Page - 96 - in Book of Full Papers - Symposium Hydro Engineering

Table 1 RCC Fine Sand Gradation Sieve Size INITIAL SPECIFICATION Percent Finer by Mass FINAL SPECIFICATION Percent Finer by Mass 9.5 mm (3/8 inch) 100 100 4.75mm (No. 4) 95-100 90-100 2.36 mm (No. 8) 75-95 55-80 1.18 mm (No. 16) 55-80 35-60 600 No. 30) 35-60 25-45 300 m No. 50) 24-40 15-35 150 m No. 100) 12-28 10-25 75 m No. 200) 8-18 8-18 The design intent of the RCC cementitious materials was to develop a mix that would attain an unconfined compressive strength of about 17 MPa (2,500 lb/in2) at 90 to 120 days, which is expected to give about 27.6 MPa (4,000 lb/in2) at one year. To meet this requirement, a target of 50 percent cement and 50 percent Class F Fly Ash was developed for initial mix design testing. The specification included a range of cement and fly ash components (by weight as shown in the table below) with a target mix at 103 kg of cement and 103 kg of fly ash per cubic meter (175 lb of cement and 175 lb of fly ash per cubic yard) to allow DWR the flexibility to modify the cementitious material content. Table 2 RCC Material Specification Location Batch Proportions - kg/m3 (lbs/yd3) Aggregate Size Range, Percent by Volume of the Total Aggregate Cement Fly Ash Water Group 1 38 mm- 4.75 mm (1.5 in. to 1/4 in.) Group 2 4.75 mm minus (No. 4 minus) Gated Spillway Chute 59.3- 118.7 (100-200) 59.3-118.7 (100-200) 112.7-127.5 (190-215) 60-64% 36-40% RCC Full-Scale Trial Placement: An initial full-scale trial placement was conducted in June 2017 to validate contractor placement means and methods as well as for evaluating the production uniformity of the on-site RCC batch plant. Several key aspects of the construction were tested, including: general placement, Grout Enriched Vibratable RCC (GEVR), forming of 60 cm (2 foot) high steps, and placement of the 1:1 unformed slopes. During this trial placement, the base RCC mix for foundation replacement was finalized as 103/119 kg/m3 (175/200 lb/yd3) of cement/fly ash. The amount of water was tested to produce a VeBe time 96