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Precast Structures

Cast-in-Place Underground Vault

Manteca, California, USA

The utility agreed to the crystalline waterproofing combined with a rolled-on membrane for extra protection. In total, the team mixed Xypex Admix C-500 into 80 cubic yards of concrete mix. The vault project was complete on time and budget. Soon after, the utility selected Machado and Sons Construction to build another vault. Machado plans to use Xypex on that one as well. 

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When Machado and Sons Construction, a general construction company located in Turlock, California, was contracted by a gas and electric utility company to build a cast-in-place underground vault in Manteca, California, it looked for ways to improve the client’s conventional practices for waterproofing underground concrete structures.

Typically, the large utility vaults (29 ft x 22 ft x 15 ft) are wrapped with a membrane to protect from water intrusion.

Steven Perry with Machado and Sons Construction, says, “We recommended Xypex crystalline waterproofing as a way to insure long-term waterproofing in the vault and as a way to compress the construction cycle.”

Added to the concrete at the time of batching, Xypex admixture waterproofs and protects the concrete over time by forming a microscopic, mesh-like barrier across the diameter of the concrete’s pores, which plugs the pores against the flow of liquids, even against extreme hydrostatic pressure. The admixture is able to seal static hairline cracks up to 0.4 mm

The utility agreed to the crystalline waterproofing combined with a rolled-on membrane for extra protection. In total, the team mixed Xypex Admix C-500 into 80 cubic yards of concrete mix.

The vault project was complete on time and budget. Soon after, the utility selected Machado and Sons Construction to build another vault. Machado plans to use Xypex on that one as well.

The contractor hopes to delete the use of the membrane on future underground vaults and other concrete structures in the future. “Not only does the admixture provide long-term protection from water intrusion, it also can save us about two weeks in time that would normally be required to install a membrane,” adds Perry. “That’s a significant amount of time, particularly when we’re working in urban areas where we need to minimize construction impact to the public.”