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In 1911 the log cabin was enjoying renewed popularity as a style for resort and recreational buildings.
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A major concern in underwater concreting is that the water in which concrete is placed will wash away cement and sand or mix with the concrete and increase the water-cement ratio.
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After the death of Mrs. Anna Marie Johnson of Billings, Montana late in 1984, her family decided to build a chapel in her memory.
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When concrete flatwork has to be resurfaced, the first steps in the process are often the most critical.
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Putting together 921 pieces to make a pair of bridges isn't easy, particularly when the parts weigh as much as 32 tons each.
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Some users call it the shrink form--a reasonable enough name for a hydraulically-powered machine with a core that shrinks.
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The diamond is the hardest substance known to man. Diamond saw blades can grind out-of-spec concrete flatwork to tolerance without causing any damage or lessening the structural integrity of the surface. They can also groove slabs to produce a skid-resistance texture, and have many repair...
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How do you find the chemicals needed for removing stains from concrete?
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All too often the concrete in a concrete house gives way at the roof line to conventional stick construction. Not so with a system recently developed in Florida using expanded polystyrene foam forms, shotcrete walls, and pumped concrete on the roof.
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Concrete floors have been used on a large scale in single-family houses. Toronto developer J.D.S. Investments Limited started using a precast hollow-core slab floor system in apartment construction because it was fast and simple to erect, even in freezing weather.
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One of the 1985 Concrete Reinforcing Steel Institute Design Awards was presented to the Lawson residence in Alta, Utah.
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The September 1984 issue of Concrete Construction contained the results of a research study of the previous year by Ernie Karl Schrader III, who was 10 years old at the time the work was done.
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After ten years at a cost of two billion US dollars, the Delta Project--a storm surge barrier in the Eastern Scheldt of the Netherlands--is nearing completion.
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A single truck can deliver a precast basement wall system which requires no poured footings.
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One concrete roof tile manufacturer is so confident of the durability of the product that he gives a 50-year warranty with every installed roof.
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On West 57th Street just a few feet east of Carnegie Hall rises the sumptuous new Metropolitan Tower, New York City's tallest residential building and tallest reinforced concrete building.
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The City of Boulder chose cast-in-place concrete for the box culverts carrying Colorado's Goose Creek under the Foothills Parkway. These 7-barrel and 5-barrel culverts, each more than 300 feet long, were built with 5x8-foot barrels.
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A relatively small building, Unity Temple, in Oak Park, Illinois, has assumed an importance in concrete history far beyond its size and appearance.
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Before trying to remove stains, study the general principles and methods that make success possible, particularly the use of bandages and poultices.
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A growing number of architects and owners are opting for concrete flatwork that resembles slate, brick, tile, stone or even wood. Stamped concrete creates an illusion of expensive slate or tile at a fraction of the cost.
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Adding an air-entraining agent to concrete dramatically improves resistance to surface scaling caused by freezing and thawing and deicing agents.
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Two examples of floors that must be made superflat are those in narrow-aisle high-rise storage facilities and those in television studios.
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Each tool for finishing concrete has a specific purpose, and choosing the right tool is important. But knowing how to use the tool correctly is what really counts.
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For 50 years power floats and trowels have been used for finishing large areas of concrete flatwork. In order to achieve the highest production rates and greatest profits, the machine must be used efficiently. Efficiency comes only with knowing the machine and its proper uses.
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The formwork trades refer to the practice of using single-post shores in two tiers as double decking; occasionally triple decking (three tiers) has been used. Over the past 30 years this characteristically unstable system has been the cause of innumerable formwork-shoring collapses.
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Located on the Potomac River about a mile upstream from Washington, DC, the Little Falls Dam has been the site of 22 drownings since 1975.
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Deviations from standard test methods may cause good concrete to be rejected or poor concrete to be accepted.
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The American Concrete Institute (ACI) has developed one of the most successful nationwide certification efforts devoted exclusively to the concrete industry. The examinations required for certification as a Concrete Field Testing Technician--Grade I cover physical testing of fresh concrete in...
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Laboratory testing is the common element which all participants in the construction process utilize to provide assurance that their part of the process is correct.
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Ten jagged and textured cast towers and other free-standing totems shown recently at an Oberlin, Ohio gallery were titled collectively "The Gathering" by sculptor Elizabeth Burger.
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There's a good market for concrete curb and gutter work in many areas of the country.
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Before trying to remove stains, study the general principles and methods that make success possible, particularly the use of bandages and poultices.
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THE PROBLEM: Reinforcing steel frequently must pass through a construction joint to lap with bars in the next placement and establish continuity--for example at wall and slab intersections or at vertical joints in walls.
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Every year in the United States, more than 100 people are killed in trench cave-ins. Most of these accidents happen on smaller jobs in excavations less than 20 feet deep. Even if the excavation is only 5 feet deep, a cave-in can kill or maim workers setting forms, placing concrete, stripping forms...
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This article is primarily concerned with the joints that are needed to allow the concrete structure to function properly. It also gives some instruction about installing various embedded items that may be required: sleeves, anchors and other inserts, waterstops, heating ducts, radiant heating...
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Said to be economical for spans between 24 and 34 feet, a patented composite floor system consists of hollow-core precast planks supported at the ends by composite beams. The planks are set on precast beam forms that are supported by scaffolding. Beams are then cast by filling the pocket between...
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Pumping concrete from the bottom up made good sense to engineers and superintendents assigned to the Providence Hospital construction project in Mobile, Alabama.
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Color Concerto was designed for Purdue University Calumet in Hammond, Indiana with color as the primary purpose of the sculpture.
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Of all types of outdoor concrete flatwork, tennis courts may be the most demanding surfaces.
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Two hundred fifty thousand dollars were saved when a computer program was used to compute costs of over 1700 columns in a high-rise building already under construction in Chicago.
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St. Peter's, the majestic basilica in the Vatican, is the largest church in the world.
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Today is an exciting time for the concrete pavement industry. There are more opportunities and more changes taking place in the construction of concrete than at any time in recent history.
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Will manufactured, engineered wood beams and girders revolutionize formwork construction as manufactured plywood panels did in the past?
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To some specifiers and owners who want to get the best pavement buy for a highway, street or parking lot, the method for choosing between concrete and asphalt seems simple.
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Moisture in concrete slabs is essential for curing. But it can be detrimental to the adhesion of floor-covering materials such as resilient tile or sheet flooring, paints, coatings and sealers.
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The reason tolerances are more important today is that construction has become more sophisticated.
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On Thursday September 19, 1985 at 7:19 A.M., an earthquake jolted a large part of Mexico, causing enormous material damage and great loss of life in Mexico City and several other local towns. The Mexican Cement and Concrete Institute (IMCYC) responded immediately to official requests and with a...
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Unless all necessary measures are taken, and thoroughly executed, the part of a building that is below grade will most likely be troubled from time to time with intruding water.
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Joints in concrete flatwork help to minimize uncontrolled cracking. But if joints aren't properly planned cracks may still occur and mar the appearance of an otherwise good quality concrete job. When an area is irregularly shaped it is particularly important to carefully plan joint configurations...
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Concrete dome roofs for large water reservoirs have several advantages over flat roofs.
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Polypropylene fibers have been suggested as an alternative to using welded fabric wire for crack control purposes in concrete slabs.
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In the past several years, an increasing number of contractors have placed concrete containing polypropylene fibers. Fiber manufacturers have promoted the material as a practical alternative to the use of welded wire fabric for control of shrinkage and temperature cracking.
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A 23-foot-high concrete noise barrier at Heathrow Airport received a 1985 Commendation of The Concrete Society, England for "...an unusual but highly appropriate application of the use of concrete to fulfill an entirely technical function."
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Mixing water fit to drink has always been a basic requirement for good concrete.
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What happens to leftover concrete after the plant parking lot and driveways are all paved over? After the nearby landfills are filled? Nearly 130 producers replied to a Concrete Construction questionnaire on this subject.
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Stripping formwork from under a slab can be risky business, especially when the forms are large, heavy pieces.
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Forming and stripping practices, particularly for flat slab and flat plate construction, have developed to a high degree of efficiency during the past 25 years.
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Producing concrete with the correct yield and being able to verify that yield is extremely important to every ready mix producer and to every contractor.
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The popular assumption is that the driving public has an antipathy to tolls.
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Placing concrete for an addition to a water treatment plant in North Dakota was complicated by limited access to the construction site.
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You probably have already seen them enhancing sidewalks, driveways or shopping centers, but you may also find them in industrial facilities withstanding heavy truck loads. They are called concrete pavers, concrete paving stones, or concrete paving blocks.
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The decision to remove and replace faulty concrete can be a costly one.
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The slump test is a commonly used tool for quality control of fresh concrete at the jobsite and for enforcement of specifications. It has limitations however, that should be recognized. Unfortunately, slump does not describe the properties of workability, pumpability, and finishability that are so...
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Because accounting and estimating software programs follow most contractors' existing manual procedures, the contractor has to adjust his operating procedures only slightly to benefit from computerization in these areas.
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Ferrocement was the medium chosen by sculptor Frederic A. Nassaux for creation of the white danseuse Isadora. This composite material gave him plasticity without the massive weight of conventionally cast concrete.
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Our company is building an 8-foot-thick mat foundation for a sewage treatment plant. We want to use expanded metal as a forming material at the vertical construction joints. Since the mat is heavily reinforced, there are many penetrating reinforcing bars.
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Why don't we get grooves and ridges of reasonably uniform width and depth when we broom a slab for slip resistance?
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We've been searching for published standards for the tolerances allowed in finishing residential flatwork. Are there any you know of? Specifically, are there any standards for basement floor slabs that are intended for possible future living space? We hav
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Why do we sometimes see a series of ridges along the radius lines in the sweeps of the trowel on a floor surface? It doesn't happen often, and I haven't been able to figure out what's different when it does.
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How do I cut contraction joints across a wide slab of fresh concrete without using a bridge?
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We hear recommendations both for and against using internal vibrators in constructing floors and other flatwork. What's best?
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This detail shows a construction joint we are using on several underground structures.
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I want to make some concrete signs with recessed lettering and I need the name and address of a company that manufactures reversed letters for the purpose.
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This is my second year as a contractor doing residential and some commercial work, primarily walks, driveways and parking areas.
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We were pouring a slab for an outside loading area and had a sudden heavy rain on the last day of a two-day pour.
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Is there anything one can do, short of putting a slip joint between a slab and the masonry bearing wall that it rests on, to prevent breaking the bond to the mortar joint between them?
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Recently we put in a floor very close to some power lines. When we realized that the handles of bull floats could easily come into contact with the power lines, we quickly slit some large rubber hose to slip over the handles and bound it in place with ele
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We are concerned with the maintenance of a cast-in-place school building built in our town in 1937--one of four local schools built by the Works Progress Administration (WPA). In its lifetime it has had several coats of paint. Finally it has become necess
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A customer reports that he got a nice white color when he applied our curing agent to a broomed-finish pavement the day after finishing. However, he complains that the same curing agent leaves the concrete looking dark when he applies it immediately after
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Our firm was hired to repair leaks in the concrete roof of a college building in North Carolina. The roof doesn't have many cracks, but most of the joints are leaking where PVC (polyvinyl chloride) waterstops placed in the joints have separated from the c
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We recently installed a concrete walk that was damp cured. We have noticed thin but deep cracks in a few spots. The contractor called them "heat cracks." Though they are not wider than one's fingernail I am concerned that they will worsen as the freeze-thaw season approaches.
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I think there is a typographical error in "Recommended Practice for Concrete Formwork, ACI 347-78 (Reaffirmed 1984)."
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Has anyone ever written up a list of things that a contractor can readily do to prepare for some of the problems that often come up unexpectedly?
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I would like to know how contractors cope with concrete slabs poured in the summer and sealed with a sealer. I've used two different types of sealer but in both cases I got salt scaling the following spring where salt had been thrown around. I know it is
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Concrete is sticking to the forms of our stringline curb forming machine and peeling off the newly formed curb as the machine moves on. Temperatures have been very warm, rising to about 90 to 95 degrees F in midafternoon. What causes this problem, and wha
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We constructed some white flatwork with 3/4-inch redwood separators between panels. The top 3/4 inch above the redwood was caulked. This white concrete adjoins an area of pattern-stamped dark gray concrete, so we were asked to use a black caulking materia
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Is there an accurate, quick and inexpensive way to determine the percent of water in aggregate?
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This picture shows a foamy area that showed up on a 35-foot column after the forms were stripped. On close inspection you can see exposed aggregate, both fine and coarse, in the defective area. In some places you can even see exposed rebar.
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Why does good concrete crack at random locations even though the sidewalk has been jointed?
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We contracted to remove and replace a cracked and broken topping in a 6 x 40-foot area of the second floor of a two-story concrete garage. The structural steel of this building, built about 50 years ago, is buried in the concrete. Although the owner thoug
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Last December we cast the first and second floors of a building by placing concrete 2 1/2 inches thick over precast plank. Late in April the owner reported that extensive random cracking has appeared on the first floor and a small amount on the second flo