Fully Automatic Mortar Vertical Expansion Rate TesterAutomatic Collection and Calculation of Mortar Expansion Rate

Vertical Expansion Rate of Expansion Mortar for GroutingDeterminationSelf-Compacting Concrete Tester

Digital Display Grouting Mortar Vertical Expansion Rate Tester for Concrete Mortar

I. Equipment Introduction

The concrete cement mortar vertical expansion rate testing instrument for grouting is based on the national standard GB50119-2013 "Design Code for Application of Concrete Admixtures." This code applies to the use of fourteen types of admixtures in concrete engineering, including ordinary water reducers, high-range water reducers, air-entraining agents, air-entraining water reducers, retarders, retarding water reducers, retarding high-range water reducers, accelerators, accelerating water reducers, antifreeze agents, expansion agents, pumping agents, waterproofing agents, and flash-setting agents. This testing method is suitable for determining the vertical expansion rate of expansion mortar used for grouting.

II. Main Technical Parameters

1. Testing instruments and tools shall comply with the following specifications:

2. Dial indicator: Range 0-10mm;

3. Glass plate: Length 140mm x Width 80mm x Thickness 5mm;

4. Steel pressure block: Diameter: 70mm, Thickness: 5mm, Mass: 150g;

5. Test mold: 10mm x 10mm x 10mm cube test mold, assembly seams shall be filled with butter to prevent water leakage;

6. Scoop: Width 60mm, Length 160mm;

7. Tamping rod: Can be replaced with a steel saw blade;

III. Installation:

1. Steel base plate: The surface should be flat and placed horizontally on the workbench, with a levelness not exceeding 0.02;

2. Test mold: Place on the steel base block without shaking;

3. Glass plate: Place flat in the center of the test mold, leaving a 10mm gap on both sides between the plate and the inner edge of the test mold;

4. Digital dial indicator and dial gauge should be securely fixed to the gauge stand clamp, but the gauge rod should be able to move freely up and down. When installing the dial gauge, press down the gauge head, ensuring it is not tilted forward, backward, or sideways;

5. Fix the dial indicator stand to the steel base plate, as close to the test mold as possible to shorten the cantilever length of the horizontal rod.

IV. TestSteps:

1. The water content for the grouting material should be based on the water amount required for a flowability of 250±10mm.

2. After mixing the grouting material with water uniformly, immediately pour it into the mold from one side of the glass plate. When the height reaches about 50mm, use the tamping rod to poke 6 times on each side of the test mold and 6 times in the center. When the height reaches 90mm, repeat the poking process as before to expel air as much as possible. The final layer of grouting material should be poured in one go until it flows out from both sides. Minimize the upward buoyant force exerted by the grouting material on the glass plate.

3. On both sides of the glass plate, gently shape the surface of the grouting material into a slope using a small knife, with the high edge level with the glass and the low edge level with the top inner surface of the test mold. The time for shaping the slope should not exceed 30 seconds. Within 30 seconds after that, cover the grouting material surfaces on both sides of the glass plate with two layers of wet cotton cloth.

4. Place the steel pressure block in the center of the glass plate, then lower the dial indicator measuring head onto the steel pressure block. Record the dial indicator reading h0 within 30 seconds to establish the initial reading.

5. Starting from the initial reading, water once every 2 hours. Water continuously 4 times. After that, water once every 4 hours. Maintain moist curing until the required age, and measure the height readings of the specimens at 3 days and 7 days.