Research on the mix proportion and on-site construction technology of a four-graded roller compacted concrete

Abstract

In order to improve construction and production efficiency, and fully leverage the technical and economic advantages of continuous pouring and rapid rise of roller compacted concrete, the four-graded roller compacted concrete was widely used in hydraulic engineering. Based on the characteristics and testing methods of four-graded roller compacted concrete, the multiple sets, the effects of mix proportion, maximum particle size of coarse aggregate, and compaction degree were analyzed. The differences in construction technology between three-graded roller compacted concrete and four-graded roller compacted concrete were compared, and the more suitable construction technology parameters for four-graded roller compacted concrete were obtained. When the water consumption and vibrating compacted (VC) value are within the range of 71kg/m³~70kg/m³ and 3.5s ~ 6s, respectively, the VC value and air content of four-graded roller compacted concrete are optimal. Choose 30%~32% for sand ratio. The combination ratio of natural coarse aggregates (extra large: large: medium: small) adopts 25: 30: 25: 20. The VC value of 3.5s is suitable. After 6 times of heavy rolling and vibration rolling, the surface has a good slurry state, with a relative compaction degree exceeding 98%. The vibration force is 395kN, and the working speed is 1.0 ~ 1.5km/h. The suggestions as follows: when the layer thickness is 0.4m, the four-graded roller compacted concrete should be rolled twice without vibration, six times with vibration, and two times without vibration; When the layer thickness is 0.5m, the four-graded roller compacted concrete should be rolled twice without vibration, eight times with vibration, and two times without vibration.