Tire for a vehicle carrying heavy loads, comprising a new tread

A tire intended to equip a vehicle bearing heavy loads, this tire comprising a tread including at least one rubber composition based on at least:

• an elastomer matrix predominantly comprising a copolymer based on styrene and butadiene having a glass transition temperature Tg strictly above −65° C. and below or equal to −30° C.,
• a reinforcing filler predominantly comprising silica,
• a chemical crosslinking system,
• an agent for coupling between the elastomer matrix and the reinforcing filler,
• a plasticizing system comprising from 2 to 15 phr, of at least one plasticizing resin having a glass transition temperature Tg of greater than or equal to 20° C., and of which the total content of the plasticizing system in the composition ranges from 2 to 17 phr, and
• an agent for modifying said copolymer based on styrene and butadiene, optionally already grafted onto said copolymer, said modifying agent being a 1,3-dipolar compound of general formula (I):
• A-E-D (I)
• the symbol D represents a functional group comprising at least one nitrogen atom and being capable of bonding to said copolymer via a cycloaddition of [3+2] type on a carbon-carbon double bond of the chain of said copolymer,
• the symbol E represents a divalent spacer group connecting group D to group A,
• A represents a functional group chosen from C1-C20 alkyls, C7-C18 alkylaryls, C7-C18 arylalkyls, optionally substituted nitrogen-based heterocycles of 5 to 6 atoms, optionally substituted sulfur-based heterocycles of 5 to 6 atoms, ester groups, phosphate groups, dialkylamino groups and associative groups comprising at least one nitrogen atom.