Today, most large vehicle scales are installed with above ground or concrete pit foundations. Depending on state or regional requirements, scales can also be installed in a shallow pit, as opposed to the deep pit required by older mechanical scales.
A pit installation requires less space than an above ground scale since longer approaches are generally required for aboveground configurations. However, pit-styles require sump pumps and drains, and are generally more vulnerable to corrosion due to potential standing water.
PROPER SITE PLANNING FOR TRUCK SCALE FOUNDATION
Before we talk about truck scale foundations, it’s important to think about the overall site to make sure we find the perfect location to actually locate the foundation.
To ensure the longest lifespan and best performance for your truck scale, proper site planning is essential. Your truck scale supplier will help you select the best site, considering the traffic flow of your operation, the best location for a foundation, electrical and conduit requirements, soil conditions and drainage, ease of maintenance and accessory locations.
Before purchasing your new truck scale, it may be helpful to draw out a flow map of your current operations and determine if there are any areas for improvement. It is also important to consider future site use when planning. If you expand your site in the future, will the traffic flow and truck scale location still allow for easy operation?
Creating an efficient traffic flow is important to keep operations running smoothly. Be sure there is adequate room around the scale to perform maintenance and to accommodate driver safety. Is there often a waiting line to use your truck scale? Consider the amount of space needed to accommodate a line of trucks, if needed.
Plot out traffic patterns on your flow map, marking where trucks enter the site, load and/or unload material, and exit the site. Make sure there is plenty of room for drivers to maneuver. Take a test drive with a full-size truck around your plotted traffic flow to test for any tight spots or potential safety issues. Note any special filling or dumping that must take place on site to accommodate for the space needed.
Choosing a Truck Scale Foundation Type
Even the toughest scales are put at risk with a poor foundation… Many factors, such as the slope of the site and soil conditions, must be considered prior to construction. The ground must also be free of any settling prior to scale installation. If the foundation is not properly constructed according to the certified drawing provided by your truck scale manufacturer, your truck scale foundation could shift, causing the scale to be outside acceptable calibration tolerance.
Concrete curing periods can vary depending on the type of concrete being used. Work with your scale supplier to integrate the foundation and approach design into your installation and site plan. Your scale supplier should also be able to recommend local contractors with truck scale foundation experience. Of course all of these decisions will be factors in the overall truck scale installation costs.
Above Ground Foundation or Pit Foundation
Until the early 1970s, all truck scales were mechanical and installed in expensive concrete pits. Today, most scales are installed above ground or in concrete pits with floor foundations. With the benefit of new modular construction, scales can also be installed in a shallow pit, as opposed to the deep pit required by older mechanical scales.
One of the biggest reasons for choosing a pit-type installation is space—or lack of it. A pit installation requires less space than an aboveground installation since longer approaches are generally required for aboveground foundations. However, pit-type scales require sump pumps and drains, and are more vulnerable to accelerated rust and corrosion due to the potential of standing water in the pit.
Truck Scale Foundation Designs
Deep Pier Foundation
Typical for colder climates such as those found in northern areas of North America, the deep pier foundation places part of the foundation below the frost line to eliminate the negative effects that freeze-thaw conditions can have on foundations. Discuss with your scale supplier if a deep pier foundation meets your application requirements, or if a deep pier or other specific foundation design is required by your state and region. Similar to isolated pier foundations, the deep pier foundation also requires 2,500-3,000 PSF soil bearing pressure.
Shallow Pier Foundation
Shallow pier foundations are a cost-effective solution for truck scale sites with adequate soil compaction and a warmer climate that will not encounter frost line issues. Discuss with your scale supplier if a shallow pier foundation is best suited for your application and meets state and regional requirements.
Floating Slab Foundation
A full slab foundation is a continuous or monolithic pour of concrete that runs the entire length of the weighbridge. This is the second most cost-effective type of foundation and is designed for ground that has a soil bearing pressure of at least 1,500 PSF. Discuss with your scale supplier if a floating slab foundation is ideal for your application and location, as well as meets state and regional requirements.
Pit Foundation
The pit foundation is available in numerous depths, from two to six feet. Your pit depth should best fit your needs as well as adhere to all federal, state and local requirements.
Drainage Away From Truck Scale
One other thing to think about with truck scale foundations is water drainage and avoiding buildup that can collect under the truck scale or excessive water standing in the pit. Efficient water drainage around the foundation is key to preserve scale components. The installation site should have adequate runoff, allowing water to easily drain away from the scale. Areas with heavy rain and melting snow should take extra consideration when planning site drainage.
We sincerely hope that the information contained in this article assists you in your truck scale buying journey. If you need a truck scale quote or purchasing advice, please contact our truck scale sales department by calling (919) 776-7737 or you can complete the Request a Quote form on our website at your convenience.