The development of an ecofriendly binder containing high volume of cement replacement by incorporating two by-product materials for the use in soil stabilization

The development of an ecofriendly binder containing high volume of cement replacement by incorporating two waste materials for the use in soil stabilization. This paper investigates the possibility of replacing ordinary Portland cement (OPC) by two waste and by-product materials for the use of a silty clay soil stabilization purpose. The soil was treated by 9.0% OPC where this mixture was used as a reference for all tests. Two by-product materials: ground granulated blast furnace slag and cement kiln dust were used as replacement materials. Consistency limits, compaction and unconfined compression strength (UCS) tests were conducted. Scanning electron microscopy (SEM) analysis was carried out for the proposed binder to investigate the reaction of products over curing time. Seven curing periods were adopted for all mixtures; 1, 3, 7, 14, 28, 52, and 90 days. The results showed that the strength development over curing periods after cement replacement up to 45–60% was closed to those of the reference specimens. The microphotographs of SEM analysis showed that the formation of Ettringite and Portladite as well as to calcium silicate hydrate gel was obvious at curing periods longer than 7 days reflected that the replacing materials succeed to produce the main products necessary for binder formation.