ASSEMBLY INSTRUCTIONS/OPERATIONS
classification is from the American Concrete Institute. Although the F number system is only a few years old, it offers these advantages:
a)The system controls both flatness and levelness.
b)There is a standard test method.
c)The system recognizes the statistical nature of profile testing on random traffic floors.
d)The system is infinitely variable.
FIGURE 40
One of the major limitations of the F number system is that it does not control the surface regularity at joints. Because joints are statistical anomalies, the standard test method forbids measurements within 24 inches. The designer specifying by F number has two methods to accommodate the problem. The first solution is to locate joints at locations where surface regularity is not important. The second solution is to design specifications for the joints themselves.
The TR 34 tolerances for defined traffic floors
The TR 34 System divides defined traffic floors into three categories:
a)Superflat
b)Category 1
c)Category 2
For each category, the TR 34 System specifies limits for three properties:
Property 1 is the difference in elevation between two points 12 inches apart, measured in the direction of vehicle traffic. This is the levelness tolerance.
Property 2 is the difference in slope over 24 inches measured in the direction of vehicle traffic. This is the flatness tolerance. It is identical as the 24 inch curvature utilized in the F number system.
Property 3 is the difference in elevation between opposite points in the left and right wheel path, measured perpendicular to the direction of vehicle traffic. As with Property 1, it is a levelness tolerance. The TR 34 System specifies different values for Property 3 depending upon whether the distance between left and right wheel paths is more or less than 5 nominal feet
The Superflat category is intended for very narrow aisle warehouses where the highest standards are required. Category 1 is suggested for very narrow aisle warehouses where the vertical lift height is between 26 and 43 feet. Category 2 is for very narrow aisle warehouses where the vertical lift height is under 26 feet and the use of low rise, automatically controlled vehicles. No matter which category of surface regularity is specified, it is accomplished by measuring elevations on 12 inch centers. This is very similar to an F number survey, but with an important distinction. In an F number survey, the elevation profiles are made on the floor at random. With the TR 34 System, the survey measurements are made on the actual paths of the vehicles that will utilize the floor.
Improving the wear resistance of concrete floors by grinding with the DFG Series SURFACE GRINDER
Poor wear resistance can often be traced back to a surface that is weaker than underlying levels of the pour. This an occurrence can result from bad finishing techniques, improper curing or early freezing.
Where surface weakness is a problem, grinding can be a solution. The process is similar to the early age technique. The grinding depth is typically 1/16 to 1/8 inch. A large project should not be attempted until a small test area has proven that the technique will produce the desired results. Usually only a square yard of floor is ground with the normal wear tests performed.
Repair costs can be minimized by grinding only those floor areas that accommodate traffic. For example, in a pallet rack warehouse, it may be necessary to grind only the aisle areas and not under any of the racks. The grinding process can adversely affect the surface regularity. Where specific properties are important, it may be
OPERATION AND PARTS MANUAL REV #3 (07/13/06) | PAGE 38 | |
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