Influence of Addition of Admixtures and Lime on the Properties of Pond Ash-Based High Strength Flowable Fills

Flowable fills or controlled low strength materials (CLSM) are currently considered as better alternative to the conventional fills for various civil engineering applications such as backfill behind retaining walls, bedding layer of pipelines and as subgrade and subbase for pavements, etc. Cement is the primary binding material added along with fine aggregates and water in producing flowable fill mixes. In this paper, the influence of adding lime and admixture along with the regular constituent materials in the production of CLSM mixes is investigated.. Lime contents of 1 and 2% and superplasticizer of 0.2, 0.6 and 1% were added along with regular CLSM mix. The properties of flowable fills, such as flowability and unconfined compressive strength of different mixes of flowable fills, are considered to identify the effect of both lime and admixture addition on the plastic and in-service properties. Based on the experimental analysis, it was concluded that the addition of lime was found to be more effective than that of superplasticizer addition for high strength flowable fills as the unconfined compressive strength values obtained for lime added mixes were significantly higher.