Leading the way in building advanced oncology radiation chambers
Agile™, a self-levelling, self-consolidating concrete material, was recommended by Nuvoco Vistas Corp. Ltd. for constructing a state-of-the-art Oncology Radiation Chamber at Kiran Multi Speciality Hospital in Surat; the first-of-its-kind in Gujarat. This was made possible by Nuvoco’s Construction Development and Innovation Centre (CDIC), which provided complete customised solutions that also met the stringent regulatory requirements.
The scope of work involved the construction of three bunkers of 256 sq. m (2754 sq. ft.), as per the Atomic Energy Regulatory Board (AERB) regulations. These require the density of concrete to be uniform throughout the structure with minimum density being more than 2400 kg/m3. It bears pointing out that AERB has non-negotiable and stringent guidelines and does not permit commissioning of a facility unless those specifications are met.
Agile™ a free flowing concrete with self placing properties is an ideal solution for structures with complex configurations or requirements. In this case, Agile was used to achieve the desired density and to minimise voids within the concrete by more than 50 per cent as compared to normal concrete. One of the challenges faced during execution was that the structure was approximately five metres below ground level. The laying and changing of the pipeline were critical to maintain a cohesive mix and to avoid pump choking. This was done by maintaining the maximum core temperature below 70°C and a temperature gradient less than 20°C by using higher pozzolane materials in concrete.
The Nuvoco team provided method statement for placement of concrete, evaluation report of the performance of different mix-designs to fulfil the requirements of the job-site and designing of proper shuttering for better performance of Agile™. With proper planning and execution, the Nuvoco team was able to complete the project and hand it over to the hospital team a month before the deadline, thereby saving considerable costs. Nuvoco supplied 800 cubic metres of M30 Agile™ with temperature control for this project.
Challenges tackled by different types of Nuvoco concrete:
Congested reinforcement of beam and more depth of beam (1.5mt) which makes it quite difficult to use the vibrator for compaction and get a good finish without filling defects.
Solution: Agile (Self-compacting Concrete)
The bigger size of beam and mass concrete, the more chances of difference in temperature gradient leading to thermal cracks in concrete.
Solution: Regletherme (Temperature Control Concrete)
The floating columns up to 12th floor needed heavy post-tension of beams that required to attain 50% strength in 3 days.
Solution: Instante (Early Strength Concrete)