,

(2

.10)

P − P

1

2

where R – the required value of the corrected parameter (fineness modulus of

aggregate, specific surface, quantity of aggregate of definite fraction); P1 and P2

– values of the corrected parameter of aggregate accordingly with large and

less its value; n –volume content of aggregate with the less value of the given

parameter in the sum of volumes of the aggregates mixed up.

50

2.3. Consolidation (compaction) concrete

Achievement of necessary high-quality concrete is possible only at

the careful consolidation of concrete mixtures.

ties

oper

ues of pr

Val

Porosity

Fig. 2.8. Influence of porosity of

concrete on compressive strength

(1), tensile strength (2), dynamic

modulus of elasticity (3)

51

The compacting factor (D ) of fresh concrete is determined by a

cp

compaction ratio:

D = 1− P

(