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  • Take the Sweat Out of Hot-Weather Concreting

    Hot weather can have many negative effects on fresh and hardened concrete properties, including increased water demand, accelerated rate of cement hydration, increased moisture and slump loss, faster setting times, increased plastic- and drying-shrinkage cracking, and lower ultimate strengths. But...

     

Other Articles

  • Curing During the Pour

    An early start on concrete curing can provide many benefits, especially for hot-weather placements. It can help to prevent stickiness, sponginess and surface crusting conditions that can cause finishing problems. It can also eliminate plastic shrinkage cracking and reduce drying shrinkage cracking...

     
  • Keep Your Cover with Side Form Spacers

    If you're a concrete contractor, it's important that you maintain adequate clear cover in vertical concrete structures. With proper cover, reinforced-concrete structures are likely to exhibit improved structural integrity and finished appearance as well as greater resistance to fire and corrosion...

     
  • The Impact of Metric Rebar Conversion

    Because federally funded construction projects are now required to be designed in metric units and built with metric materials, mills are reducing and will eventually eliminate their output of inch-pound bars and produce soft metric bars instead. Fortunately, the use of soft metric rebar will not...

     
  • Getting the Curves Straight

    From the street, it appears that the glass facade of the new Rio Suites Hotel, Las Vegas, wraps around the curved building like smooth cellophane. But the "curved" edge of each floor slab actually is segmented to fit the flat panes of glass. Had just one of these segments on a single floor been...

     

PROBLEM CLINIC

  • Required Joint Depth for Early-Cut Saws

    We used an early-cut saw to joint a concrete floor immediately after finishing. The floor is 6 inches thick and the sawcut depth is 3/4 inch. Although the floor has no random cracks, the engineer says we now have to chase the joints with a conventional saw so the cuts are 1 1/2 inches deep...

     
  • Can Acid Cleaning Cause Driveway Deterioration?

    I run a pressure-washing business in Georgia. To remove the red clay that stains many driveways, I wet the driveway, then use a low-pressure hand sprayer to apply a dilute solution of muriatic acid (one part commercial-grade muriatic acid to three parts water). After that, I immediately rinse the...

     
  • There Are Thickness Tolerances for Driveways

    Questions such as the one in the March 1997 Problem Clinic (p. 313), where a reader asks if there is a published thickness tolerance for residential driveways, bring out the importance of placing important construction parameters in easily accessible formats. There are recommended tolerances for...

     
  • Cast Stone Differs From Precast Concrete

    What is the difference between cast stone and precast concrete? Or is there a difference?