Application of alkali-activated slag in roller compacted concrete

Abstract

One of the most widespread techniques in concrete pavement construction is roller-compacted concrete (RCC) in which Portland cement is used. Recently, an inclination has been seen toward alternative cementitious materials due to environmental concerns expressed over the production of Portland cement. Alkali-activated slag concrete (AASC) has been proposed as a solution to this problem. However, the application of this type of concrete in RCC has been rarely investigated. This study was to fill this gap in the existing literature experimentally. A solution of sodium hydroxide and sodium silicate helped to activate the slag content of AASC. The mechanical and rheological properties of roller-compacted alkali-activated slag concrete (RC-AASC) were assessed by measuring compressive and flexural strengths, optimum compaction moisture, setting time, and strength development of concrete samples. In mix design of RCC, determination of its optimum compaction moisture is a crucial step; therefore, the optimum moisture required for ultimate compaction was estimated, while the variation in combination of alkali activator affected this optimum moisture. The results indicated that the compressive and flexural strengths of RC-AASC with minimum cementitious content were comparable to those of conventional RCC which is mentioned in ACI 327R-14.