Effect of Fly Ash and Cement on the Engineering Characteristic of Stabilized Subgrade Soil: An Experimental Study

Table 4

Effects by fly ash and cement on the FSI value.

Mix proportion	Free swell index (%)	Degree of expansiveness	Percentage decrease (%)
0% FA+0% OPC	41	High	—
5% FA+2% OPC	34.3	Moderate	16.34
10% FA+4% OPC	26.4	Moderate	35.60
15% FA+6% OPC	20.6	Moderate	49.75
20% FA+8% OPC	12	Low	70.73