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Does high fly ash concrete provide the same passivating protection as portland cement?
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What causes popouts? Popouts on a concrete surface are from absorbant aggregates that freeze and expand.
We're soon starting a job that calls for structural lightweight concrete. How does this material differ from normal weight concrete and what should we be prepared for in working with it?
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Can fiber reinforcement be used in a swimming pool deck or will fibers at the surface be a problem for bare feet?
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I am planning to build a house using structural concrete insulated panels (SCIP)—that is, foam panels that have wire grids on each side and are faced with shotcrete, such as 3-D panels or the Solarcrete system. Is it possible to use foamed or cellular concrete as the facing for these systems? What...
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What's the nominal weight of standard concrete?
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Is there a difference between w/c and w/cm?
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Is it worth the performance enhancement and peace of mind to go with the more expensive polycarboxylate admixture as opposed to using a naphthalene-, lignin-, or melamine-based admixture?
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Questions about the effects on curing of temperature and superplasticizers.
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I am a concrete contractor in the Southwest and to beat the heat in the summertime, I cast my slabs early in the morning, starting before dawn. By avoiding the heat of the day, doesn't this reduce the need for curing?
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What tests can I use to determine if the curing has been effective?
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I am using a superplasticizer in my concrete. I have heard that since this is a water-reducer, the need for curing water is reduced. Is this correct?
We've been asked to bid on a polishing project on a recently placed slab. The engineer had been concerned about controlling concrete drying shrinkage. He developed a concrete mix design optimization plan that resolved many of the problems that occur on industrial slabs on ground. The slab has...
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Is it permissible to use synthetic aggregate produced from FGD sludge in lightweight concrete?
Over the past fifty years, CONCRETE CONSTRUCTION's contributors have enjoyed serving our readers by finding innovative answers to their concrete quandaries. We look back at fifty years of Problem Clinics.
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Have you ever experienced problems with delay in setting in the presence of ground granulated blast furnace slag or fly ash and water-reducing admixtures, especially using imported cement?
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I am planning a pour for a 15-foot-high wall and am concerned about form pressures.
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I am going to glue some fiber reinforced polymer on a concrete beam, but I'm concerned that some oil spilled on the beam may prevent the epoxy glue from adhering well. How can I remove oil that has been spilled on the concrete?
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In an effort to encourage students to become more aware of the American Concrete Institute (ACI) and someday become members, the ACI Construction Liaison Committee, along with the Kansas and Missouri Chapters of ACI, sponsored a competition to solve a construction problem.
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I have heard about the greater influence temperature has on strength development with high volume fly ash concrete, but I can find little in the way of quantifiable data. Is there a greater sensitivity to changes in ambient conditions with HVFA? And is the relationship between test specimens and...