Wednesday, 28 February 2018

How to Anchor Rods in Concrete and Stone

Anchoring rods in set cement concrete and stone require a material that can create a strong bond between the rods and the cement. Ordinary cement mixtures fail to bond to the rod strong enough to anchor them. A bonding and grouting solution is thus required.

Polyester resin based anchoring grouts are the answer to this problem. They form extremely tight and strong bonds between the rod and the substrate. These grouts set extremely fast and can be placed under water. The bond is thus both high strength and water proof.

Anchoring grouts are used for high strength corrosion resistant anchoring of bolts and bars from 10 - 51mm diameter into concrete, rock, masonry or brickwork where high speed of installation and early application of load is required.

Permanent installation of reinforcement starter bars, foundation bolts, base plates, balustrading, barriers and safety fences, railway tracks, tie-back anchors, reinforcement dowelling abutments,
ground anchors for towers, cranes, dock sills are typical applications for anchoring grouts.

The high strength of the cured resin permits strong anchors to be created. The ultimate bond strength developed depends upon:
Strength of host material
Length of resin bond to bar
Hole preparation and formation
Type and dimension of bar

Anchoring grouts are usually supplied as 2 pack products. A Polyester resin and a catalysed filler powder.

Method of Application

Hole preparation and formation
Optimum performance of anchoring grouts require rough sided, dust free holes. Uses of rotary percussive drills with air or water flushing is recommended.
Diamond drilled holes should be under-reamed unless necessary safety factors are incorporated.
Cast holes should preferably be inverse dovetail configuration.
If parallel sides holes are cast they should be rough to provide adequate keying.

Bar preparation
All bars should preferably be degreased and all flaky rust removed.

A complete pack of resin and catalysed filler should be mixed in one operation. Mixing may be carried out mechanically. When a smooth, even consistency is achieved the grout is ready for
use and should be placed well within the gel time of the grout. Do not attempt to mix partial pack components.

Polyester resin grouts for vertical holes 
The grout should be poured steadily into the prepared holes. The anchor bar is then pressed into the hole to the required depth.
Slight agitation of the bar will assist in achieving a complete bond. The bar should then be left undisturbed in the required position until the resin is set.

Polyester resin grout for overhead and horizontal applications
The grout should be injected to the rear of the hole to avoid air entrapment.

Anchoring Grouts available :

Fosroc Lockfix S

Fosroc Lockfix P - overhead and horizontal 

Also available at our store :


Sunday, 25 February 2018

Plug Active Ground Water Leaks

A common problem when excavating for a foundation, basement or  under ground water tank is ground water seeping or gushing into the dug out area. The water can flood the complete excavation and not allow any masonry or concrete to be laid. Many times, even after pumping out the water, it keeps flooding. The only way to get any construction activity done, is to plug the leakage of ground water.
To do this we need a fast setting cement mix that does not crack on setting. A variety of products for this purpose are available, each having the goal of instantly plugging any leakage. The settings times can vary from a minute to 20 minutes. Choosing a mix with the right balance of setting time and compressive strength is the key to successfully plugging the ground water leak.

How to use a plugging cement mix?
Once the problem spots are identified, press the plugging cement into the seeping water with light pressure. Apply as much of the plug cement required to plug the leak.
Plug all leaks until ground water stops seeping into the excavation.
After the plug cement is fully set, apply a bond slurry, created using a a latex based product, over the entire surface of the plug cement.
While the bond slurry is still wet, pour the concrete or apply the masonry.

Areas of application
This method can be used to plug leaks while excavating for a foundation, excavations for basements and under ground water tanks. 


Also available at our store :