Concrete Products

AUG 2014

Concrete Products covers the issues that attract producers of ready mixed and manufactured concrete focusing on equipment and material technology, market development and management topics.

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www.concreteproducts.com August 2014 • 33 FEATURE GRANITEROCK The Bibko 4000 can separate coarse and fne aggre- gate from up to 45 yd. of returned concrete and truck washout per hour. It operates without ramps or mainte- nance-prone butterfy valves; conveys slurry water for truck washout or two batch plants' water weigh batch- ers for recycling in select orders; and, can collect yard water for use in the reclaiming loop. The basic model ships with galvanized steel body; dual wash chamber plus proprietary discharge conveyor; slurry water han- dling package; slurry agitator system; plus, electronic controls, wiring and plumbing components. Approaching peak construction season, Tracy, Ca- lif.-based DHE Inc. delivered the Redwood City plant a 45-yd./hour capacity Bibko 4000 concrete reclaimer, fed by a six-truck, 6.5-yd. buffer vessel, plus a 21,000-gal. Noble slurry tank equipped with four agitators running on 3-hp motors. With the exception of a few painted reclaimer components and motor housing parts, all sur- faces are galvanized and all equipment above-grade. "This is a huge improvement compared to systems of the past," says McGrath. "When we looked at safety and maintenance, the above-grade approach was much pre- ferred to a slurry pit." California will eventually require monitoring of below grade pit seepage, including basic settling ponds, he adds, and Graniterock does not want to be behind the curve once regulations take hold. More immediately, the Bibko 4000 eliminates waste hauling from concrete production to recycling areas and conserves what McGrath notes is a scarce commodity in many parts of California. "We want to minimize water usage and are training drivers to be as effcient as pos- sible cleaning their trucks," he affrms. "It's a continu- al learning process, but for now we have the reclaimer station set so when drivers have less than 2.5 yards of returned material, they push a button for a 250-gallon washout. We allow a second 250-gallon charge for trucks returning with larger loads." Truck washout lines draw from the Nolan tank or the third of three sections forming a 10,000-gal. settling pond. Prior to the reclaimer installation, settled mate- rial, along with hardened, returned concrete placed in rows, was hauled to the plant's recycling area. The pond will remain in the short term for stormwater capture; the structure could give way to more productive yard use down the road. The reclaimer station is built on former powdered pigment storage space, between central mixed and tran- sit mixed plants. Redwood City team members transfer reclaimed coarse and fne aggregate to dedicated stock- piles. On a typical production day, the Bibko equipment will capture 10–27 yd. of material, maintaining water and slurry volumes in agitation. DHE equipped the rect- angular Nolan tank for real-time specifc gravity, tem- perature and water level measurement. A variety of pri- vate and public work under current market conditions has enabled Graniterock to pick and choose days for gray water and reclaimed aggregate recycling. Measured in recycling effciency, reduced material transfer outside the Concrete Division and lower equip- ment maintenance requirements when compared to pri- or attempts at capturing recyclable aggregate and slurry water, success with the new reclaimer has Graniterock on track to install a similar unit at San Jose Concrete.

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