Global Chemicals Japan

Special thickening agent for NATM VISCO TOP UT

Thickening agent, VISCO TOP UT greatly reduces dust generated from sprayed concrete

Background & challenges

Measures to counter dust have long been a challenge in mountain tunnel constructionThere is now increasing demand for dust control measures due to guidelines revisions

The amount of dust generated when spraying concrete in mountain tunnel operations is extremely high and has become a serious social issue, resulting in litigation over the damage it causes to the health of tunnel construction workers.In Japan, dust guidelines were revised in April 2021, amending the acceptable dust concentration from 3 mg/㎥ or less to 2 mg/㎥ or less. Further reinforcement of dust measures is becoming a challenge.

Challenge of using set accelerators in sprayed concrete

Accelerators are used in sprayed concrete due to the occurrence of what is called rebound.A large number of powder type accelerators are used in Japan due their superior strength properties; however, they also pose the problem of a large amount of dust generation.

VISCO TOP UT achieves dust concentrations of 2 mg/㎥ or less, with half the amount of general dust-reducing agents


  • Significantly reduces dust generation
  • No need for additional admixture
  • Improves the properties of fresh concrete (aggregate versatility)


  • Appearance: White powder
  • Dosage: Cement x 0.05 - 0.1%
  • Packaging: 10 kg/box



Dust control

Significant dust reduction complies with new guidelines

Example of sprayed concrete mix



Easy to use

No need for additional admixture


Reliable quality

Superior strength

Early strength (pullout test)


Long term strength (core compressive test)


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