Waterproofing with osmotic cements of underground concrete structures exposed to backflow or negative thrust from an unconfined aquifer

CLEANING, PROTECTION AND PASSIVATION OF REINFORCING RODS

• Remove all the flaking parts until the solid concrete surface is reached.

• Remove the flaking and loose parts via chipping. Surface mortars, oils, release agents, dust and dirt in general will be removed with hydro-sandblasting.

• Uncovered rods must be cleaned down to the bare metal and all the rust parts must be removed.

• Immediately after cleaning, the reinforcing rods will be treated and protected to avoid any oxidation by applying a coat of STRATO FER using a brush.

• The missing parts and the reinforcing rod cover will be restored by applying thyrotrophic and fibre-reinforced cement mortar with compensated shrinkage GEORAPID or, alternatively, RESISTO TIXO. Average coverage: 1.8 Kg/dm3

• Any low thickness surface irregularity will be smoothed with thyrotrophic and fibre-reinforced cement mortar with compensated shrinkage GEORAPID or, alternatively RESISTO UNIFIX or RESISTO LEVEL. Average coverage: 1.8 Kg/dm3

 

WATERPROOFING WITH OSMOTIC CEMENT

The following solution allows you to waterproof underground concrete structures which are exposed to water infiltration including backflow or negative thrust phenomenons (i.e. in the presence of aquifers).

Preparing the laying base

• Block in advance any water infiltration with quick-setting waterproof cement BETONRAPID in order to prepare the surface for the application of OSMOSEAL.

• Any localised transudation and percolation must be blocked in advance by mixing OSMOSEAL with BETONRAPID 3:1 (premix dry products).

• Remove any plaster down to the concrete surface. Clean the surfaces from scales, mortars, oils, release agents, friable parts and dust via chipping and brushing, and wash them with high-pressure water.

• Remove any nails and plugs and cut in depth the iron spacers by chipping the surrounding parts.

• Plaster the concrete joints, gravel nests and all the chipped areas with compensated shrinkage mortar RESISTO UNIFIX.

Creation of rounded edges

• Make the rounded connection edges between floor and walls with compensated shrinkage mortar RESISTO TIXO after dovetailed uncasing. We recommend that you insert a bentonite thickness before the creation of the rounded edges.

Preparing the product


• OSMOSEAL will be prepared by diluting the dry product with 20% of water (5 litres for the 25 kg pack), taking care to mix the product thoroughly in order to avoid any lumps, until you obtain a mortar with honey consistency. Pour in the water and then the powder product and mix using a low RPM mechanical mixer. Add to the OSMOSEAL water mix 1/3 of acrylic latex LATICRYL to improve adhesion and waterproofing.

 

Application

• Wet the surfaces before the application of the osmotic cement OSMOSEAL avoiding water films.

• Apply 2 criss-cross coats of OSMOSEAL with mortar consistency, using a Tampico fibre brush and consuming at least 3 kg/m2.

• Waterproofing will be performed with full protection, i.e. walls and floor.

 


Description of the layers and related product data sheets:

1. Waterproofing sealing

BETONRAPID


2. Connector piece

RESISTO TIXO

GEORAPID


3. Waterproofing

OSMOSEAL


4. Screed

QUICKCEM

QUICKCEM PRONTO

QUICKTERM

QUICKCEM PRONTO HP

DRYCEM

DRYCEM PRONTO


For proposals or different solutions please contact our technical department of Index S.p.A.
 
For many other stratigraphy and / or insights, you can consult the following documentation: