Masonry structures are prone to brittle failure due to seismic forces or compressive overloads. Historical buildings, made with blocks of natural stone, were often built with high structural redundancy that is reflected in their high weight. Static overloads are also worrisome since high levels of compressive loads may cause sudden collapse. Thus structural strengthening of masonry buildings results necessary if architectural heritage should be preserved for the future generations. In recent years fibrous composites made with a polymeric matrix (FRP) were employed as strengthening materials due to their high strength, low weight and easy of installation. In this research work a novel retrofitting technique is presented for the confinement of masonry columns subjected to compressive loads. The use of steel strands immersed in a cementitious matrix is described in terms of mechanical properties of steel-confined columns. The structural behaviour of steel-confined columns was also compared to that of FRP-confined columns. Mechanical behaviour of steel-confined masonry and FRP-confined masonry were found to be very similar. The advantages of the proposed techniques respect to confinement with FRP consist of the use of cementitious matrix that: does not require specialized labour and dry surface, allows moisture migration through the masonry surface of the column, is not prone to premature degradation or debonding under fire events, is easily removable with mechanical tools without damaging the masonry core.
Structural strengthening of masonry columns: a comparison between steel strands and FRP composites
MICELLI, Francesco;
2007-01-01
Abstract
Masonry structures are prone to brittle failure due to seismic forces or compressive overloads. Historical buildings, made with blocks of natural stone, were often built with high structural redundancy that is reflected in their high weight. Static overloads are also worrisome since high levels of compressive loads may cause sudden collapse. Thus structural strengthening of masonry buildings results necessary if architectural heritage should be preserved for the future generations. In recent years fibrous composites made with a polymeric matrix (FRP) were employed as strengthening materials due to their high strength, low weight and easy of installation. In this research work a novel retrofitting technique is presented for the confinement of masonry columns subjected to compressive loads. The use of steel strands immersed in a cementitious matrix is described in terms of mechanical properties of steel-confined columns. The structural behaviour of steel-confined columns was also compared to that of FRP-confined columns. Mechanical behaviour of steel-confined masonry and FRP-confined masonry were found to be very similar. The advantages of the proposed techniques respect to confinement with FRP consist of the use of cementitious matrix that: does not require specialized labour and dry surface, allows moisture migration through the masonry surface of the column, is not prone to premature degradation or debonding under fire events, is easily removable with mechanical tools without damaging the masonry core.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
