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Slump Loss in Pump Lines Concrete Construction Magazine

Directors: UPCOMING MONTHLY MEETING - Concrete

slump at the end of the pump line. Once the slump loss during pumping can be determined, acceptance or rejection of concrete based on slump can then be de-termined at the delivery point. For exam-ple, if a 1-1/2 in. slump loss during pump-ing has been established and …

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Lightweight Concrete for Pumping| Concrete Construction

Best Mix for Pumped Concrete | JLC Online

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Testing Fresh Concrete at Point of Delivery

Making Concrete Pumpable| Concrete Construction Magazine

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Seeing a shrink? | Roads & Bridges

For the concrete temperatures below 68°F measured at the plant, the slump loss were below 4 in. Thus, if the slump values were kept above 8 in. at the plant, a minimum of 4 in. would be achieved at the jobsite, which was satisfactory for placement. SC concrete finished easily at these slump values.

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Why Pump Concrete? | Construction Equipment

Sep 28, 2010 · A concrete pump places concrete faster and more accurately with less labor than any other method. A job that would take five men two and a half hours to pour would only take three men one hour to pump. Contractors who pump concrete consistently report labor savings of 50 percent compared to truck dumping.

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Technical Questions and Answers Archive - American

Wet-mix is more difficult to pump as it has more internal friction pushing the low-slump concrete through the line. Shotcrete contractors will try to minimize the delivery line length in wet-mix to make pumping easier and reduce the chance for plugs in the line. With proper planning, concrete mixture selection, and delivery line choices, wet

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Title Slide - PCA

The type of member or construction. pump lines, and other equipment for handling concrete should be shaded, painted white, or covered with wet burlap to reduce the effect of solar heating. Forms, reinforcing steel, and subgrade should be wetted with cool water just before the concrete is placed Delays contribute to slump loss and an

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Experimental Observation on Variation of Rheological

Dec 29, 2018 · Looking at the rheological properties and slump test results from T7-S30, T7-S50, and T7-S80 (in Table 3, Figs. 2 and 3), it was found that the rheological properties of concrete changed due to pressure and shearing inside the pump. In all three cases in the T7 test, the slump and the slump flow increased, and the viscosity decreased.

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Concrete Acceptance Testing - NRMCA

Jun 04, 2021 · NRMCA Pre-Construction Checklist – Concrete Acceptance Testing Page 4 of 5 Notes Note 1: *MS, ACI 318-19 (26.12.1.1(c)), ACI 301-20 (Section 1.7.3.1), and ACI 311.6-18, Specification for Testing Ready Mixed Concrete (Section 1.2.2) require that the agency performing acceptance testing comply with ASTM C1077 Standard Practice for Agencies Testing Concrete and

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Concrete Slump Test Procedure, Applications & Types of Slump

Feb 16, 2017 · Procedure of Concrete Slump test: The mold for the concrete slump test is a frustum of a cone, 300 mm (12 in) of height. The base is 200 mm (8in) in diameter and it has a smaller opening at the top of 100 mm (4 in). The base is placed on a smooth surface and the container is filled with concrete in three layers, whose workability is to be

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Concrete Slump Test for Workability -Procedure and Results

Concrete slump test is carried out from batch to batch to check the uniform quality of concrete during construction. The slump test is the most simple workability test for concrete, involves low cost and provides immediate results. Due to this fact, it has been widely used for workability tests since 1922.

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10 Tips for Concrete Management in - For Construction Pros

Jan 28, 2020 · "You can lose a lot of slump when you pump [lightweight concrete]," Lloyd says. Because lightweight that is not saturated absorbs water so quickly, Lloyd advises putting the lightweight aggregate in a pit and soaking it before mixing. "Water sprinkling is not enough," he cautions. "You will lose slump."

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A Contractor's Guide to Superplasticizers

tion, the concrete may lose that additional slump after 30 minutes. Fi g u r e 1 shows slump loss at va r i-ous mixing times of concre t e s t reated with different superplasti-c i ze r s. In the 90-minute time f ra m e, the smallest slump loss is 1 inch compared to the larg e s t slump loss of over 4 inches. References 1.

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Principle of mix design for pumpable concrete

Sep 23, 2020 · A loss of slump during pumping is normal and should be taken into consideration when proportioning the concrete mixes. A slump loss of 25 mm per 300 meters of pipeline length is not unusual, the amount depending upon ambient temperature, length of the line, the pressure used to move the concrete, moisture content of aggregates at the time of

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Good Vibration Equals Quality Concrete | For Construction Pros

Jan 02, 2020 · 2. Plunge the vibrator vertically into the concrete. Use a uniform spacing not to exceed about one and a half times the radius of influence over the entire placement area as illustrated in Figure

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"Pouring" concrete? - JLC-Online Forums

Jul 15, 2004 · The concrete was a Super-P mix, designed specifically for the project to allow the mix to be pumped into the ins and outs of the walls. The mix design spec from the concrete supplier is very specific on how to check the mix: The load should show a 2" slump when it arrives at the site. Ten minutes prior to placement, you add the Super-P.

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Construction Practices and Defects in Drilled Shafts

fluid concrete with coarse aggregate as small as is feasible and slump generally in the range of 7 to 9 in. (175 to 225 mm). In addition, slump loss must be controlled such that if delays occur in placing the concrete, the concrete will retain at least marginally acceptable fluidity. The use of well-graded aggre­

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NCDOT Construction Unit

slump from the truck after the Contractor adjusts the water. 2) Concrete is placed in the pump and a sample is taken at the discharge end of the pump after any grout or slick pack used to lubricate the lines is completely clear of the lines. (This sample should be taken from a …

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MAPEPLAST N10, technical sheet | Mapei UK

Plasticizing admixture for concrete with low slump loss Where to use Its principal uses are for: • ready-mix concrete (especially in hot weather); • pumped concrete; • mass concrete. Consumption Dosage in volume: From 0.2 to 0.5 l per 100 kg of cement. Packaging …

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Slump Loss in Pump Lines| Concrete Construction Magazine

Mar 01, 1972 · Slump loss generally does not occur in small line pump systems. If long lengths of flexible hose are used, a slump loss may occur because of the higher coefficient of friction in the hose line. There are no specific data available on slump loss in small line systems. However, the American Concrete Institute JOURNAL, November 1970, page 950, contains an article which points out the possible slump …

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