Anti-seismic light, ductile, sustainable and reversible timber Quercus Cerris floors for reinforcement in conservation design

It is now entered in the common practice that anti-seismic upgrade of timber floors is made by set-ting metallic connectors to the beams trough planking and by pouring in situ reinforced concrete slab. Leaving out the problem of the consequent rapid decay of the floor boarding, because of high resistance brought by the slab, people noticed on the occasion of latest earthquakes in the center of Italy, that such practice bring about clear worsening in buildings’ seismic behavior leading to arising before non-existent torque forces and, very often, to the collapse of exterior walls, owing to loss of their verticality and hence their balance. Designing conservation of Cafaro Palace in Sant’Arsenio (Salerno) was realized by using a new technique, developed by Lembo & Marino in the Constructions Technology Laboratory (La.Te.C.) of Basilicata University (Potenza, Italy) which uses a new material, Quercus cerris laminated timber, engineered by means of a specific thermo-hygrometric treatment. This treatment confers very high performances (working loads of 40,9 N/mm2) and allows to achieve trusses with very small-sized elements, so as to be set in the floors’ plan, fulfilling the function of retaining the external walls, binding them in their plan. Constrained at extremities by hinges, the trusses allow the floor to remain warp able, and let all walls to participate to resistance against the horizontal seismic forces thanks to their resistance and stiffness; in this way, the onset of dangerous torques is avoided. The system is light, ductile, sus-tainable, reversible, durable and not particularly expensive or difficult to carry out; it can be easily industrialized by typified basic components.