Experimental analysis of concrete block masonry walls with rectangular openings strengthened by ferrocement overlays

This paper reports on some results of a comprehensive study about the use offerrocement overlays in the rehabilitation of masonry walls. The main focus is directed to the experimental analysis that was carried out on 1, 800 mm wide and 2, 000 mm height concrete block masonry walls with rectangular 800mm x 600mm openings. These hollowed walls were subjected to distributed loads over a small area at the top. Three different situations were tested: undamaged wall, rehabilitated wall (previously damaged) and strengthened wall (without previous damage). The rectangular opening was introduced in each wall to create a situation of stress deviation in the plane ofthe wall, thereby inducing compression, tension and shear stresses. This test setup permitted to observe the efficiency offerrocement coatings in a condition quite similar to the real cases. The analysis of the test results involved former data obtained in experiments over distinct concrete block panels under axial and diagonal compression. These data are inserted just to give numerical references for the main analysis in focus. In addition, the data show how ferrocement overlays can improve the ductility, rigidity and strength of masonry walls under compression and splitting actions. Based on this study, it can be stated that this technique offers several interesting aspects that may be applied both in rehabilitation (strengthening or repair) of masonry structures and in the construction of new masonry structures with special performance requirements. Also theoretical evaluations and some guidelines could be derived for rehabilitation design.