METHOD FOR INJECTION SEALING OF CONCRETE AND REINFORCED CONCRETE STRUCTURES AND GROUTING MORTAR FOR IMPLEMENTING THE SAME

FIELD: civil engineering. SUBSTANCE: sealing includes subsequent injecting the grouting mortar through injectors. The injecting is carried out to the depth of the structures through a group of point like injectors fastened to the earlier drilled wells of the structure. The injectors are hydraulically interconnected within the sealing portion. There are three subsequent stages of injecting. The first and second stages use grouting mortar of similar composition but different water/cement ratio equal to 0.65 - 0.85 and 0.35 - 0.55 respectively. The mortar contains Portland cement, micro-silica, SURFACE ACTIVE SUBSTANCE, quartz sand of 0.140 mm and (0.140 - 0.315) mm size, and complex mineral addition - the product of joint milling the aluminate cement of 500 grade containing 12 - 15 % three-calcium aluminate of cement weight, calcium sulphoaluminate, and quartz sand of not more than 0.140 mm size in ratio 1:1:1 with the following content of the components in the mortar (% by weight): 35.5 - 40.0 Portland cement of 500 grade; 1.5 - 3.5 micro-silica of (25-35)x1000 square centimeters per gram specific surface; 25.0 - 35.0 quartz sand of less than 0.140 mm size; 35.0 - 38.0 quartz sand of (0.140 - 0.315) mm size; 0.25 - 1.5 surface active substance; 4.5 - 6.5 the above complex mineral addition; the balance being water. At the final stage of injecting used is grouting mortar of the following content (% by weight): 30.5 - 43.5 Portland cement of 500 grade; 1.5 - 3.5 micro-silica of (25-35)x1000 square centimeters per gram specific surface; 30.5 - 33.5 quartz sand of less than 0.140 mm size; 0.5 - 2.0 surface active substance; 2.5 - 4.5 the above complex mineral addition; the balance being water. The method is implemented at each stage of injecting the mixers under the following sequence. First during 15 - 20 sec the pressure is increased up to operating one equal to 2.0 - 6.0 kilo per square centimeter, which is stopped on achieving the constant absorbing of the grouting mortar at the level of 0.01 - 0.05 l per minute. The injecting under the stopped operating pressure is performed for 3 - 10 minutes. Then the pressure is smoothly decreased during 10 - 12 sec to zero and then the injection system becomes disconnected from the injectors. The injectors are withdrawn from the wells, and the wells are plugged by filling with concrete mortar of the following content: 35.5 - 40.5 Portland cement of 500 grade; 1.5 - 3.5 micro-silica of (25 - 35)x1000 square centimeters p