International Concrete Abstracts Portal

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  • The International Concrete Abstracts Portal is an ACI led collaboration with leading technical organizations from within the international concrete industry and offers the most comprehensive collection of published concrete abstracts.

International Concrete Abstracts Portal

Showing 1-10 of 2697 Abstracts search results

Document: 

CI4202Grumski

Date: 

February 1, 2020

Author(s):

Scott Grumski

Publication:

Concrete International

Volume:

42

Issue:

2

Abstract:

The article discusses how automated testing of construction materials can help eliminate human error and increase efficiency. It describes differences between manual, semiautomated, and fully automated testing. An example of an automated testing platform is provided.


Document: 

SP-337_06

Date: 

January 23, 2020

Author(s):

Edward (Ted) Moffatt, Michael Thomas and Andrew Fahim

Publication:

Special Publication

Volume:

337

Abstract:

In 1978, the Canadian Centre of Mineral and Energy Technology (CANMET) initiated a longterm study to determine the performance of concrete in a marine environment. Between 1978 and 1994, over three hundred prisms as part of 14 different experimental phases were placed at the mid-tide level at the Treat Island exposure site. Treat Island is an outdoor exposure site operated by the U.S. Army Corps of Engineers, and lies in the Passamaquoddy Bay, part of the Bay of Fundy, near the town of Eastport in Maine. Following 25 years of exposure, the blocks were retrieved after being exposed to tidal conditions representing approximately 18,250 cycles of wetting and drying, and 2,500 cycles of freezing and thawing. This paper presents the durability performance of concrete from several phases of the CANMET study. This includes concrete incorporating various levels of supplementary cementing materials (up to 80% by mass of cementing material in some cases), with normal density and light-weight aggregate. The paper also compares output from the service-life model Life-365 with experimental chloride profile data. The results indicate the efficacy of SCMs in increasing the concrete resistance to chloride penetration. However, use of very high levels of these materials was found to render the concrete more susceptible to surface scaling. The results also showed that Life-365 model can predict chloride penetration adequately with very simple inputs.


Document: 

SP-337_05

Date: 

January 23, 2020

Author(s):

Kjell Tore Fosså and Widianto

Publication:

Special Publication

Volume:

337

Abstract:

This paper describes the development in concrete technology for offshore concrete structures from the 1970’s until now and discusses some potential topics for future research which would result in more cost-effective offshore concrete structures.

Most of the offshore concrete structures constructed in the last 4 decades are still in operation, with no or only minor maintenance required, even though the average age for these structures in the North Sea is more than 25 years. The compressive strength in offshore structures has gradually increased from about 40MPa (5800 psi) in the 1970’s to more than 100MPa (14500 psi) in some of the latest concrete structures. Standards and concrete specifications have been revised several times during these years. In parallel, the knowledge from several research and development programs has been used to further improve the concrete properties and overcome the limitations. Focus has been primarily to improve the compressive strength of the concrete as well as the durability and concrete workability. The cement and admixture industry have been heavily involved in research programs to further adapt and develop these material properties. The result of the product developments in the concrete constituency has also improved cost-effectiveness and durability (including overall life-cycle cost-effectiveness) for offshore concrete structures.

With the new generation technology, the technical limitations we face today will be overcome. With more knowledge and improved technology, the quantity and size of cracks in concrete in service are expected to be reduced, which would also improve durability. In addition, the focus in the future will also be on sustainable and environmentally friendly materials.


Document: 

SP-336_05

Date: 

December 11, 2019

Author(s):

Lisa E. Burris, Prasanth Alapati, Kimberly E. Kurtis, Amir Hajibabaee, M. Tyler Ley

Publication:

Special Publication

Volume:

336

Abstract:

Cement production is one of the largest contributors to CO2 emissions in the U.S. One method of reducing emissions associated with concrete is through usage of alternative cements (ACMs). Some of the more common ACMs include calcium sulfoaluminate cement, calcium aluminate cement, ternary calcium aluminate-calcium sulfate-portland cements, and chemicallyactivated binders, all of which have been shown to have lower carbon footprints than ordinary portland cement (OPC). However, the durability, and more specifically, the shrinkage behavior, of these cements has not been adequately examined, and must be better understood and able to be controlled before ACM concrete can be effectively used in the field. As a first step in increase understanding of shrinkage in ACMs, this paper examines chemical, autogenous, and drying shrinkage in the ACMs listed above. Results show that, despite greater quantities of chemical shrinkage, CSA, CAC, and chemically activated fly ash binder undergo less autogenous and drying shrinkage than OPC.


Document: 

SP-336_01

Date: 

December 11, 2019

Author(s):

James Lafikes, Rouzbeh Khajehdehi, Muzai Feng, Matthew O’Reilly, David Darwin

Publication:

Special Publication

Volume:

336

Abstract:

Supplementary cementitious materials (SCMs) in conjunction with pre-wetted fine lightweight aggregate to provide internal curing are being increasingly used to produce high performance, low-shrinking concrete to mitigate bridge deck cracking, providing more sustainable projects with a longer service life. Additionally, the SCMs aid in concrete sustainability by reducing the amount of cement needed in these projects. This study examines the density of cracks in bridge decks in Indiana and Utah that incorporated internal curing with various combinations of portland cement and SCMs, specifically, slag cement, Class C and Class F fly ash, and silica fume, in concrete mixtures with water-cementitious material ratios ranging from 0.39 to 0.44. When compared with crack densities in low-cracking high-performance concrete (LC-HPC) and control bridge decks in Kansas, concrete mixtures with a paste content higher than 27% exhibited more cracking, regardless of the use of internal curing or SCMs. Bridge decks with paste contents below 26% that incorporate internal curing and SCMs exhibited low cracking at early ages, although additional surveys will be needed before conclusions on long term behavior can be made.


Document: 

CI4111ExcellenceConcrete

Date: 

November 1, 2019

Publication:

Concrete International

Volume:

41

Issue:

11

Abstract:

Projects that received the Excellence in Concrete Construction Awards for 2019 were selected based on architectural and engineering merit, creativity, innovative construction techniques or solutions, innovative use of materials, ingenuity, sustainability and resilience, and functionality. King Abdulaziz Center for World Culture (ITHRA), Eastern Province, Saudi Arabia, won the Overall Excellence Award and the first-place in Mid-Rise Buildings category.


Document: 

SP334

Date: 

October 9, 2019

Author(s):

Moncef L. Nehdi

Publication:

Special Publication

Volume:

334

Abstract:

To improve the eco-efficiency and sustainability of concrete, the cement and concrete industry can exploit many byproducts in applications that could, in some cases, outperform conventional materials made with traditional ingredients. This Special Publication of the American Concrete Institute Committee 555 (Concrete with Recycled Materials) is a contribution towards improving the sustainability of concrete via using recycled materials, such as scrap tire rubber and tire steel wire fiber, GFRP waste, fluff, reclaimed asphalt pavements, recycled latex paint, and recycled concrete aggregate. Advancing knowledge in this area should introduce the use of recycled materials in concrete for applications never considered before, while achieving desirable performance criteria economically, without compromising the quality and long-term performance of the concrete civil infrastructure.


Document: 

SP333

Date: 

October 9, 2019

Author(s):

Yail J. Kim, John J. Myers, and Antonio Nanni

Publication:

Special Publication

Volume:

333

Abstract:

Concrete bridges play an important role in the efficiency and reliability of transportation civil infrastructure. Significant advancements have been made over the last decades to enhance the performance and durability of bridge elements at affordable costs. From an application perspective, novel analysis techniques and construction methods are particularly notable, which have led to the realization of more sustainable built-environments. As far as the evaluation and rehabilitation of constructed bridges are concerned, new nondestructive testing approaches provide accurate diagnosis and advanced composites, such as carbon fiber reinforced polymer (CFRP), have become an alternative to conventional materials. This Special Publication (SP) contains nine papers selected from two technical sessions held at The ACI Concrete Convention and Exposition – Spring 2018, in Salt Lake City, UT. The objective of the SP is to present technical contributions aimed to understand the state of the art of concrete bridges, identify and discuss challenges, and suggest effective solutions for both practitioners and government engineers. All manuscripts were reviewed in accordance with the ACI publication policy. The Editors wish to thank all contributing authors and reviewers for their rigorous efforts. The Editors also gratefully acknowledge Ms. Barbara Coleman at ACI for her knowledgeable guidance in the development of the SP.


Document: 

SP-333_01

Date: 

October 1, 2019

Author(s):

Rafael A. Salgado, Serhan Guner

Publication:

Special Publication

Volume:

333

Abstract:

A significant number of in-service bridges have been subjected to loads above their original design capacities due to the increase in traffic and transported freight in the past decades. Externally bonded fiber-reinforced polymers (FRP) is a non-destructive retrofit technique that has become common for the strengthening of overloaded cap beams of bridges. However, there is a lack of analysis methods for the retrofitted cap beams that can accurately predict the retrofitted structural response while accounting for the critical material behaviors such as bond-slip relationships, confinement effects, and redistribution of stresses. In this study, an analysis methodology using nonlinear finite element models is proposed for cap beams retrofitted with externally bonded FRP fabrics. A two-stage verification of the proposed methodology was employed: a constitutive modeling and critical behavior of materials verification using experimental results available in the literature; and a system-level load capacity determination using a large, in-situ structure. The proposed methodology was able to capture the FRP-concrete composite structural behavior and the experimentally observed failure modes. The FRP retrofit layout created using the results of this study increased the capacity of the initially overloaded cap beam in 27%, granting it a 6% extra capacity under its ultimate loading condition.


Document: 

CI4110Hover

Date: 

October 1, 2019

Author(s):

Kenneth C. Hover and Michael J. Schneider

Publication:

Concrete International

Volume:

41

Issue:

10

Abstract:

Instructional and research labs in concrete materials and structural behavior present the same safety hazards as a typical construction site. The responsibility to keep students safe in the lab brings a tremendous opportunity. Not only can educators protect their students on campus—they can also prepare those same students for the realities of safety management and hazard identification and prevention in their post-academic careers.


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