More stories about Aggregates

  • A Problem with Lignite

    Seven days after our contractor poured a concrete driveway, the concerned homeowner called us, instead of the contractor, when he started noticing small pop marks throughout the concrete. After speaking with the concrete finisher and after considering all of the possibilities, we concluded it was...

  • Mixed Results

  • Figuring the Specific Surface Area

    I am looking for a way to calculate the specific surface area (total surface area) of an aggregate that I am using in concrete.

  • More on Limestone Aggregate and Warehouse Floors: A Reader Responds

    As a specialist in industrial floor-hardening products, I am responding to a couple of comments in the "Troubleshooting" column from the October 2002 issue. The comments were in reference to specifying limestone as coarse aggregates in concrete floor slabs. In the last paragraph, the column...

  • 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...

  • Gray-Water Compensation

  • Lower Strength with Fibers?

    A participant in Aggregate Research IndustriesÆ Industry Forum (www.aggregateresearch.com/forum) recently posted an interesting question that has challenged our industry since fibers were introduced. The participant started by stating that heÆs noticed a disturbing trend in a recently prepared set...

  • Concrete Temperature and SCC

    One question recently posed on Aggregate Research Inc.Æs Industry Forum (www.aggregateresearch.com/forum) drew a number of interesting and important answers that may help you this season. The questioner wrote: ôIÆve noticed that a variation in ambient temperature can have a big effect on the...

  • Railing Toward Plant Efficiency

  • Do Guidelines for Recycled Aggregates Exist?

    I work for the Ohio DOT. I am looking for sources of information where recycled concrete (RC) was used as aggregate in new concrete. Have you used recycled aggregate in new concrete? What was the new concrete used for? What problems did you encounter with recycled concrete as an aggregate?