Is it possible to create exposed-aggregate walkways with enough rock at the surface to make pedestrians think they're walking on gravel paths? Ahal Contracting Co., St. Louis, proved the task can be done when its crews placed 40,000 square feet of exposed-aggregate walkways for the Missouri Botanical Garden's Boxwood Garden and the Kemper Center for Home Gardening. The four different concrete mix designs used for the project contained aggregate concentrations higher than those found in the typical exposed-aggregate mix.
If you're a concrete contractor, it's important that you maintain adequate clear cover in vertical concrete structures. With proper cover, reinforced-concrete structures are likely to exhibit improved structural integrity and finished appearance as well as greater resistance to fire and corrosion. Without it, the reinforcement is vulnerable to corrosion and the concrete to early deterioration. Though designers specify clear cover for vertical formed surfaces, they seldom specify the means for maintaining it. That's the contractor's responsibility.
Your job: to cut control joints in a highway's green concrete as quickly and efficiently as possible. One of the easiest ways to do that is to use a saw with a horsepower (hp) rating of at least 65. Most of today's big jobs can be cut to size with the 65- to 75-hp saws featured in this product roundup. And if you plan to tackle a monster job, be sure to check out the 112-hp saw or the 250-hp span saw also described in the article. No matter which of these saws you choose, you're sure to have plenty of power to play with on your next job. These versatile machines can be used to tackle many jobs, ranging from the full-depth removal of slabs to the shallow control-joint sawing that's the focus of this roundup.
Many dams, especially earthen embankment dams constructed prior to 1960, do not meet today's higher hydraulic design criteria. Hydrologically deficient, these earthen dams were simply not designed to safely store or pass at least one-half the calculated probable maximum flood. As engineers search for cost-effective ways to rehabilitate deficient embankment dams, more and more of them are discovering the value of roller-compacted concrete (RCC) overlays.