Photo by Nomeus, 2008 -

ACCO Aerated Concrete Systems Plant

Photo(Nomeus, 2008 – Though the plant was closed, electricity still ran through the buildings.

Built in 1969, General Electric opened a new factory as part of GE’s lighting-systems division, manufacturing incandescent lamps. The factory operated until it closed in 1982. GE reopened the factory a year later as part of it’s robotics operation. It is best to note that at the time, the robotics industry was doing poor as robots were relegated to marginal tasks and were nearly mothballed entirely. The industry’s reputation suffered massively during the 80s and almost disappeared entirely.

GE designed and developed the software and central processing unit, or brain, for robotic welding sites. Automation Intelligence designs and manufactures industrial computer controls that sometimes are used in robotics.

The company, like some others in the automated-welding business, overestimated the size of the market. Citing the poor economic outlook for the robotics industry, in January 1987, General Electric closed it’s robotics plant, putting 118 employees who manufacture computer-driven mechanical arms out of work. The land and factory were later sold.

Photo(Nomeus, 2008 – The plant closed down in 2007, possibly along with other CEMEX plants at the time as a form of consolidation.

In 1999, Florida Crushed Stone Co. reopened the plant as an aerated-concrete plant. Costing an estimated $10 million renovation, the project began back in 1987 when the robotics plant closed down. The project laid dormant for a few years before Orlando was seen as a great location from a sales standpoint and labor pool.

The aerated concrete process is explained below.

Unlike most other concrete applications, AAC is produced using no aggregate larger than sand. Quartz sand, lime, and/or cement and water are used as a binding agent. Aluminum powder is used at a rate of 0.05%–0.08% by volume (depending on the pre-specified density). When AAC is mixed and cast in forms, several chemical reactions take place that give AAC its light weight (20% of the weight of concrete) and thermal properties. Aluminum powder reacts with calcium hydroxide and water to form hydrogen. The hydrogen gas foams and doubles the volume of the raw mix (creating gas bubbles up to ⅛ inch in diameter). At the end of the foaming process, the hydrogen escapes into the atmosphere and is replaced by air.

When the forms are removed from the material, it is solid but still soft. It is then cut into either blocks or panels, and placed in an autoclave chamber for 12 hours. During this steam pressure hardening process, when the temperature reaches 374° Fahrenheit (190° Celsius) and the pressure reaches 8 to 12 bars, quartz sand reacts with calcium hydroxide to form calcium silica hydrate, which accounts for AAC’s high strength and other unique properties. After the autoclaving process, the material is ready for immediate use on the construction site. Depending on its density, up to 80% of the volume of an AAC block is air. AAC’s low density also accounts for its low structural compression strength. It can carry loads up to 1,200 PSI, approximately only about 10% of the compressive strength of regular concrete.

Explanation from

With the plant opening, it immediately became the largest supplier and producer of autoclaved aerated material. The plant operated with great success, causing Florida Crushed Stone Co. to be bought out by Rinker Materials, better known in Florida as CEMEX or Florida Materials. The plant operated until it’s closure in 2007. The facility was later demolished in 2011.

Photo(Nomeus, 2008 – These autoclaves were used in the production of the light-weight material ACCO became known for.

Photographer: Nomeus
Year Taken: 2008
Website: FLURBEX

Photo by AKBC, 2009


Photo(AKBC, 2009): Part of the old phosphate factory can be seen just behind the post office.

The Pembroke Mine was a phosphate mine and village that was first purchased in 1905 by a French company. The mine has changed several times with a second resurgence in the 40′s. There was at one time 50 or more miner homes in the kudzo vine filled land around the area. Now all have fallen in and are not easy to find because of the overgrowth of vine. The commissary and Post Office is still on the corner however boarded up.

In the heyday of the mine the store did not use money for purchases but paper vouchers. In this way the miners were kept “owing the company store.” It is not easy to quit and leave when you owe money to the mine. The mine laboratory is still there and still in use as a laboratory since it was built in 1906. The area of the mine has housed everything from the phospahate mine to a company who built the gantry for the Redstone rocket, of early space race fame.

There is a humorous story circulated that in the 40′s – 50′s a miner was working in a mine pit and struck a buried cache of phophorous that was left from the time when a German firm owned the mine. Since phosphorous burns with a hot and smokey white light when mixed with oxygen the strike of the shovel brought about a white light explosion. The miner ran leaving his car and all his tools in the pit hollering that he had unearthed a “hole to hell.”

Information by Mike Woodfin,

Photo(Courtesy of the Florida Archives, 1983): The Pembroke post office and commissary is still standing, though boarded up.

Photographer: AKBC
Year Taken: 2009

Archive Photos