Feasibility Study of No-Slump Concrete for Mass Concrete Construction.

摘要

Three no-slump concrete mixtures containing crushed limestone aggregate, two with 4-1/2-in. maximum-size aggregate and one with 3-in. maximum-size aggregate, were proportioned with 255 lb of Type I portland cement with various water-cement ratios. Tests on the no-slump concrete were performed at the U. S. Army Engineer Waterways Experiment Station in December 1972. The no-slump concrete was produced and placed over a 3-day test period, 4-6 December 1972. Two test sections of various lift heights were constructed on top of a 15-ft-wide concrete slab. Both 4-1/2- and 3-in. maximum-size aggregate concrete was placed, leveled, and compacted in successive lifts all in the same day or in successive lifts separated by 1-1/2 to 2 days. The concrete was batched in a semiautomatic plant and mixed in a 2-cu-yd Koehring tilting drum mixer. Mixed concrete was hauled to the placement in 5-cu-yd trucks, leveled by a bulldozer, and rolled and vibrated with an 11-ton self-propelled vibratory roller. Observations of the 3-day operation demonstrated the feasibility of mixing, hauling, spreading and leveling, and compacting no-slump concrete for a massive section. Results of tests on drilled core specimens indicated that the unit weight and strength properties of the concrete were satisfactory using the roller compaction technique. (Author)