Structural Uses of Stone and Timber in The European Historical Construction

This paper investigates the stone masonry with timber reinforcement through Europe.It is a remarkable practice,either historical or contemporary,consisting of combining different materials to build up a masonry.This technology shows a wide variety of typological,formal,and technological types of buildings across Europe as it is strongly influenced by the nature and availability of local materials,the cultural aspects of the various communities,and the soils geological nature.As a consequence,the same constructive typology is based on different premises and leads to many interesting results.In this paper,the various uses of such a mixed stone-timber masonry are shown in relation to the above-mentioned factors.It is important to stress that this traditional technology is also highly contemporary as it is highly exploited in many countries.Furthermore,novel regulations have been issued to regulate such a discipline.Finally,as a very common constructive technology,many historical buildings present such a mixed structural configuration,independently from the generating factors.In such a perspective,this study aims to describe the most common constructive features,as well as develop guidelines for preservation,whereas the typology is present,or design criteria for consolidation and structural improvement,whereas necessary.

Mixed Stone-timber Masonry in Traditional Construction: Structural, Architectural and Anti-seismic Features across Europe

This paper investigates the stone masonry with timber reinforcement through the European traditional and historical architecture.It is a remarkable practice consisting of combining different materials to build up a masonry.This technology shows a wide variety of typological,formal,and technological types of buildings across Europe as it is strongly influenced by the nature and availability of local materials,the cultural aspects of the various communities,and the soils geological nature.As a consequence,the same constructive typology is based on different premises and leads to many interesting results.In this paper the various uses of such a mixed stone-timber masonry are shown in relation to the above mentioned factors.One of the most interesting aspect is the use of such a mix stone-timber as an anti-seismic device,especially in the Southern and Mediterranean countries,giving evidence to a great sensibility of the ancient builders to very specific topics.It is also important to stress that this traditional technology is also highly contemporary being exploited in many countries,especially in the far northern ones.Furthermore,novel regulations have been issued in order to regulate such a discipline,especially the use of timber for large structure and infrastructure.Finally,as a very common constructive technology,many historical buildings present such a mixed structural configuration,independently from the generating factors.In such a perspective,this study aims to describe the most common constructive features,as well as develop guidelines for preservation,whereas the typology is present,or design criteria for consolidation and structural improvement,whereas necessary.

Independent and complementary bio-functional effects of CuO andGa_(2)O_(3) incorporated as therapeutic agents in silica-and phosphate-based bioactive glasses

The incorporation of therapeutic-capable ions into bioactive glasses(BGs),either based on silica(SBGs)or phosphate(PBGs),is currently envisaged as a proficient path for facilitating bone regeneration.Inconjunction with this view,the single and complementary structural and bio-functional roles of CuO andGa_(2)O_(3)(in the 2e5 mol%range)were assessed,by deriving a series of SBG and PBG formulations startingfrom the parent glass systems,FastOs®BG e 38.5SiO2d36.1CaOd5.6P2O5d19.2MgOd0.6CaF2,and50.0P2O5d35.0CaOd10.0Na_(2)Od5.0 Fe2O_(3)(mol%),respectively,using the process of melt-quenching.The inter-linked physico-chemistry e biological response of BGs was assessed in search of bio-functional triggers.Further light was shed on the structural role e as network former or modifier e ofCu and Ga,immersed in SBG and PBG matrices.The preliminary biological performance was surveyedin vitro by quantification of Cu and Ga ion release under homeostatic conditions,cytocompatibility assays(in fibroblast cell cultures)and antibacterial tests(against Staphylococcus aureus).The similar(Cu)anddissimilar(Ga)structural roles in the SBG and PBG vitreous networks governed their release.Namely,Cuions were leached in similar concentrations(ranging from 10e35 ppm and 50e110 ppm at BG doses of 5and 50 mg/mL,respectively)for both type of BGs,while the release of Ga ions was 1e2 orders ofmagnitude lower in the case of SBGs(i.e.,0.2e6 ppm)compared to PBGs(i.e.,9e135 ppm).This wasattributed to the network modifier role of Cu in both types of BGs,and conversely,to the network former(SBGs)and network modifier(PBGs)roles of Ga.All glasses were cytocompatible at a dose of 5 mg/mL,while at the same concentration the antimicrobial efficiency was found to be accentuated by the coupledrelease of Cu and Ga ions from SBG.By collective assessment,the most prominent candidate material forthe further development of implant coatings and bone graft substitutes was delineated as the38.5SiO2d34.1CaOd5.6P2O5d16.2MgOd0.6CaF2d2.0CuOd3.0Ga_(2)O_(3)(mol%)SBG system,which yiel-ded moderate Cu and Ga ion release,excellent cytocompatibility and marked antibacterial efficacy.