You've heard about spy chips in clothes and ID cards, but now this technology is being used in construction as well. Here's how one firm keeps its cement on track

Accidents do happen. But if you accidentally mix up your cement deliveries, it is going to take more than a polite apology to get things right.

"Because of the nature of the product, it looks the same, if we get the wrong grade of cement to a customer, who is, for example, building a bridge, they might have to tear it down," says Rick Sheehan, logistics general manager at Cemex, formerly Rugby Cement.

But Sheehan need no longer fear, because his company is now using smart technology which allows its tractor units to ask its trailers what they are carrying. The system is called radio frequency identity technology (RFID).

Low frequency radio tags are attached to each trailer and tag readers fitted to each tractor unit. The tags contain little computer chip which stores information.

It is more usual to hear about RFID in relation to retail, healthcare and aviation applications, but it is starting to appear in some parts of construction too.

Cemex delivers cement to 700 UK customers, distributing it from five manufacturing sites using 180 tractor units and 150 bulk trailers.

it is more usual to hear about RFID in relation to other applications, but it is starting to appear in construction too

The RFID system used by Cemex ensures the right trailer is coupled to the right tractor. Beyond ensuring the essential fact that the cement is the right grade, it has also enabled the cement producer to improve its service for customers.

In addition to the RFID system, in-vehicle computers are added to locate vehicles through the global positioning system (GPS). This allows for data to be fed back to the central operations centre in real time. The operations centre can then keep track of all scheduled deliveries, ensuring that they are going to the correct customer, with the correct grade of product, at the correct time. This data is also automatically fed into the planning system, which enables improvements in the future accuracy of plans.

Before RFID, Cemex had no idea where its fleet was, making it almost impossible to determine whether or not the tight logistics schedules were being adhered to. This created problems with clients as there was no way of pre-warning them of delivery or of a delay in the scheduled delivery time.

After the RFID System has correctly identified the correct coupling of tractor unit and trailer, the vehicle is ready for despatch. At this stage the system provides one final line of defence against making an incorrect delivery. Each of the manufacturing plants and delivery locations are surrounded with an imaginary geographical fence, or geo-fence, which creates a record of the event whenever a delivery is made. The details of this event are then automatically compared to a set of business rules. These rules stipulate that a certain tractor unit can only be coupled with a certain trailer and must leave the site at a certain time. On compliance with these rules the delivery driver will be given the signal to make the delivery via the illumination of a ‘GoDel' light, which is installed in the vehicle cab.

The system has not only provided a far more efficient delivery process, improving productivity and turnaround times, for Cemex, but has also made its customers happier: "It improved our customer relations so much because customers knew exactly when their delivery was going to be made," says Sheehan.

They’re in concrete too...

Cemex has also been involved in a joint RFID project with the Building Research Establishment (BRE) called Tag ‘n’ Track. This system, implemented at its precast concrete factory in Somercote, uses online software for production and quality control.

Cemex uses Tag ‘n’ Track, which is part-funded by the UK Government, in the production of crossing bearers for the rail industry. This is an ideal application for the RFID technology as, unlike railway sleepers, the bearers for a crossing set are often unique items, which have to be individually tracked through the supply chain. This tracking is enabled by a rewritable RFID tag, which is incorporated into the plastic reinforcement spacers in each blank bearer.

At the initial stage of production the tags provide a similar level of information to barcodes such as identity and product information. The real benefits of the RFID tags can be realised once the blank bearers begin to be processed for a specific order. This production stage involves the drilling of the bearers, the attaching of fastenings and quality control. The RFID tags allow for the automation of the drilling process, the monitoring of drill efficiency and the tracking of each bearer through the quality control process, all in real time.

What is RFID?

  • RFID, radio frequency identification, is a method of remotely storing and retrieving data. Unlike barcodes, RFID tags do not require a line of sight for identification, meaning that it does not need to be scanned to be read.
  • An RFID system consists of two main components, these being an RFID reader and an RFID tag. The reader and the tag work together to provide the user with a non-contact way of uniquely identifying objects.
  • The tags themselves consist of two main parts; the integrated circuit and the antenna. The integrated circuit contains all of the workings of the tag. This includes the memory and the microprocessor. The antenna determines the read range of the tag
  • RFID tags come in two different forms; active and passive. Active tags have a power source on board, i.e. a battery. Passive tags use instead a low-level radio frequency electro-magnetic field, which acts as a ‘carrier’ of power from the reader to the tag. Passive tags have a far lower read range than active tags. For example passive tags with a read range of 5mm are used in London Transport’s Oyster Card system, whereas active tags with a read range of around 25m are being used by Amec to track and trace assets and materials at the Heathrow Terminal 5 site.
  • RFID tags can be both read and write capable, this allows for information to be written back to the tag. This enables the tag to be updated with information at different stages of a process.
  • Other applications in construction include the tracking of products in the installation process, the confirmation of the receipt of components, the
    confirmation of hand over status and dispute resolution. Companies in the construction industry currently using RFID systems include Amec, Lafarge Aggregates, Laing O’Rourke and Corus.

Source

Construction Manager

Postscript

Dr Ranjit Bassi of BRE will be discussing RFID in construction at the forthcoming RFID in Construction Forum on 25 May at the Olympia 2 Conference Centre in London. His presentation, along with others from Laing O'Rourke, Amec and Costain, and a special range of discussion groups, will focus on the issues and possibilities that RFID technology presents in the construction sector. Construction Manager has secured 20 places for readers to gain a complementary place to the event. To apply for one of these free places please email Dominic Matthews, the organiser, at dom@rfidforum.com referencing Construction Manager.