Econocrete at JFK Airport
- 10 April 2007
- Company & Industry News
What is Econocrete?
Increasingly used in the US, econocrete is lean concrete that may be made with low-cost, locally available aggregates that do not meet conventional specifications. Interest in the use of econocrete has developed in the last few years due to the high cost and dwindling supplies of high-quality aggregates in some areas of the US. In the past, substantial quantities of natural aggregates and crushed stone sources have been discarded or rejected because of restrictive specifications or other reasons. Much of this material could be used in concrete structural elements if proper attention were given to developing mix designs to meet the structural requirements and environmental conditions to which it will be exposed. This is where econocrete comes in.
Federal Highway Administration and local governmental agencies are now supporting the movement of the econocrete concept from the laboratories into the field. The mixes are based on laboratory tests and are designed for specific strength and durability levels in accordance with their intended use.
The possible applications of econocrete are as varied as the many structural elements of modern highway paving systems. It is a durable concrete with a well -distributed air void system. Water reducing admixtures are often included in the mix to improve work ability at the low slump ranges that result in higher strengths.
This project by The Conti Group of New York is the largest asphalt contract for JFK in 20 years. It has been developed to accommodate the new Airbus 380, which is the world's largest airliner with a wingspan of 262 foot. And by using econocrete, they have managed to reduce the total cost of the project.
They are using the continuous mixing plant, which is a Rapid Mix 400 for this application. The Rapid Mix 400 manufactured by Rapid International Ltd, based in N. Ireland, is a totally mobile and completely self-contained unit, mixing up to 400 tonnes per hour, depending on the application. It uses the hydraulic system to change the plant from its travel mode into a fully operational plant in minutes which perfectly suits a project such as this. Its self-erecting silo has a capacity of up to 50 tonnes and fitted with a twin shaft continuous mixer, it is also used in applications such as soil stabilisation and dam construction.
The Conti Group are producing the econcrete at JFK by milling asphalt recovered from the demolition of old runways, screening it, and then mixing it in the Rapid Mix 400 with cement and water. Because econocrete uses 70 to 80 percent of the material from the old runway, it provides huge economic benefits to the airport as well as being more environmentally friendly.
Though the project is still ongoing in JFK airport and in several other airports around the US, it is hoped that the success of econocrete and its clear benefits not only to the customer but also to the environment will prompt many more airports around the US to consider using econocrete for their airport runways.
Rapid International Ltd
96 Mullavilly Road
T: 028 3884 0671
F: 028 3884 0880