Grey, the new green

In an effort off-set the supply shortage of aggregates leading up to the World Cup infra projects, Lafarge has opened a recycling plant that replaces natural aggregates in concrete

A line of trucks arrive at the site with construction waste to be recycled.
A line of trucks arrive at the site with construction waste to be recycled.

Concrete is the basis of every infrastructure project and any shortages will have a disastrous effect on the rollout of these mega-developments.

Salim Kutty, company manager, Lafarge Aggregates in Qatar, explains that when all the projects leading up to FIFA were combined to gain an understanding as to what the demand and supply issues on aggregates and concrete and bitumen etc would be – for metros, highways and stadia – and capacity for the various ports and quarry production capacity was calculated, the demand outstripped supply by almost double.

He explains how the demand arises: “We divide the application of aggregates into two parts, imported and local. Aggregates and concrete are imported predominantly from the UAE, which includes materials for road building. Roads comprise five courses: the top two courses are the wearing course and the base course, which are bituminous or asphalt. These are imported along with the concrete and below them are the non-bituminous layers. The materials for the latter are produced locally as well as pipe-surround, cable-surround, road-base, sub-base, soak-aways and marine applications.

“Local product demand comes to about 40-million tonnes per year, for the next four years, but the market capacity is from 15 to 20 million tonnes, resulting in a huge gap between local and imported products which, when added together, you are looking at about 35-million tonnes deficit per year.”

The solution is to lessen the demand on imports and produce more product locally, while creating sustainability and complying with carbon emissions. In this regard, Lafarge Qatar, Readymix Qatar and Qatar Quarry Co. (QCC) succeeded in proving to the Ministry of Environment/Qatar Standards that the durability of recycled aggregates (RA) in construction is a viable option and received the approval to use it for the replacement of natural aggregates in concrete, a first of its kind venture in Qatar.

Situated at Rawdat Rashid site in Qatar, the RA plant was officially launched on 9 March. The plant will address all issues, from sustainability to cost-effectiveness and assisting with the supply chain.

Previously a quarry, and now filled with construction and demolition (CND) waste, the recycling site stands ten metres above its original basin and as far as the eye can see. The recycled waste comprises three components: 90% CND waste, some limestone from reservoir excavations, or cut-and-fill from road-works for example, and here McCluskey adds: “This has become a resource so levels have dropped significantly, from about 60 to 70% over the past 12 months, as the bigger projects are storing it” and last, return concrete which is what is unused on site and dumped and is 100% recyclable.

A combination of jaw crushers and impactors, the Scottish OEM McCloskey plant is a bespoke design that separates CND waste, removing metals, plastics and other contaminants as it passes through a modular system. Valued at around QAR30 million, comprising older equipment and the new plant, Kutty describes the operation: “It is not conventional quarrying equipment, as the material is not from a simple ‘clean’ blasting operation. It has magnets, blowers and manual picking stations,” and adds, “Also, it is specific to this hot, dry climate, so it doesn’t need washing plants.”

The entire operation will produce three million tonnes of recycled waste per year, of which two million tonnes will be produced by the new plant.

Recently, Qatar Primary Materials Company (QPMC) bought three quarries in the UAE to alleviate the supply, but Kutty is adamant that there is more than a simple supply issue: “Also to be considered is the quarry capacity, the freight from the load port and its capacity, to the discharge port, coupled with stock-piling issues.”

“It’s about physically getting it on to the ground in Qatar,” says Mark McCluskey, operations manager, Lafarge.

Supply is further exacerbated by port logistics: “Currently, the cargo vessels wait about 40 days to berth,” says Kutty. “There are so many ships lined up waiting, that the waters are unsafe to accept any more vessels,” he maintains. “The situation is critical in the anchorage and the waters approaching the ports. What is needed is more berths for on-loading and off-loading, but that will take four years to build per berth, conservatively speaking,” he adds.

Even the new Hamad Port won’t alleviate the issue as it’s built for container vessels, as Kutty points out: “It is not for bulk cargo, it’s a container terminal. For aggregates you need bulk cargo facilities, including conveyors and bulk cargo cranes.”

Says Kutty, “The CO2 footprint from transporting aggregate from Fujairah to Qatar is roughly 35kg per tonne of material, whereas transporting from the quarry to project sites equates to about 2kg per tonne aggregate. Extrapolated one can see the savings and the positive carbon impact.”

While the operation will not see profits for at least a year, Kutty is confident that the outcome will impact positively on the shortages within the sector and anticipates installing more machinery in the not too distant future to handle a greater volume of recycled product.

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