Consistency and Workability

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Precast Texas-Style

The PCI show proves everything's bigger in precast. More

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New Products
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Best of the Best

WOC attendees and editors select Most Innovative Product winners. More

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Fast Lane

Route 90 is one of the South's most traveled scenic highways. But more importantly, it's a major Gulf Coast artery, carrying travelers from the Florida Panhandle to New Orleans and beyond. So when Hurricane Katrina destroyed the existing four-lane bridge between Biloxi and Ocean Springs in 2005, the Mississippi Department of Transportation (MDOT) knew the structure had to be rebuilt as quickly and durably as possible. More

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Silica Fume's Advantages

As a producer, I would like to learn more about adding silica fume to my mix. What are its effects and where can I get more information? More

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Managing Paperwork
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Standardized Tests for SCC

More of our customers are starting to ask us about the possibility of using self-consolidating concrete. What’s going on with the development of standardized tests for SCC? More

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Cleaning Slump Block

What are the most effective products to clean and to seal the older type slump block. I’m working on a 1977 vintage slump block home. More

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A Caisson Problem

I have a ready-mix customer who is supplying concrete for caissons. The mix design is an ordinary caisson mix (similar to CDOT Class BZ) designed for 6- to 8-inch slump placements. The caissons range from 30 to 60 inches in diameter and are 20 to 25 feet deep. They have not encountered any water during drilling. The concrete is being placed with a tremie, with the top 10 feet being vibrated after the tremie is withdrawn. The problem is that sometime before the concrete hardens, a vertical subsidence of 3 to 4 inches occurs in the middle of the caisson. Anchor bolts placed in the plastic concrete are no longer in the correct position. Why is this occurring? More

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What Causes Cement Balls?

How can we eliminate the cement balls that we’ve recently discovered in our concrete? This problem seemed to start after we recently installed a new batch controller on our transit-mix plant. Before that, we had operated the plant manually. We’ve always monitored slump and mix consistency closely. Also, since the problem has started, we have been very diligent in checking that our drivers rotate their drums for the required 100 revolutions on each load. Thinking that our mixer fins were causing the problem, we brought every driver in on the last rainy day to clean out every mixer. Then the mechanics measured every fin to be sure that they were within manufacturers’ tolerances. Yet we still have this problem. Also, we often notice color variations when we produce integrally colored concrete. But even with uncolored concrete, customers report that some areas of the hardened concrete are a darker gray than others. Do you think that this is an equipment failure, a driver problem, or some batching problem? More

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