HYDRAULICALLY BOUND CONCRETE-LIKE ROAD BASE MATERIALS CONTAINING HIGH VOLUME WASTE DUST AGGREGATES

The paper presents laboratory test results on hydraulically bound 'concrete-like' road base materials containing high volume of limestone, steel slag and blast furnace slag waste dusts compared with control mixtures. These mixtures incorporating waste dusts were designed as potential road base concrete-like pavement layers and contain higher levels of (4mm-0.0 mm) limestone dust, than would be the case in standard un bound road base mixtures. The combined influence of the limestone waste dust and steel slag and or blast furnace slag waste content is to enhance the stiffness of the road base materials and save materials and cost during road construction. Triaxial repeated load tensile tests were performed on the un bound and bound materials to measure their resilient modulus and the results were compared. The test results show important improvements in the bond strength between the content of road base materials, namely; waste aggregates and primary aggregates in all the mixtures that were tested. This offers the prospect of using these materials in road base materials to reduce the use of primary aggregates and thus minimize the cost of roads and highways construction.