Effect of polymer latex on concrete/repair bond strength in harsh environment

The objectives of this investigation were to study the effect of polymer latex on concrete/repair bond strength under cyclic freeze-thaw, and temperature changes. Styrene Butadiene Rubber (SBR) and acrylic polymer latexes were used as partial replacements of mixing water in repair mortar. Concrete slabs of 600 X 300 X 100 mm were cast and after curing for 28 days, they were saw cut in such a way that each slab produced two sawn surface slabs with 600 X 300X 50mm dimensions. After repairing the saw cut surfaces of these slabs by polymer modified repair mortars, they were exposed to cyclic freezing and thawing, and to very high and low temperatures. Subsequently, the specimens were tested for concrete/repair bond strength at the end of each cycle. Since the concrete/repair interface faces shear stresses during the cyclic freeze-thaw and temperature changes, the friction-transfer method was used for the bond strength assessment. The respective results were compared with those of the ordinary sand/cement mortar that had no polymer.

Keywords:

Concrete repair , bond strength , friction-transfer , freeze-thaw , temperature