Category Archives: Grout

What are the various types of Grout and where are they used?

Grout is a mixture of water, cement, admixtures and sometimes fine aggregate. It is used for placement into narrow cavities such as rock fissures or holes, to fill and consolidate two adjoining objects into a solid mass.

Grout is typically categorized as either a sanded grout or a neat grout. As the name implies, a sanded grout contains cement, sand, admixtures and water, while a neat grout contains cement, admixtures and water. Sanded grouts are normally used for general void filling and neat grouts are normally used for grouting around piles, cables and post-tensioning tendons.

Amherst Island Wind Farm, Loyalist, ON

The Amherst Island Wind Farm is located on Lake Ontario, near Kingston, in the town of Loyalist. This project involved the installation of 26 wind turbines generating 75 MW of generating capacity, with each turbine generating 2.7 MW of power. The project involved over 1,700 people including management and skilled labourers.

KING PT Precision was used to anchor the outer set of the anchoring rods for numerous turbines. Initially, a generic grout was used on the first few turbines. However, it was soon discovered that the site could not achieve pull-test strength values fast enough. So, PT Precision was then used for the remaining wind turbines.

PT Precision was chosen over KING’s typical anchoring grout, MS Cable, because PT Precision has higher initial and 28-day strengths. An early age strength of 30 MPa (4350 psi) was required by 3 days, in order to maintain the schedule for this massive project. PT Precision often achieved these values before 3 days, which allowed the General Contractor to proceed to the next stage of the project whenever possible.

The specification also called for a fairly high 28-day compressive strength of 60 MPa (8700 psi), which PT Precision was also able to achieve. Each turbine had 24 boreholes around its perimeter, and also had a bore depth of 52 ft (15.8 m) in length. Approximately 14 to 16 bags of PT Precision were used per borehole. The anchoring rods were subjected to a pull-test force of 2,000 KN to ensure proper bonding of the grout to the rock geology. KING In-Pakt Precision was also used on this job, with regard to a bearing plate between the mud slab and the steel bearing plate.