Aggregate Industries comes clean on best truck wash down practices

Augmenting a policy to keep vehicles in drive or forward gear at Aggregate Industries US is the installation of automated, drive-through mixer truck wash down equipment—a best management practice with safety, quality control and water conservation benefits. Aggregate Industries US began piloting water spray systems at four Minnesota plants in 2008. It enlisted a commercial vehicle wash equipment specialist, Key Solutions of Dassel, Minn., to tailor mixer-suited nozzle bars and racks, and oversee system engineering and installation.

With capital expenditures limited throughout the market downturn, the producer confined the automated truck wash down to Minnesota. Managers noted time savings for outbound drivers and at the close of business, when mixer trucks subjected to pressure water spray cycles required less cleaning than those drivers had washed with yard hoses. Aggregate Industries quality control staff also took note of slump and strength uniformity of orders delivered in trucks passing through automated wash down racks. Technicians attributed mix quality and consistency to the controlled amount of slump-adjusting water—typically 3.2 to 3.4 gal. per cycle—added to drums during the spray pass through. Pilot systems were set for 30-second wash down cycles using 12 gallons of water.

A Cost Saving Initiative review throughout Aggregate Industries’ operations found the automated truck wash down method in Minnesota ready for wider distribution. From 2008–2012, notes Aggregate Industries/Meyer Material Area Manager Brent Blankenhorn, “There was a top-down effort to identify ways of getting mixer trucks in and out of plants faster, and improving plants’ overall safety records. Plants running the automated wash down units demonstrated driver time cost savings, in the course of deliveries and at the end of shifts that could be duplicated in other states.”

Indirect savings from the quality control aspect of water dosing consistency played a big part in the decision to deploy automated wash down stations beyond the Minnesota plants, as did the safety benefit of curtailing drivers’ time on truck ladders, adds Blankenhorn, who is responsible for four Meyer Material operations serving Chicago’s northern suburbs.

Pump station with reservoir and 30-hp motor.
Pump station with reservoir and 30-hp motor.

Leading up to the producer’s plan to install wash down stations across other regions—beginning in 2013 at plants of 60,000 yd. or higher annual output—Key Solutions owner Shad Brand teamed with mixer truck equipment specialist Shumaker Industries to assist in standardizing the patented Load and Go Ready Mixed Truck Wash Systems; fabricate and assemble key frame and pump station components in its Northumberland, Pa., plant; and, commercialize the equipment.

Shumaker Industries announced the Load and Go at the 2013 World of Concrete, a springboard to 16 installations for the year. Aggregate Industries ordered two systems each for plants in Denver, Las Vegas, Maryland and Illinois. In addition to deliveries in the latter state, the producer capped the year’s automated mixer wash down rack deployment at a Milwaukee Meyer Material plant—the first Load and Go configured for an all front discharge mixer fleet. Other Aggregate Industries installations include plants with rear and front discharge mixers.

The system has two main components. A small footprint (32- x 28-in.) pump station features 45-gal. reservoir; 30-hp motor; ball and solenoid valves; and, touch screen control panel with PLC functions enabling an infinite combination of mixer fleet-specific water volume, pressure and wash cycle settings. Shumaker Industries and Key Solutions staff use Aggregate Industries’ settings as Load and Go baseline: 12 gallons of water piped at 1,200 psi over 30-second cycles.

With a footprint just under 15 ft. wide, 9 ft. deep, the wash down system has a four-leg aluminum frame rack bearing on a 24-in. high, ¼-in. thick galvanized steel fabricated foundation, options for which include 20-in. cast-in-place columns or continuous wall/footer, or comparably dimensioned precast blocks. The foundation and rack afford 11.5 feet of horizontal (ground level) and nearly 15 feet of vertical clearance. Aluminum construction imparts rigidity in the Load and Go frame to dampen high-pressure water jolts.

North Chicago was one of two Meyer Material plants in Illinois to equip mixer alleys with the Load and Go automated wash down system.
North Chicago was one of two Meyer Material plants in Illinois to equip mixer alleys with the Load and Go automated wash down system.

Also fitted with galvanized steel and stainless steel components, the standard package has a 1-in. water line charging two top and two side spray bars, fitted with 40 or more of proprietary Key Solutions nozzles. “Every ready mixed plant has different points depositing materials on mixer trucks,” says Brett Shumaker, who has spearheaded the Load and Go commercialization and overseen the Aggregate Industries plant installations. “The spray bars can be customized and nozzles aimed in a configuration best suiting an individual operation. No cookie-cutter approach can maximize system performance.”

Although having a cleaner fleet, creating less residual water, and narrowing the tolerances on quality control variables are all important aspects of the Load & Go wash system, Shumaker Industries is wise to users’ return on investment targets.

The manufacturer cites a sample ROI provided by a producer that used a 60,000 yd./year plant benchmark, thus equating to a minimum of 6,000 10-yd. deliveries. With a 30-second spray cycle, a plant can save up to 9 minutes and 30 seconds per order, in comparison to the typical 10-minute mixer driver, ladder and hose routine. At the 6,000-order level, a plant can realize time savings north of 900 hours per year, according to the Shumaker Industries calculation.

— Shumaker Industries, Northumberland, Pa., 800/326-9349;