12 QUESTIONS FOR POTENTIAL BROKERS
sand’s capabilities to ODOT and the general contractor, so the company was comfortable breaking even on the delivered sand price. ODOT saw a cost savings using the casting sand com- pared to natural sand.
Case Study 3: Highway Sub-base Layer
Wisconsin has areas of soft native soils that cause problems in road con- struction. Typically, the upper layers of the soft soil are removed and replaced with 12 in. and greater-sized crushed rock in order to provide an adequate working platform for construction traf- fic. Te crushed rock is more expensive than regular fill material and sometimes has to be transported a great distance from the quarry to the rock site. A working group from the
Wisconsin Department of Trans- portation considered new techniques to deal with soft soils, including using gray iron casting sand from a Wisconsin green sand metalcasting facility, for a 0.9-mile segment of Wisconsin State Highway 60 (STH 60) in 2000.
Te sand was placed in bulk along
a 166-yard stretch as a 33-in. sub- base layer. Te control section used reclaimed stone from cuts made as part of the highway’s modifications. Te casting sand used was fine with a narrow range of grain sizes. Te dry unit weight was 71% of the gravel, and the optimum water content was twice that of the gravel due to the bentonite content (10%). Te sand was placed and compacted using stan- dard construction equipment. Water leach tests were conducted on
the casting sand according to ASTM D 3987 to determine its suitability for use as a subbase material, and it met all requirements in Section NR 538 of the Wisconsin Administrative Code for byproducts used in confined geotechni- cal applications. The physical and environmen-
tal properties of the sections have been monitored for more than eight years. During that time period, the pavement performance has been the same for both the foundry sand and control sections. The casting sand for this project
April 2011 MODERN CASTING | 37
Rather than dedicate personnel to running a beneficial reuse program, metal- casting facilities may choose to have outside contractors manage their program. Below are basic questions to ask potential firms to obtain a general understanding of the contractor and its investment and experience level in the casting industry. • How long have you been in business? • Who else are you working with in the metalcasting industry and beyond? • What else do you do to generate revenue? • What is your background relative to metalcasting or industrial recycling? • Are you an active member of a state or national metalcasting association, and if so, for how long?
• Does anyone in your company sit on industry technical committees or state cast metals boards. And if so, for how long?
• What is your technical expertise? • What is your annual revenue? • What type of equipment do you own and operate? • Where is my sand going after you handle it? • Who do you know and work with at the U.S. Environmental Protection Agency, the state environmental agency, the local board of health, etc. • Do you provide analytical testing services?
was provided at a reduced cost for the demonstration. However, casting sand as a general rule is less expen- sive than select materials, such as crushed stone.
ONLINE RESOURCE
For tools, resources, regulatory informa- tion and more beneficial reuse case stud- ies, visit
www.foundryrecycling.org.
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