# The Mortars of Florence Riverbanks: Raw Materials and Technologies of _Lungarni_ Historical Masonry
## 6 Conclusions  
This paper presents the results of an integrated study performed to typify the property of riverbanks, through characterization of masonry composed of coarse aggregates and mortars. The opportunity to take core samples from different masonry of _Lungarno delle Grazie_ and _Lungarno degli Acciiauoli_ allowed us to characterize raw materials and technologies used for the preparation of the mortars and to highlight similarities or differences among samples belonging to different riverbanks. Particular attention was paid for historical masonry that conduct the function of a load-bearing wall and are submitted to the extreme condition of complete saturation. Moreover, the presence of internal defects and inhomogeneities in the masonry was evaluated. Rubble masonry is internally composed of mortar; a complete mineralogical, petrographic, and physico-mechanical characterization was carried out, using multi-analytical methods. The macroscopic analysis identified at least four main types of masonry present in the various portions of the riverbanks of _Lungarno delle Grazie_ and _Lungarno degli Acciiauoli_, in particular: mortar with decimeter-sized coarse aggregates (type X), mortar with centimeter-sized coarse aggregates (type Y), modern mortar with millimeter-sized coarse aggregates (type Z), and modern mortar with centimeter-sized coarse aggregates (type W). The mortars of the _Lungarno delle Grazie_ consist of a natural hydraulic lime binder, obtained burning a marly limestone and identified by underburnt fragments of a marly limestone, known in the Floentrine area as Pietra Albherese (Monte Morello Formation). The aggregate is abundant, its composition is heterogeneous, and it varies from silicate to carbonate. Type X and Y were identified via macroscopic description on the basis of the different grain size distribution of coarse aggregate, but the composition of fine portions (mortars) is almost equal. Compressive strength and ultrasonic results of X and Y types show results compatible with materials characterized by good compactness and a high level of cohesion. The porosimetric results show rather high values. This aspect must be considered in planning interventions of maintenance and restoration. In _Lungarno degli Acciiauoli_, with the exception of the C4 and C5 samples, which are made from modern hydraulic binder, the other cores extracted appear to be made starting from a natural hydraulic binder that is obtained by cooking marly limestone with the addition of an aggregate of predominantly silicate composition and is well selected and with variable particle size from sample to sample. In this riverbank, the X and Y types of mortars are observed, while the W and Z types are found in cores C4 and C5. The cores C4 and C5 were obtained from different raw materials, and such compositions develop different technological characteristics: higher values of compressive strength and ultrasonic values and lower porosity values. These samples come from the _Lungarno degli Acciiauoli_, which was destroyed during the 1966 flood and later rebuilt. Furthermore, the results of the investigation allow identification of different construction phases, which are compatible with the construction age previous to or after the flood of 1966. The results demonstrate a good compactness and a high level of cohesion of masonry; such information is useful for planning emergency interventions and for supporting planned restoration activities. This methodology has made it possible for good correlation of multi-analytical techniques, obtaining consistent and useful results for the evaluation of the properties of masonry. Such methodology could be extended to the other riverbanks of Florence or other historic riverbanks in other sites.