Standard: ASTM C187-04, ASTM C191-04, AASHTO T 129-06, AASHTO T131-06
Vicat Apparatus
The Vicat Apparatus is used to determine the setting time and consistency of cement paste, mortar, and concrete. The apparatus consists of a plunger, a mold, and a measuring device.
The test involves placing a cement sample in the mold and applying a standard plunger to create an indentation in the sample. The setting time is determined by measuring the depth of penetration of the plunger over time. This helps engineers and researchers understand the characteristics of cementitious materials and ensures that they meet specified standards for construction projects.
The vicat frame consists essentially of a metal stand with a sliding rod. An adjustable indicator moves over a graduated scale. The needle or plunger is attached to the bottom end of the rod to make up the test weight of 300 g. The frame is supplied with basic ASTM & AASHTO accessories.
Features of Vicat Apparatus
- Metal Stand with Sliding Rod: The frame of the Vicat apparatus is usually made of metal and includes a sliding rod mechanism. This rod allows for precise adjustment of the position of the plunger or needle.
- Adjustable Indicator: An indicator is attached to the sliding rod, which moves over a graduated scale. This indicator allows for accurate measurement of the depth of penetration of the plunger into the cement sample.
- Plunger or Needle: The bottom end of the sliding rod is attached to a plunger or needle. This component applies a standard test weight (typically 300 g) to create an indentation in the cement sample.
- Graduated Scale: The frame includes a graduated scale against which the indicator moves. This scale is typically marked in millimeters and allows for precise measurement of the depth of penetration.
- ASTM & AASHTO Accessories: The Vicat apparatus often comes with additional accessories that comply with ASTM (American Society for Testing and Materials) and AASHTO (American Association of State Highway and Transportation Officials) standards. These accessories may include molds, testing procedures, and other equipment necessary for conducting standardized tests.
Technical Specifications
| Model Number |
NL 3012 X / 004 |
| Standard |
ASTM / AASHTO |
| Dimension (mm) |
215(W)x160(L)x323(H) |
| Approx. Weight |
4.0 kg |
Set Consists Of:
| Model Number |
Parts Description |
| NL 3012 X / 004 – P 001 |
ASTM / AASHTO |
| NL 3012 X / 004 – P 002 |
Initial Needle Ø 1.0 mm ± 0.05 |
| NL 3012 X / 003 – P 004 |
Consistency Plunger Ø10mm |
| NL 3012 X / 003 – P 005 |
Glass Plate 4 x 98 x 98 mm |
Optional Accessories
| Model Number |
Parts Description |
| NL 7034 X / 005 A |
Glass Thermometer -10°C to 50°C x 1°C Div. |
Standard
- ASTM C187-04: This ASTM standard provides a test method for determining the amount of water required to produce a standard consistency of hydraulic cement paste using a vicat apparatus. It's titled "Standard Test Method for Amount of Water Required for Normal Consistency of Hydraulic Cement Paste".
- ASTM C191-04: This ASTM standard outlines the procedure for determining the time of setting of hydraulic cement using the vicat apparatus. It's titled "Standard Test Methods for Time of Setting of Hydraulic Cement by Vicat Needle".
- AASHTO T 129-06: This AASHTO standard specifies the procedure for determining the consistency of hydraulic cement using the vicat apparatus. It's titled "Standard Method of Test for Determining Consistency and Density of Hydraulic Cement Using the Vicat Apparatus".
- AASHTO T131-06: This AASHTO standard provides a test method for determining the setting time of hydraulic cement using the vicat apparatus. It's titled "Standard Method of Test for Time of Setting of Hydraulic Cement by Vicat Needle".
Test Procedure
- Preparation of Cement Paste or Mortar: Prepare a sample of cement paste or mortar according to the specifications of the standard being followed (e.g., ASTM or AASHTO). The proportions of cement, water, and any additives should be accurately measured and mixed thoroughly to achieve a homogeneous mixture.
- Setting Up the Apparatus: Set up the Vicat apparatus on a stable surface. Ensure that the sliding rod is vertical and the graduated scale is clearly visible.
- Preparation of Test Mold: Place the mold on a flat surface and fill it with the prepared cement paste or mortar, ensuring that it is compacted evenly and free from air voids. Smooth the surface of the sample using a straightedge.
- Setting the Initial Position: Lower the plunger or needle of the Vicat apparatus gently onto the surface of the cement sample, without applying any additional pressure. Adjust the indicator on the graduated scale to the initial position.
- Initiating the Test: Start the timer and allow the cement sample to undergo the setting process undisturbed. The setting time is typically determined by measuring the depth of penetration of the plunger or needle into the sample at regular intervals.
- Measuring the Penetration: At specified time intervals, lower the plunger or needle gently onto the surface of the cement sample and measure the depth of penetration using the graduated scale. Record the measurements accurately.
- Recording the Setting Time: Continue taking measurements until the penetration depth reaches a specified value, indicating the initial set, or until the penetration ceases entirely, indicating the final set. The setting time is typically determined based on these measurements.
- Calculating Results: Calculate the setting time of the cement sample based on the measurements taken during the test. Follow the formula or procedure specified in the applicable standard (e.g., ASTM or AASHTO).
