METHOD OF PRODUCING COMPLEX ADDITION FOR CONCRETE MIXTURE Russian patent published in 1999 - IPC

FIELD: building materials. SUBSTANCE: at first method involves the presulfonation process of phenol waste with 1/20-1/10 part of sulfonating agent at 120-150 C for 0.5-0.9 h in air medium under vacuum 75-250 mm Hg up to removal 50-75% of volatile substances from the reaction zone or in medium of gaseous nitrogen at its specific consumption 1.5-2.5 m³/h per m³ of reaction mass volume followed by the sulfonation stage in the presence of measured amount of sulfonating agent. After sulfonation the reaction mass is diluted with water up to concentration 40-50% and thermocatalytic polycondensation is carried out for 0.8-2.5 h under excessive pressure 0.2-1.2 atm and 80-130 C followed by dilution of the reaction mass up to concentration 20-35% (by dry matter), neutralization of an acid oligomer with 10-30% sodium, potassium or calcium hydroxide an aqueous solution to pH 6-8 at 40-80 C and modification of the obtained neutralized mass at 40-80 C and pH 6-8. Method ensures to obtain high-effective complex addition that can be used in concrete mixture, technology of concrete and ferroconcrete articles making. Method provides the increase of strength, hardiness and sulfate-resistance of ready concrete by 10-20, 17-25 and 8-12%, respectively, as compared with the known method. EFFECT: improved method of producing, improved properties of concrete articles. 2 cl, 5 tbl, 6 ex