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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 30 Abstracts search results

Document: 

19-012

Date: 

January 1, 2020

Author(s):

Gabriel W. Cook and Cameron D. Murray

Publication:

Materials Journal

Volume:

117

Issue:

1

Abstract:

Belitic calcium sulfoaluminate cement (BCSA) is a hydraulic, rapid-setting alternative to ordinary portland cement (OPC) with reduced energy demands and CO2 emissions. BCSA cement has numerous current and potential applications, including transportation repair and precast manufacturing. Currently, limited research exists regarding the structural performance of BCSA cement concrete, restricting its potential implementation. Thus, the purpose of this research is to provide insight into the flexural performance and behavior of reinforced BCSA concrete beams. Overall, BCSA concrete had similar cracking and loading behavior to the OPC beams, with increased moment capacity for compression-controlled specimens. Furthermore, BCSA cement concrete showed increased tensile strength and ductility when compared to OPC. Overall, the flexural strength of the BCSA cement concrete was higher than the control OPC concrete and the predicted flexural strength based on compressive strength, indicating the current flexural strength equations are applicable for BCSA reinforced concrete design.

DOI:

10.14359/51719074


Document: 

17-254

Date: 

May 1, 2019

Author(s):

Duo Zhang and Yixin Shao

Publication:

Materials Journal

Volume:

116

Issue:

3

Abstract:

Carbonation curing has demonstrated potential of improving concrete performance while facilitating carbon dioxide utilization. However, reinforcement corrosion behavior in carbonation-cured concrete has not been documented. This paper presents a study on chloride-induced corrosion in reinforced concrete subjected to carbonation curing. A special carbonation curing process was developed for precast non-prestressed applications. Performance of carbonation curing was evaluated by concrete compressive strength, pH value, and carbon dioxide uptake, while corrosion resistance of the carbonation-cured concrete was assessed by reinforcing bar mass loss and concrete chloride content. To understand the mechanism, concrete and cement paste were further characterized using mercury intrusion porosimetry, absorption, and electrical resistivity tests. Micromorphology was assessed by scanning electron microscopy. It was found that apart from rapid early-age strength gain, carbonation curing could significantly reduce chloride permeation in concrete concerning both total and free chloride contents. It was attributed to the reduced pore size and pore volume by calcium carbonate precipitation. With subsequent 28-day hydration, the carbonation-cured concrete displayed a pH over 12.0 at the surface of steel reinforcing bars and a micromorphology similar to the non-carbonated reference. The direct corrosion tests showed that the corrosion-induced mass loss of steel reinforcing bar was lessened by 50% in concrete subjected to carbonation curing.

DOI:

10.14359/51714461


Document: 

16-183

Date: 

September 1, 2017

Author(s):

A. Gil, F. Pacheco, R. Christ, F. Bolina, K. H. Khayat, and B. Tutikian

Publication:

Materials Journal

Volume:

114

Issue:

5

Abstract:

There is still a concern regarding concrete structures’ fire safety, mostly due to the occurrence of concrete spalling. Although many tests have already been carried out, there is no clear definition about the parameters of the factors that influence its occurrence. This paper aimed to compare three different types of concrete panels, with dimensions of 300 x 315 x 10 cm (124.0 x 39.4 x 3.9 in.), composed of reinforced concrete (RC), prestressed concrete, and polypropylene microfiber RC. The panels were exposed to the standard fire curve based on ISO 834, aged 28 days, measuring the temperatures in panels’ surfaces. Prestressed concrete panels experienced explosive spalling 18 minutes after the test began. RC panels and the panels with polypropylene microfiber addition maintained their integrity and structural stability for 240 minutes, failing in the thermal insulation criteria at 210 and 140 minutes, respectively. Although polypropylene microfiber concrete panels presented no spalling of concrete, conventional concrete panels attended the standardized criteria for a longer period due to its better thermal insulation.

DOI:

10.14359/51689715


Document: 

15-449

Date: 

January 1, 2017

Author(s):

Gail M. Moruza and H. Celik Ozyildirim

Publication:

Materials Journal

Volume:

114

Issue:

1

Abstract:

The Virginia Department of Transportation (VDOT) incorporates innovative materials into its concrete structures to ensure durable and cost-effective infrastructure. However, poor consolidation can reduce the durability of VDOT concrete structures because it leads to unacceptable amounts of voids in hardened concrete that increase its permeability and reduces its strength. Self-consolidating concrete (SCC) that has high flow rates and the ability to move through congested reinforcement is a new addition to VDOT concretes; it facilitates placement, minimizes consolidation problems, and improves structure longevity. This paper summarizes VDOT’s use of SCC in bridge structures both in precast and castin-place applications. In precast applications, beams were fabricated with normalweight and lightweight SCC. In cast-in-place applications, drilled shafts, pier caps, and substructure repairs were cast with normalweight SCC. Summaries of field applications by VDOT as well as lessons learned through implementation are included in the paper.

DOI:

10.14359/51689480


Document: 

15-144

Date: 

July 1, 2016

Author(s):

M. J. Da Silva, B. P. De Souza, J. C. Mendes, G. J. S. Brigolini, S. N. Da Silva, and R. A. F. Peixoto

Publication:

Materials Journal

Volume:

113

Issue:

4

Abstract:

Proposed herein is the use of steelmaking slag as aggregates (SSA) for precast concrete elements used as permeable paving blocks (pavers). For this study, SSA was subjected to segregation of metallic and nonmetallic fractions—the latter being used in the present work. The SSA had its particle size distribution adjusted. Subsequently, it was physically and chemically characterized. Five mixtures were designed: four with SSA and one with natural aggregates as a reference mixture. The pavers built were characterized physically (expansion, morphology, porosity, water absorption, void content, and absolute density); environmentally (leaching and dissolution); and mechanically (compression and flexural strength). As result, SSA pavers showed physical, mechanical, aesthetic, and environmental characteristics significantly similar to the conventional ones, indicating its technical and environmental feasibility.

DOI:

10.14359/51688986


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