Abstract

Composites made of fibers embedded in organic or inorganic matrices are efficient systems for reinforcing historical masonry structures to provide strength and ductility with a negligible mass increment. As it is well known, the structural performance of the composites mainly relies on their adhesion to the substrate. There are different methods to test the adhesion of the composite to the substrate: in laboratory direct shear test is the most commonly employed, while on-site the bond between the reinforcement and the substrate is checked by the pull-off test. In this paper, the adhesion of different composites to the same substrate made of fired-clay bricks is investigated by both the shear test and the pull-off test to qualitatively assess the difference in the two methods. Additionally, to investigate whether the bond is affected by the presence of water in the pores, half of the specimens were tested in water saturated conditions. Three different types of matrix (based on epoxy resin, natural hydraulic lime and Portland cement) were used for the composite matrix, without changing the geometry, the type of masonry substrate and the fibers (galvanized steel cords).

Abstract

The inner bay of the city of Puno has been the subject of various investigations that seek to recover and enable floodprone areas, through strategic urban development projects (urban infrastructure) and protection works. On the other hand, the characteristics of soft soil deposits, such as those in the inner bay of Puno, represent a risk of problems with excessive settlement of the infrastructure. This study presents an engineering characterization of the lacustrine soil deposits in the inner bay of the city of Puno, around Lake Titicaca. The site lies around the Pier of Puno city at Lake Titicaca, the highest navigable lake in the world, approximately a few hundred meters in front of the National University of the Altiplano of Puno (UNAP) and a few hundred meters to the southward of the Pier of Puno city. Physical, strength, and deformation properties were determined from standard laboratory tests. The material studied corresponds to the shallow layers of the study area, corresponding to sedimentary soils of the lacustrine units and fluvial-alluvial deposits of the inner bay of Puno. These lacustrine soils are classified as highly plastic silts and organic clays (MH and OH). The results show the significant influence of the quality of soil samples, due to the sampling method and storage time, on consolidation and resistance parameters. Finally, this study provides valuable insights into the influence of sample quality on consolidation parameters and shear strength of the lacustrine soils in the inner bay of Puno city around Titicaca Lake.