Performance of clay stabilized by cementitious materials and inclusion of zeolite/alkaline metals-based additive

Abstract

RoadCem (RC) is an additive produced based on nanotechnology and comprises of synthetic zeolites and alkali earth metals as some of its components. The geotechnical properties of a soil stabilized by adding RC to partly replaced cementitious materials are studied. Various combinations of the additives were investigated with the objective of reducing the amount of OPC by 50% by an inclusion of RC and ground granulated blast furnace slag (GGBS) in the stabilized soil. Laboratory studies involving index property testing, oedometer swell-deformation, unconfined compression tests and microstructural examinations were carried out on both the natural and 7-& 28- day cured samples of the stabilized soil. The influence of RC on the mechanical properties of the stabilized soil was examined by comparing the performance of the stabilized soil mixtures that contain the RC and the mixtures without the RC added. Results indicated the positive effect of RC as noticed by the tremendous strength gain in 7 days with the OPC reduced by 50% in the stabilized soil. Swelling decreased significantly to 0% after 28 days curing with the settlement also reasonably reduced for nearly all the percentages of the OPC substituted. The stabilized soil’s microstructure revealed the mechanism of cementation observed as an encapsulation or “wrapping effect” as a result of the presence of RC. A comparison of the RC-modified soil containing the by-products GGBS and PFA indicated that GGBS was more effective in the enhancement of engineering properties than PFA. Overall, as well as meeting some of the standards set for road pavement applications, the results obtained from this research are very promising for the ongoing discussions on reducing carbon foot-printing by OPC replacement.