Around the globe, the name Kawasaki has become synonymous with quality and innovation. Kawasaki is a total systems engineering company, leading the way in hydraulics and supplying equipment for a huge range of applications including industrial, construction and marine.
Kawasaki has been developing expertise in hydraulic machinery for nearly 100 years, so that now their products can be found around the world on land and sea.
This major concrete repair project included the preparation of the concrete substrate and installation of the proprietary TPR crack repair system with quad-axial fabric reinforcement.
The Problem
Kawasaki Precision Machinery utilise a product racking system mounted on a concrete slab suspended on piles. Cracks have appeared above the piles necessitating a repair or replacement operation for the 100m X 20m racking area.
As cracking exhibited in a piled floor should not automatically be deemed ‘non-structural’, further investigation was needed to deduce the importance of the cracks, and a suitable remedial action. The cracks below the flooring were determined to be normal non structural shrinkage cracks and as such were not considered as important. The cracks over the piles, however, were judged to be stress fractures due to pressures exerted over the piles as indicates by the curve B in the diagram. These cracks required urgent remedial action
The Options
Just two options were presented by the nature of the damage to the suspended concrete slab. Complete replacement or repair using TPS Systems products and Dama expertise. Taking into account the interruption to operations of several months in a full replacement repairing the floor was the preferred option. This involved two periods of 8 days where operations over part of the warehousing were interrupted. In terms of cost, without taking into account the additional downtime in replacement, repair was again the preferred option at 20% of the replacement cost.
The repair operation took place during two distinct phases each lasting 8 days. The amber phase included the repair of the flooring below the storage racking while the green phase concentrated on the operations flooring.
Technical Detail
Preparation
The Background Surface was prepared by Shotblasting with a machine connected to a Filtration Unit, (or Vacuum), via plastic hose and powered by 3 phase 415volt/ single phase 110volt generator housed in the vehicle Transporting the equipment to the site. “Shot”/Steel abrasive, propelled at high velocity within the body of the machine surface was used to clean and texture the surface prior to application of the specified product with debris collected in the Filtration Unit.
ScreedShield®
The super low viscosity of the primary resin component of Screedshield® is designed to allow it to flow into the smallest of spaces within a porous substrate where it polymerises and strengthens the material to improve its compressive and flexural properties. It is used to repair cracks, voids and broken screed materials.
ScreedShield Plus®
ScreedShield Plus® completes the repair process by adding strength to the prepared floor in all directions. Several options are available and for this project with it’s very high weight bearing requirement a quad-axial 4 ply system was used to strengthen and improve the mechanical characteristics of the substrate. With a combined ply weight of 144 gsm and a floor thickness of just 5mm this solution is rapid, effective and very long lasting.
Further reading