The Effect of Hydrated Lime Mixing Forms and Ratios on Performance in Asphalt Pavements

Abstract

In this study; the water damage problem and indirect tensile strengths were investigated for different hydrated lime additive ratios and different hydrated lime adding methods. In this regard, many identical briquettes modified with hydrated lime have been produced. HL was used both in the bituminous binder (wet method) and as part of the filler aggregate. The hydrated lime was added in two different ways to form the defined equivalent ratios. By producing nine identical briquettes in each option, the values of water damage and ITS in both unconditioned and modified mixtures were compared, and the level of significance differences between the identical briquettes and mixtures was questioned. Increasing the HL content increases the standard deviation between identical samples in terms of ITS. The workability of the mixture is adversely affected by the increase in the hydrated lime ratio. When HL is mixed into the asphalt cement (AC), the standard deviations of ITS values among identical samples remain lower due to the increase in mixing rates. Increasing the ratio of adding HL to the asphalt cement reduces the ITS ratios compared to the option of adding filler to aggregate. If HL is added to the mixture in low HL content, the water damage ratios show, on average, higher water damage resistance (15% higher) than the HL being added to the AC. However, if the HL content is increased to medium and high levels, mixing HL to AC creates higher water damage resistance than adding it as filler.

Size Effect of Hydrated Lime on the Mechanical Performance of Asphalt Concrete

“…A life cycle cost analysis [ 3 ] showed that HL addition saved approximately 20$ per ton on asphalt concrete, whilst increasing the expected service life of the constructed pavement by 38%. Extensive research has reported the results of the stiffening effect of HL on asphalt mixes [ 4 , 5 , 6 ] and improvement in fracture-, aging-, and moisture-resistance of asphalt concretes with HL. addition [ 7 , 8 , 9 , 10 , 11 ].…”