An Investigation Of The Frost Resistance Of Air Entrained And Nonair Entrained Roller Compacted Concrete Rcc Mixtures For Pavement Applications

Roller-compacted concrete (RCC) pavement use a paving technique in which a zero-slump portland cement concrete mixture is placed using asphalt concrete pavers and compacted with vibratory and rubber-tired rollers. A reason for using RCC pavements is its durability in freezing and thawing conditions. Conventional concrete pavements are air-entrained for protection in freezing and thawing conditions. However, attempts to air-entrain RCC mixtures have met with little success. Nonair-entrained RCC has performed well in freezing and thawing field conditions in the past, but laboratory samples have demonstrated poor frost resistance. Objectives of this study are: (a) to determine if a proper air-void system can be entrained in RCC pavement mixtures using various dosage rates and aggregate gradings, and (b) to evaluate frost resistance and investigate material, construction, and site conditions which might influence the frost resistance. Results of the study demonstrated that various RCC mixtures may be entrained with air voids sufficient to protect the concrete from frost damage. RCC may also be effectively air-entrained in field applications. Studies of selected sites have shown that nonair-entrained RCC pavements have performed well in freezing and thawing climates. Keywords: Air entrainment/voids; Pavements/frost heave; Frost/resistance; Aircraft/parking facilities; Concrete/mixtures; Construction materials. (MM).

This report presents the results of a laboratory investigation that was conducted for the purpose of validating mixer- uniformity requirements for roller-compacted concrete. The purpose of the investigation was to verify existing guidance or, if necessary, recommend changes to existing guidance. The investigation included both air-entrained and nonair-entrained concrete. The results indicate that existing guidance is appropriate for Vebe consistency, water content, coarse aggregate content, compressive strength, and air-content determinations. However, the results indicated that existing guidance could he too restrictive for the unit weight of air-free mortar determinations. A recommendation was made to consider revising current guidance on the allowable range for unit weight of air-free mortar.