DELTA BLOC UK | Collaborative Approach Shaves 5 Weeks from Construction Programme
BmJV were tasked with replacing 10km of steel barrier in the central reserve of the M1 between Junction 15 & 16 and rather than take the traditional approach of slip-forming the rigid concrete replacement barrier, they collaborated with DELTA BLOC UK to consider the use of their innovative pre-cast concrete rigid barrier system.
Having acquired good knowledge of the DELTA BLOC range of products, bmJV, along with their designers Atkins, were looking to realise the benefits a precast solution has to offer over the forming of wet concrete on site – which has been typical on the Highways England network over the last decade. The key benefit being speed of installation.
A construction programme was jointly developed using the projected outputs per installation crew per day and when viewed against the more traditional methods of constructing the central reserve barrier it was deemed counter productive to revert back to what has been the default method for so long. The key for DELTA BLOC UK was to deliver on site what had been promised.
DELTA BLOC DB 80E precast system was installed at an average of 600 linear metres of barrier per working shift – significantly higher than anything bmJV had previously experienced using slipform construction. This huge increase in speed of installation generated a 5 week time saving on the scheme, which as a whole contributed to reduced costs, road user disruption and removed the risk of unforeseen issues affecting any follow on activities.
It wasn’t all plain sailing however; the speed in which the barrier was able to be installed meant that problem areas on site could not be worked on immediately due to the required civils works. This was no problem for the DELTA BLOC DB 80E system. Due to the fact you are working with precast modular pieces it allows the Installation Team to change work fronts immediately with minimal impact on outputs when unforeseen critical path issues are identified on site. In close dialogue with bmJV, DELTA BLOC UK were able to work flexibly and adapt to working in an alternative sequence to overcome the issues as they happened, maintaining the required outputs built into the programme.
The modular, off site construction approach also meant less waste is generated in production providing a more sustainable, environmentally friendly product.
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With absolutely no reliance on good weather, the DELTA BLOC precast system was installed to programme unaffected by the often unpredictable British weather which can create conditions which often delay slipform operations. This was another key factor in maintaining the required level of output.
In addition to quicker installation outputs the use of the DELTA BLOC precast system will provide future benefits when it comes to maintaining the barrier system. In the unlikely event that barrier repairs need to be completed following a vehicle impact, pre-cast sections can be easily replaced in one shift as opposed to the multiple shifts often needed for in-situ concrete repairs. The simplicity of the maintenance process was jointly presented to the NDD Area Team by bmJV and DELTA BLOC UK and 18 members of the Area Team have since received industry recognised training to allow them to conduct their own maintenance ‘in house’ as required.
Delivery truck movements are also halved when installing the DELTA BLOC DB 80E system compared to the number of concrete truck mixers attending site for the same length of slipform barrier, again reducing traffic entering and exiting the works zone, improving safety, reducing CO² emissions, keeping the network flowing all of further demonstrating the positive benefits of the precast installation process.
All of the above advantages contribute to reduced costs, reduced road user delay and a more free flowing network.
Highways England recently published their Delivery Plan of Major Improvements with 5 Strategic Outcomes and 4 Key Enablers to achieve the desired outcomes. These were: Collaborative Relationships, Delivering Performance and Efficiency, Managing Risk and Uncertainty, People and Company. Based on the results of this scheme alone the efforts of bmJV to engage early with DELTA BLOC UK and the appetite of Atkins to break away from the “norm” and design a scheme using a pre-cast alternative show that this solution can go a long way towards helping Highways England meet their Outcomes and deliver their Plan of Major Improvements.