Preparation of Concrete Mixture. Norms for Consumption of Materials

Preparation of Concrete Mixture

            All components of concrete mixture are batched by weight. The composition of concrete mixture recommended for manufacturing of concrete paving slabs according to State Standards of Ukraine DSTU Б. B.2.7-145:2008. Concrete Paving Products Not Mountings. Specifications is as follows, weight percent.     

ü  for grey paving slab

  • Portland cement of grade 500:    23 percent
  • granite macadam, 0.05 to 0.10 mm fractions:    57 percent
  • washed river sand:    20 percent
  • plasticizing agent following a recipe of the additive Manufacturer (percent of cement weight)
  • water (of cement weight):    30 to 40 percent

    Attention!

  1. The moisture of concrete aggregates shall be taken into consideration.
  2. A slight correction of the number of components ranging from 1.5 to 3.0 percent of the cement weight is possible during the manufacturing process.   
  3. The concrete moulding mixture is prepared in forced-type concrete mixers.
  4. The concrete mixture is covered with water at a temperature ranging from 30 to 32 °C.
  5. The moulding mixture shall be stirred at least during 15 minutes. And at the same time, the dry components (or the components with natural moisture content) are stirred at first with the aqueous solution of plasticizing agent being added to attain the norm afterwards.
  6. A period from the moment of preparation of the concrete moulding mixture until manufacturing of the paving slabs shall not exceed 70 % of the initial setting time of cement.
  7. When the concrete moulding mixture is being prepared, the natural moisture content of aggregates must be considered with the relevant correction being introduced into estimated amount of water poured into the concrete mixer.

 

Norms for Consumption of Materials 

            The norms for consumption of raw materials used to manufacture the concrete paving slabs are cited with consideration for five-percent in-process loss.

Item No.

Name of materials

Per 1 m2 of slab, kg

Per daily output 50 m2, kg

1.        

Portland cement of grade 500

22.1

1105

2.        

Granite macadam, 0.05 to 0.10 mm fractions

53.8

2690

3.        

Washed river sand

18.8

940

4.        

Water

9 L

450 L