Raft Slab-on-Grade Foundation

by Jim Houlette, PE July 12, 2019

A Raft Slab-on-Grade foundation can be as simple as a 4” thick slab with no reinforcement and a shallow perimeter rib to an 8” thick slab heavily reinforced with deep ribs spaced roughly 10’o.c.  The wide range of concrete thicknesses and reinforcement is a function […]

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Understanding Long-Term Losses in Post-Tension Tendons

by EVstudio AEP July 11, 2019

As a structural designer, I started my career working on post-tension structures.  Those of you who have been with us for some time know that those can include things as small as a single tennis or basketball court as well as some of the tallest […]

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Post Tension Slab-on-Grade Foundation

by Jim Houlette, PE April 19, 2019

A Post Tension (PT) slab-on-grade (SOG) foundation is based on a typical raft SOG foundation with one major difference; high strength steel tendons pulled into tension.  Tendons are typically ½” diameter made of 7 steel wire strands that is then greased and encased in a […]

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Code Requirements for Concrete Slabs on Grade

by Sean O'Hara, AIA, LEED AP March 27, 2018

The International Residential Code (IRC) lays out a series of requirements for pouring a concrete slab on grade. Its more than just forms and pouring concrete! The slab has to be at least 3.5″ thick and possibly thicker for expansive or other difficult soils. The […]

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Concrete Foundation Cost Savings: Slab On Grade Foundation with Imported Soils vs. Drilled Pier Foundation

by evstudio June 20, 2010

This week I’m working on the structural design of three different concrete foundations for three pre-engineered metal buildings (PEMB) in the state of Texas. All three soils reports indicated that expansive soils were going to be a factor in the foundation design and all three […]

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