PCCP管芯混凝土碱含量控制和骨料碱活性抑制措施研究

Research on alkali content control and alkali-aggregate activation preventive measures of PCCP concrete

南水北调北京段工程PCCP管道的管芯混凝土强度设计等级为C50～C60,属高强高性能混凝土,PCCP管芯混凝土碱含量控制和骨料碱活性抑制,是直接影响混凝土的耐久性和PCCP使用寿命的关键因素。为此,进行了大量的试验研究工作,找出了PCCP管芯混凝土碱含量控制和骨料碱活性抑制措施,为PCCP管道的质量控制提供了依据。

There are two parallel Pre-stressed Cylinder Pipes（PCCP） with Length of 56 km and diameter of DN4000 in the Middle Route Project of South-to-North Water Transfer in Beijing section. The maximum operating pressure of the pipeline is designed to be 0.8MPa. The maximum depth of covering soil is 10m and theconcrete strength grade of the pipe is designed to be C50 to C60, which belongs to the category of high-strength and high-performance concrete.The alkali control and alkali-aggregate reactivity prevention of the PCCP are the key factors which directly influence the durability and the service life of PCCP project .Therefore,a lot of experiments have been carried out to search of the controlling measures to control the concrete alkali content and alkali reactivity prevention.