Concrete construction

Global demand for cement, the binder in concrete, is forecast to reach 4.7 billion tonnes in 2017, with sales expected to expand by more than +5% a year over the next four years, according to research company Freedonia.

While this represents a slight decline in pace from the 2007 to 2012 period, altogether, Freedonia’s figures constitute a fairly robust outlook for this key construction material.

At the same time there is a drive among the concrete construction sector’s equipment manufacturers to produce more versatile and efficient equipment, fuelled by the ever-present need for contractors to improve productivity.

New technology is playing a big role in the latest developments. Telematics systems that allow machines to be monitored remotely are spreading to every corner of the construction industry, for instance, often aiming to help to improve efficiency and performance of equipment.

Paving

Indeed, Guntert & Zimmerman (G&Z) has introduced a remote monitoring and diagnostics system in the concrete paving market – its new Equipment Guidance and Operation Network (EGON). This a modular network of controllers, on-board and remote monitoring and diagnostic options. It allows G&Z service technicians to remotely troubleshoot equipment issues from anywhere in the world, with the target of helping contractors maximise paving time.

Available on all G&Z slipform paving equipment, EGON’s display gives an overview of key systems, including the status of all machine inputs and outputs, faults, fuel levels and electronic monitoring of hydraulic pump pressure and filter conditions.

A web-based remote user interface allows programme updates and remote troubleshooting, as well as location monitoring, data logging and maintenance reminders, among other functions.

In addition, a Stringless Preparation Kit can be included as an option on all G&Z pavers and support equipment. NoLine is comprised of an EGON software upgrade and a hardware kit, including telescopic masts for the total station prisms and battery backup to allow stringless paving.

Pumping

Putzmeister has also been focussing on computer-controlled interaction between man and machine for its truck-mounted concrete pumps. It has developed a new radio remote control for its 38-5 truck-mounted concrete pumps, the Ergonic 2.0.

Designed to conserve energy and reduce emissions, the device monitors the interaction between outriggers, boom movements and pump functions. The control unit is larger yet lighter than its predecessor, with a high-resolution colour screen, and boasts new safety features such as guaranteeing the boom can only be moved in a permitted working envelope.

Specific machine settings are transferred via a chip card and the radio remote control can be used for other Putzmeister truck-mounted concrete pumps simply by exchanging the chip.

Reed, meanwhile, has concentrated on increasing the range of pumps available in the smaller size category. It has introduced a new compact concrete pump – the Mine30, designed for sites with very limited space.

It measures 2.44 m x 1.18 m and is 1.64 m tall, making it small enough to be cross mounted on a truck or other carrier. Fork channels on the side and end come standard.
Offering a maximum output of 23 m3 per hour, Reed’s S-Tube allows for pumping grout, pea-gravel concrete, shotcrete mixes, and “big rock” concrete with aggregates up to 38 mm. The Mine30 can be powered by an electric, diesel, or air motor.

Falsework & formwork

Manufacturers in the falsework and formwork sector have also been working to develop equipment and techniques to improve efficiency and flexibility for contractors. Doka, for instance, has a range of modular formwork that can be tailored to the complex demands of the energy sector, where fast construction progress is a important.

As well as specific systems for dam construction (see the large structures feature in the November 2013 issue of iC), Doka offers specific systems for building tanks, silos and cooling towers. Its SK175 cooling-tower formwork, for example, is a fully mechanised, self-climbing system for pouring 1.5 m high sections that is said to produce precise forming within short cycling times.

“If Doka is hired for a particular construction lot, we will develop a custom formwork solution for each individual task,” said Andreas Guttenbrunner, head of Doka’s competence centre for power plants.

Peri also tailored its working platforms to the needs of the energy sector with a contract to support construction of the 1,600 MW coal-fired Eemshaven power plant in Groningen, the Netherlands. Its Peri Up Rosett Flex modular scaffolding system provided safe access for welding and insulation work on the plant’s two 35 m high, 64 m long filters for flue gas desulphurisation.

Assembly of the modular scaffolding for the 35 m high working platform was carried out using a guardrail in advance, making rope protection unnecessary. In addition, the Peri scaffolding worked around the existing steel structure as well as those walkways already mounted.

Concrete accessories

Chicago Pneumatic meanwhile has focussed on productivity gains with its latest concrete poker range. Customers can now choose mechanical, electric or pneumatic pokers from the manufacturer to best meet their specific application and concrete type.

Freshly poured concrete has air voids which must be removed to increase its density and finished strength. Depending on the concrete’s depth and slump, this can be achieved using a poker or screed.

The company’s new VPM mechanical pokers are designed for mid-sized sites using medium-to-high slump concrete. VPE electric pokers, meanwhile, are aimed at medium-to-high slump concrete, while the VPP pneumatic poker range is designed for jobs of any size with low-to-high-slump concrete requiring high-speed vibration.

In addition to pokers, the company’s new concrete product line includes walk-behind screeds. The LBG 1200 hand-held screed provides surface vibration only and is said to be suitable for slabs of all types and concrete of all consistencies. Recommended for smaller slabs and medium-to-low slump concrete, the LBG 800 bull float screed provides deeper vibration and single-step levelling.

Further new products from Chicago Pneumatic include the launch of the CP CombiForm lightweight, leave-in-place screed rail system, together with a new range of STG power trowels and new concrete floor saws.

Advances are also being made in other corners of the concrete industry such as the reinforcement sector. Here, manufacturer Bamtec claims its prefabricated rebar reinforcement elements saved around 40% in laying time and also cut the amount of steel used by around -7% on an office construction project in Germany.

A total of 1,542 custom-made reinforcement elements will be installed on the project, each tailored to match the slab geometry of the building’s structure. According to Bamtec, about 610 tonnes of steel will be installed in the slabs, the floors and underground walls.

A production plant automatically assembles the bars for the project according to the plans via CAM-files. The bars are automatically selected, cut and welded to separate elements for each of the two reinforcement directions.

Each element is then rolled up when finished and supplied to the construction site where they are simply positioned and rolled out. This technology is said to remove the resource-intensive process of arranging and wiring single bars together, leading to time and cost savings.

“Thanks to fully automated production, the steel bars can be staggered in a very precise way, which would hardly be possible with a normal loose bar reinforcement, or if so only with a huge effort,” said Franz Häussler, CEO of Häussler Innovation GmbH and son of the inventor of the technology.

A new kind of lifting system was also tested to position the wall reinforcement that enabled components measuring up to 100 m² to be moved into position safely and swiftly.

“The principle involved here is that elements can be rolled out on the device, pre-assembled and secured before being lifted into position as complete sections of internal or external reinforcement“, explained Mr Häussler. “This could in future cut installation time by about -60%, relieving the workers from the awkward and partly dangerous process of steel fixing on the scaffolding.”

From innovations in rebar reinforcement to new remote monitoring and diagnostics systems, change is coming to every aspect of the concrete construction industry.

It will be interesting to see how quickly emerging markets adopt the latest technology, as well as how manufacturers tailor and adapt new designs to their specific target markets.