Displaying items by tag: infrastructure

Austria/Germany: Austria-based Porr says it has used a new annular gap mortar bound with granulated slag, instead of cement, on the Filder Tunnel stage of a project for Deutsche Bahn near Stuttgart. The engineering company reports that the pilot project was a success and the ‘practically cement-free construction material’ has already been patented. Porr is now looking for further cooperation partners.

“The nature of the soil means that a cement-based construction material would not have been suitable,” said Porr’s chief executive officer Karl-Heinz Strauss. “This gave us the opportunity to use this brand new construction material”. He added, “Apart from allowing us to contribute to reducing CO², this construction material has two fundamental advantages. It is less sensitive to environmental factors than concrete containing cement. And it can be transported for long periods without any problems before it is processed as it needs an activator to fully harden”.

Image copyright: Arnim Kilgus

India: The Border Roads Organisation (BRO) plans to launch a pilot scheme in Arunachal Pradesh to build roads using steel slag. It will work with the Central Road Research Institute (CRRI), according to the Press Trust of India. The intention is to explore building long-lasting roads using an alternative materials to conventional aggregates. The topography of the state - with high annual rainfall, forest vegetation and soil diversity – has also prompted the project partners to try using new materials and techniques.

US: The Slag Cement Association (SCA) has announced the recipients of its 2021 Slag Cement in Sustainable Concrete Awards program. Thirteen construction projects were chosen to showcase the broad applications of slag cement and its impact on creating more durable and sustainable concrete. The infrastructure winners included projects with slag cement supplied by companies including Argos USA, Cemex, Lehigh Hanson, Ozinga, Skyway and St Mary’s Cement. These projects included work on roads, bridges, residential construction, a concert venue, a sport stadium, airports, a theme park and a hydroelectric dam. Two research projects on slag cement from Cleveland State University and Florida State University were also recognised.

India: The first steel slag road in India has been built in Surat, Gujarat. The 1.2km road is located at Hazira Port, according to the Times of India newspaper. It was constructed by using steel slag aggregate in place of natural aggregate. The higher strength of the material has also allowed for the thickness of the road to be reduced by 30%. Around 100,000t of steel slag was used. The joint project was a collaboration between the Council of Scientific and Industrial Research, the Central Road Research Institute, the Union Ministry of Steel, government think-tank NITI Ayog and ArcelorMtttal-Nippon Steel.

US: Cementos Argos subsidiary Argos Florida Cement has won the Slag Cement Association (SCA)’s Durability and Infrastructure awards at its 2022 Sustainable Concrete Project of the Year Awards. The producer won the awards for its supply of slag cement to two projects in Florida in 2021. Its involvement in the American Bridge Company’s SR 679 Pinellas Bayway Bridge – Structure E replacement won it the Durability award, while its involvement in Superior Paving’s State Road 52 realignment. Argos Florida Cement congratulated its customers, who also received the awards.

UK: Tarmac has demonstrated a new concrete product using a high proportion of slag with Align, the joint venture building part of HS2, a new high-speed railway line. It demonstrated the potential to use very high ground granulated blast furnace slag (GGBS) content in excess of 90%, as an alkali activated cementitious material conforming to BS EN197, the standard for cementitious materials allowed to be used in ready mixed concrete, to significantly reduce carbon emissions, whilst still producing a quality finish and allowing normal construction and demoulding times.

Demonstration and testing at full scale used one of three Tarmac concrete batch plants at a Chalfont Lane construction site in Hertfordshire. A structural slab forming part of the new viaduct pre-cast factory and a vertical wall were poured. Tarmac says that the mixes, designed to Align concrete specification, exceeded expectations in both fresh and hardened properties, and showed that the new concrete can be produced in normal concrete plants and placed via mixer truck and by skip with a tremie pipe. The new low carbon concrete has a carbon footprint following industry BSI PAS2050 calculation rules that gives a 62% reduction in CO₂e per cubic metre of concrete, compared to a standard CEM I concrete, meeting the same specification in the same raw materials. The footprint covers all aspects of the concrete production and supply with no carbon off-setting applied, delivering an actual footprint of 133kg/m³ CO₂e. This represents a saving of 220t CO₂e for every 1000m³ produced.

“Together we’ve shown this new concrete is fit for purpose in slabs and walls, with good repeatability and works with standard production and construction methods. This product is a great step along the industry zero carbon routemap, and the demonstration will help accelerate adoption of this new concrete,” said Robert Gossling, head of commercial engineering solutions at Tarmac.

Tarmac is supplying concrete for the construction of the Central 1 section of HS2 Phase One that is being built by Align. This includes a 22km section of high-speed rail infrastructure incorporating a 3km viaduct across the Colne Valley, a 16km twin-bored tunnel, and five vent shafts handling both intervention and tunnel ventilation facilities.

UK: Hanson has delivered its 10,000th load of Regen ground granulated blast furnace slag (GGBFS) from its Port Talbotsite in Neath Port Talbot to the building site of the upcoming Hinkley Point C power plant in Somerset. The GGBFS will be used in concrete production there. The latest batch brings the company’s total deliveries to the project to over 230,000t of GGBFS.

Head of nuclear operations Stewart Cameron said “Around 200,000t of CO₂ has been saved in reaching this milestone Regen GGBS load. It is a credit to all those involved as we continue to meet the standards expected of this high-profile project.”

UK: Hanson’s Regen Ground Granulated Blast furnace Slag (GGBS) product is being used by BAM Nuttall and Network Rail in the first and second phase of building a new sea wall in Dawlish, Devon. So far 4600m³ has been supplied to the project that is intended to protect a railway line from the sea. The bespoke mix being utilised for the project uses Regen GGBS to create a pumpable low carbon concrete that is strong enough to withstand erosion, waves and storm winds while reducing the amount of carbon generated by two-thirds.

“From the earliest phase of this project, we have considered how this scheme can limit its environmental impact without compromising the strength and resilience of the structure. The final design uses piles buried deep in the bedrock to create stability for the structure. Those piles are protected by prefabricated facing panels created off-site and reinforced by concrete poured in behind the visible section of wall,” said Jack Brookes, site agent for BAM Nuttall.

The project has also had to face difficult logistical, technical and operational challenges created by pouring large amounts of high specification concrete up to 200m through the night in very short tidal windows. Hanson plans to supply a further 4500m³ of concrete to the project.

UK: DB Group has supplied its Cemfree concrete product to a site in Birmingham, West Midlands for use by the Environment Agency in a flood defence project. It says that the agency will use the concrete “for kerb bedding and backing over several kilometres in conjunction with various recycled products in an effort to reduce the projects’ carbon footprint.” Cemfree is a low carbon concrete made using ground blast furnace slag (GGBS) and pulverised fly ash.

Egypt: Suez Cement subsidiary Ready Mix Beton says that it has secured a contract for the supply of concrete for the construction of two new monorail lines projects. Due to begin in late-2020, the contract covers the construction of a monorail line between Cairo and the New Administrative Capital and another between 6 October City and Giza. The company says that it will use Suez Cement’s CEM III/A ground granulated blast furnace slag (GGBFS) cement to produce concrete for the 96km monorail network.

Suez Cement said, “CEM III/A cement is highly recommended when building thick concrete supports and massive structures because its hydration temperature of less than 210kJ/kg reduces cracking compared with Ordinary Portland Cement (OPC) when the applied concrete is subjected to dual exposure to sulphates and chloride ions, as happens in coastal areas.”