The monitoring of structures and infrastructures is nowadays a pivotal activity for guaranteeing the safety of their users. Environmental conditions and exceptional events could affect their performance and integrity, shorten their service lives and even produce unexpected failures. The development of multifunctional smart structural materials with enhanced or novel properties could help to prevent or reduce damages and collapses. Among other building materials, concrete is particularly suitable for such improvements due to its composite nature. The authors have developed a smart concrete doped with carbon microfibers capable to sense variations of applied strains/stresses. The investigation started from the analysis of the performances of small and medium samples, up to the manufacture of two full-scale RC beams. These applications at realistic scales are crucial for a diffuse use of such smart materials in civil engineering. The paper describes the novel characteristics of the smart concrete samples at different scales, investigating their main physical, electrical, and monitoring capabilities. Dynamic tests on full-scale beams are also carried out and discussed.