Manual Vicat Apparatus

The Manual Vicat Apparatus measures the setting time of cement paste, which tells a site how long a mix stays workable and when it has hardened enough for the work to move on. Each determination gives two figures: the initial setting time, when the paste starts to stiffen, and the final setting time, when it has hardened.

Both are found by dropping a weighted needle into paste held in a mould at intervals and reading how far it sinks on the graduated scale. The apparatus follows EN 196-3 and ASTM C191, the European and North American methods for cement setting time.

Laboratories use the results for research on new binders, for quality inspection of incoming cement and for compliance work in concrete formulation. Because the frame is operated by hand, the technician sees every penetration and can judge each reading before it goes into the record.

The apparatus works to EN 196-3 and ASTM C191, the two main methods for the setting time of cement paste. For highway and transportation work it also meets AASHTO T131, and it covers the ISO method for setting time and soundness as adopted in Europe, EN ISO 9597.

The same frame serves related materials. EN 480-2 uses it to find the setting time of mixes that contain admixtures, and EN 459-2 applies it to building lime. Laboratories that also report to GOST 310.3-76 or GOST 31376-2008 can run those methods on it as well.

Where a laboratory works to more than one of these standards, it keeps one frame and changes the accessories that the method calls for. The readings for every standard then come from the same stand, rod and scale, which makes results easier to compare between test programs.

Order the accessory set that matches the standard on your test reports, because the frame, designated VicatGen/M, is supplied on its own. The needles, moulds and plates that go with it are decided by the method, so the set is chosen together with the frame.

For EN 196-3 and the related European methods we supply the basic EN accessory set, reference NG-L028. For ASTM C191 and AASHTO T131 the set is reference NG-L0028/A, made up to the North American methods.

A laboratory that reports to both families of standards can order the frame with both sets and change accessories between test series, keeping a single stand on the bench.

Name the standards you report against when you ask us for a price, and we will put the frame and the matching accessory set on one quote.

Initial setting time is the time from adding water to the cement until the paste has stiffened enough that the 1 mm needle can no longer penetrate to within 5 to 7 mm of the bottom of the mould. Before that point the needle sinks almost to the base; after it, the paste begins to hold the needle up.

In practice the filled mould sits under the rod, the needle is lowered until it touches the surface of the paste, and the rod is released. The penetration is read on the graduated scale, and the drop is repeated at intervals on fresh spots of the paste, with the needle wiped clean between drops.

The stopwatch starts when water meets cement, so the clock runs from mixing and not from the first drop. That reading matters on site, because it marks the end of the time available to place and compact the mix.

Final setting time is reached when the 1 mm needle still marks the surface of the paste but the 5 mm attachment no longer leaves an impression. At that point the paste has hardened enough to carry a light load without being indented.

The change from initial to final set is gradual, so the operator keeps dropping the needle at intervals after the initial reading and looks at the surface as closely as at the scale. The first drop on which the attachment leaves no mark gives the final setting time, counted from the moment water was added.

Under EN 196-3 the mould is turned over after the initial set, so the final readings are taken on the smooth face that was against the base plate. The interval between the two figures shows how quickly a cement or a mix stiffens, which helps when scheduling finishing work on site.

The 300 g figure is the total mass of the moving parts: the sliding rod together with the needle or plunger screwed into its lower end. Setting time standards fix this mass, so that a reading taken on one apparatus means the same as a reading taken on another.

Penetration depends directly on the load behind the needle. A heavier rod would sink deeper into the same paste and report a later set, and a lighter one would do the opposite, so the mass belongs to the definition of the test itself.

On the Manual Vicat Apparatus the needle and the plunger each screw into the rod to make up that weight, so the load stays the same whichever part is fitted. Replacement needles and plungers are best taken from the accessory set for your standard, which keeps the moving mass at the value the method sets.

The plunger is used before the setting time test, to bring the cement paste to standard consistency. Trial pastes are mixed with different amounts of water, and the plunger is dropped into each one until the paste that holds it at the depth the method requires is found.

That water content is then used to make the paste for the setting time determination. Fixing the consistency first matters because a wetter paste stays soft longer and a drier one stiffens sooner, so two laboratories testing the same cement at different water contents would report different setting times.

On the Manual Vicat Apparatus the plunger screws into the bottom of the rod in place of the needle, and the same graduated scale reads its penetration. One frame therefore carries out both steps of the method: the plunger for consistency and the needle for setting time.

The scale is read through an adjustable indicator that moves with the sliding rod, so every drop of the needle shows up directly as a distance on the graduations. Before a series of readings the indicator is set to the reference point the method calls for, and each later reading gives the depth the needle reached.

For each reading the operator lowers the needle until it just touches the paste, releases the rod and reads the scale once the needle has come to rest. Letting the rod fall freely, without pushing or slowing it, keeps the load down to the weight of the moving parts alone.

The same scale serves the plunger and the needle, so consistency and setting time are read from one set of graduations. A clean scale and a rod that slides freely are the two points worth checking at the start of each testing day.

Besides the frame and its accessory set, a setting time determination needs a balance, a measure for the mixing water, a stopwatch, a glass dish, an enamel tray and a trowel.

The balance weighs the cement and the water to the accuracy the method requires, and the stopwatch starts the moment water meets cement, which is where the setting clock begins. The glass dish holds the paste while it is prepared, the enamel tray gives a working surface for mixing and for the mould, and the trowel fills and levels the mould before the first penetration.

EN 196-3 and ASTM C191 both prepare the paste in a standard mechanical mixer, so many laboratories add one to the bench. Our mortar mixers cover that step, and the paste then reaches the Vicat mould mixed the same way for every test.

Yes. Besides cement, the apparatus works to the related lime and gypsum standards, because those binders also stiffen with time once water is added and are checked with the same needle principle. For building lime the method is EN 459-2, which uses the Vicat needle to find the setting times of limes with hydraulic properties.

Gypsum plasters set much faster than cement, so the readings come at shorter intervals, but the principle stays the same: a needle of fixed weight dropped into the paste, with the penetration read on the scale.

Running these materials on the same frame keeps a lime or plaster laboratory on one instrument and one way of reading, with the needle, mould and plate following the standard in use. For a producer that makes both cement-based and lime-based products, one apparatus covers the setting checks on both lines.

Admixtures such as accelerators and retarders exist to change setting time, and the Manual Vicat Apparatus measures how much they change it. It works to EN 480-2, the European method for the setting time of mixes that contain admixtures.

The test compares two mixes. A reference mix without the admixture and a test mix with it are prepared under the same conditions, and the Vicat needle finds the setting times of both. The difference between them shows whether a retarder delays set by the amount claimed, or an accelerator brings it forward.

For a concrete producer this is a practical check before a new admixture or a new dosage goes into production, for instance when hot weather calls for more working time. Because the frame is operated by hand and needs no power, the comparison can run on the same bench where the mixes are made.

The Manual Vicat Apparatus measures 15 × 19 × 31.8 cm (5.9 × 7.5 × 12.52″) and weighs 3 kg (6.6 lbs), so it takes a corner of a laboratory table. It needs no services of any kind, and it can be carried to whichever bench the paste is mixed on.

That makes it a practical choice for plant laboratories, teaching laboratories and sites that run a few setting time tests a day, where the operator is at the bench anyway while the paste is prepared and the readings are taken.

Where setting time is run many times a day, or where the result has to be free of operator timing, the Automatic Vicat Apparatus performs the same determination under motor control and stores the data. Some laboratories keep both, with the manual frame as a second station for busy days.