Modification of soft soils with ground granulated blast furnace slags with activated magnesium oxide

• Main Author: Kwek, Kathryn Kai Yun
• Other Authors: Teh Cee Ing
• Format: Final Year Project
• Language: English
• Published: 2016
• Subjects: DRNTU::Engineering::Civil engineering
• Online Access: http://hdl.handle.net/10356/68966
• Institution: Nanyang Technological University

Increased environmental consciousness have led to the replacement of cement in soil improvement with ground granulated blast furnace slag (GGBS). Reactive magnesia (MgO) has been found to be effective in activating GGBS and when incorporated into soils, showing superior qualities when compared to soil stabilised with PC, lime and lime activated GGBS. However, MgO activated GGBS (MgO-GGBS) is a novel binder and in most studies, are tested using sand specimens compacted by hand ramming. Hence, the aim of this study is to investigate the effect of MgO-GGBS on a soft soil prepared by static compaction. Kaolin was treated with varying amounts of MgO-GGBS and the strengths of the specimens were determined by the unconfined compression test. The results indicated that an increased binder content in the clay mixes led to higher strengths while increased MgO contents accelerated the hydration process to achieve high early strength. It was also observed that the optimum MgO to binder content ratio for achieving the highest strength is between 10% − 20%. The results indicated that for GGBS-MgO kaolin a 28-day strength of at least 2 MPa can be achieved for binder contents between 10% and 40%. Blue colouration was also found to be present in specimens cured with more moisture and with higher binder contents at early ages.