OPTIMIZED DESIGN OF AGGREGATE PARTICLE SIZE DISTRIBUTION FOR SELF-COMPACTING CONCRETE

摘要

Solid particles in paste are not packed in contacted with the neighboring ones because of paste's obstructing, and packing density of solid particles in paste could not be calculated directly by Stovall model which has a premise that all solid particles are packed contiguously.In this paper solid particles and paste film coated around with certain thickness are imaged as compound particles packed contiguously, whose packing density could be calculated by Stovall model, and the packing density of solid particle in paste could be obtained by establishing the relationship of actual and imaginary packing systems. Self-compacting concrete (SCC) mixture is viewed as a three-level imaginary compound particle system: 1)stone + sand paste film system; 2) sand + cement paste film system; and 3) cement + water film system. Particle size distribution of solid particles in each packing system was optimized using the proposed calculation method, 10% sand paste and 24% cement paste were reduced for SCC with optimized aggregates than the one with original aggregates. Passing capability,flow spread and compressive strength of optimized SCC were tested to be satisfactory.