Analysis Of Linear Shrinkage

RHA; same trend for LL and PL. The Linear Shrinkage (LS) decreases as the RHA content increases, enhancing the volume stability of the soil. The results obtained from the researches’ work are shown below in Figure 2.7. Figure 2.7: Variation of OMC, LL, PL, PI, and LS with RHA content
Roy (2014) conducted a research on the soil stabilization using RHA and cement, using the soil sample from Burdwan, India by disturbed sampling method. The CBR value obtained from the experiment is to evaluate the strength of the stabilized soil. The RHA used for the experiment was collected from Bishalakshi Rice Mill in Burdwan and has been grounded as well as sieved through 0.075mm aperture before use. The chemical composition is presented below in Table 2.6.
As Ray (2014) reported, the MDD decreased, while the OMC increased with the increment of the RHA content. The lowering in the MDD can be attributed to the replacement of fine soil particles with the RHA in the mixture. This explains the use of RHA as fillers with low specific gravity in the voids. For OMC, the increment is caused by the addition of RHA, which lowers the amount of free silt and clay fraction thus forming a much coarser materials with large surface area. More water is required to compact the soil-RHA mixture. For CBR, the value increases with the RHA content from 10% to 20% together with soil and 6% of cement. Roy (2014) clearly stated that for unsoaked samples, the CBR value increased by 106% for 10% RHA content. Further addition of the RHA content up to 15% has lowered the CBR value. The extra RHA has immobilized the reaction by occupying too much space within the sample, thus reducing the bond between the soil-RHA mixtures. The results for MDD and OMC shown in Figure
When burned in ordinary way, the rice husk produce a crystalline silica ash; when burned under suitable condition, a highly reactive black non-crystalline silica residue with pozzolanic properties is produced (Isah, 2015). Temperature and duration of the combustion are of utmost importance in producing good quality of RHA.

2.5.4 Sago Ash (SA)
In a recent study done by Jawawi (2015) on the stabilization of Mukah peat taken at Mukah-Dalat road, the researcher utilized the sago ash as the by-product soil stabilizer. The tests conducted using various proportion of RA on the peat soil samples. The experiment conducted with sago ash together with Mukah peat is the standard proctor test in determining the MDD and OMC of the SA-peat mixtures. The MDD and OMC values are essential for the determination of the best sample mix proportion for UCS test. The MDD and OMC values are shown below in Table 2.10.
Table 2.10: The values of MDD and OMC obtained (Jawawi, 2015)
Sample MDD (kg/m3) OMC (%)
Original Peat 315 90
95% peat + 5% SA 320 86
90% peat + 10% SA 330 80
85% peat + 15% SA 343 82
80% peat + 20% SA 362