CONCRETE | TECHNICAL


1


1/2


1/2 b=600mm


I=250mm 2


Above: prEN 14488-3 Three-point bending test on square panel with notch


Steel fibres are a more efficient, durable and


sustainable means of concrete reinforcement compared to rebar. Using steel fibres can save 50% on the steel and concrete compared to traditional reinforcement, especially in precast lining. In this holistic approach, the high performance steel fibre already plays an important role.


Dramix®


Indeed, steel fibre reinforcement can significantly reduce the embodied carbon in segmental linings, compared to steel bar reinforcement. Rebar mass per unit volume of concrete in tunnel segments ranges between 90kg/m3


to 160kg/m3 . Considering a CO2


of 1.85 for steel, carbon emission is about 166.5kg/m3 296kg/m3


about 40kg/m3


to meet standard performance Class 5e,


according to fib Model Code 2010 for such applications with only fibre reinforcement, and equates to carbon emission of about 35kg/m3


. This means a reduction of 4.7 to 8.4 times in CO2 emission.1


MOVING TO PSCL Permanent sprayed concrete (PSC) is a proven technology that has been used for many applications in underground works throughout the world. The ITA report N°24, ‘Permanent Sprayed Concrete


factor to


. In comparison, the mass per unit volume of Dramix 4D 80/60BGP steel fibres in tunnel segments is


Lining’, published in October 2020, is to give infrastructure owners and their advisors the confidence to incorporate Permanent Sprayed Concrete Linings (PSCL) into their underground space design.2


Dramix 4D 65/35BG in C35/45


7,00 6,00 5,00 4,00 3,00 2,00 1,00 0,00


FR1,m FR2,m Above: Dramix® FR3,m FR4,m 4D 65/35 BG in C35/35 residual strength July 2023 | 11


20Kg/m2 25Kg/m2 30Kg/m2 35Kg/m2 40Kg/m2


[N/mm2


]


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