International Concrete Abstracts Portal

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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 1-10 of 706 Abstracts search results

Document: 

CI4108Spotlight_1129B

Date: 

August 1, 2019

Publication:

Concrete International

Volume:

41

Issue:

8

Abstract:

Selecting a curing method for concrete depends on product type and local climate conditions. Polarmatic Oy from Tampere, Finland, provides thermal-energy units for various curing applications including warm, moist air; circulating warm water; and turbosteam. A Polarmatic unit is used by a precast concrete producer in Canada for heating aggregates, curing concrete, heating mixing water, and heating its buildings.


Document: 

CI4108NPCASustainabilityAwards

Date: 

August 1, 2019

Publication:

Concrete International

Volume:

41

Issue:

8

Abstract:

The Sustainability Awards program of the National Precast Concrete Association (NPCA) recognizes member companies for contributing to sustainable construction projects and for instituting sustainable practices in their plants.


Document: 

CI4107Q&A

Date: 

July 1, 2019

Author(s):

Donald F. Meinheit and Loring A. Wyllie Jr.

Publication:

Concrete International

Volume:

41

Issue:

7

Abstract:

Q: We are planning to use threaded reinforcing bars as anchor rods for connection of base plates (of steel or precast columns) to cast-in-place foundation elements. We intend to specify that the bars are supplied with threaded heads. In ACI 318-14,1 it seems that the design of headed reinforcing bars could be governed either by Chapter 25—Reinforcement Details or Chapter 17—­Anchoring to Concrete. However, the headed reinforcing bars shown in the commentary of Chapter 25 appear to be used in joints of concrete elements (for example, a beam framing into a wall or column) and subjected primarily to tension forces. In our application, the bars will anchor steel or precast elements to concrete and are subjected to tension forces, shear forces, or both. Can we use the provisions in Chapter 25 to design the anchor rods?


Document: 

CI4102Powell

Date: 

February 1, 2019

Author(s):

Leahann E. Powell, Timothy Barnard, and Shiraz Tayabji

Publication:

Concrete International

Volume:

41

Issue:

2

Abstract:

The article provides details of rapid rehabilitation of a bridge approach slab on I-10 near Quincy, FL, using precast concrete panels. The existing cast-in-place approach slab had been in service since the bridge was constructed in 1976, and it was exhibiting cracking and settlement. The rehabilitation only required a total of 2.5 days to allow for continuous construction during the two travel lane panel placements, all the time maintaining one lane open for traffic.


Document: 

SP327-39

Date: 

November 1, 2018

Author(s):

Mohanad M. Abdulazeez, Ahmed Gheni, Omar I. Abdelkarim, and Mohamed A. ElGawady

Publication:

Special Publication

Volume:

327

Abstract:

This paper presents the seismic behavior of two large-scale hollow-core fiber-reinforced polymer-concrete-steel (HC-FCS) precast columns having two different footing connections. The precast HC-FCS column consists of a concrete shell sandwiched between an outer fiber-reinforced polymer (FRP) tube and an inner steel tube. The steel tube was embedded 635 mm (25 inches) into a reinforced concrete footing, while the outer FRP tube confined the concrete shell only i.e. it was truncated at the top surface of the footing. One connection included embedding the steel tube into the footing. The other one included using a corrugated steel pipe (CSP) embedded into the concrete footing outside the steel tube to achieve better confinement. This study showed that the connection including the CSP is deemed satisfactory and was able to develop the plastic flexural capacity of the HC-FCS column providing good ductility and energy dissipation compared with the other connection type.


Document: 

SP327-33

Date: 

November 1, 2018

Author(s):

Mamdouh El-Badry, Mohammad Moravvej, and Parham Joulani

Publication:

Special Publication

Volume:

327

Abstract:

An experimental evaluation of a hybrid FRP-concrete slab-on-truss girder bridge system is presented. The girders consist of pretensioned top and bottom concrete chords connected by vertical and diagonal truss members made of concrete-filled fiber-reinforced polymer (FRP) tubes. The truss members are connected to the chords by means of long double-headed glass FRP (GFRP) bars. The chords are also reinforced with GFRP longitudinal bars and transverse stirrups. The deck slab is connected to the top chords of the girders using double-headed GFRP studs. The truss girders are thus lighter and more durable than the conventional precast I-girders. The experimental program consisted of fabricating and testing eight full-scale truss girders including four 2.83-m (9.28-ft) long 2-panel trusses and four 9.82-m (32.22-ft) long 8-panel trusses, all having the same cross-section dimensions with 1.32-m (4.33-ft) overall depth. Two of the 2-panel and two of the 8-panel girders were reinforced with GFRP reinforcement. The remaining four were reinforced with steel and used as control specimens. Two of the 2-panel and two of the 8-panel girders were covered with a one-meter wide concrete slab connected to the girder top chord by either steel or GFRP double-headed studs. Tests under static loading showed excellent performance of the system in terms of strength and stiffness.


Document: 

CI4010Gillen

Date: 

October 1, 2018

Author(s):

Steve Gillen, Daniel J. Gancarz, and Shiraz Tayabji

Publication:

Concrete International

Volume:

40

Issue:

10

Abstract:

This article describes a recently implemented method for making rapid, full-depth repairs of continuously reinforced concrete pavement. The method is based on the use of precast concrete panels and it results in continuous longitudinal reinforcement throughout the repair area, making it suitable for the repair of multiple lanes or large areas, with minimal impact on traffic.


Document: 

SP-330-12

Date: 

September 26, 2018

Author(s):

Ricardo Remus, Christiane Roessler, and Horst‑Michael Ludwig

Publication:

Special Publication

Volume:

330

Abstract:

Power Ultrasound (PUS) is widely used in various technical processes (from pharmaceutic to ceramic and fuel industry) to disperse suspensions and to control crystallization processes. Previous investigations by the authors have shown that a short PUS treatment during mixing process effectively accelerates the growth of strength determining C-S-H phases and thus hydration and setting of Portland cement pastes.

The present study concerns the workability, the strength development and the durability of sonicated concretes. Results of study shows, that flowability is increased after sonication and stiffening of cement paste can be fully compensated. The strength development is significantly accelerated and durability testing on sonicated concretes reveals that negative effects of PUS on carbonation behaviour, freezing/thawing- and sulphate-resistance can be excluded. The advantage of using PUS to accelerate early-strength development of concrete is that little or no chemical accelerators or heat treatment are required. Enhancement of cement reactivity by PUS application during mixing possibly paves the way for application of cements with low CO2-footprint for precast concrete production.


Document: 

SP328-01

Date: 

September 12, 2018

Author(s):

Rico J. Massa, William D. Cook and Denis Mitchell

Publication:

Special Publication

Volume:

328

Abstract:

An experimental program was carried out on full-scale precast pretensioned I-girders to study the influence on the shear response of carbon fiber reinforced polymer (CFRP) shear strips epoxied to the sides of the girders. The test program demonstrated that the CFRP shear strips were effective in increasing the shear strength of the webs and in controlling the shear crack widths. The shape of the I-girders makes it difficult to properly anchor the vertical shear strips. The curved epoxy transitions between the web and the flanges at the re-entrant corners together with the use of horizontal CFRP strips in the regions of the re-entrant corners helped to improve the anchorage of the vertical CFRP strips. The shear resistance components from the concrete, the stirrups and the CFRP shear strips, were determined experimentally and compared with analytical predictions. The results from this experimental study are compared with the test results from other researchers. The design approach of the 2014 Canadian Highway Bridge Design Code provides conservative estimates of the shear strength of the webs.


Document: 

CI4009Klinger

Date: 

September 1, 2018

Author(s):

James Klinger, Frank Salzano, Tim Manherz, and Bruce A. Suprenant

Publication:

Concrete International

Volume:

40

Issue:

9

Abstract:

Embedded steel plates with headed studs (embeds) serve as connections to structural steel framing, façade and curtain wall systems, elevator rails, steel or precast stairs, mechanical-electrical-plumbing components, and miscellaneous additional items. The need to coordinate with other trades, tolerance conflicts, and other issues can make embed placement difficult for the concrete contractor. Members of the American Society of Concrete Contractors (ASCC) provide recommendations directed at ways that design and construction teams can improve the constructability of embeds.


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