The Research Of Construction Techniques Of Rccd In The High Altitude And Cold Zone

RCCD is wide used in hydraulic engineering because it takes advantages of concrete dam's structure and material and earth-rock dam's construction method. This paper studied and summarized raw materials performance, construction mix proportion, construction technique, temperature control technique of RCCD which located in high altitude zone where is very hot in summer and very cold in winter with great amount of evaporation, this paper is done through conduction prototype test, combining construction practice of RCCD of Long Shou hydropower station in Gan Su province, aiming at wicked weather condition in high altitude and cold zone.The performance of RCC is mostly decided by raw materials performance, we should chose proper roller compacted concrete raw materials and study their performance so that the quality is guaranteed. Reasonable concrete mix proportion is very important for RCCD to improve it's performance of crack resistance, seepage control and frost resistance since the high altitude and cold zone have bad weather and great amount of evaporation, and since season changing need higher request for concrete adaptability. Air temperature change rapidly in high altitude and cold zone even in winter, this make temperature load possess have a big portion in dam stress analysis to produce complete penetration crack, the endurance of RCCD are affected by these factors. Therefore, we must take anti-crack method into consideration to prevent RCCD produce temperature crack in construction stage or in operating period. Effective construction techniques must be taken to meet the capability need of RCCD in high altitude and cold zone for it's great amount of evaporation which quicken roller compacted concrete solidification and effect their quality.The paper reveals that choosing appropriate raw materials can meet RCCD the need of intensity, crack resistance and erosion-resistance in high altitude and cold zone; it have a great good effect on frost resistance and durability of roller compacted concrete when to be mixed into right external agent; according to construction condition, dynamic control of roller compacted concrete's VC value, improving construction techniques of RCCD in mixing, transporting, entering silo, silo operating and so on, adapt weather condition and ensure the quality of roller compacted concrete; taking proper protection and temperature control measure can reduce and control the happening and development of crack of RCCD dam.