ZAJĄC BOGUSŁAW1; KWIECIEŃ ARKADIUSZ 2

1) Assistant Professor, Cracow University of Technology, Department of Civil Engineering, boguslaw8zajac@gmail.com

2) Associate Professor, Cracow University of Technology, Department of Civil Engineering, akwiecie@pk.edu.pl

Repair of masonry structures using materials of high strength and stiffness, not compatible mechanically from the thermal point of view, can cause in many cases unexpected damages, when cyclically changed temperatures of high gradient occur. In the paper, there are presented laboratory research on thermal elongation coefficients of various materials, using an injection or adhesive layer in repair and strengthening of masonries. The obtained results showed high variety of their values and differences when compared to the values characteristic of masonry. However, not only the thermal elongation coefficient is important but also the elastic modulus of joined materials. Knowledge about both parameters allows calculating thermal stress factors of materials, and thus the level of stress generated by temperature changes. The obtained results indicated that the lower level of thermal stress is generated in masonries by highly deformable polyurethane materials than by classically using epoxy or mineral materials.

Keywords: Masonry, thermal stress, flexible bonding, polyurethane adhesive