Applied Research Journal
Volume:2 Issue: 12, Dec 2016

Compaction curves are widely used in civil engineering especially for road constructions, embankments, etc. Obtaining the precise amount of Optimum Moisture Content (OMC) that gives the Maximum Dry Unit weight dmax is very important, where the desired soil strength can be achieved in addition to economic aspects. In this paper, three peak functions are used to obtain the OMC and dmax through curve fitting for the values obtained from Standard Proctor Test. Another surface fitting was also used to model the Ohio’s compaction curves that represent very large variation of compacted soil types. The results showed very good correlation between the values obtained from some published sample tests and the values obtained from curve fitting for both cases of single curve and multiple Ohio’s curves. The easiness of obtaining OMC and dmax. From the results of curve fitting encourage users to utilize this procedure, in addition to its accuracy.

One of the major problems facing the road construction engineer is the collapsible granular soil which may be used for embankment construction. Problems appears when such compacted soil come in touch with water, it exhibits cracking and uncontrolled settlement. Collapsible soils are defined as any unsaturated soil that goes through a radical rearrangement of practice and great loss of volume upon wetting, with or without additional loading. An attempt has been made in this investigation to stabilize the collapsible soil of Nasiriya with asphalt emulsion. Specimens of pure and asphalt emulsion stabilized soil have been prepared using optimum fluid content and tested. The first group of specimens of (60x60x20) cm have been tested for direct shear under various normal stresses of (27.5, 55, 83, 110, and 220) kPa. Under dry and soaked conditions. The second group of specimens of (75) mm diameter and (19) mm height have been tested for compressibility characteristics at dry and soaked test conditions. It was concluded that the cohesion has increased (30 and 9) folds and the angle of internal friction exhibits (3.7 and 8.3) folds increment for dry and soaked for asphalt stabilized soil as compared to untreated soil. The compression index (Cc) decreases by (78 and 15) % after stabilization for dry and soaked test conditions respectively, while the void ratio exhibits an increments of (21.4 and 70.5) % for dry and soaked test as compared to untreated soil.

Using wood ashes as a replacement for cement is one of the promising ways to increase the pressure resistance (pushing resistance) and also is the heat insulation of concrete blocks. Current study is about using wood ashes as a partial replacement for the cement materials with the percentage of 10 %, 20 % and 30 % of ashes and its admixture with cement, ballast and sand during building the blocks. Experiments showed that pressure resistance of the sample blocks that contained 10% wood ash was 10 % more than the control sample. Furthermore, 10% of wood ashes are suitable for building concrete blocks and the blocks are near the standards and also in the sample containing 30 % of Pozzolan ash, less water absorption is observed.