International Concrete Abstracts Portal

The knowledge of dissolution processes of aggregates and supplementary cementing materials (SCMs) in alkaline solutions can help to describe the expansion of concretes caused by alkali-silica reaction (ASR) and the effects to avoid ASR by using SCMs in more details. Therefore, dissolution experiments in alkaline solutions under different pH values and different temperatures were performed using aggregates in the original grain size and SCMs in different ratios. The concentrations of soluble silica and additionally alumina were determined by ICP-OES. The investigations showed that up to now the “best” conditions to explain the damage behavior of concrete structures are a pH value of 13 (e.g. 0.1 M KOH solution) and a temperature of 80 °C. The evaluation bases on the parameter “excess silica” which is calculated from the dissolved silica and alumina of the aggregates and the SCMs. It was demonstrated that SCMs reduce and sometimes stop the dissolution of aggregates. The efficiency of the SCMs depends on their amount and chemical composition.

Fiber-reinforced polymer (FRP) reinforcement for concrete has gained popularity in the past two decades due to its high strength, cyclic load resistance, and insensitivity to chloride corrosion. This paper presents the results of an experimental evaluation of FRP reinforcing bars made completely from recycled materials with two surface conditions: externally bonded helical glass rovings and lathed circumferential grooves. Tensile testing indicated that only grooved bars provided adequate bonding within concrete systems due to bond failure of the external helical rovings under tensile loading. The performance of 1.0 m (39.4 in.) hollow beams reinforced with grooved recycled bars, commercially available FRP bars, and #2 (6.4 mm or 0.25 in.) steel bars was evaluated. Recycled and commercial FRP-reinforced beams had nearly identical performance, indicating that the recycled bars are feasible for use as reinforcement in concrete, although neither FRP-reinforced beam performed as well as steel-reinforced beams.

Editors: V. Mohan Malhotra, Pawan R. Gupta, Terence C. Holland

The Canada Center for Mineral and Energy Technology (CANMET) of Natural Resources of Canada, Ottawa, has played a significant role for more than 40 years in the broad area of concrete technology in Canada. In recent years CANMET has become increasingly involved in research and development dealing with the supplementary cementing materials, high-performance normal weigh and lightweight concretes, and alkali-aggregate reactions. As part of CANMET’s technology transfer program, an international symposium on Advances in Concrete Technology was sponsored jointly with the American Concrete Institute (ACI) and other organizations in Athens, Greece, May 1992. In June 1995 CANMET, in Association with ACI and other organizations in Canada and the U.S., sponsored the Second CANMET/ACI International Symposium on Advances in Concrete Technology in Las Vegas, Nevada. For the Athens symposium, the CANMET publication, “Advances in Concrete Technology,” constituted the proceedings of the symposium. Proceedings from the Las Vegas symposium were published by ACI as SP-154.

In August 1997, CANMET, in association with ACI and other organizations in Canada and New Zealand, sponsored the Third CANMET/ACI International Symposium on Advances in Concrete Technology in Auckland, New Zealand. The main purpose of the symposium was to bring together representatives from industry, universities, and government agencies to present the latest information in concrete technology, and to explore research and development. Thirty-three refereed papers from 15 countries were presented and distributed at the symposium. Proceedings were published as ACI SP-171.

In June 1998, CANMET, in association with ACI, Japan Concrete Institute (JCI), and several other organizations in Canada and Japan, sponsored the Fourth CANMET/ACI International Conference on Recent Advances in Concrete Technology in Tokushima, Japan. More than 80 papers from 20 countries were received and reviewed in accordance with the policies of ACI. Sixty-one refereed papers were accepted for presentation at the conference and for publication as ACI SP-179. In addition to the refereed papers, more than 30 more papers were presented and distributed at the symposium. In July-August 2001, CANMET, in association with ACI and several organizations in Singapore, sponsored the Fifth CANMET/ACI International Conference on Recent Advances in Concrete Technology in Singapore. More than 100 papers from more than 25 countries were received and reviewed in accordance with the policies of ACI. Forty-six refereed and more than 25 additional papers were accepted for presentation at the conference and published as ACI SP-200. In June 2003 CANMET, in association with ACI and several organizations in Romania, sponsored the Sixth CANMET/ACI International Conference on Recent Advances in Concrete Technology in Bucharest, Romania. More than 40 papers presented at the conference were distributed “as received,” and no formal ACI special publication was published.

In May 2004, CANMET, in association with ACI and several organizations in the U.S., sponsored the Seventh CANMET/ACI International Conference on Recent Advances in Concrete Technology in Las Vegas, Nevada. Seventeen refereed papers from more than 10 countries were presented and distributed at the conference. The proceedings, consisting of refereed papers, were published as ACI SP-222. In addition to the refereed papers, 20 additional papers were presented and distributed at the conference.

In May 2006, CANMET, in association with ACI and several organizations in Canada and the U.S., sponsored the Eighth CANMET/ACI International Conference on Recent Advances in Concrete Technology in Montreal, Canada. Proceedings of the conference, consisting of 17 refereed papers, were published as ACI SP-235. In addition to the refereed papers, more than 30 additional papers were presented and distributed at the conference.

In May 2007, CANMET, in association with ACI and several organizations in Canada, Europe, and the U.S., sponsored the Ninth CANMET/ACI International Conference on Recent Advances in Concrete Technology in Warsaw, Poland. Proceedings of the conference consisted of 10 refereed papers that were published as ACI SP-243. More than 20 additional papers were presented and distributed at the conference. In October 2009, ACI, in association with several organizations in Canada, Europe and the U.S., sponsored the Tenth ACI International Conference on Advances in Concrete Technology in Seville, Spain. Proceedings of the conference consisting of 20 refereed papers that were published as ACI SP-261. In addition to the refereed papers, more than 20 additional papers were presented at the conference and published in a Supplementary Papers Volume.

In May 2010, the Committee for the Organization of International Conferences (COIC) (formerly CANMET/ACI Conferences), in association with the Chinese Ceramics Society (CCS) and several other organizations in China, sponsored the Eleventh International Conference on Advances in Concrete Technology and Sustainability Issues in Jinan, China. More than 40 papers were presented at the conference. The proceedings of the conference were published by the (CCS), Beijing, China.

In October 2012, the COIC, in association with ACI, sponsored the Twelfth International Conference on Advances in Concrete Technology and Sustainability Issues in Prague, Czech Republic. The proceedings of the conference consisted of more than 30 refereed papers that were published as SP-288. In addition to the refereed papers, more than 40 other papers were presented at the conference and were published in the Supplementary Papers Volume.

In July 2015, the (COIC), in association with the ACI sponsored the Thirteenth International Conference on Advances in Concrete Technology and Sustainability Issues in Ottawa, Canada. The proceedings of the conference consisting of 28 refereed papers were published by the ACI as SP-303. In addition to the refereed papers, more than 40 other papers were presented at the conference and were published in the Supplementary Papers Volume.

Many thanks are extended to the members of the Technical Paper Review Panel who met in Bahamas in October 3 to 11, 2014 to review the papers. Without their dedicated efforts, it would not have been possible to publish the proceedings for distribution at the conference. The cooperation of the authors in accepting the reviewers’ suggestions and in revising the manuscripts accordingly is greatly appreciated.

The help and assistance of Dr. Pawan R. Gupta and Prabha Gupta are gratefully acknowledged in the administrative work associated with the conference, and processing of the manuscripts for both the ACI proceedings (SP-303) and the Supplementary Papers Volume.

Note: The individual papers are also available. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP-303

In the present study, the effects of porous ceramic waste aggregate (PCWA) on the mechanical properties and durability of the steam-cured fly ash concrete are investigated. The replacement ratios of fly ash were 0%, 20% and 40% by mass, and those of PCWA were 0%, 10% and 20% by volume. Three kinds of curing conditions: dried after steam curing (D-Steam), sealed after steam curing (S-Steam), and sealed curing (Sealed), were used. The experimental results show that the compressive strength of the fly ash concrete with 20% replacement of PCWA increased regardless of curing conditions, and the pore volume decreased. The autogenous shrinkage of the S-Steam cured fly ash concrete was reduced significantly by using 20% replacement of PCWA. The carbonation resistance of the D-Steam cured fly ash concrete was also improved by using 10% replacement of PCWA and 40% replacement of fly ash.

Durability based design of RC structures has gained great significance in recent decades and various mathematical models have been proposed. One of the famous models was proposed by fib. The effect of local conditions on the prediction of the models is one of the most important issues. Hence, regional investigations are necessary. The Persian Gulf is one of the most aggressive regions of the world. In this study, the fib model performance was evaluated by comparison with field measurements on some marine RC structures located in this region. The results show that the parameters in the fib model did not result in good agreement with some of field data. The model parameters were modified for application to this environment. In order to do this, a laboratory study was performed and nine different concrete mixtures with various percentages of silica fume were prepared. Evaluation of the modified model results shows that the modifications produced more reliable results than the original model for this environment.