Early Riser

CalPortland lifts Concrete Products business

PHOTOS: Concrete Products, Prinzing-Pfeiffer

The new machinery eases product molding with cast-in step inserts; the SCP-branded steps are inserted as product curing begins. CalPortland Concrete Products® underscores the long term, field safety aspect of steel-reinforced, copolymer propylene steps firmly secured to cast-in inserts.

CalPortland Concrete Products® launched as Southwest Concrete Products (SCP) in the mid-1960s, a good period for entrepreneurs promoting precast methods as an economical alternative to the laborious practice of building manhole and vertical underground structures with clay or concrete brick. Located in Ontario, Calif., near the middle of the Los Angeles to Inland Empire sprawl, the company spent its first two decades establishing a strong brand in wet cast products.

SCP management approached the mid-1980s determined to maintain a lead in manhole production, and ushered dry cast drainage or utility structures into the market with the help of a Prinzing Mistral 150/250 machine from Germany. Population growth and infrastructure upgrades throughout southern California were easily driving demand to match dry cast machinery output.

The equipment performed dutifully in the 36- to 60-in. diameter product range for 30-plus years, more than half under the ownership of CalPortland Co. ®, based in nearby Glendora, Calif. A nod from the parent company enabled CalPortland Concrete Products to elevate safety, efficiency, quality and material optimization with the late-2017 installation of a new Mistral 150/250 automatic pipe and manhole machine from Prinzing-Pfeiffer, a member of Germany’s Topwerk Group.

The current generation machine fits the original equipment footprint, but required negligible vibration pit modification, and operates in tandem with new Prinzing-Pfeiffer automatic base pallet feeder and hoop welding models. The Mistral 150/250 has set up access from three sides, allowing optional base ring and molded product handling systems. It fabricates 36- to 60-in. diameter manhole or companion structures in lengths to 8 feet. Among its advanced features or processes are GEBA, which ensures precise product length, and step feeding system, which integrates the consolidation of plastic and galvanized steps into an automatic process. Pit placement of a central vibrator reduces machine noise levels, while Prinzing-Pfeiffer vibration technology imparts uniform concrete compaction and bughole-free surfaces.

The charter machine cast vertical structures with conventional reinforcing cages, fabricated on automated Apilion welding equipment CalPortland Concrete Products now uses for large, wet cast structures. Most new Mistral 150/250 product has horizontal reinforcement only: Steel hoops of uniform diameter on manhole bases and risers, and varying diameter for cones. Secured with circular plastic chairs, the hoops are placed manually on base rings and at specified mold core points. Forms are then lowered into the pit, filled with zero slump mixes, pressed and compacted.

The switch from cages to hoops equates to significant steel savings and lower energy consumption rooted in curtailed welding processes. The reinforcing steel-optimized structures, nevertheless, meet performance requirements of ASTM C478-18 Standard Specification for Circular Precast Reinforced Concrete Manhole Sections.

Measured against the legacy machine’s manual method tendencies, the Prinzing-Pfeiffer Mistral 150/250 brings new fabricating efficiency to manhole bases, risers and cones with cast-in steps. Production crews can place SCP-brand manhole step inserts concurrent with the reinforcing hoops. Robust molding and compaction of product walls secure the inserts to a level whereby steps would require chiseling or hydrodemolition to pull out. Crews install press-fit steps—injection-molded, copolymer propylene with a center core of ½-in. steel reinforcement—after base, riser or cone units are transferred from the machine platform to the curing chamber.

CalPortland® Concrete Products casts manholes, risers and cones with the new generation Mistral 150/250, a versatile machine that can also handle conventional concrete pipe plus rectangular or square boxes. Installed adjacent to a pit, the machine comprises a press with top vibration, outer mold, mold core, frequency controlled central vibrator with quick-change clamping, and automatic concrete feeding system. After a base pallet or ring is shifted over the mold core, the outer mold is positioned and the entire platform lowered. The hopper feeds mixes to a spreader that charges the mold, then retreats to make way for the press. The Ontario machinery is set to run on two- to six-minute cycles; de-molded product is transferred by forklift truck, although Prinzing-Pfeiffer can equip the Mistral 150/250 with factory-supplied shifter, ratchet feeder, carrying device or robotic cranes.

The automatic hoop-welding Apilion PP HWM-S system consists of a wire spool and straightener; hoop templates of varying diameter; wire feeding, cutting, welding and cooling devices; plus transfer to a portable collection rack. The replacement of cages with hoops in dry cast products sharply lowers Ontario plant steel requirements.

INVESTMENT CYCLE

Like peer operators that started with a narrow range of small products, CalPortland® Concrete Products has built an inventory of progressively larger underground or utility offerings representing better solutions to cast-in-place concrete, brick, block or plastic alternatives.

The new Prinzing-Pfeiffer Mistral machine is the centerpiece of the CalPortland Concrete Products operation, which also harbors a small dry cast ring machine and an array of formwork for standard or licensed product. The latter include Redi-Rock International’s retaining walls (above and below) plus the newer Pole Base product, whose ease of delivery and placement is reflected in traction from developers and contractors unaccustomed to a precast alternative to cast-in-place foundations and decorative enclosure of lower lighting structure sections.

The new machine’s output is part of an inventory that has grown to 1,500-plus utility and drainage products. CalPortland Concrete Products serves residential or commercial property developers and state or local agencies in Los Angeles, Orange, Riverside, San Bernardino and San Diego Counties. It delivers about 40 percent of total production with a fleet of five boom trucks dispatched to inland and coastal sites, from San Diego to Santa Barbara.

Upgraded Ontario plant machinery runs in lockstep with CalPortland corporate safety and energy efficiency goals. “The old equipment had dated mechanical functions, relays and switches,” says CalPortland Precast Division General Manager Gary Pollard. “This new machinery is much safer. The automatic base ring feeding aligns perfectly. We are also seeing savings in concrete mixes, as the machine casts to target wall thickness. The old machine was going up to ½-in. too thick in some spots. We are now casting manholes, risers and cones with the hoop reinforcements and seeing huge energy and material savings over our old cage fabrication.”

“Once you learn how to operate and use new plant equipment, you realize how much more efficient it can be and how much potential it holds,” adds General Sales Manager Dave Ennis, who observed the original Prinzing machine throughout its Ontario tour of duty. During Concrete Products’ mid-summer plant visit, he reflected on a host of improved Prinzing-Pfeiffer Mistral 150/250 safety, efficiency and steel-optimizing metrics compared to its predecessor. The quantity of sensors programmed to shutdown the equipment and disable moving parts has gone from three to 20, for example, while base pallet ring transfer time from staging to precise machine platform alignment has been cut from minutes to seconds. Energy and steel savings are especially apparent when measuring the weld points required on old cages versus the new hoops used to attain ASTM C474-grade reinforcement on a typical manhole.

Concrete mix and reinforcing steel optimization are consistent with the lower production costs management could expect from an investment on the order of the Mistral machinery. Finished dry cast products’ reduced embodied energy levels likewise align with benchmarks CalPortland Co. sets for Environmental Protection Agency Energy Star program participation. Lower energy factors throughout concrete, cement and aggregate operations positioned the producer in 2018 to earn the EPA Energy Star Award for a 14th consecutive year—by far the industry’s strongest track record.

The Mistral 150/250 delivery and Ontario plant upgrade are concurrent with major investments (> $500 million) through which CalPortland is shoring up its stake in southern California cement, aggregate and concrete production and distribution. Leading the outlays is the Oro Grande cement plant, acquired from Martin Marietta Materials in 2015 and located less than an hour northeast of Ontario. A clinker grinding upgrade under way will bring annual finishing capacity to more than 2 million tons. Oro Grande succeeds CalPortland’s flagship Colton cement plant, which has depleted limestone reserves but continues as a grinding and storage site to supply Type I/II cement to CalPortland Concrete Products and sister Catalina Pacific ready mixed plants. All are mobilizing amid a solid rebound of southern California building markets and ramp up for the Los Angeles-hosted 2026 Olympic Games.