Experimental Cold In-Place Recycling with Hydrated Lime

Abstract

The Kansas Department of Transportation (KDOT) uses cold in-place recycling (CIR) for approximately 120 to 160 km of pavement a year as a part of its 1-R maintenance program. Originally KDOT used asphalt emulsions as the additive in CIR mixtures, but on the basis of performance concerns it currently uses type C fly ash. Recent research indicates that the use of CIR with asphalt emulsion and hydrated lime, introduced as hot slurry, provides improved performance. KDOT constructed two test sections on US-283 using type C fly ash and cationic slow set (CSS-1) with hot lime slurry. Samples of the materials were obtained and laboratory evaluations undertaken to evaluate the performance of CIR with hot lime slurry. Two additional mixing grade asphalt emulsions, cationic medium set (CMS-1) and high float (HFE-150), were evaluated as well. Laboratory samples were tested for tensile strength, moisture sensitivity, and resilient modulus. Laboratory compacted samples were tested for rutting resistance and moisture damage by using the asphalt pavement analyzer (Georgia rut tester). Results indicate that the use of hot lime slurry resulted in an improvement in material properties that affect the performance of CIR pavements, regardless of the emulsion used, and that CIR with hot lime slurry could be an alternative to the use of type C fly ash.

Polymer modified bitumen emulsions (PMBEs)

“…A breaking agent is sometimes used in order to promote destabilization, such as hydrated lime or cement (Cross, 1999;Niazi and Jalili, 2009). Note that very stable milk of lime with 45% solid fraction is now available and is being used as an emulsion breaking agent in microsurfacings or even tack coats.…”

Modelling the Effects of Hydrated Lime Additives on Asphalt Mixtures by Fuzzy Logic and ANN

“…HL decreases the failure risk of the asphaltaggregate bond mechanically and has a positive effect on this problem even with lack of water in the environment [1,6]. HL increases the tensile strength of the pavements [8,9] by increasing the elasticity modulus of the mixture [10,11]. It especially increases the strength by helping dispersion of the strains caused by traffic loads [12].…”

Suggesting a Simple Design Method for Cold Recycled Asphalt Mixes With Asphalt Emulsion

“…Nowadays, there are various codes to design of cold recycled mixes in different countries based on experience and research. However, there is no unique standard or approved method for mix design, structural design, laboratory evaluation method and quality control characteristics for CIR (Apeagyei, Diefender 2013, Asphalt Recycling and Reclaiming Association 2001Bessa et al 2016;Cox, Howard 2015;Du 2015;Kavussi, Modarres 2010;Kim 2007;Lee 2003;Martinez-Echevarria et al 2012;Tebaldi et al 2014). Different institutions includ-ing the Joint Committee of AASHTO 1 -AGC 2 -ARTBA 3 , AI 4 and ARRA 5 have presented general methods for designing CIR mixes based on hot mix asphalt (HMA) design methods.…”

“…The first step of these methods is the assessment of pavement condition and evaluation of recycled aggregates (including gradation, the amount of asphalt of RAP materials, etc. ), and then laboratory samples are prepared to estimate the optimum amount of additives (water and emulsified asphalt) (Cox, Howard 2015).…”