ACI Global Home Middle East Region Portal Western Europe Region Portal
Email Address is required Invalid Email Address
In today’s market, it is imperative to be knowledgeable and have an edge over the competition. ACI members have it…they are engaged, informed, and stay up to date by taking advantage of benefits that ACI membership provides them.
Read more about membership
Learn More
Become an ACI Member
Topics In Concrete
Home > Publications > International Concrete Abstracts Portal
Showing 1-5 of 35 Abstracts search results
Document:
SP289
Date:
October 1, 2012
Author(s):
Editors: Terence C. Holland, Pawan R. Gupta, V.M. Malhotra
Publication:
Symposium Papers
Volume:
289
Abstract:
This CD contains the proceedings from the Twelfth International Conference on Recent Advances in Concrete Technology and Sustainability Issues held in Prague, Czech Republic, in October 2012. The 34 papers include Advances in Geological CO2 Sequestration and Co-Sequestration with O2; Self-Compacting High-Performance Concretes; Dynamic Performance of Eco-Friendly Prestressed Concrete Sleeper; Parameters Influencing the Performance of Shrinkage-Compensating Concrete, and much more. 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-289
DOI:
10.14359/51684136
SP289-34
September 14, 2012
Silvia Collepardi, Mario Collepardi, Giacomo Iannis, and Alessandro Quadrio Curzio
Ground bottom ash (GBA) from Municipal Solid Wastes Incinerators (MSWI) does not perform as well as other mineral additions -such as silica fume or fly ash produced by coal burning- due to the presence of aluminium metal particles which react with the lime formed by the hydration of portland cement and produce significant volume of hydrogen in form of gas bubbles which increase the porosity of concrete and reduce its strength. Due to this drawback, a new process was developed to separate the aluminium metal particles through a mechanical removal of metals and a wet grinding of bottom ashes. At the end of the process, GBA was used as aqueous slurry to replace portland cement. In the present work GBA with a maximum size of 1.7 mm (0.07 min) was used to replace about 10% of portland cement in self-compacting concretes (SCC). Mixtures with shrinkage-reducing admixture (SRA) and a CaO-based expansive agent were also manufactured to reduce the drying shrinkage and the related cracks. Moreover, an alternative way to reduce both number and length of cracks was adopted by using SRA combined with polyvinyl alcohol (PVA) macrosynthetic fibres. Corresponding mixtures with silica fume or fly ash were also manufactured. GBA performed as well as silica fume in terms of mechanical properties, durability and crack behavior, and much better than fly ash.
10.14359/51684283
SP289-32
Peter Paulik, Michal Panik, and Vladimír Necas
Nowadays, many nuclear power plants are approaching their designed lifetime and the question of their decommissioning is being increasingly discussed. In connection with the dismantling of the nuclear facilities large quantities of typical decommissioning waste material are produced. Among this waste material, there is a significant amount of radioactive steel. Its level of radioactivity just slightly exceeds the regulatory limits set for unconditional release into the environment and, moreover, contains radionuclides with relatively short half-life. Disposal of all this kind of steel in specialized repositories would require considerable financial investments. Therefore, re-melting and reuse of this steel in the construction of bridges seems like an advantageous alternative. The article deals particularly with the possibilities of using slightly radioactive steel in concrete bridges construction and the risks related to this issue.
10.14359/51684281
SP289-33
Amor Ben Fraj, Mohamed Miraoui, Frederic Boinski, and Pierre Mounanga
This study examines the early-age and durability properties of mortars made with Dredged Marine Sand (DMS). Both physical and mechanical properties of the DMS mortars were investigated and compared to those of mortar prepared with conventional aggregates. Results showed that the substitution of Standardized Sand (SS) with DMS had no significant effect on mortar hydration. For a rate substitution of 25%, the mechanical properties of mortars increased, particularly in case of air curing. The increasing of substi¬tution rate of SS with DMS, slightly decreased the mortar density and increased entrapped air and total porosity. For a substitution rate of 50% and more, a decrease of the mechanical properties was measured. Chloride migration coefficients of tested mortars followed similar trends.
10.14359/51684282
SP289-29
W. Siriwatwechakul, J. Siramanont, and W. Vichit-Vadakan
The use of superabsorbent polymers as internal curing agents in high performance concrete has gained much interest in research and slowly gaining interest among industrial producers. Although there have been many publications on the microstructure of internally cured system, little interest has developed in the actual mechanisms of absorption and desorption of superabsorbent polymers in high pH systems and how they are related to the structure of the polymers themselves. Results in the literature indicate that the polymer structure actively interacts with the ions present in the solvent, which results in a strong ion filtration effect. This paper demonstrates that this ion filtration effect is due to electrostatic interaction. The timing and dominance of this effect can heavily influence the effectiveness in internal curing. In particular, concrete containing superabsorbent polymers demonstrate different strength gain behaviors when cured in lime-saturated water.
10.14359/51684278
Results Per Page 5 10 15 20 25 50 100
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.
Edit Module Settings to define Page Content Reviewer