通过现场碾压工艺试验,对比三级配与四级配碾压混凝土在现场施工工艺方面的差异,提出四级配碾压混凝土施工工艺参数,为四级配碾压混凝土在水电工程中的推广及应用提供技术指导。试验结果表明,四级配碾压混凝土用水量为71kg/m^3、VC值为3s~5s时,拌和物大骨料表面砂浆包裹充分,具有较好的抗分离性,表面液化泛浆情况好,可碾性好。四级配碾压混凝土施工工艺参数为:层厚为0.5m时采用2遍无振+8遍有振+2遍无振碾压,层厚为0.4m时应采用2遍无振+6遍有振+2遍无振碾压(其中有振碾压激振力为395kN),行走速度为1.0~1.5km/h,相对压实度均可达到或超过98.0%。
To provide a technical support to application of four-graded RCC in hydropower projects, a test on rolling technology of four-graded RCC and three-graded RCC is conducted on dam site, and construction parameters of four-graded RCC are recommended in this work. Results show that with water consumption of 71kg/m^3 and VC value of 3s -5s in the 4-graded case, the mortar can sufficiently coat large aggregate and the mixture has good performances of roller compacting and anti-separation. The parameters are as follows: non-vibration rolling 2 times, vibration roiling 6 times and non-vibration rolling 2 times for a 0.5m-thick layer; non-vibration rolling 2 times, vibration rolling 8 times and non-vibration roiling 2 times for a 0.4m-thick layer. Both maintain a roller exciting force of 395kN and a walking speed of 1.0 - 1.5km/h. Then the relative compaction can reach or exceed 98.0%.