September 2, 2021
The evolution of dowel design
What do we mean by load transfer?
Industrial flooring, hardstanding, and service yards are usually made up of several panels. As load is applied to the surface, the panels need to work together to support the load. This interaction between the panels is known as load transfer and is measured in terms of Load Transfer Efficiency (LTE). Poor load transfer, when the panels deflect and don’t transfer the load from one panel to the other efficiently, is known to create high slab stresses and damage which reduces the service life of the concrete ground supported slab. In applications with poor load transfer, the costs are multiple, from downtime and costly repairs, through to damage to vehicles and materials handling equipment, and even injury caused by employees tripping and falling on uneven surfaces.
Better performance by design: dowel technology
The history of dowels
The benefits of tapered plate dowels
Danley’s PD3® design, for example, features a tapered and sleeveless plate dowel that provides optimum performance in limiting joint deflection to provide superior joint stability. The PD3® dowel provides the highest deflection control tolerance in line with ACI Standards, limiting joint spalling, facilitating load transfer and providing the lowest risk of restraint. When used at alternate intervals with plate dowels, the system maximises the percentage of steel at the joint, while the debonding material allows for close steel-to-concrete contact and allows shrinkage without restraint and without the need for a plastic sleeve. The design offers the best serviceability, lowest maintenance and longest lifespan for any slab on ground application.
Conclusion - why dowel design matters
As well as offering a reliable and predictable joint performance that overcomes the shortcomings of its round, square and rectangular predecessors, Danley’s tapered plate dowel solution complies with TR34, TR66, Britpave Concrete Hardstanding Design Handbook, ACI 330.2R-17, and ACI 360R-10 specifications/regulations. When considering a pavement with the same truck activity (1000 trucks per day), an optimised pavement with dowels can reduce slab thickness and concrete volume by almost 20% – reducing both the cost and raw material usage significantly and adding to the solution’s sustainability credentials.
Tapered plate dowel systems eliminate one of the biggest frustrations for designers, contractors and owners alike – joint spalling. By switching to tapered plate dowels, or Danley’s Strategic Reinforcement™ Design solution, all stakeholders stand to benefit from reduced cost of ownership, faster installation and improved efficiency.