Shrinkage-Reducing Admixture Effect On Rubberized Cement Performance

Within the last decade, interest in using waste rubber in concrete has been increasing due to sustainability concerns. However, previous work has shown a surface mismatch between rubber and paste, leading to diminished performance. The objective of this work is to determine the efficacy of shrinkage-reducing admixture (SRA) on the performance of rubberized cement samples; beyond reducing shrinkage, the use of SRA is believed to improve the adhesive bond at the interface. From initial testing, another effect was observed: adsorption of SRA on the rubber surface. Various mechanical tests and characterization techniques were implemented to understand the efficacy of these modifications. Results concluded that SRA implementation within the bulk mixture or as a pre-treatment lowered rubber contact angle, which subsequently improved compressive and pullout strength, as well as damping ratio of rubberized cement samples. By pretreating rubber, limitations associated with using SRA in the mixture design may be bypassed.