Seven-hour mix affords Cemex customer wide placement berth

23 Ship 400

Each 60-yd. pour began at 5:30 a.m. with the first six trucks rolling onto the barge. Four hours later, they exited the vessel, making way for six more trucks.

Can-do attitude, combined with innovative mix designs plus solid planning and execution, positioned Cemex USA’s Houston Ready-Mix business to work twice on a highly unusual project that took drivers and trucks on a four-hour, Houston Ship Channel voyage.

The waterway was hobbled with a massive power outage in October 2010 after a barge bearing 1,500 tons of scrap metal slammed into an electrical tower—repairs and lost business totaling $1 billion. To prevent future collisions, tower owner Centerpoint Energy, a major supplier of gas and electric utilities, called on Bo-Mac Contractors in 2012 to construct concrete barriers. The specialist in civil, piling and marine construction services then turned to Cemex for high performance concrete.

“They called us for our technical expertise, and basically wanted to know if it would be possible to put our trucks on barges to transport them to the pour site in the middle of the channel,” says Cemex Territory Account Manager Eric Edwards, noting the delivery method was a first for the Houston operations.

The plan called for floating four trucks out to the repaired tower base to pour small concrete barriers preventing future power outages. The job was accomplished with no problems, but over time the barriers proved inadequate and several more collisions had occurred. Centerpoint Energy enlisted Bo-Mac in 2015 to build a more permanent tower protection structure, concrete for which would again arrive from a Cemex Houston plant.

The design for a new, more robust barrier system called for 650 yd. versus 40 yd. on the initial structure. It would require six pours, two trips per day, two times a week and up to six trucks for each trip. And if the large increase in project size wasn’t enough, market conditions added another factor. The first project occurred in a down market, the second at a sharply busier time for Houston ready mixed producers.

The one-and-a-half hour trip from mixer truck barge boarding to the pour site called for a mix that could go the distance without losing slump. “It required a mix design that could essentially be put to sleep,” Edwards explain. “It was an opportunity for our team to showcase just what we were capable of doing. Safety, quality control and operations were notified, and we went to work.”

The team devised a 5,000 psi mix that incorporated a high range water reducer plus Recover 7, a set delay additive. The mix provided Bo-Mac crews up to seven hours to complete the pour before setting. “Our team’s customer-focused approach to this project was the key to success. We are proud to have completed this unique and challenging project safely and successfully,” affirms Cemex Regional President, Texas and New Mexico Scott Ducoff.