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Commitment through the Years

With its humble beginnings as a sand and gravel producer in Austin, Texas, Capitol Aggregates has grown into a strong regional supplier of construction materials. With the ability to produce a wide variety of aggregates and cement, Capitol Aggregates truly has been A Texas Tradition since 1957.

Our Legacy

In 1963 H.B. Zachry purchases a former lithium plant with land and spends less than two years converting  it to cement plant using the existing limestone from the quarry.  By 1965, Capitol's cement plant goes online in San Antonio with capabilities of producing one million barrels —approximately 188,000 tons — of cement annually. It was the cheapest "new" cement plant built in the United States.

Capitol Executes a Long-Term Contract with Chemical Lime, LTD

Capitol executes a long-term contract with Chemical Lime, Ltd. to mine aggregate materials on its property in Marble Falls. 


Completion of the Marble Falls Quarry 

The company's efforts to expand continues with the completion of the Marble Falls Quarry and a new dredging operation at the Austin River Plant.


Capitol Introduces Eco-Ment Endure


ECO-MENT ENDURE is the first blended cement marketed in Texas-2009

Capitol Introduces Eco-Ment Spec

ECO-MENT SPEC, the first Portland Limestone Cement marketed in Texas-2012


Expansion into South Texas


Capitol Aggregates purchases 1100 acres in New Braunfels, Texas. This new property will allow Capitol to focus its efforts in its core South Texas markets.The company also completes the divestiture of its Marble Falls quarry and supporting Seward Junction and Manor distribution terminals.

Capitol Cement Acquires the First Environmental Product Declaration


Capitol Cement acquires the first Environmental Product Declaration(EPD) for cement in North America -2015


H.B. Zachry Company receives a contract from the United States Air Force to rebuild runways at Bergstrom Air Force Base in Austin, Texas. Rather than purchase materials from another supplier, the company determines it would be more efficient to start its own sand and gravel and ready mix operations, so Zachry purchased Austin Sand and Gravel which became Capitol Aggregates.

Perfect Safety Record

The cement operation receives its first of 17 Portland Cement Association Safety trophies for a perfect safety record. 




Dry Kiln Addition 

The cement plant's dry kiln addition becomes a reality when the first clinker is produced in December. 

Capitol Purchases Delta Materials


Capitol purchases Delta Materials which produces high-quality sandstone used to build safe, durable Texas highways. 

Capitol Aggregates is incorporated on March 27, 1957​

Capitol's Cement Plant goes online in San Antonio

Expansion in Georgetown

Construction begins on a new crushed stone operation in Georgetown 

Zachry purchases Trans-Pecos Valley Southern Railroad/Hoban Plant

On February 28, 1968, Trans-Pecos Materials along with the Pecos Valley Southern Railroad were incorporated by Zachry Company interests.

Henry Bartell Zachry passes

Henry Bartell Zachry, Jr., passed away on June 10, 2020, He believed in the goodness of people and considered it both a duty and a privilege to serve others, from his family to his employees to his fellow citizens.





Capitol begins dredging the Colorado River in Austin to increase the river's depth and width. The huge endeavor took 12 years to complete.

Capitol begins dredging the Colorado River

Rio Medina Plant

CA built the Rio Medina Plant in 2017 and started running the operation for product and loadout in January 2018. This operation services the west and north side of San Antonio because of growth opportunities moving west of San Antonio with residential homes and businesses.

New Finish Mill

A new finish mill was constructed at the cement plant increasing cement production and expanding the ability to create Eco-Ment® blended cement.


Austin RIver Plant closes

The Austin River Plant closed in December 2022 after exhausting its sand and gravel reserves.  It had been in operation for 15 years.

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