Technical data

BENTO GEL TYPE BENTONITE (SEALANT)

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BENTONITE IN CIVIL ENGINEERING

Bentonites begun to be used for this purpose in Europe in the fifties, and later in the USA. They are used to cement craks and crevices in rocks, absorbing moisture in order to prevent it from causing tunnels or excavations to collapse. They are also used in waterproof trenches and stabilization ponds.

In order to be suitable for use, they must be highly thixotropic; other important characteristics are viscosity, a high swelling capacity, and good dispersibility. Given their features, sodium or calcium activated bentonites are best suited for this kind of use.

The applications of bentonite in this field can be summarized as:

  • Waterproof membranes around ground barriers, or as excavation support
  • Subsidence prevention. In building sites, walls can be prevented from collapsing by lubricating them with bentonite grout.
  • Piping protection: as a lubricant and as crack filler.
  • Cements: it improves malleability and plasticity.
  • In tunnels: It contributes to stabilization and support in tunnel boring. It acts as a lubricant (3% to 5% sodium bentonite mud, under certain pressure, holds the front of the tunnel). It is also possible to carry the extracted material suspended in bentonite fluids.
  • In grounding systems, it provides safety in case of damage to the underground wiring.
  • Carrying suspended solids.

BENTO GEL TYPE BENTONITE (SEALANT)

Description: Sodium montmorrillonite

Chemical composition: Hydrated silicate with general formula (Na, CA); (Mg, Al)2 (OH)2Si4O19.11H2O, containing quartz, feldspar, and gypsum impurities.

Average Chemical Analysis

COMPOUND CONTENT
SIO2 (g/100g) 63.03
AL2O3 (g/100g) 17.30
Fe2O3 (g/100g) 4.33
TiO2 (g/100g) 0.69
P2O5 (g/100g) 0.07
MnO (g/100g) 0.02
CaO (g/100g) 0.23
MgO (g/100g) 3.49
Na2O (g/100g) 2.71
K2O (g/100g) 0.44
SO3 (g/100g) 0.20
PPC a 1000 ºC (g/100g) 7.38

SPECIFICATIONS

BENTO GEL TYPE BENTONITE (SEALANT): Natural sodium bentonite featuring high hydrating speed, high water retaining capacity, and very low permeability.

TYPICAL PHYSICOCHEMICAL CHARACTERISTICS API STANDARDS, SPECIFICATION 13A.

Type of material Moisture (%) Swelling capacity (ml) Methylene blue absorption Marsh Funnel 6% Casa Blanca Method Limit Permeability
BENTO GEL Max.13.5 Min.32 ml Min.50 Min.30´´ > de 350 10 a la - 7 Mínimo

NOTE: Tests performed according to Brazilian ABNT(CEMP) strandards using distilled water. Moisture and density determined by means of the Proctor test.

APPLICATION RATE: The proportion of bentonite to use varies between 3% and 10%, depending on the type of soil and the pessure or erosion it is subjected to.

AVAILABLE IN:

25 Kg bags, palletized, fastened with hoops and waterproofed with 200 micron heat shrink wrap and 1000Kg BIG BAG.