The　normal　service　of　reinforced　concrete　hollow-slab　beams,　which　are　widely　used　in　small-　and　medium-span　bridges,　is　a　topic　of　interest.　This　paper　presents　an　experimental　study　on　four　existing　hollow-slab　beams　removed　from　a　real　bridge.　The　mechanical　properties,　including　failure　mode,　load-deflection　response,　crack　development　and　load-strain　response,　were　investigated.　Moreover,　a　fibre　beam　element-based　model　updating　method　was　applied　to　these　hollow-slab　beams　for　material　property　parameter　inversion　and　quantitative　structural　performance　evaluation.　The　two-step　model　updating　achieved　accurate　inversion　of　the　material　property　parameters.　The　updated　fibre　beam　element-based　model　can　reproduce　the　load-deflection　response　and　crack　width　development　well,　i.e.,　achieve　quantitative　structural　performance　evaluation,　and　can　assist　with　further　maintenance　decisions　such　as　designing　a　strengthening　scheme.　The　results　indicate　that　evaluating　the　ultimate　capacity　on　the　basis　of　stiffness　is　not　very　reliable　because　a　member　with　greater　stiffness　may　not　always　possess　a　greater　ultimate　capacity.　The　yield　strength　of　steel　bars　is　the　predominant　parameter　of　the　ultimate　capacity;　thus,　to　evaluate　the　ultimate　capacity,　more　attention　should　be　given　to　assessing　the　yield　strength　of　steel　bars　instead　of　testing　the　stiffness　under　a　normal　service　load.　Although　the　initial　stiffness　values　of　these　existing　hollow-slab　beams　decreased　by　17　similar　to　33　%,　the　beams　exhibited　high　ductility,　and　their　actual　residual　ultimate　capacity　values　exceeded　the　design　expectations　by　7　similar　to　10　%.　In　future　bridge　maintenance　projects,　the　fibre　beam　element-based　model　updating　method　can　be　implemented　with　deflection　and　crack　data　from　field　static　load　tests　to　predict　material　property　parameters　and　to　quantitatively　evaluate　performance.