Growth of the North American concrete masonry landscape market has spurred demand for more paving stone and segmental retaining wall unit finishing machinery. In addition to greater emphasis on a wider range of colors and shapes, producers are turning to tumbling and antiquing machinery to create product with weathered or slightly distressed finishes. The 2003 Manufactured Concrete Products Exposition saw the debut of a host of such machinery, including models shown here:

BESSER CO.

The company's rustic surface aging machine gives concrete units an aged appearance by transforming the edges of the units into soft contours. The concrete units maintain their structural integrity, according to the company, while taking on a weathered, old-world appearance. The machine processes the vertical and horizontal edges on one face of a straight concrete masonry unit. The semi-automatic machine handles 4-, 6-, and 9-in.-high and up to 24-in.-wide units one at a time. Material removal is accomplished in a single pass.
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COLUMBIA MACHINE

The CPT 60 heavy-duty tumbler offers variable speeds as slow as 3 mph, and variable decline from 0 to 15 in. Designed to tumble pavers and segmental retaining walls, the unit's oversized components are said to have a long operating life. Fewer culls are required due to the tumbler's low transition height. Arranged conveyors at ground level are said to eliminate elevated walkways and provide a safer work environment. The system integrates with existing cuber or Columbia QBR 200 automatic or semi-automatic cubers, and the modular design allows for multiple layout options, varying degrees of automation and future expansion. The cylindrical drum includes a rubber liner and features the Columbia retention clip that is said to increase drum liner life and reduce the time needed to reline the drum. The tumbler is available with a simple cube-dispensing system and includes variable-speed drum rotation and an optional dust control package.
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D.I.T.

The company introduced two new unit-finishing models. The first is a high-speed, high-strength automatic splitter capable of 90-ton force action in less than one second. This is the second version of the 48-in., in-line system called Sharky. Producers are using the system to split and tumble their segmental retaining walls; and some are splitting pavers and concrete bricks, then tumbling to achieve the desired weathered look. All assemblies are free-floating and supported by shock absorbers. The top blade assembly is linked to cylinder rod end while the bottom assembly is linked to cylinder piston end to equilibrate pressure on the top and bottom blades. The top cutting head consists of segmented, 2-in.-wide knives resting on an inverted trapezoidal block leveling system; the bottom cutting blade knives rest on a dry, resilient cushion.

The second model is the Squidly Plus, a 20 cube/hr., automatic recubing system and aligning turntable for all types of pavers. Paver sorting is done by a centrifugal turntable, then aligned in rows on a twin conveyor with a gate indexing 48 in. (or 2 rows of product) at a time. A pusher brings the tumbled paving stones on the spreading table, which redistributes the gaps between random multi-length pavers, assuring a straight cube on all four sides.

The company also continues to offer its portable tumbling plant, anchored on a low-bed truck. The rubber-lined tumbler's rib-caged design keeps dust and cuttings away from the products during tumbling. The unit is kept secure with an inclined trunnion wheel. Lifting bars distributed in a spiral fashion inside the tumbler make the products roll and wear on themselves without imposing much impact stress on the concrete product.
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HESS MACHINERY

Hess has developed a full range of automatic splitting and treatment systems for the artificial aging of concrete products. Complete cubes of product are treated within minutes, waste and labor free, including cubing, according to the company.
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PACO EQUIPMENT

The rustic appearance of concrete products aged with the company's Ram model is achieved through a process that randomly breaks, rounds and softens the corners and edges of one to four unit faces at a time. This technology is said to preserve the structural stability and strength of the concrete, allowing the treatment of a variety of products, either hard or soft split from 2 to 8 in. high, including solid segmental retaining wall (SRW) units, cored SRW units, lipped SRW units, standard concrete brick, random-length veneer brick and architectural block. In addition, there is no limitation on the length or weight of the product; therefore, new heavy-application SRW ranging from 40 to 48 in. long can be treated. Using a tumbling system with 3-in.-high retaining wall units, cull rates for this unit are only about 5 to 7 percent. The system has been adapted for both block and paver plants.
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PATHFINDER SYSTEMS

The Profiler machine is said to be a flexible, accurate and cost-effective face-texturing system for concrete blocks, segmental retaining walls and bricks. Positioned between a splitter and packaging machine, this fully adjustable profiler is capable of producing as much as 30 units per minute with the aid of two attendants. Designed to keep up with three-at-a-time block production and splitter lines, the unit affords on-line processing as well as off-line flexibility for smaller orders. A heavy-duty, belt-driven conveyor located at the top and bottom secure units ranging from 3 to 8 in. tall and 3.5 to 22 in. wide. The four profiler heads adjust to provide desirable face textures to products. The indexing of the heads is controlled by precise manual, industrial-grade limit switches and can be adjusted.
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VENA

The manufacturer's tumbling line starts with a double- or quadruple-dumper system. The tilt-and-push system constantly and smoothly charges the feeder, which in turn feeds the input conveyor that provides the tumbler. The PLCs and sensors control the speed and flow of products, making it possible to do color mix if desired. The tumbler has variable speed and inclination, and rubber liners prevent the stone from coming in contact with metal.

The Vena system has three models of sorting: 1) manual, which allows a company to redo any type of pattern using two workers to sort the stones and lift-truck operators for charging and unloading the system; 2) automatic, to sort and cube standard size products using only one worker to supervise the operation and a lift-truck operator to feed and unload; and 3) F.A.S.T. (Fully automated sorter and tumbler system), which will tumble, sort and cube rectangular and square-shaped stones of different sizes. Custom-built and programmed to meet a producer's requirements, this system works using one worker to supervise the operation and lift-truck operators for the rest.

The cuber will automatically cube heavy tumbled pavers or SRW, while the pallet indexer will provide a constant feed of what the cuber needs for pallets. The company also offers a heavy-duty, 48-in. splitter.
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WOOLFORD ENGINEERING

The manufacturer's automatic, inline texturing process can process all concrete units without damage to other surfaces — a key factor if units have protruding detail such as locking or positioning sections. The process chamfers top, bottom and both sides of units in a single pass. The machine will accommodate units with radius faces and will process units as high as 12 in. and as wide as 24 in.

The machine is controlled by a menu-based PC and can be programmed for various configurations of product. Height control is push-button. Block positioning is random and incremental, so no repeat pattern is visible. With this controllable positioning method, various textures are possible. The unit processes at speeds from 5.5 seconds to 3 seconds, depending on flow. In most cases, these cycle speeds will maintain continuity with a standard block machine operating in the seven-cycle range.
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