The optimization of the composition and properties of the building mixture for repairing roads with the organic additive «Emulbit»

The Department «Building Materials and Articles» of the Siberian Federal University has carried out research on the development of organic and mineral compositions in the form of dry building mixtures for repairing asphalt concrete roads and offered an original technology of making repairing mortar from the dry building mixture produced directly on the place of work. The special feature of the technology is that the repairing mixture is mixed with water in combination with complex additive «Emulbit» to match the properties of the asphalt concrete covering being repaired. The optimal additive «Embulit» dosage has been chosen according to the results of its influence on the compression and bending strength, adhesion to the foundations, water absorption and frost-resistance. The analysis of the results of strength changes in different hardening periods has shower, that maximum strength increase of the hardened mortar (up to 20 %) occurs when additive amount in the compositions is 1-1,5 %. It can be explained by the fact that after forming a mineral frame of the material combined with bitumen water emulsion special conditions are created for the hydratation of a hydraulic binder. The additive «emulbit» in the composition in the amount of 1 % of the whole binder increases adhesion strength of the hardened mortar to the foundation by 40 % and dicreases water absorption by 17-20 % in comparison with the composition without «emulbit». With this additive amount the repairing composition has the required indices of compression, bending, adhesion strength, water absorption and frost-resistance.