462 RADIOLOGICAL CLEANUP OF ENEWETAK ATOLL using a standard column vibrator and vibratory power screed to dislodge entrappedair and prevent honeycombing. The power screed also provided a rough finished surface (Figure 8-47). Finishing was accomplished using a woodenscreedfollowed by the working of the surface with a bull float. The final finish was applied using coarse brooms to provide a wearing surface (Figuré 8-48). Edging trowels were used to finish the joints between adjacent sections. After the cap section was finished, curing compound was applied evenly over the entire surface. Although soil-cement operations were finished 26 days later than scheduled, the time was made up during capping byutilizing additional manpower and equipment. The cap wasfinished on 6 September 1979, 9 days ahead of schedule. Over 6,000 cubic yards of concrete were used in construction of the cap itself (Figure 8-49). Several problems arose during cap construction. While the first section was being placed, the concrete became extremely stiff and difficult to work. This was caused by the very high temperatures, which caused the concrete to hydrate much faster than normal. In order to slow down the rate of hydration, the USAE painted transit-mix truck drums white to reflect as much of the sun’s radiation as possible and sprayed the aggregate and sand with water prior to mixing them with cement. The accompanying evaporation produced cooling and increased the workability of the concrete. RT FIGURE 8-47. POWER SCREED. Runit (Yvon: