Increasing the Monolithic Nature of Masonry Made of Cellular Concrete Blocks by Using Polyurethane Foam Glue as a Masonry Mortar

Abstract

This study is a continuation of previously published work [1]. The results of experimental determination of the strength of normal adhesion (under axial tension) in masonry made of autoclave–hardened cellular concrete blocks of compressive strength classes B1,5-B3,5 on cement mortars and polyurethane foam adhesives are presented. The tests were carried out in the laboratory of the Department “Reinforced Concrete and Stone Structures” of the Moscow State University of Civil Engineering (National Research University). The experiment was carried out on samples-cubes with a size of 150x150x150 mm, which were cut out of cellular concrete blocks, fastened (glued) together using masonry (binding) compositions. In the course of the study, it was found that when using various polyurethane foam glue compositions in masonry made of cellular concrete blocks of compressive strength classes B1,5–B3,5, the resistance to axial stretching over an unbound section (normal adhesion) of the masonry increases by approximately 9–25%. It was also found that the nature of the destruction of samples made on polyurethane foam adhesives (destruction occurs along the body of concrete), indicates the monolithic nature of the masonry. The analysis of the results obtained makes it possible to conclude that the resistance to axial tension along the unbound section of the masonry depends on the strength of the material from which the block is made, and not on the compressive strength of the masonry (binder) mortar used, as indicated in table 11 of SP 15.13330.2012 “Stone and reinforced masonry structures”. This factor must be taken into account when calculating masonry from autoclave-hardened cellular concrete blocks on polyurethane foam compositions.