International Concrete Abstracts Portal

International Concrete Abstracts Portal

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.

Showing 1-5 of 51 Abstracts search results

Document: 

SP320

Date: 

September 1, 2017

Author(s):

Arezki Tagnit-Hamou

Publication:

Symposium Papers

Volume:

320

Abstract:

The purpose of this international conference is to present the latest scientific and technical information in the field of supplementary cementitious materials and novel binders for use in concrete. The new aspect of this conference is to highlight advances in the field of alternative and sustainable binders and supplementary cementitious materials, which are receiving increasing attention from the research community. The conference was held in Montréal, Canada from October 2 to 4, 2017. The conference proceedings, containing 50 refereed papers from more than 33 countries, were published as ACI SP-320.

DOI:

10.14359/51701166


Document: 

SP-320_28

Date: 

August 1, 2017

Author(s):

Evin Dildar Dzaye, Geert De Schutter, and Dimitrios Aggelis

Publication:

Symposium Papers

Volume:

320

Abstract:

Studying the mechanisms affecting the very early age hydration as well as the microstructure of cementitious materials is essential to improve concrete performance. Consequently, it is necessary to monitor and understand the early age hydration process. In this work, continuous acoustic emission (AE), ultrasonic pulse velocity (UPV), and capillary pressure monitoring has been applied on consolidated and non-consolidated cement paste to study the process of hydration mechanism as well as the formation of the microstructure. Preliminary experiments have presented a large rate of AE activities in the fresh state. Ultrasonic tests exhibited an increase of pulse velocity during hydration while capillary pressure and heat evolution were also monitored. The purpose of this study is to verify the sensitivity of AE to follow the ongoing processes in fresh cementitious material and the possibility to contribute to a better monitoring of the process as an additional tool.

DOI:

10.14359/51701066


Document: 

SP-320_24

Date: 

August 1, 2017

Author(s):

Tahar Tioua, Abdelouahed Kriker, Abderrahim Bali, Gonzalo Barluenga and Mourad Behim

Publication:

Symposium Papers

Volume:

320

Abstract:

An experimental study was carried out to assess the effect of low volumetric fractions of short natural date palm fibers (DPF) compared to polypropylene fibers (PPF) on self-compacting concrete (SCC) flowability and hardened properties. Fibers can reduce concrete shrinkage cracking at early age and enhance other hardened concrete properties, although reducing other characteristics as SCC flowability. The use of DPF instead of PPF has two advantages: their use in construction provides new outlets for low cost agricultural resources, and the valorization of natural fibers allows to reduce environmental impacts, since these are renewable raw materials and need little energy to be produced. Slump flow, V-funnel and L box tests were used to assess flowability. Mechanical and physical properties, including compressive and flexural strength, were also measured. It was found that DPF can successfully replace PPF although DPF reduced SCC flowability slightly more than PPF, but produced similar effects in SCC hardened properties.

DOI:

10.14359/51701062


Document: 

SP-320_25

Date: 

August 1, 2017

Author(s):

Oscar A. Mendoza Reales, Emílio C. C. M. Silva, Maria D. M. Paiva, Pedro Duda, and Romildo Dias Toledo Filho

Publication:

Symposium Papers

Volume:

320

Abstract:

Nanoparticles have a great influence on the rheology of cement matrices due to their inherent physical and chemical properties. This work quantifies the relation between matrix rheology and surface area of nanoparticles (carbon nanotubes, nanosilica and nanoclay), by comparing them with the effects of some equivalent microparticles (microsilica and metakaolin). Class G cement pastes blended with micro- or nanoparticles were prepared using a water-to-cementitious material ratio of 0.45 and a viscosity modifying agent to prevent segregation and settlement. Static yield stress, dynamic yield stress, and plastic viscosity were determined to characterize the rheology. The first was measured directly, while the other two were obtained by fitting a Bingham model to the descending portion of a flow curve. It was found that micro- and nano- particle substitutions of similar composition and surface area have similar effects on the rheological parameters, indicating that the influence of nanoparticles is mainly governed by their specific surface area.

DOI:

10.14359/51701063


Document: 

SP-320_26

Date: 

August 1, 2017

Author(s):

Rolf Andreas Lauten

Publication:

Symposium Papers

Volume:

320

Abstract:

Characteristics of a sodium carbonate-activated slag concrete in presence of different plasticizers are presented and discussed. Inclusion of a calcined clay in the activator system allows for a more rapid curing in a system that is known to cure slowly. Depending upon the plasticizer (lignosulfonate, polycarboxylate or naphthalene sulfonate), slump retention is either improved relative to the control or inferior. Compressive strength of concrete prisms can be recorded after 24 hours, but set times determined from temperature as a function of curing time indicate longer set times. The longest slump retention is obtained with lignosulfonate, and the compressive strength at 28 days is comparable among the three plasticizers. Surprisingly, lignosulfonate appears to be as efficient as the other plasticizers when it comes to fluidization of the concrete mixes.

DOI:

10.14359/51701064


12345...>>

Results Per Page 




Edit Module Settings to define Page Content Reviewer