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International Concrete Abstracts Portal

Showing 1-5 of 10 Abstracts search results

Document: 

SP-307-06

Date: 

March 1, 2016

Author(s):

Ed McLean, Chris Ramseyer, and Seth Roswurm

Publication:

Symposium Papers

Volume:

307

Abstract:

In the modern transportation industry, nearly all bridge decks are constructed of concrete. Of the concrete bridge decks currently in service across the US, almost all contain large numbers of cracks. These cracks are the bane of deck longevity. They allow the ingress of salts that cause corrosion of the reinforcing steel, exacerbating concrete cracking and loss of structural capacity. A survey conducted several years ago by Folliard et al. (2004) for the FHWA found that more than 100,000 bridges suffered from early-age cracking. This paper presents a case study of bridge decks in Ohio and Michigan that are essentially crack-free. Some of these bridge decks are located on high volume highways/interstates and are up to 30 years of age. In addition, several of these bridges have adjacent standard Portland cement concrete sister bridges built at the same time, with identical spans and construction details handling traffic flowing in the opposite direction. Comparison of these bridges offers unique insight into a simple, effective solution for mitigation of bridge deck cracking.


Document: 

SP-307-05

Date: 

March 1, 2016

Author(s):

Edwin McLean and Seth Roswurm

Publication:

Symposium Papers

Volume:

307

Abstract:

Owners, engineers, and contractors have been forced to contend with drying shrinkage for as long as portland cement has been used in slabs-on-ground, containment structures, and other concrete elements. The resulting cracks and warping have long-lasting impacts on both the performance of the concrete and the lifetime maintenance cost. Various construction methods have historically been used to mitigate this issue including modified mix designs, curing compounds, joint detailing, and transfer devices to reduce warping (curling). With advances in type K shrinkage compensating cement technology, however, designers and contractors now have access to a concrete that can eliminate shrinkage cracks, extend joint spacing to extremes, vastly reduce costly joint construction, and shorten construction schedules. This solution reduces not only construction costs but also maintenance costs on the structure for years to come. Shrinkage compensating concrete (SCC) produced using ASTM C845 Type K cement has been used in floors, elevated building decks, bridge decks, post-tensioned concrete, and containment structures since the mid 1960’s. Today, Type K SCC cement technology is even better understood, making way for higher performing concrete elements.


Document: 

SP-307-07

Date: 

March 1, 2016

Author(s):

Chris Ramseyer, Kyle Renevier, and Seth Roswurm

Publication:

Symposium Papers

Volume:

307

Abstract:

Type K Shrinkage Compensating Concrete (SCC) concrete is uniquely suited for use in slabs and walls because it typically requires fewer expansion joints than a convention portland cement (PC) concrete. This allows for continuous placement of much larger slabs and walls and facilitates the construction of high performance smooth slabs with few interruptions. Typically shrinkage-compensating concrete construction practice is to pour adjoining wall sections a minimum of five days apart in order to allow for the initial expansion of the material. The need for unrestrained expansion is implied in the ACI 223R-10 Design Guide in Chapter 5 in a discussion on sequencing the placement of wall segments. This paper discusses testing that was performed at two different locations, spanning both two different times of year and two unique climates. The tests used vibrating wire strain gages (VWSG) to investigate the restrained behavior of a wall segment in a six million gallon clear well tank in Springfield, IL, as well as the unrestrained behavior of two slabs-on-grade in Los Angeles, CA. Measurements were taken for a minimum of 30 days and a maximum of 170 days. Testing results are then compared to similar scenarios using ordinary PC concrete.


Document: 

SP307

Date: 

March 1, 2016

Publication:

Symposium Papers

Volume:

307

Abstract:

Editor: Chris Ramseyer

With the exception of #9, these Papers were presented at: ACI National Convention, Fall 2012 Toronto, Canada. In the Technical Session Shrinkage Compensating Concrete – Past, Present, and Future Part 1 and Part 2.

This publication is dedicated to Edward K. Rice

Ed Rice has been involved in Shrinkage Compensating Concrete from its inception. As co-founder and President of T.Y. Lin and Associates from 1952 through 1970 Ed Rice promoted the novel use of concrete and concrete systems. As early as 1956 T.Y. Lin and Ed Rice provided the necessary funding for fundamental research by Alex Klein on expansive cements. This research led to the development of the Chemically Prestressed Concrete (CPC) co that was primarily in the pipe and roof slab business. In 1965 under Ed Rice’s direction as Chairman of CPC, Ed licensed Kaiser to run the first full scale burn at their Cushenberry cement plant and commercially produce the first shrinkage compensating concrete clinker in the world.

In the fifty years since the first production run of shrinkage compensating cement Ed Rice has consistently worked to advance concrete cement technology. He holds 22 US patents in the field of concrete and building technology. For the last forty years Ed Rice has led CTS Cement Manufacturing Co., the largest producer of shrinkage compensating cement in North America. Often Ed Rice worked behind the scenes helping to promote shrinkage compensating concrete and the work of younger engineers. Ed Rice has been a consistent and steady advocate for both increased research on the behavior of shrinkage compensating cements; and increased use of shrinkage compensating concrete to produce stable and durable concrete structures.

Note: The individual papers are also available. Please click on the following link to view the papers available, or call 248.848.3800 to order. SP-307


Document: 

SP-307-03

Date: 

March 1, 2016

Author(s):

Chris Ramseyer and Seth Roswurm

Publication:

Symposium Papers

Volume:

307

Abstract:

Shrinkage compensating concrete is one of the most common products currently used to mitigate the influence of drying shrinkage cracking in slabs, beams and other structural components. Type K expansive concretes have proved effective for prevention of structural and aesthetic damage due to tensile cracking in many modern applications. However, the ACI 223R-10 technical guide still indicates that a shrinkage compensating slab cannot expand adequately if it is surrounded on all sides by mature reinforced concrete. The objective of this project was to investigate whether the presence of a stiff external restraint condition, which may be provided by adjoining concrete, prevents a Type K expansive concrete slab from compensating for shrinkage. To investigate this behavior, the field condition of a slab-to-slab interaction was simulated using a steel restraint system with varying degrees of stiffness and amounts of Type K expansive cement component. Test frames were instrumented to evaluate the force and displacement responses of the Type K expansive concrete to the different boundary conditions provided by varying the steel restraint system. The results of this investigation support a conclusion contrary to that currently found in the ACI 223R-10 guiding document. This study concludes that a Type K expansive cement concrete does not suffer a severe reduction in shrinkage compensation in the presence of a very stiff boundary condition.


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