Abstract
With millions of square meters of ageing exposed concrete surfaces throughout the
world, concrete patch repair is becoming a major component of the civil construction industry. To
ensure effective and efficient repairs and rehabilitation of deteriorating concrete surfaces, patch
materials with excellent workability during the repair phase and durability during its design life
cycle are required. The addition of polymer emulsions to cementitious repair mortars increase the
setting time, crack resistance while negatively affects the strength properties of the mortar. Polymer
emulsions include natural rubber, polyacrylonitrile and polivinylacetate, to name just a few [1].
This paper focus on the effect of adding different polymer emulsions at varying dosages to
cementitious repair mortars to obtain a better understanding of the influences on setting times, crack
formation properties and curing regime requirements for optimal strength development. Ambient
temperature and relative humidity were kept constant during the testing cycles.
The results obtained indicated that the introduction of a polymer emulsion tend to reduce
both the initial and final setting times of the repair mortars but that is extends the duration between
initial and final set when compared to unmodified repair mortars. Compressive strength reductions
were observed when adding polymer emulsions to the repair mortar but it was clear that crack
formation was eliminated with the addition of the emulsions.