In September 2002, Allen Engineering was invited to participate in ACI International’s Concrete Slab on Ground Seminar. The seminar was held at Hurlburt Field in Ft. Walton Beach, Florida, and sponsored by the 823rd Red Horse Squadron of the United States Air Force.
The seminar consisted of indoor presentations and discussions, as well as an outside slab construction. The topics covered in the seminar were subgrade preparation, mix design, reinforcement, dowels, joints, cracking, concrete finishing techniques and equipment, hand tool use and selection, edging, load transfer, curling, and Ff and Fl numbers.
Jerry Holland and Cecil Bently of Lockwood Greene gave the seminar. Also speaking at the seminar were Nigel Parkes (PNA Construction Techno-logies), and Jim Bridgeman (Regional Sales Manager for Allen Engineering).
The 20´ x 40´ slab constructed on the second day utilized two mix designs, one being the traditional mix used by the Red Horse Squadron, and the other designed by Jerry Holland having less sand and better aggregate gradation. The airmen witnessed how these subtle changes led to a concrete mix that used less water, yet was much easier to place and finish. After the slab was screeded, it was pan floated using an Allen Pro 900 non-overlapping riding trowel. Finally, the slab was finished using the Allen Pro 1200 non-overlapping trowel which combines a lightweight design with high rotor speed to give a nice tight finish. Cecil Bently was on hand to go over some edging techniques and the proper use of hand tools with the participants.
The airmen were given an opportunity to get some “hands-on” training, and everyone, including the instructors, left the seminar feeling like they had learned something new.