
Displaying items by tag: concrete
Hoffmann Green Cement Technologies signs deal with Bouygues Construction to develop low carbon concrete
05 July 2019France: Hoffmann Green Cement Technologies and Bouygues Construction have signed a 30-month initial technical and commercial collaboration agreement to develop and test concrete formulations using new cement made from Hoffmann’s H-EVA technology. Hoffmann Green Cement inaugurated its pilot plant at Bournezeau, Vendée in late 2018. The unit will manufacture cement products using flash-calcined metakaolin and blast-furnace slag. Bouygues Construction is a global construction company with a presence in over 60 countries.
US: Researchers from CalPortland have published a peer-reviewed study looking at the absorption or carbonation of CO2 by buildings, pavements and structures made from concrete. The authors argue that this negative effect on CO2 emissions is not being considered in global, national and regional greenhouse gas accounting methods. The paper calls for focused studies on CO2 uptake in concrete within the context of its overall Life Cycle Assessment (LCA).
“It is time to further examine the value of concrete in the built environment as a significant carbon sink,” said Allen Hamblen, president and chief executive officer (CEO) of CalPortland. “To do so accurately, we must specifically look at the net effects of CO2 sequestration in concrete and evaluate all structures over their lifetime within a circular economy.”
The study looks at previous attempts to quantify the effect of concrete carbonation, notably using work by the Swedish Environmental Research Institute (SERI) that examined data from several European countries to develop practical models to gauge the extent of CO2 uptake by concrete globally in the built environment. Different models estimated that 15 - 20% of CO2 emissions from clinker production were reabsorbed over the lifetime of concrete structures.
France: HeidelbergCement France has finalised the acquisition of Cemex’s Centre region aggregates and ready-mixed concrete businesses. The acquisition includes seven aggregate quarries and 28 ready-mixed concrete plants. The acquired aggregates reserves and resources amount to about 25Mt. HeidelbergCement France will fully integrate the operations into its own network.
“With this acquisition, we strengthen our vertically integrated market position in central France,” said Bernd Scheifele, chairman of the managing board of HeidelbergCement. “The operations fit very well into our existing network of aggregates and ready-mixed concrete plants in the Paris region, and we expect significant synergies.”
UK: Hanson has been part of a new continuous concrete pour record in the UK as part of its work at the EDF Energy’s Hinkley Point C (HPC) new nuclear power station in Somerset. It supplied raw materials for the concrete to main civil engineering contractor BYLOR, which operates the on-site concrete production plant. The 9000m3, five-day, pour was to construct the last of five reinforced concrete segments that make up the cross-shaped foundations on which all of the first nuclear reactor’s buildings will sit. The record-breaking pour beats the previous UK record set by the Shard skyscraper in London.
The completion of the foundation platform, which is up to 4m thick, represents a significant milestone for the project, described by EDF Energy as J-zero. It marks the transition from below ground activity to the construction of permanent reactor buildings above ground.
Hanson says that mix design for HPC took three years of development and testing to ensure that the concrete was of the required quality mandated by the Office for Nuclear Regulation. The subsidiary of Germany’s HeidelbergCement has 65 employees directly involved in the HPC project team. To date Hanson has supplied 51,000m3 of concrete, 2.5Mt of aggregates, 210,000t of marine sand, 65,000t of cement; 105,000t of ground granulated blast furnace slag (GGBS) and 125,000t of asphalt.
US: Charah Solutions plans to open a grinding plant to make supplementary cementitious materials (SCM) from natural pozzolan at Oxnard in California. The unit will be accessible by truck and railway. It will sell pozzolan and other materials to concrete product manufacturers throughout south California.
The Oxnard plant will be operated in partnership with Diversified Minerals, a supplier and manufacturer of standard and custom blend cement and concrete products. It will receive natural pozzolan by truck and rail and then grind pozzolan marketed under the brand MultiPozz pozzolan. MultiPozz pozzolan will be distributed throughout Charah Solutions’ MultiSource materials network of more than 40 nationwide in the US with international sourcing and distribution.
“Fly ash is becoming more difficult to source in California, which is forcing the construction industry to look for viable alternatives. Natural pozzolan and other SCMs that meet ASTM specifications are generating very high interest. With Charah Solutions’ resources and DMI’s strategic partnership with the only active pozzolan mine in Southern California, we are both the closest and the first to bring these products to market,” said Jim Price, chief executive officer (CEO) of Diversified Minerals.
US: Cemex has announced that it is supplying concrete, including a specialised self-consolidating mix, along with thousands of tonnes of aggregates for the replacement of the Sixth Street Viaduct Bridge in Los Angeles, California. The original 915m-long bridge, which has served as a backdrop in numerous films, was built in 1932 and is in need of replacement.
Cemex will supply 34,400m3 of ready-mix concrete. This will include 4800m3 of Evolution, Cemex’s range of self-consolidating concrete product that, in this instance, was tailored to fit the bridge’s design and the requirements of the client, CalTrans. Cemex will also supply a fibre-reinforced concrete solution for the bridge deck and structure itself. The US$482m structure, funded by a mixture of state and Federal funds, is expected to open in late 2020.
Germany/Portugal: Talleres Alquezar has been using two BHS mixers in a modular plant to produce a total volume of 400,000m3 of hydro dam concrete in Portugal since 2017. Two DKX 4.5 type twin-shaft batch mixers, each with a capacity of 4.5m3, have been integrated into the plant. Germany’s BHS says that using twin-shaft batch mixers has shown that can be utilised successfully to produce this kind of specialised concrete.
Three hydro dams are being built on the Tâmega River that are expected to generate 1760GWh for the Iberian market once they have been commissioned as part of Spanish energy group Iberdrola’s large-scale hydroelectric project in Portugal. 242,000m3 of concrete is needed in Daivões for the dam wall alone, which is planned to be 78m high and 265m long. Spain’s Talleres Alquezar is the project partner for this hydro dam. Once built, the construction in Daivões is expected to dam up to 56,200,000m3 of water.
Mexico: A team led by José Iván Escalante Garcíaat at the Saltillo unit of the Center for Research and Advanced Studies of the National Polytechnic Institute (Cinvestav) is researching the use of volcanic ash in making blended cements and concrete. Volcanic ash is being considered to reduce the clinker factor of cement due to its abundance, low cost and its appropriate chemical composition. A clinker substitution factor of up to 80% has been achieved using volcanic ash. The research group has developed 15 alternatives to Ordinary Portland Cement (OPC) using waste or materials or minerals.
France: Cemex has supplied over 0.3Mm3 of ready-mixed concrete and more than 0.55Mt of aggregates for the Grand Paris Express project over the past three years. It has used mobile on-site concrete plants and a local network of 21 plants in Île-de-France to support the large-scale railway infrastructure scheme.
"The Grand Paris worksites present a daily challenge to deliver ready-mix concrete on time, supply aggregates to our production sites, and move earthworks from the stations and tunnels out of Paris,” said Benjamin Lecendrier, Major Projects Director at Cemex France.
The Grand Paris Express worksites on metro lines 11, 14 and several sections of line 15 South have involved most of Cemex’s staff in the Île-de-France region, with four full-time operatives working in a dedicated unit. Given the scale of operations, logistical organisation is a challenge, with the twin demands of delivering construction materials and removing 40Mt of earthwork by 2030.
Simon Marriott appointed as managing director of Concrete Products by Aggregate Industries
05 June 2019UK: Aggregate Industries has appointed Simon Marriott as the managing director of its Concrete Products division. He has also been promoted to the executive committee of the company as part of a strategic decision to raise the profile of the division. The new role will give him responsibility for all hard landscaping aspects of the business including Charcon, Bradstone, Masterblock, Charcon Construction Solutions and Simply Paving. He will also lead the marketing communications function.
Marriott started his career as a plant manager before moving to Bardon Aggregates in 1996. When it merged with Camas to become Aggregate Industries, he become general manager of the Express Asphalt division and later became director of the mainstream asphalt division’s southern region. He then ran Bardon Concrete and Aggregate Industries’ cement importing function, before becoming director of Concrete Products in late 2015.