AGGREGATE REQUIREMENTS FOR RCC PAVEMENTS - A CASE STUDY

摘要

Roller Compacted Concrete (RCC) is commonly used today for a variety of pavement applications, when strength, durability, and economy are primary factors. RCC contains the same basic ingredients as conventional Portland Cement Concrete (PCC). However, unlike conventional PCC, RCC mixes are typically drier, designed to be stiff enough to be compacted with vibratory rollers. This can exaggerate aggregate related issues that may not be as noticeable with conventional PCC. Thus, it is important that the aggregate specifications be strictly enforced with RCC. This paper documents a case study of the need for careful control of the nature of the dust fraction for aggregate used in RCC pavement. It is demonstrated that gradation alone is not suitable for control of aggregates to be used in concrete of any kind, especially RCC which often contains higher percentages of material passing the No. 200 (75 μm) sieve. Laboratory testing, coupled with visual inspections of stockpiles is the only sure way to identify potential problems with aggregates before construction begins.