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  • Making Information Work for You

    A wise construction leader uses production information to determine a crew's efficiency. When properly educated on what performance numbers mean, even an hourly laborer can benefit by recognizing acceptable or nonacceptable work.

     
  • What Is the Biggest Problem with Concrete Core Testing?

    What alternative does the contractor have when concrete test cylinders show strengths are below specification? Is core testing required whenever this happens or are nondestructive tests like the rebound hammer sufficient? Who is responsible when the specified concrete strength is not met?

     
  • Damage to Concrete Placed in Hot Weather

    While durable concrete can be successfully placed in hot weather, increased rates of hydration and evaporation in fresh concrete and other problems can adversely affect concrete quality.

     
  • Insulated Concrete Form Construction

    Insulated concrete forms (ICF) are leading the way as a forming system and a construction technique for above grade homes. Polystyrene forms are held together by form ties and concrete is placed inside these forms. When the concrete cures, the forms remain in place to serve as insulation and...

     
  • Slabjacking: Pump It Up

    Slabjacking has many advantages over slab removal and replacement.

     
  • Getting Connected

    The Xtender, a new mechanical tension and compression rebar splicing system, finding widespread acceptance in the western United States, has both structural and field installation advantages. Bar end preparation is quick, simple, and economical and can be done either in the shop or in the field...

     
  • Roden Crater

    After 2 years and numerous changes, in January 1999 the final contract was signed for the first phase of artist James Turrell's largest work based on the changing experience of light.

     

CONCRETE BASICS

  • Entrained Air in Concrete

    Concrete always contains air bubbles. During concrete mixing and placement, these bubbles are first formed, then ruptured, merged, and floated out of the mix. But once the concrete has hardened, the bubbles that remain are fixed in place forming the air-void system in hardened concrete.

     

PROBLEM CLINIC

  • Flaking Driveway

    I had a new concrete driveway poured in September of 2000. In January of 2001, I noticed that the very thin top layer is chipping and flaking.

     
  • Settling In

    Before we purchased our home, part of the foundation under the house dropped approximately 4 inches. At that time the owner hired a contractor to fix the problem. By digging down alongside and putting jacks under the foundation, the contractor raised the

     
  • Soundproofing With Concrete

    Do you have any information about concrete mixes for better soundproofing? The contractor wants to use the smallest amount of concrete between building floors but wants to achieve maximum soundproofing benefits.