Where the transaction consists of the performance of unpaid work, the provisions of articles 131-23, 131-24 of the Penal Code and articles R. 623-14, R. 623-16 and R. 623-17 of the Penitentiary Code are applicable to the performance of this work and the powers conferred by these articles on the sentence enforcement judge or on the director of the penitentiary integration and probation service are exercised by the mayor.