Screed

About: Screed is a research topic. Over the lifetime, 1899 publications have been published within this topic receiving 11118 citations.

Motor grader having material distribution attachment

Abstract: A motor grader can be adapted for laying down a layer of granular material such as base rock or cold mix asphalt by mounting a dispensing hopper attachment onto the front of the motor grader and a spreading and leveling screed onto the moldboard. As the motor grader advances, it pushes a dump truck that continuously loads materials into the hopper. Those materials are in turn continuously discharged at a metered rate of flow through the bottom of the hopper and onto the roadbed. The resulting swath of materials passes between the front wheels of the grader as the grader continues to advance, whereupon the screed engages the swath and spreads the materials in opposite lateral directions while leveling them to the desired depth. The screed has swept-back wings that may be extended as necessary to adjust the overall width of the screed, and outboard shields on the outermost ends of the wings confine the spread materials to the roadbed and prevent their accidental discharge into ditches and the like alongside the roadbed. The crown of the deposited layer can be varied by tipping the nose of the screed upwardly or downwardly to the extent necessary or desired.

Obergfoll concrete screed level

Abstract: Today's process of screeding, or evening out, wet concrete is an inefficient and arduous system requiring two (or more) men, a 2×4 wooden beam, and wooden forms to level the surface of wet concrete. The Obergfoll Concrete Screed Level, or “OCSL,” allows a single person to screed concrete as accurately, more easily and in less time than it takes the standard two man screeding technique used today. The OCSL is uniquely designed to allow a single person to accurately level and screed wet concrete. The screeding bar also incorporates a leveling bubble allowing for continuous verification of even leveling throughout the screeding process. The ergonomically designed dual handles act as convenient and efficient levers, allowing easy and accurate screeding of heavy wet concrete by one single operator, instead of the customary two or three person job.

Evaluation of the Effect of Sampling Location on Laboratory-Measured Quality Control Parameters

Abstract: The sampling of hot-mix asphalt (HMA) is an important part of the quality control testing process. The quality of the sample can have a significant effect on the test results. When a sample of HMA is taken, the technician's goal should be to obtain a sample that is representative of the mixture that will be placed on the pavement and is not segregated or contaminated by foreign materials. Several possible choices exist for sampling locations. Samples may be taken from the back of the haul truck at the plant with either a shovel or a robotic sampling device. Samples can be taken at the paving site directly behind the spreader after the mix has been released from the screed but before the first roller has passed over it. Samples can also be taken with cores being cut from the compacted roadway. Each of these methods has its advantages and disadvantages. For this study, samples of two mixes were taken at various locations (truck by shovel, truck by robotic device, behind the spreader, and cores) for a period...

Cementitious binders, activators and methods for making concrete

Abstract: A cementitious binder comprises at least 90 % by weight of a hydraulically- active material comprising ground granulated blast furnace slag (GGBS) and/or pulverised fuel ash (PFA), and at least 0.1 % by weight of CaO in an activator composition for the hydraulically-active material. The cementitious binder does not comprise any Portland cement and is, therefore, more environmentally friendly. The binder further comprises a superplasticiser such as a polycarboxylate ether (PCE). A concrete, mortar, grout, screed or render may be formed from a mixture of the cementitious binder, aggregate particles, water and superplasticiser.

Sport-hall flooring

Abstract: In the case of a sports-hall flooring, in particular for gymnasiums, having a flexible layer applied on an underflooring or naked flooring of screed or the like, on which layer an impact-absorbing and force-absorbing layer is arranged, if appropriate with a film of plastic or the like in between, the impact-absorbing and force-absorbing layer comprises at least two plies of polyolefin sheets. The polyolefin sheets of at least one ply have on their surface facing the other ply a nonwoven fabric and are bonded to the other ply with the nonwoven fabric being incorporated.