Modification of High-Lime Dry Mixes for Restoration

Saint-Petersburg State University of Architecture and Civil Engineering, 190005 Saint-Petersburg, Russia

^* Corresponding author: c3a@bk.ru

Abstract

Lime dry mixes for plaster and masonry are widely used for the restoration of architectural monuments. At the same time, lime mortars in modern conditions can be considered as insufficiently technological, since their hardening largely depends on the relative humidity of the ambient air and requires a rather long period of exposure to achieve normalized strength. This leads to a slowdown in the pace of work and a general increase in the cost of restoration. To overcome this shortcoming while maintaining other performance characteristics of the lime mortar unchanged, it is proposed to modify the composition of the mix by introducing an additive that accelerates setting and hardening in the optimal quality. In this paper, additives of various nature are considered. The most effective additives from the point of view of setting and hardening acceleration, but not radically changing the basic operational properties of the solidified mortar, have been determined. Compressive strength and vapor permeability were considered as the main properties of solutions.