# Parametric Analyses of the Response of Masonry Walls with Reinforced Plaster
## 2 Experimental Test  
### Specim and Experimental Set-Up  
The geometry of the specimen, defined according to the suggestions given by ASTM-E-519-02 [21], was 1290 mm \(\times\) 1290 mm, with a 250-mm thickness. Solid clay bricks, assembled with mortar joints of 10 mm, were considered. The bricks were the \"Rosso Vivo A6R55 W\", which are very common in existing masonry buildings in Italy, produced by San Marco Terreal, with dimensions of 250 mm \(\times\) 120 mm \(\times\) 55 mm. The bricks were arranged in English bond layout (Figure 1a). A lime-cement mortar classified as M2.5 by Italian Building Code [14] was used for bed joints, with 1:5 water/cement ratio by weight. The mechanical characterization of the materials was derived from three-point bending and compressive tests, performed according to ASTM C293 [30] and ASTM C348 [31]. The average compressive strength of the bricks was 23.3 MPa. The mean value of mortar compressive strength was 5.4 MPa, and the mean flexural strength was 2.1 MPa. In the reinforced configuration, a steel mesh of 6-mm-diameter wire (B450C class) with a spacing of 100 mm in both horizontal and vertical directions was embedded in the plaster as reinforcement. A cement-based mortar was adopted for the plaster (Figure 1b). Experimental tests (i.e., three-point bending and compressive tests) were also performed for the plaster mortar, which gave a mean compressive strength of 33.91 MPa and a mean flexural strength of 6.38 MPa. The RP was connected to the masonry wall by using steel anchors in the form of steel-ribbed rebars (B450C, 8-mm diameter, 200-mm embedment depth), bent at one end with a 90-degree hook 50 mm in length (Figure 1c). The anchors were installed with a hybrid adhesive into boreholes 10 mm in diameter and following a quincunxes pattern with a density of 5 anchorage/m\({}^{2}\). The plaster was applied on both sides of the specimen.  
The diagonal compression (DC) test [16; 17; 18; 32] was used for the characterization of the in-plane behavior of the masonry panels. The test consists of loading a masonry assemblage of compression along with one of the diagonals, thus causing tension failure, with the specimen splitting apart parallel to the direction of load. It should be stressed that the test is not able to catch all the possible failure modes (e.g., rocking/crushing), but only the diagonal cracking failure, which is a recurrent failure mechanism usually observed after earthquakes [33; 34].  
Two hydraulic jacks, each with a capacity of 300 kN, were placed on both sides of the wall (Figure 2a), along the diagonals of the specimen. The load was continuously monitored with a couple of load cells. Two steel shoes with L-shaped cross-sections and 150 mm in web length were placed at the ends of the main diagonal to transfer the diagonal  
Figure 1: (**a**) Unreinforced masonry specimen; (**b**) retrofitted specimen; (**c**) anchor detail.  
displacement applied by hydraulic jacks. The tests were performed under displacement control at a displacement rate of 0.05 mm/s. Two linear variable differential transformers (LVDTs) were fixed along the diagonals of each lateral surface, with a 90-degree angle between them (gauge length of about 800 mm) (Figure 2b). Another two LVDTs were applied on each face, orthogonally to the front and backside of the specimen, to monitor the out-of-plane deformation of RP.