Reinforcement of load-loading masonry walls with shotcrete

The analysis of the types of damage to vertical load-bearing elements of masonry from explosive impacts is carried out, the main signs of such damage requiring special reinforcement methods are described. Modern methods of restoring the bearing capacity of masonry require refinement and adaptation when considering cases of explosive impacts. A substantive examination of the load-bearing walls revealed a decrease in the adhesion forces between the brick and mortar, degradation of the connections between the outer verst and the main masonry array. To restore the bearing capacity of damaged elements, a modern method is proposed, consisting in the device of one-sided applications of shotcrete, which allows to restore the destroyed connections inside the masonry and provides a high level of mechanization of labor. Experimental studies were conducted to determine the physical and mechanical characteristics of shotcrete, as well as the adhesive strength between the concrete of the application and the masonry brick, which ensures the compatibility of the reinforcement structure of shotcrete and existing masonry. Tests were carried out on 20 samples with a ceramic brick base to determine the physical and mechanical characteristics, prisms and cylinders made of shotcrete were tested. It is determined that the technology of applying shotcrete at a speed of 150 m / s leads to a decrease in the specific weight of the mixture due to its compaction. It is established that with the same modulus of elasticity of shotcrete and heavy concrete, the prismatic strength of shotcrete is significantly greater. According to the research results, the modulus of elasticity of shotcrete is 26400 MPa, the average prismatic strength of shotcrete is 42 MPa. The obtained characteristics can be used for numerical modeling and computational justification when developing a structural reinforcement project.

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