Tanggang railway Laboratory of China Railway 20th bureau successfully completed the concrete mix proportion work

Tangshan news (correspondent Liu Shumei and Wang Xianghui) Tanggang railway Laboratory of the station has arranged the work plan as a whole and promoted the experiment and detection work rapidly since the acceptance was successfully completed on December 10. As of January 4, 2020, the concrete mix proportion experiment has been completed efficiently.

for the laboratory, the concrete mix proportion is the primary work of the project construction, is the component of the project responsibility cost control, and is also the work with great labor intensity and workload. In order to do a good job of concrete mix proportion experiment in advance, after sampling cement, fine aggregate, coarse aggregate, fly ash, water reducing agent, air entraining agent and mixing water, the laboratory has made a detailed plan, cooperated with each other to carry out the experiment, screened qualified raw materials, and prepared materials for the next step of concrete mix proportion design.

according to the requirements of design drawings and code for durability design of railway concrete structure, the design requirements of concrete mix proportion in the beach salt alkali environment where the project is located are higher than those of previous projects. The minimum concrete strength grade of pile foundation, bearing platform, pier body and other parts shall reach C50, the air content shall be ≥ 6.0%, and the durability index shall meet the specification requirements. After 25 days' hard work, the laboratory personnel overcame various technical difficulties and successively completed the design and trial mix of 15 concrete mix proportions required by different strength grades, such as C50 pile foundation concrete mix proportion and C50 ordinary concrete mix proportion. All performance indexes of the mixture reached the allowable value of the specification. The standard test pieces required for each test are made, and after curing to the test age, the C50 pile foundation concrete mix proportion test piece and C50 common concrete mix proportion test piece used on site are selected for the durability evaluation of concrete (including the minimum strength grade, chloride ion content, alkali content, chloride ion diffusion coefficient, salt resistant crystallization dry wet cycle coefficient, concrete bubble spacing system Number, electric flux, frost resistance grade, crack resistance, reinforcement protection, alkali aggregate reactivity, etc.). At the same time, the laboratory personnel went to the source of group A and B materials for field sampling inspection, and found that the indicators of group A and B materials in situ can meet the needs of subgrade filling on site. The completion of the concrete mix proportion experiment of

has made a strong guarantee for the construction and production of the project in the first quarter of 2020.

on the occasion of the coming of the new year, Tanggang railway project laboratory wishes all the colleagues fighting in the construction line a happy new year, a smooth work, good health and family reunion!