TU Dresden, Institute of Construction Materials

This paper reports the results of a research on the strengthening of masonry by means of highly ductile cementitious materials with short polymeric fibres, so-called Strain Hardening Cement-based Composites (SHCC). A SHCC composition with 1.8% by volume of PVA fibre was developed as a result of a series of appropriate rheological experiments on fresh concrete with subsequent spraying, as well as of mechanical tests on hardened concrete. Subsequently, specimens comprised of three bricks reinforced by spraying were monotonically loaded using deformation-controlled regimes in order to investigate the strengthening effect of the SHCC layer. The tests showed that the static load bearing capacity of such triplet specimens increased significantly as a consequence of this measure. The increase in the energy absorption of the specimens was, however, even more pronounced, and the load carrying capacity remained high even at high deformations. In further laboratory tests masonry walls were strengthened by means of sprayed SHCC layers and subjected to cyclic loading. A pronounced increase in mechanical performance was observed in comparison to reference masonry walls without such strengthening layers.

Key words
SHCC, spraying, strengthening, masonry