2.8　Quality Control

2.8.1　The deviation requirement for sleeper overall dimension

The deviation requirement for sleeper overall dimension，see Table 6.

continued

2.8.2　Sleepers appearance quality requirement

Sleepers appearance quality requirement，see Table 7.

2.8.3　Other quality requirement

1.The day 28 sleeper strength shall not be lower than the design strength grade C60，and the compressive strength test shall comply with the requirement of GB/T 50081-2002.

2.The chloride penetration value of concrete shall be less than 1 000 C.The chloride penetration test shall comply with the requirement of ASTM C 1260.

3.The pull-out resistance of the embedded sleeve shall be not less than 60 kN（5 pieces of sleepers shall be selected from each batch，and 4 sleeves shall be selected from every one piece of sleeper），there shall be no visible cracks around after testing，and little mortar peeling off is allowed.

4.The total alkali content in concrete shall not be over 3.5 kg/m3.When the aggregate is of potential basic active，the alkali content shall not be over 3.0 kg/m3.The total chloridion brought in the concrete by cement，admixture，sand，stone，additive and water shall not be more than 0.10％ of the total binding material.