In this issue, our Case Study article describes our recent restoration of an elevated concrete walkway at the Dexter Southfield private school located in Brookline, MA. Significantly, the project was put on a fast track to be completed between the spring and fall semesters. Our Masonry 101 article describes how concrete applications are dependent upon the strength of the concrete formulation.
We are optimistic that the year ahead will be a successful one for our clients. If you have any comments or questions, or would like an estimate on a masonry repair project, we can be reached at 617-445-0274 or at www.abbotbuilding.com.
Sincerely,
Michael Norman, President
Abbot Building Restoration Company, Inc.
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Abbot Restores Elevated Concrete Walkway at Brookline Private School
Fast Track Project Completed Between Spring Commencement and Fall Semester
Abbot recently restored the elevated concrete walkway located behind one of the classroom buildings at the Dexter Southfield School in Brookline, MA.
Abbot was initially contacted by the facilities director at the school to investigate the problem. Subsequently, the school decided to bring in their general contractor, C.E. Floyd Company, Inc. (Bedford, MA), to oversee the project.
 During the investigation, it was found that the steel decking that supported the concrete walkway had severely deteriorated. In addition, sections of the structural steel that supported the decking had also deteriorated. Based on these findings, it was determined that the concrete walkway, the steel decking, and sections of the supporting steel all had to be removed. To remedy the problem, new steel was fabricated to support the new decking, new decking was installed, and new 5000 PSI concrete was poured and finished to meet the school's specifications. To protect the new concrete, the owner decided to seal the walkway with a specially formulated water repellant coating to prevent freeze-thaw damage and prolong its useful life.
Significantly, the project had to be fast tracked so that it could be completed between Spring commencement and the new Fall semester.
Dexter Southfield is a 36-acre private school serving pre-kindergarten through grade 12 located on Boston-Brookline line.
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Concrete Uses Depend Upon Strength
In our Case Study article, we mention that 5000 PSI concrete was used to finish the elevated walkway at the Dexter Southfield School.
Concrete is made up of three main ingredients: water, Portland cement, and aggregates. The ratio of the ingredients changes the properties of the final product, which allows the engineer to design concrete that meets specific needs. Admixtures can be added to adjust the concrete mixture for specific performance criteria.
 There are many different types, strengths, and compositions of concrete, each with characteristics that make them appropriate for different applications.
Strength is typically determined by compression testing, and is expressed in pounds per square Inch (PSI). Normal concrete mixes range from 2500 PSI to 5000 PSI, with engineered design mixes of 10,000 PSI or higher used in specialized applications. Lower strengths are also available for grouts and other low stress applications. The following are common uses for various strength concrete formulations:
- 2500 PSI concrete may be used in driveways, walkways, and even floor slabs on grade. This concrete is usually the cheapest available from batch plants. However, many concrete professionals prefer a higher strength product due to warranty concerns. Further, some building codes may not allow its use for all of these applications.
- 3000 PSI concrete is a standard multipurpose mixture for general use in construction. It is durable, has sufficient cement to provide good finishing characteristics, and can be placed fairly wet without sacrificing quality.
- 3500 PSI concrete is used for applications where surface spalling is not acceptable, and significant loading is expected. One example would be paving curbs, where heavy traffic may drive on the surface. Other uses include building footings, bond beams, grade beams, and floor slabs where heavy loads may be moved or stored.
- 4000 PSI concrete is used for heavy traffic pavement, heavy use floor slabs like shops and warehouses, and concrete footings designed to support heavy loads.
- 5000 PSI, like the strength used at the Dexter Southfield School, and higher concrete mixes are usually used for specialized construction projects where high impact resistances, very low wear rates, or extreme conditions are expected.
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Abbot Building Restoration Company, Inc.
28 Allerton Street, Boston, MA 02119
Tel: 617-445-0274 � Fax: 617-445-0277
[email protected] � www.abbotbuilding.com
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Featured Articles
Case Study
Abbot recently completed a fast track restoration of a concrete walkway at the Dexter Southfield school in Brookline, MA.
See full article below
Masonry 101
Concrete uses are dependent on the strength of the concrete formulation.
See full article below
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