Experimental evaluation of plasters durability aimed at maintenance planning and scheduling

The phase of building management has a strategic importance because of the necessary scheduling of maintenance during executive planning. Moreover, in order to obtain the greatest sustainability of the intervention, a reasonable duration of service life must be balanced with global quality-cost ratio. A contribution towards this objective is given by the reduction in the achievable resources and raw materials consumption through the improvement of the durability requirement of building and its parts. This is true even for the interventions on the existing public building stock, especially if there is lacking of maintenance planning and scheduling. This work, taking cues from a maintenance intervention "at happened breakdown" on an Engineering school building in Palermo, deals with the introduction of process innovations in the management phase, directed towards preventive intervention strategies. Beyond the collection of the informative data, the time behaviour of envelope surfaces is monitored through a viewpoint system. Particular attention has been given to the finishing plaster (rasante) layer and the relative colour, to be evaluated depending on the different technical solutions and exposure to weather conditions. The study, following the methodology of ISO 15686, also foresees accelerated ageing tests on samples of different materials, in order to formulate hypothesis and correlations on the degradation evolution, from a maintenance planning and scheduling viewpoint. The correlations were obtained by taking the colour difference as a representative parameter of the evolution of colour in natural and artificial aging conditions. The results show that the different exposure of surfaces to weathering induces a different decay of surfaces colour, compatible with that induced in the laboratory at different steps of artificial aging.