Question: Your March issue, page 106, included a problem posed relative to repairing of concrete slabs on the ground.

Answer: We have a new product called Xyoquik which may be the answer. Although Xyoquik is not packaged for on-the-job mixing, it can be readily mixed from bulk materials or could be prepackaged. Xyoquik is a psuedo concrete which will cure to 100 percent ultimate strength within 1 hour at 70 degrees Fahrenheit. It is waterproof and resists most acids and bases as well as salt. Its ultimate strength is more than twice that of the concrete substrate and although not quite as abrasion resistant as conventional concrete, it is more than adequate for most applications.It can be poured in slabs up to four inches thick and feathered to virtually zero. Xyoquik has an inherent resiliency which makes it tend to be self-stress relieving to prevent cracking and crazing due to either temperature changes or earth movement.Conventional mixing equipment can be used, but a continuous type mixer is recommended when the volume of this type of work would justify the cost. The continuous type mixer is available from several sources as a stock item and may be mounted on a trailer for a mobile unit. With such a set-up the labor would be reduced to a minimum.The Xyoquik formula and process is available on a license basis in many states. Interested readers may contact us.

Paul O. Gunton

Innovation Unlimited

1789 Larkspur Avenue Pomona, California 91767

Sir: Under your column "Problem Clinic" subtitled "Does anyone know," the problem of topping sunken concrete floors, patching concrete slabs, feathering topping out to nothing, must look like concrete when finished, etc., may be solved by using "5 Star Grout," a 5000# grout mixture available at most concrete supply companies. (I do not recall the manufacturer's name.)It feathers and adheres beautifully and some jobs may justify the expense.When reinforced and handled like concrete it makes a tremendous slab.

Jim Earnest

Cobb/Adams/Benton Architects Birmingham, Alabama