The action of ethyl methyl cellulose in cement finishing mortar

Finishing mortar pollution resistance and whitening resistance test using the following mix ratio: cement. Limestone powder: quartz sand 2:1:7; latex powder 1.8%; monk water agent 0.2%; wood fiber 0.2%: pigment 0.4. Hydroxyethyl methyl cellulose mixture: 0.1%, 0.2%. 0.3%, 0.4%, 0.5% (according to cement quality). The amount of water add according to the flow degree of the new mortar is controlled at (170 x 5) mm. Mortar additives are prepared according to the above mix ratio under standard conditions [(23 x 2) * C, (65 x 5)%RH] according to JC / T1024-2007 after 28 days). According to the degree of pollution, it is divid into 0 and 1. 2. 3. 4.

The whitening resistance of mortar additive is teste by two test methods: sprinkling and immersion. Stir the mortar and stand at the above mix ratio for 5 minutes. Apply it to the cement fiberboard, control the thickness at 4-5 minutes, and then test it according to the following method.

  • (1) Water pouring test, the mortar test plate is maintaine under standard conditions until days. Refer to the 9.10 “anti-alkaline” in the Wall Finish Mortar UC / T1024- -2007).
  • (2) The water immersion test mortar test plate is maintaine until 1 day and 7 days respectively under standard conditions. Then immersed in water, taken out to dry 8 hours later, and observe the surface whitening situation. Mortar white grade from light to heavy is divided into ” 0, +, + +. The four grades of +++” represent no visible plain white, mild plain white, moderate plain white, and severe plain white, respectively. Drop water on the surface of mortar and observe the disappearance time of water droplets. Evaluate the quality of its surface hydrophopathy, and evaluate the three grades of excellent, medium and poor. Cement-finished mortar with X-ray diffraction meter (0.4% M30000 mixed by XRD).
The surface phase was analyzed, and the sample was prepare in the following four methods:
  • (1) Mortar test plate maintenance for 1 day by using the water immersion method (tap water) to test its pan-whitening performance. And then remove the mortar surface pan-whitening material for XRD test.
  • Mortar additives (2) The mortar test plate is immerse in deionized water after 1 day. And takes out after 2 days. The deionize water of the immersed test plate is drie in (60 x 2) C electric blast drying box, and take the dried powder for XRD test.
  • (3) According to the following two mix ratio of forming 20mmX20mmX2mm on the XRD sample frame curing for 7 days in the surface dripping to promote its white, the white surface XRD test. For example: ① white cement: water-100,50; ② white cement: M30000: water =100:0.4:50.
  • Mortar additive (4) Take (3) the invisible white area of the mortar made according to the mix ratio ② for XRD test. The mortar surface was observe using a scanning electron microscope (SEM) and a light microscope.


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