How to bond old and new concrete - Extending a concrete slab.

Renovating your construction? Need to extend your roof slab? Want to build a new balcony or chajja? You will need to extend an existing concrete slab. Old and new concrete are not exactly best of friends. Old and new concrete have to be bonded to create a water tight joint. Epoxy bonding agents are the ideal solution. Also new rods have to be anchored into the old concrete slab. To achieve this, polyester anchor grouts are the solution.

Materials Required
. Anchoring Grout
. Epoxy Bonding Agent
. Mason's tool kit
. Hammer drill and Bit
. Reinforcements Steel Rods
. Concrete Mix

Procedure
. Chip the old concrete slab to expose reinforcement rods.
. Drill 12" deep holes the diameter of the steel rebars at regular intervals in the section of the exposed slab.
. Mix the polyester resin and filler powder of the anchoring grout and partially fill the holes.
. Push the rebars into the holes within 15 minutes of filling the holes and allow the grout to set.
. Mix the 2 part epoxy bonding agent and apply on the exposed concrete with a brush.
. Pour the new concrete within 45 minutes of applying the bonding agent.
. Allow the concrete and bonding agent to set.

We have a water tight new construction.

Products in store

Epoxy Bonding Agents

. Fosroc Nitobond EP

Polyester Anchoring Grout

. Fosroc Lokfix

In Store now at 
Shree Venkateshwara Traders
#712, Modi Hospital Road, WOC,
Mahalaxmipuram, Bangalore 560086

Ph: 9036092531
Email : venkateshwara.traders@gmail.com

Repairing a Damaged Concrete Slab - Spalling

Concrete spalling occurs mainly due to 2 reasons: 

1. Carbonation. Iron/steel rods corrode due to carbonation (penetration of gases such as sulphur dioxide, carbon dioxide etc) and increase in volume leading to cracks in concrete and ultimately spalling.

2. Corrosion of rods due to moisture penetration into concrete. Porous concrete/lack of water tightness.

Repairs can be carried out as follows. 

Materials Required

. Cement

. Concrete aggregates such as sand and jelly.

. Latex Bonding agent.

. Mason's Tool Kit

Application

. Hack the surface to obtain a sound concrete surface.

. Remove all debris.

. With a rust removing agent clean the iron/steel rebars.

. Prepare a mix/bond slurry by mixing Latex Bonding Agent : Water : Cement in the ratio 1:4:8 by weight.

. Apply over the surface to be repaired using a hard broom or brush. 

. Prepare a concrete mix with the Latex Bonding Agent as an admixture in the concentration of 5-10% by weight.

. While the bond slurry is still in the wet condition, apply the concrete mix using a trowel.

. Plaster over the concrete to get an even surface.

Voila... repaired concrete!