New Materials for the Rehabilitation of Cultural Heritage - Czech ...

New Materials for the Rehabilitation of Cultural Heritage 14
An experimental investigation was recently carried out [20], in which columns with and
without the application of strands were tested. Octagonal columns were considered with 520
mm diameter and 1200 mm height. The application of 10 strands (1.0 mm) in correspondence
of each mortar joint evidenced that the column capacity was almost doubled (Tab. 2). In case
of strands in alternate joints the column capacity increase was approximately 50%. The
maximum vertical displacement increased considerably in confined columns. In Fig. 7 the
samples near collapse are shown. In the unconfined sample the significant vertical cracks are
evident; cracks are more diffused in confined samples.
Table 2 –Results of tests on confined columns with stainless steel strands [20]
Strand location Column capacity (kN) Max vertical displacement (mm)
Sample 1 Sample 2 Sample 1 Sample 2
None 756.6 824.8 14.66 29.60
Alternate joints 1274.9 1161.7 48.97 46.20
Every joint 1636.7 1454.2 60.79 61.28
(a) (b)
Figure 6 –Column confinement with stainless steel strands: (a) view, (b) application.
Figure 7 –Columns at the end of the test: (left) plain column, (center) strands in alternate joints,
(right) strands in all mortar joints.
Removal of
damaged mortar
10 stainless steel
strands (1 mm)
Fiber reinforced
mortar (3 mm)
Lime mortar
as protection