ABSTRACT
In the paper, strength and deformation characteristics of heavy fluid concrete with a higher content of acidic ash from thermal power plants were compared with those of ordinary concrete over a 10-year period.
The ashes used were fly ash from electric filters of the West-Siberian thermal power plant and hydraulically removed ash from dumps of the South-Kuzbasskaya power plant.
The effectiveness of use of low-calcium ash depends chiefly on the degree of the dispersity and on the presence in them of active silica and alumina.
Strength development of concrete incorporating ash was more rapid compared with that of concrete without ash. At one to 500 days, the strength increased by 8 to 10 % every 100 days and it did not increase beyond this period. The strength of concrete incorporating ash increased by 60 % (21 to 33,5 MPa) over a 10-year period as compared with 24 % (20,5 to 25,5 MPa) for concrete without ash. Concrete containing ash had a lower cement content (by 26 %) and a higher slump (20 cm versus 10 cm).
The axial compression and initial modulus of elasticity increased by 50 to 65 % and 25 to 29 %, respectively. Testing concretes under loads (0,25 to 0,5 of Rprism) also gave better results for the concrete incorporating ash.
