In this paper, the mechanical performance of pretensioned concrete girders manufactured with ultra-high performance fibre reinforced concrete (UHPFRC) and carbon fibre reinforced polymer (CFRP) tendons is explored both experimentally and analytically. For the experimental investigation, four UHPFRC beams with either steel or CFRP tendons are tested under four point bending to failure. Digital image correlation is used to monitor the development of cracks. These results are then used to validate a rational analysis technique based on the modelling of concrete cracking and crushing through the application of partial interaction mechanics which is then compared to that suggested by codes of practice