The Portland Cement Association's research and development projects provide support to its development programs, and programs of the American Concrete Pavement Association, the Cement Association of Canada, and allied industry groups.

Projects are developed and monitored by these organizations and PCA standing committees. The R&D Work Programs Committee, which is made up of representatives of all standing committees, assist with program management.

Following is a listing of the work by subject area. It should be recognized that materials projects, which are monitored within Product Standards and Technology, are applicable to a number of markets. More detailed summaries are provided for projects related to cement manufacturing.

Product Standards and Technology

CEMENT TECHNOLOGY

Advanced Cement-Based Materials (89-01a).

PCA participates as an Industrial Partner of the Center for Advanced Cement-Based Materials (ACBM), which is based at Northwestern University, Evanston, Ill. Other Center consortium institutions include the University of Illinois at Urbana-Champaign, University of Michigan, Purdue University, and the National Institute of Standards and Technology. The Center uses a multidisciplinary program to address major technical issues facing the cement and concrete industries. Project topics are established by the Center with collaboration of the Industrial Partners. PCA can use this fundamental research to identify solutions to problems related to poor durability, life-cycle predications, and waste utilization. Results of the fundamental research also can be used to improve methods for measuring permeability, durability, and strength. The research information can be published in PCA reference books, information sheets, and newsletters.

Optimum Sulfate Content of Portland Cement (02-09).

Calcium sulfates (gypsum, anhydrite) have long been added to portland cement. The optimum amount is chosen to regulate set and achieve best strengths. However, assertions have been made that calcium sulfate impairs long-term durability. Practical experience and laboratory studies show that warm-cured products may exhibit dimensional instability. Safe limits on warm curing have been set, but, in the absence of hard data, are based on empirical criteria and tests. The proposal has as its objective re-examining the role of sulfate in the longer-term performance — >1 to 2 years — by determining sulfate distributions in portland cement and analyzing their relevance to performance. The optimum and maximum safe sulfate will be recommended for warm-cured mixes.

Environmental Technology

Environmental Life Cycle Assessment of Portland Cement Concrete (00-21).

The objective of this work is to participate in the development and maintenance of the Athena Sustainable Materials Institute environmental life-cycle inventory/assessment model of building materials. Athena has become an active part of the U.S. and Canada environmental life-cycle assessment community. With PCA's membership and participation in Athena, the most accurate and up-to-date environmental life-cycle information on portland cement and concrete products can be included in the models and other work completed by Athena, including the U.S. Database Project, which was initiated in 2001 and encompasses all products including building materials. PCA will become a full member of Athena from 2000 to 2005, and participate as appropriate. Travel funds will be available for representatives of Athena to participate in PCA meetings in an advisory role. Both Cement Association of Canada and CEMEX are members of Athena Institute, serving with associations and companies representing wood products and energy, and with U.S. and Canadian government officials.

Effect of Pavement Type on Fuel Consumption (98-21).

This work will provide the industry with quick and reliable test methods to: 1) predict the long-term effectiveness of supplementary cementing materials (SCMs) in controlling expansion of concrete due to alkali-silica reaction (ASR), and 2) quantitatively assess the extent of deterioration and the risk for future distress of concrete affected by ASR based on new and innovative petrographic methods or procedures using the scanning electron microscope and the image analyzer. The objectives of the second phase of the project will be to include a second field exposure site in a region with a different climatic environment that the test site in Canada. In a number of locations in North America, deterioration of concrete pavement has been attributed to alkali-silica reactivity. In response, two state departments of transportation have instituted limits of 0.4% on the alkali content of cements. Such limits present difficulties for cement manufacturers, for whom it is already difficult or even impossible to produce cements meeting these requirements. This project provides data for alternatives to low alkali-cement specifications through the use of pozzolans to control the expansion associated with alkali-silica reaction.

Raw Material Sulfur Dioxide Emission Potential (01-10).

The results from this project will identify the range of sulfur dioxide (SO₂) stack emissions attributable to raw material sulfur sources throughout the North American portland cement industry, and to provide information on dependence of the efficiency of sulfur retention in the kiln feed on the sulfur species and limestone properties in the feed, and on the circulation of sulfur from the kiln.

Testing Methods and Control Technologies for Mercury Air Emissions (03-13).

This project will evaluate mercury stack testing methods for applicability to portland cement kiln emissions and to determine the mercury control technologies available to the cement manufacturing industry and other industrial processes. If mercury limits are proposed on the portland cement industry, control technologies that are applicable to other industries may be effective for cement manufacturing. An evaluation of mercury control technologies would provide guidance on systems that are available or under development, and how those systems may possibly impact the cement manufacturing process, create solid and other waste issues, and affect the final product.

Mercury Testing of Raw Materials (03-14).

This work will evaluate current mercury testing methods of raw materials and determine the mercury content of various traditional raw materials and industrial byproducts (i.e. fly ash) that may be impacted by mercury control technologies in those industries. It is necessary to ascertain what the best analytical method is for determining the mercury content of raw materials, especially industrial byproducts. With those findings, traditional raw materials and industrial byproducts from industries using proven and novel end-of-pipe mercury control technologies will be collected and analyzed for their mercury content and speciation. By understanding how mercury control technologies in other industries will impact their byproducts, portland cement manufacturers will be better prepared to respond to changes to the mercury input from raw materials.

Manufacturing Technology

In addition to the research projects listed above, the members of the Manufacturing Technical Committee (MTC) sponsor research on manufacturing technology. The MTC research program is supported solely by the dues of the members. Following is a list of the MTC projects.

Search of World Wide Literature.

This project provides a compilation of internationally published material concerning materials preparation and finishing, pyroprocessing, auxiliary equipment (dust collectors, conveying systems, and storage), and wear. The search involves scheduled updates twice per year. An updated list of literature on these topics would serve as a valuable source of information for members. The list also could stimulate ideas for new MTC projects and provide a starting point for projects.

The Effect of Raw Mix Particle Size Distribution on Clinker Burnability and Grindability.

The goal of this project is to develop further understanding of the relationship between the particle size distribution of raw mix and the burnability and grindability of clinker. The development of a standard test for determining optimum kiln feed particle size distributions also may be considered. Recent developments in grinding and separating equipment increase the opportunity to modify raw mix particle size distribution. Understanding the influence of this modification on clinker burnability and grindability could lead to increased efficiency of either one or both of these manufacturing steps.

Response to Expected PM_2.5/PM₁₀ and Community Health Regulatory Standards.

The purpose of this project is to compile accurate PM₁₀ and PM_2.5 emission factor data and chemical characterization data. These data are needed to demonstrate to regulatory agencies that portland cement plants are not major sources of PM_2.5 and should not be targets of new particulate control strategies designed to implement the recently promulgated National Ambient Air Quality Standards for PM_2.5 in the United States or new particulate control standards developed in Canada in the future. These data also are needed to replace or supplement the limited PM₁₀ emission factor data presently available in the U.S. EPA Compilation of Emission Factors. These emission factors are used in both the U.S. and Canada.

Review of Mill Summary.

To review and compare information found in the 1988 MPC Mill Summary and PCA's current publication, Plant Information Summary, to assess the relevance in updating the Mill Summary. The existing Mill Summary contains a great deal of technical information on North American mills in use in 1998. However, the information may be out of date. Current publications do not get to the same level of detail. A review of the information will 1) establish if useful information can be obtained by updating the summary; 2) determine who will benefit from the information; 3) determine what mill information is necessary to include; and 4) assess methods for obtaining the mill information.

Identification and Measurement of Static Charge in Ball Mills.

To identify whether static charge exists in ball mills and, if so, find the origin and obtain a means of measuring the static charge produced. Static electricity is reported to exist in ball mills, negatively affecting the efficiency of the grinding process and lowering productivity. Previous testing, performed through Task Committee 1, of a device said to reduce electrical discharge in mills was inconclusive. The identification and the magnitude of any static charge present in the mill will direct Task Committee 1 with the end objective of reducing it. Reduction of static in ball mills will improve production, decrease costs, and address safety concerns.

Dust Collector Systems as Removal Devices for Sulfur Oxide Capture in Cement Plants.

To search and review available information on the comparative dry scrubbing efficiencies of fabric filters and electrostatic precipitators for removal of SO₂ from cement kiln flue gases. This comparison should allow optimization of SO₂ removal at the final stages of the flue gas treatment process, and make better systems for dust collection and acid gas removal in cement kiln systems.

Detached Plume Manual: Guidelines for Cement Plant Personnel.

The objective of this project is to provide practical steps that can be taken by operations personnel at cement plants to combat detached plumes when they occur. The practical, hopefully useful approach will emphasize management of parameters over which the operator can exercise some control. A significant number of cement plants in North America experience detached plumes from the kiln stack, either periodically or nearly constantly. Whereas these plumes normally do not contain highly toxic or dangerous components, they are by virtue of their very fine particle size visible even when the quantity of material is quite small. As environmental awareness grows, more of the public notices any emission from the product manufacturing sector, especially when it is visible. Although at present there are few laws governing detached plumes, this situation is expected to change dramatically as a result of this increasing public awareness. EPA also is placing more stress on control of fine particulates (especially those <2.5 um in diameter), because of their respirable risk. It is important for the industry to understand and combat these emissions to control pollution and avoid unwanted public and regulatory scrutiny.

PCA Education Foundation Awards

In addition to the research projects described above, PCA sponsors an Education Foundation Award. The Education Foundation was established in 2001 to help finance education programs in nearly every facet of the cement and concrete industries, from university research fellowships to career recruitment and craft training. In October 2002, PCA awarded its first round of fellowships for cement- and concrete-related research. Seven university students took home $20,000 grants and plaques to commemorate the awards.

The winning proposals, chosen from 36 entries, are:

• “Development of Self Consolidating Concrete Containing Type F Fly Ash.” Professor: Surendra P. Shah; Student: Raissa Douglas, Graduate Student, Civil Engineering, Northwestern University.

• “Self-Curing, Water-Entrained Concrete Using Water-Absorbent Polymers.” Professor: R. Douglas Hooton; Student: Hoa Lam, Graduate Student, Civil Engineering, University of Toronto.

• “Optimized Mix Design for Roller-Compacted Concrete Pavements” Professor Norbert Delatte: Student: Anshuman Sehdev, Graduate Student, Civil Engineering, University of Alabama at Birmingham.

• “High-Strength Concrete Columns with Intervening Normal Strength Floors.” Professor: Scott D.B. Alexander; Student: Ehab Abdel Wahab, Graduate Student, Civil & Environmental Engineering, University of Alberta.

• “Fast-Track Concrete on Aprons: How Does One Address Cracking.” Professor: Susan Tighe; Student: James Smith, Graduate Student, Civil Engineering, University of Waterloo.

• “Investigation of the Cause and Effect of Air Void Coalescing in Portland Cement Concrete Mixes.” Professor: Shane Buchanan; Student: Gabe Camposagrado, Graduate Student, Civil Engineering, Mississippi State University.

• “New Sensor Technologies to Measure Internal Moisture Content in Concrete.” Professor: David A. Lange; Student: Zach Grasley, Graduate Student, Civil Engineering, University of Illinois at Urbana-Champaign.