Carcass reinforcement for tire intended to bear heavy loads

A carcass reinforcement for a tire which is intended to bear heavy loads, said reinforcement comprising a composite fabric which comprises a cross-linkable or cross-linked rubber composition having a reduced hysteresis in the cross-linked state and metal cables reinforcing said composition, which comprises:

• an elastomeric matrix comprising natural rubber or a synthetic polyisoprene in a majority proportion, and
• a reinforcing filler comprising a carbon black,
• wherein said carbon black meets all of the following conditions:
• (i) 50≦CTAB specific surface area in m2/g (in accordance with Standard ASTM D3765-80)≦55,
• (ii) 45≦BET specific surface area in m2/g (in accordance with Standard ASTM D4820-93)≦70,
• (iii) 45≦iodine adsorption index IA in mg/g (in accordance with Standard ASTM D1510-81)≦70
• (iv) ratio (BET surface area/index IA)≦1.05,
• (v) 115≦DBP structure value in m1/100 g (in accordance with Standard ASTM D2414-93)≦170,
• (vi) 85 nm≦Stokes diameter dst in nm≦145,
• where dst is the diameter of aggregates corresponding to the maximum frequency of the Stokes diameters in a distribution of aggregates, and
• (vii) D50/dst≧0.0090·CTAB+0.19,
• where D50 is the difference, in the distribution of aggregates, between the Stokes diameters of two aggregates corresponding to one and the same frequency equal to 50% of the maximum frequency of the Stokes diameters, dst and D50 being measured by centrifugal photosedimentometry.