ABOUT THE 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.

International Concrete Abstracts Portal

Showing 1-5 of 225 Abstracts search results

Document: 

20-130

Date: 

March 1, 2021

Author(s):

Kai Wu, Jianan Xu, Feng Chen, Chuyang Chen, and Zhigang Chai

Publication:

Materials Journal

Volume:

118

Issue:

2

Abstract:

The reinforcing bar cages in concrete-encased steel (CES) structures are replaced with steel fibers to form the steel fiber-reinforced concrete-encased steel (SFRCES) structures, which can avoid common difficulties in the construction of a traditional CES structure. To study the bonding properties and interfacial damage between shaped steel and steel fiber-reinforced concrete (SFRC), the pushout tests of 16 specimens were conducted. Main parameters including steel fiber ratio (ρsf) (0, 1, 2, and 3%), thickness of concrete cover (Css), and effective bonding length (Le) of specimens were considered. In this paper, some important performance indicators are obtained, such as P-S curves, bonding strength, interfacial energy dissipation, and interfacial damage variables. The experimental results show that the P-S curves at the loading end and free end have the greatest difference under the peak load. A higher ρsf has a stronger constraint effect on concrete cracks, which leads to better post-peak bonding behavior. A bigger Css can delay the interfacial damage in the middle and late stages of the test. A larger Le means more elastic deformation energy can be stored at the interface, so the damage variable increases at a slower pace.

DOI:

10.14359/51730413


Document: 

20-085

Date: 

January 1, 2021

Author(s):

Mohammed Farooq and Nemkumar Banthia

Publication:

Materials Journal

Volume:

118

Issue:

1

Abstract:

The influence of factors such as cementitious matrix characteristics, fiber inclination, and temperature on the interfacial bond between fiber-reinforced polymer (FRP) fibers and cementitious matrix are studied herein. It was noticed that use of glass fibers in the form of glass FRP (GFRP) composite fiber greatly improved the bonding mechanism over using just constituent glass fibers. With matrix maturity, a steady increase in bond was observed with over 60% bond strength achieved within a day. Densification of the cementitious matrix with the addition of silica fume was found to greatly increase the interfacial bond and changed the failure mode from fiber pullout to fiber rupture and delamination. At inclined loading as well, a different failure mode in the form of fiber rupture after partial pullout was noticed. This change in failure mode from fiber pullout to fiber rupture was also accompanied by a lower apparent tensile strength at large inclination. At lower temperature of –20°C, the bond between FRP fibers and the cement matrix was found to improve, but increased brittleness in fibers was also noted. At higher temperatures, FRP fibers performed satisfactorily up to 80°C, after which a gradual degradation in bond was observed.

DOI:

10.14359/51725996


Document: 

20-080

Date: 

January 1, 2021

Author(s):

Ângela Costa Piccinini, Luiz Carlos Pinto da Silva Filho, and Américo Campos Filho

Publication:

Materials Journal

Volume:

118

Issue:

1

Abstract:

This research evaluated the bond behavior of reinforcement and the mechanical characteristics in a reactive powder concrete (RPC) replacing 35% cement with blast-furnace slag. Pullout tests were performed at the ages of 3, 7, 28, 56, 63, and 91 days on cylindrical samples. The embedded length used was double the diameter of the bar. At 3 days it presented compressive strength of 41% of the maximum obtained, which was 123.06 MPa at 91 days. There was an increase in strength until the age of 56 days and after stabilization of the curves. In pullout tests, it was noticed the considerable influence of the rib, because in tests with plain bars, the bond force was below 20% of the results with ribbed bar, which reached 54.38 MPa of strength. The compression curve was similar to the bond curve. Underestimated values were observed when the researchers’ equations were applied to calculate the maximum bond strength.

DOI:

10.14359/51725995


Document: 

19-512

Date: 

November 1, 2020

Author(s):

Job Thomas, Ardra Mohan, and Dhannya K. K.

Publication:

Materials Journal

Volume:

117

Issue:

6

Abstract:

In this study, copper slag and lime-activated fly ash were used for the manufacturing of cold-bonded aggregates. Cold-bonded copper slag fly ash (CSFA) aggregates were manufactured by varying copper slag content. The aggregate type with 37.5% copper slag and 62.5% fly ash showed optimum strength properties and was selected for the production of CSFA aggregate concrete. The strength and durability properties of concrete with a varying replacement ratio of CSFA aggregate from 0 to 100% at normal temperature and at elevated temperatures of 200, 400, and 600°C were investigated. The results show that concrete containing CSFA aggregate can be ideally used as a construction material up to a temperature of 400°C and as 100% replacement for coarse aggregate. A prediction model has been formulated using multiple regression analysis for the mechanical strength properties of concrete at different replacement ratios and exposure temperatures. A mixture design methodology is also proposed for the concrete containing CSFA aggregates.

DOI:

10.14359/51727000


Document: 

19-358

Date: 

September 1, 2020

Author(s):

Christoph Mahrenholtz and Akanshu Sharma

Publication:

Materials Journal

Volume:

117

Issue:

5

Abstract:

The world becomes ever smaller and thus the global construction industry moves closer together. For this reason, civil engineers are looking for possibilities to harmonize design—for example, in the field of reinforced concrete structures. The streamlining would ease working in an international context and could offer opportunities for optimization: harmonization allows the identification of the technically best and most economical solution. This also holds for the provisions to calculate the development length of deformed reinforcing bars which, to date, differ notably from code to code. It is not reasonable that local codes define different development lengths for identical situations in terms of geometry and material used. This paper analyzes the provisions for the calculation of the development lengths according to internationally selected national codes as a basis for this discussion.

DOI:

10.14359/51725782


12345...>>

Results Per Page 




Please enter this 5 digit unlock code on the web page.