Preventing Joint Deterioration

Concrete provides a durable, attractive paved surface for roads. It provides a longer life than any other leading paving material and does not rut or shove due to traffic or warm temperatures. Concrete’s higher reflectance keeps surfaces cooler, helping to minimize the urban heat island effect, and can lower infrastructure and ongoing lighting costs, while boosting safety for vehicles and pedestrians.

Some concrete pavements in northern states have exhibited joint deterioration: the premature disintegration of concrete around the joint. This deterioration typically begins to show after several years in place. The mechanism behind joint deterioration is complex and is understood to have a basis in freeze-thaw damage and mechanical damage.

Based on the current understanding of the mechanisms behind joint deterioration, there are four recommendations for new construction:

Recommendations for mitigation with existing pavements include applying sealants to the concrete near the joints, limiting the types of deicers used to sodium chloride, repairs to the joint, unclogging drainage systems, and retro-fitting improved drainage systems. More on preventing joint deterioration.

CP Road Map “Moving Advancements into Practice” Briefs

The National Concrete Pavement Technology Center at Iowa State University developed the CP Road Map as the national strategic plan for concrete pavement research. They identified 12 tracks for research and disseminate innovative research for each of these tracks through their “Moving Advancements into Practice” briefs. One of the most recent MAP Briefs is Preventing Joint Deterioration in Concrete Pavements: A Summary of Current Knowledge. This four-page brief discusses the causes, prevention, and mitigation of premature joint deterioration.

Other recent MAP Briefs include Fly Ash as a Supplementary Cementitious Material in Concrete Mixtures and Partial-Depth Repairs for Concrete Pavements.
Read these and other MAP Briefs.
Read the latest issue of their e-newletter.

New Edition of Innovations in Portland Cement Manufacturing

The fully revised second edition of Innovations in Portland Cement Manufacturing by PCA addresses challenges facing cement manufacturers in today’s regulatory and manufacturing arenas. The publication includes several new chapters on finish grinding, oxygen enrichment, inlet gas analysis and acoustic pyrometry. Sustainability and the environment are addressed throughout the book. Health and safety issues also take center stage. More information and purchase.

Design and Control of Concrete Mixtures, 2011 Edition
The guide to applications, methods, and materials

The industry’s primary reference on concrete technology, this fully revised 15th edition is a concise, current reference on concrete that reflects the latest information on standards, specifications, test methods and guides of ASTM International (ASTM), the American Association of State Highway and Transportation Officials (AASHTO), the American Concrete Institute (ACI), and the National Ready Mixed Concrete Association (NRMCA).

Design and Control of Concrete Mixtures presents the properties of concrete as needed in concrete construction, including strength and durability. This book is a “must have” for anyone involved with concrete. More information and purchase.

MIT Concrete Sustainability Hub Research Briefs

Five new briefs from the Massachusetts Institute of Technology’s Concrete Sustainability Hub (CSH) have recently been released. These short articles summarize exciting results of on-going research activities in the areas of Concrete Science and Life-Cycle Assessment.

Concrete Science:
What’s In Your Concrete (Part II)
The combined use of nanoindentation and statistical analysis to reveal micromechanical properties of cement hydrate phases is profiled. Two types of C-S-H, low-density (LD) or high-density (HD), can be distinguished which may be related to macroscopic strength and durability performance.

Clinker Grinding at Breaking Point
About 10-12 percent of the energy required to produce portland cement is due to grinding of raw material and clinker as well as other electrical processes. By means of atomistic simulations, the theoretical energy required to break clinker surfaces can be determined and linked to the corresponding grinding energy (power consumption) required to achieve a target fineness (specific surface). The simulation is being validated by microscratching of industrial clinker phases. The atomistic approach provides a baseline for the optimization of cement grindability.

Setting from Statistical Principles
This brief describes a new approach to quantitatively model the formation of cement hydration products, including their mechanical properties, based on statistical mechanics. The input comes directly from the atomistic simulations of composition of solution and precipitates. This provides a tool for the investigation of microstructure and property evolution during setting.

Life-Cycle Assessment:
Adopting a Life-Cycle Perspective
This brief reviews the methods of determining the environmental impacts from a life-cycle viewpoint. It is recommended that economic and environmental impacts of infrastructure be evaluated using a life-cycle perspective, enabling engineers, designers, and decision makers to better understand the impacts of infrastructure and the opportunities that exist to improve them. Two methodologies — life-cycle assessment (LCA) for environmental impact and life-cycle cost analysis (LCCA) for economic impacts — provide anayltical tools to help reach sustainability targets using cost-effective strategies.

When the Rubber Hits the Road
Fuel consumption due to pavement-vehicle iInteraction (PVI) is an essential part of life-cycle assessment (LCA) of pavement systems. Available field data for different pavements shows a high level of uncertainty and many models for effects of pavement characteristics on fuel consumption have been developed using outdated information, making it difficult to reliably implement PVI into LCA analyses. This brief reviews a mechanistic approach to derive relationships between fuel consumption, and structural and material pavement design parameters, providing engineers and decision makers with a design tool to optimize pavements for high performance fuel and green house gas efficiency.

Read the most recent news briefs from the CSH.

More information on the MIT Concrete Sustainability Hub Concrete Science program.

2011 Professors' Workshop Includes Track on Concrete Materials Properties

The PCA Professors’ Workshop, is being offered August 1-5, 2011 at the PCA headquarters in Skokie, Ill. This year introduces a new format which includes four tracks: Concrete materials properties; Engineering and economics of concrete buildings; Design and construction of concrete bridges by the AASHTO LRFD; and Design, construction, and performance of concrete pavements.

The Professors’ Workshop is designed to provide faculty in engineering, architecture, and construction management programs the tools to teach the latest developments in concrete materials, construction, and design. The week-long session includes networking opportunities to exchange ideas with professors from many universities, demonstrations by software vendors, and resource materials and publications valued at more than $1,000.

This report is a compilation of technical information for engineers, specifiers, and other concrete technologists on use of limestone in hydraulic cements in amounts up to 15% (focusing on amounts between 5% and 15%). Environmental benefits are noted as well as experience with the use of cements with limestone at these levels. The chemical and physical effects of limestone on fresh and hardened properties of concrete are emphasized and several case studies of pavements constructed with concrete made with such cements in Canada and the US are reviewed. Download the report.

The Durability of Concrete Produced with Portland-Limestone Cement:
Canadian Studies

In anticipation of the adoption of portland-limestone cements by concrete specifications and building codes, several Canadian cement producers initiated plant trial grinds to produce portland-limestone cements containing up to 15% limestone and research was conducted on properties as well as performance and durability in concrete. These cements were tested in mortar and concrete containing a wide range of SCMs and performance was compared with equivalent mortars and concretes produced with portland cement from the same plant. This report presents and summarizes the findings of these research programs. Download the report.

A workshop on Expansive Reactions in Cement-Based Materials will be held on July 27-29, 2011 at the Oregon State University in Corvallis, Ore.

The 2nd Advances in Cement-based Materials: Characterization, Processing, Modeling and Sensing conference will be held at Vanderbilt University in Nashville, Tenn. on July 24-26, 2011. Presentation topics include cement chemistry and nano/microstructure, advances in material characterization, and concrete durability.

The 2011 International Concrete Sustainability Conference will be held at the Hyatt Regency Cambridge and the Massachusetts Institute of Technology campus in Cambridge, Mass. on August 9-11, 2011. The conference will provide learning and networking opportunities for sustainable concrete manufacturing and construction with topics that include low impact development, carbon footprint, and performance-based concrete.

The 2011 Concrete Industry Day will be held on August 11, 2011 at the Kresge Auditorium in Cambridge, Massachusetts. It is sponsored by the Massachusetts Institute of Technology’s (MIT) Sustainability Hub.

Complete listing of industry conferences.