Characteristics of Preplaced Aggregate Concrete Fabricated with Alkali-Activated Slag/Fly Ash Cements

Abstract

This study assesses the characteristics of preplaced aggregate concrete prepared with alkali-activated cement grout as an adhesive binder. Various binary blends of slag and fly ash without fine aggregate as a filler material were considered along with different solution-to-solid ratios. The properties of fresh and hardened grout along with the properties of hardened preplaced concrete were investigated, as were the compressive strength, ultrasonic pulse velocity, density, water absorption and total voids of the preplaced concrete. The results indicated that alkali-activated cement grout has better flowability characteristics and compressive strength than conventional cement grout. As a result, the mechanical performance of the preplaced aggregate concrete was significantly improved. The results pertaining to the water absorption and porosity revealed that the alkali-activated preplaced aggregate concrete is more resistant to water permeation. The filling capacity based on the ultrasonic pulse velocity value is discussed to comment on the wrapping ability of alkali-activated cement grout.

Feasibility Study of Expanded Clay Aggregate Lightweight Concrete for Nonstructural Applications

“…LWAC casting process is usually cumbersome because if the ingredients are mixed conventionally in a mixer, and then poured into the mold, the aggregates float on the surface, resulting in uneven distribution of aggregates within the matrix [38,39]. Preplaced aggregate concrete (ASTM C-937 [40]) is a new method for casting LWAC in which aggregate is first placed in a mold then the mortar is added to the mold [38].…”