grout in Construction

2. Grouting
Grouting is the process of injecting materials into cavities or cracks
in concrete, masonry structures, rock-mass, subsurface soil, or rock
to increase the structure’s load-bearing capacity, and the material
used for this objective is called grout.
It is the specifically prepared cement under pressure to form a
stable suspension or liquid into pores, fissures or voids, or cement
mixtures at a high flow rate to increase strength.

3. While grout is normally a combination of cement, sand, and
water or chemical substances which can be used to fill gaps.
They are used to improve concrete cracks, gaps in tiles for sealing
& waterproofing for soil stabilization, it is also used to provide
the extra strength to the foundations of load-bearing structures.

4. Characteristics of Grouting
• Grouting is non-corrosive.
• They are not flammable, non-toxic.
• Also, they are shrinkage compensated.
• They are capable of adjustable fixtures.
• They have very good flow characteristics.
• It has an excellent bond to concrete.
• In addition, they have no blockage or bleeding.
• They are easy to use, easy to mix only add water.
• They are impact and vibration resistant.

5. Types of grouting materials:
• Cement Grouting
• Cement grouting is used for high permeability land, for which the grout is
prepared using water, sand, and cement.
• Use of cement grouting
• Cement grouting is used to provide deposit/stabilization and strengthen to
a wide variety of structures such as bridges, marine applications, dams,
and rock anchors.
• The grout material is then injected in liquid form with high pressure to fill
the hole in a specified radius around the area used for grouting. The
viscosity of the grout material is increased by reducing the water-cement
ratio as required. The grouting process is then completed by making a
second hole between the primary holes to ensure complete grouting of the
area.

8. Chemical Grouting
• Chemical grouting is a form of permeation grouting. This type of
grouting mix usually includes acrylamides, polyurethanes, acrylates,
epoxy, and sodium silicates.

9. There are two main processes of chemical grouting::
Two-shot Process
In this process, the pipe is inserted into the ground through a drill. After this, the chemical material is
pumped through the pipe in such a way one is followed by another into the soil. So that in the process of
a chemical reaction the soil can take a solid form at a rapid speed.
One-shot process
In this method, a chemical mixture of grouting material is prepared in advance and then poured
underground. This process takes time for the structure to harden. A one-shot process of chemical
grouting is used for boreholes.

10. • Structural Grouting
• A structure is constructed at the site to be mined. Structural grouting is
used to fill the gaps between concrete and rock structures and fill the
voids between mined materials. Apart from this, structural grouting is
also used to fill cracks in rocks and joints of rocks in underground
tunnels.
• Use of structural grouting
• Structural grouting is commonly done
in tunnels and underground structures.

11. • Bentonite Grouting
• Bentonite is the major component in drilling muds or fluids used in rotary
drilling. The suitability of sodium bentonite as a grouting material is 15
times its dry volume when hydrated. Due to its swelling and gel-like
permeability property, it is suitable for filling gaps between the casings.

12. • Use of bentonite grouting
• Sodium bentonite grout is typically used for sealing and covering
unutilized wells, sealing of earthen structures, and water-proofing.
• Due to the high montmorillonite (an aluminum-rich clay mineral of the
smectite group, containing some sodium and magnesium.) ​content and
the ability to swell on water absorption, this grout is suitable for
grouting of annular space between boreholes created during good
construction.

13. • Bituminous Grouting
• Hot bitumen grouting is a special type of grouting in which molten hot
coral is used as the grouting material.
•
Use of hot-bitumen grouting
• Hot-bitumen grouting is often used to cut high volumes of
underground water flow. The key characteristic of hot bitumen grout is
its temperature-dependent viscosity.

14. • Resin Grouting
• Epoxy grouts are also known as reactive resin grouts. This type of grouting
material is made from a cement-based mixture. It is not waterproof but has
the ability to absorb water when wet.