Slump Loss in Pump Lines Concrete Construction Magazine Related Information

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

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.

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

Coarseness -Workability -Consolidation A New Approach

Mix Concrete Conduct: Slump, Unit Weight, Air, and Box Test Did it Pass the Box Test? Add WR and Remix Conduct: Slump, Unit Weight, and Box Test. Make Cylinders Was WR added? No Yes Put Material from slump and box test into mixer. Discard Air test Material Conduct Air Yes No

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.

Best Mix for Pumped Concrete | JLC Online

Mar 01, 2010 · About the Author Bill Palmer. Bill Palmer is former editor-at-large of Hanley Wood's Commercial Construction Group, which includes digital and print versions of Concrete Construction, Concrete Surfaces, The Concrete Producer, Public Works, and Masonry Construction.Previously, he worked for the American Concrete Institute for 10 years as engineering editor and director of …

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.

Slump Loss and Mix Water Content| Concrete Construction

Feb 01, 1993 · Concrete does change consistency somewhat during pumping, but this is not due to a loss of water. Specified limits on water-cement ratio apply to the concrete before discharge into the pump. Under most conditions slump loss should not be too great. Your question suggests that you may not be comfortable with concrete pumping.

Lightweight Concrete for Pumping| Concrete Construction

How to Specify and Use Concrete Pumplines| Concrete Construction M…

Best Mix for Pumped Concrete | JLC Online

The loss of air can be further exacerbated due to the transition from a high pressure in the pump to a near vacuum condition in the pump line. Most field experience suggests that air loss is greatest with high cement content and flowable concrete mixtures which slide down easier; however, air loss has also been experienced in mixtures with a moderate cement factor at about 500 lb/yd³ (300 kg/m³) and moderate slump.

Loss of Air Content in Pumped Concrete — What, why, & how

How to Specify and Use Concrete Pumplines| Concrete Construction M…

Holcim super-workable concrete used in Sunland

Dec 14, 2008 · Bleed in pump lines and final form placement The super-workable concrete mix was designed by Holcim to a w/c ratio with 10mm aggregate coarse and …

Concrete Pouring Steps and Techniques - Structural Guide

Concrete can be poured into the slab by using the pump car or manually concrete can be taken into the slab. Concrete Pouring in Piles. Concreting of piles is different from the other concreting methods. Special methods are used for concrete the piles. After the excavations are completed, the tremie pipe is inserted into the excavated pile.

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

Steel Fiber Reinforced Concrete FAQ - Bekaert.com

9. Can steel fiber reinforced concrete be pumped? Yes, but expect a 0.4" to 1.2" slump loss through the hose depending on the steel fiber dose rate, ambient temperatures and hose length. A midrange water reducing agent (MrWr) is commonly used to enhance workability and ease of flow through pump lines.

Slump Loss in Pump Lines| Concrete Construction Magazine

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 losses …

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

Top 5 Ways to Ensure a Successful ICF Pour: BuildBlock ICFs

Jun 30, 2017 · Concrete that is wet (high slump) will settle more and have a greater distance between the rod and the concrete. The recommended slump when pouring BuildBlock ICF walls is between 5 and 6 inches (concrete, when pumped under pressure, will lose a ½" of slump so you may want to add a ½" of slump to the concrete going into the pump hopper).

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.

Pumped Concrete-Pump Types, Working, Technique and

Jun 30, 2018 · Pumpable concrete is the concrete which can easily pass through a pipeline without causing segregation and bleeding is called pumped concrete. They are mostly used in concrete pumps for high rise building. Using pumpable concrete you can transfer concrete from mixing place to construction place without causing any delay in concrete placing.