The deformation modulus, which reflects the resistance capacity to elastic and plastic deformation, is an important input parameter in any analysis of soils/sediments behavior that includes deformations. The development of E50 with binder content at 28 and 90 days is shown in Fig. 8(a) and (b). By comparison, the E50 is significantly increased with cement content and reaches the maximum value at 9% cement among all designed mixes. With regard to lime-treated sediments, lime addition changing from 3% to 9% tends to decrease E50. This conclusion agrees with the development of UCS of cement-/lime-treated sediments. From the test results, it is suggested that the incorporation of fly ash has a strengthening effect on E50 of lime-treated sediments, but has a weakening effect on E50 of cement-treated sediments. This is to say,
the addition of fly ash increases E50 of lime-treated sediments, but decreases E50 of cement-treated sediments. For example, E50 of SD3L at 90 days is increased from 96.2 MPa to 152.9 MPa by addition of 3% fly ash, whereas E50 of SD3C at 90 days is decreased from 95.2 MPa to 75.6 MPa. Furthermore, the lime-fly ash-treated sediments have a
higher E50 than cement-fly ash-treated sediments except SD6C3CV. This is well consistent with the UCS development of lime-/cement-fly ash-treated sediments.