| Title |
Strength and Adhesion Properties of Polymer-Modified Mortars Using Redispersible Powders and Polymer Dispersions |
| Keywords |
Redispersible Polymer Powders ; Polymer Dispersions ; Polymer-Cement Ratio ; Strengths ; Adhesion |
| Abstract |
Redispersible polymer powders are usually produced from ordinary polymer dispersions by spray drying process. In recent years, the redispersible powders of improved quality have been developed and commercialized as cement modifiers. The principle of modification of cement mortar with the redispersible polymer powders is almost the same as that with polymer dispersions. Mostly the redispersible polymer powders are added to the dry-mixed cement and fine aggregate, and then water is mixed with the mixture. During the wet mixing with water, the redispersible polymer powders are re-emulsified in the mortar, and behave in the same manner as the polymer dispersions for cement modifiers.
The purpose of this study is to ascertain the strength properties of polymer-modified mortars using redispersible powders in comparison with polymer-modified mortars using polymer dispersions, and is also evaluated the adhesion properties. Polymer-modified mortars using commercial redispersible powders and polymer dispersions as controls are prepared with various polymer-cement ratios, and tested for flexural and compressive strengths, tensile strength, and adhesion in tension. And the pore size distribution of polymer-modified mortars using commercial redispersible powders and polymer dispersions is observed. It is judged that the modification of cement mortar with the redispersible powders causes marked improvements in its strength properties like the polymer dispersions, depending on the polymer-cement ratio. Also, the adhesion of redispersible polymer powder-modified mortars is improved with an increase in the polymer-cement ratio, and is superior to that of unmodified mortar. |