimetry offers a number of advantages compared to the current practice based on isothermal solution calorimetry. As part of this research a draft test method was developed for ASTM ballot. The logic behind the major details of the test method is documented.

Fellowship Research—Predicting Temperature Rise and Thermal Cracking in Concrete (SN3030)

A thermal simulation tool was developed for predicting the temperature rise due to hydration within concrete elements, including those that contain slag or fly ash. The program sought to perform a rough thermal analysis without requiring detailed technical inputs. The simulation is designed to perform its analysis on a 2-D section through the element using a finite difference method. An experimental program involving isothermal conduction calorimetry was used to help populate the model with data for cementing materials. Results from the simulation are compared to those of two different field trials involving mass concretes with high supplementary cementitious materials replacement levels.

Shapes In Stone: Images of Concrete Architecture from PCA’s Photo Archive (DVD033)

Interesting, innovative, beautiful, and often unusual concrete buildings are featured in this unique DVD compilation of more than 1100 images from PCA’s historic photo archive. The buildings, many of them “firsts” of their kind, include residential, religious, commercial, and industrial structures in the U.S. and Canada. Some are designed by famous architects such as Eero Saarinen, Frank Lloyd Wright, Minoru Yamasaki, I.M. Pei, and others. This historical collection covers the period from 1850 to 1999. Buildings are often shown in multiple views, and include the 1964 New York World’s Fair, Expo ’67, and nearly 200 images of buildings in Chicago. All images are available in high-resolution quality.

Successful Professors' Workshops Imparts Recent Advances

PCA/ACBM Undergraduate Faculty Enhancement Workshop
PCA and the Center for Advanced Cement Based Materials (ACBM) concluded an undergraduate faculty enhancement workshop on June 20, 2007 at the PCA facilities in Skokie, Ill. The three day workshop, entitled "Teaching the Materials Science, Engineering, and Field Aspects of Concrete," gave undergraduate faculty from across the country an opportunity to learn the most recent advances in concrete technology, develop teaching methods and lab demonstrations, and communicate with colleagues. Attendees were treated to courses taught by some of the industry's leading researchers and educators. The objective of the seminar is to advance the development of tomorrow’s researchers and industry leaders by providing educational materials and resources to undergraduate programs. More on PCA's University Outreach Program.

Building and Bridge Professors’ Seminars
Architectural, civil, and construction engineering professors from U.S. and Canadian universities met at PCA for the 16th Annual Building Professors’ Seminar, July 30-August 1. The goal of the seminar is to enhance concrete curriculum by providing educators with up-to-date resources on the design and construction of concrete buildings. Topics included teaching the fundamentals of structural concrete design, economic aspects of design and construction, new design standards, and seismic design and detailing. Forums and open discussions enabled participants to compare notes on successful teaching methods.

On August 2-3, structural engineering educators attended the Ninth Annual Bridge Professors’ Seminar. The focus of this seminar was on the latest AASHTO bridge design specifications, which contain design requirements significantly different than those of the ACI 318 Building Code.

Register Now for PCA Skokie Fall Courses

• Kiln Process - October 1-4, 2007
• Aggregates and Chemical Admixtures for Use in Concrete - October 1-2, 2007
• Mill Grinding - October 22-24, 2007
• Concrete: Principles & Practices - October 22-25, 2007
• Cement Manufacturing for Process Engineers - November 5-8, 2007
• Troubleshooting: Solutions to Concrete Field Problems - November 5-7, 2007
  
  

ACI Field Testing Technician Certification Open Enrollment— Sept. 21
PCA will hold the second of two ACI Concrete Field Testing Technician Grade I Certification examinations at its Skokie, Ill., headquarters. Our qualified and experienced instructors will administer the written and performance evaluations for certifying concrete testing technicians.

Call for Papers

Second International Symposium on Ultra-High Performance Concrete
March 5-7, 2008 in Kassel, Germany
Prospective authors are invited to submit an abstract of up to 300 words by August 31.

Third North American Conference on the Design and Use of Self-Consolidating Concrete
November 10-12, 2008 in Chicago, Illinois
Abstact(s) of 200 to 300 words must be submitted by October 1.

Complete listing of industry conferences