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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 1-5 of 44 Abstracts search results

Document: 

18-518

Date: 

November 1, 2019

Author(s):

M. R. Sakr, M. T. Bassuoni, and M. Reda Taha

Publication:

Materials Journal

Volume:

116

Issue:

6

Abstract:

In this study, different types of surface coatings were applied to concrete to assess their suitability for resisting physical salt attack (PSA). Concretes with different water-binder ratios (w/b) were tested and severe PSA conditions were implemented, using sodium sulfate, to obtain conclusive trends on the performance of coatings. Visual assessment and mass loss of concrete specimens were used as physical indicators to quantify the damage, while mineralogical and microstructural studies were conducted to elucidate the damage mechanisms. Epoxy, ethyl silicate, and acrylic emulsion coatings were found successful at protecting concrete from PSA regardless of the quality of the substrate concrete, while other coatings tested were highly dependent on the concrete quality. Coatings that permit a high rate of absorption and/or desorption (evaporation) led to more severe PSA damage compared with coatings with low absorption/desorption.

DOI:

10.14359/51718058


Document: 

18-457

Date: 

November 1, 2019

Author(s):

Félix-Antoine Villemure, Mathieu Fiset, Josée Bastien, Denis Mitchell, and Benoit Fournier

Publication:

Materials Journal

Volume:

116

Issue:

6

Abstract:

Installation of drilled-in epoxy-bonded reinforcing bars is generally an effective strengthening method to increase the flexural and shear capacities of deficient concrete structures. However, most of the available studies characterizing the bond behavior of epoxy bonded bars in concrete have been carried out on sound concrete elements—that is, without any pathological material damage. This raises the question of bond capacities in existing damaged elements. This study investigates the influence of alkali-silica reaction (ASR) on the capacity of post-installed reinforcing bars. ASR is a deleterious mechanism that causes expansion and cracking in the affected concrete elements. Pullout tests on post-installed reinforcing bars having embedded lengths of 2db, 4db, and 5db with 15M reinforcing bars (db = 15.9 mm [0.626 in.]) have demonstrated a drop-in bond strength when concrete is affected by ASR. In addition, the study revealed that the progression of concrete expansion due to ASR may lead to some confinement of the post-installed reinforcing bar and possibly increases the bond strength.

DOI:

10.14359/51719069


Document: 

17-113

Date: 

September 1, 2018

Author(s):

A. Macanovskis, A. Lukasenoks, A. Krasnikovs, R. Stonys, and V. Lusis

Publication:

Materials Journal

Volume:

115

Issue:

5

Abstract:

Concrete beams reinforced by short composite macrofibers uniformly distributed in their volume were tested mechanically in bending. The short composite macrofibers were a few centimeters long and less than 2.5 mm (0.01 in.) in diameter. Macrofibers were manufactured impregnating glass or carbon-fiber tows by epoxy resin, forming unidirectionally oriented composite material rods later cut in short pieces. Such fibers were designated in the framework of the paper as macrofibers. The length-to-diameter ratios L/d of the glass and carbon macrofibers were equal to 22.9 and 28.2, respectively. The beams were loaded until the opening of the macrocrack reached 5 mm (0.02 in.). The macrofibers bridging the crack were pulled out during opening of the crack. Low-, medium-, and high-strength concretes in the range of 40 to 120 MPa (5800 to 17,405 psi) were used in the experiments. Pullout tests with single fibers were carried out. The volume fraction of the fibers in concrete was 1.5%. Two types of fiber-reinforced concrete beams with glass and carbon fibers were manufactured and tested, and the data obtained were compared with experimental results for steel fiber-reinforced concrete beams. The potential of the composite fibers was analyzed.

DOI:

10.14359/51702343


Document: 

17-003

Date: 

November 1, 2017

Author(s):

Ruohong Zhao, Christopher Y. Tuan, Daobo Fan, An Xu, and Bao Luo

Publication:

Materials Journal

Volume:

114

Issue:

6

Abstract:

An innovative conductive composite, ionically conductive mortar, is developed in this study. The directional migration of ions under external voltage makes the mortar conductive. The electrical resistance of the mortar causes the mortar to generate heat, which is used for deicing. To ensure conductivity, the number of free ions and the moisture content in the mortar must stay relatively high. The specimens were soaked in electrolyte solutions for 96 hours to saturation and coated with epoxy resin. Subsequent electrical heating tests showed that the specimens could achieve a heating rate of 19.7°C (35.5°F) in 120 minutes under 30 V AC. This heating performance would improve with increasing applied voltage.

DOI:

10.14359/51700897


Document: 

16-185

Date: 

July 1, 2017

Author(s):

Vahab Toufigh, Mostafa Jafarian Abyaneh, and Khashayar Jafari

Publication:

Materials Journal

Volume:

114

Issue:

4

Abstract:

In this investigation, polymer concrete (PC) with three different epoxy resin contents, ordinary cement concrete (OCC), lightweight concrete (LWC), and lime-mortar soil (LMS) have been studied under uniaxial and triaxial compression tests to determine their mechanical behavior by measuring axial stress-strain and volumetric strain versus axial strain curves. According to the results, PC showed higher strength, ductility, and energy absorption than that of OCC and LWC. Then, nonlinear finite element analysis (NFEA) was implemented to predict the experimental results using hierarchical single-surface (HISS) failure criterion and disturbed state concept (DSC) to capture the elastoplastic behavior of concrete materials including volumetric strain. Moreover, the pattern of failure was estimated using ultimate disturbance values obtained from the model, followed by comparison with the experimental and Mohr-Coulomb failure patterns. The proposed model is applicable to a variety of materials with different behavior, and its prediction is in good accordance with experimental results.

DOI:

10.14359/51689716


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