A.W. Hago

Stabilization of oil‐contaminated soils using cement and cement by‐pass dust

Purpose – To investigate the effect of cement and cement by‐pass dust (CBPD) as a stabilizer on the geotechnical properties of oil‐contaminated soils resulting from leaking underground storage tanks, or soils surrounding petroleum refineries and crude oil wells.Design/methodology/approach – Oil‐contaminated soil (untreated soil) and a soil treated by bio‐remediation (treated soil) as well as a natural soil were obtained from Northern Oman. These soils were stabilized with cement and cement by‐pass dust at 0, 5, 10, 15 and 20 percent, by dry weight of the soil, and cured for seven, 14 and 28 days. Compaction, compressive strength, direct shear, permeability and leaching tests were carried out on the stabilized soils.Findings – The results indicate that cement and cement by‐pass dust improve the properties of oil‐contaminated soils. Traces of arsenic, barium, cadmium, chromium and lead were found in the oil soils, but none of them exceeded the EPA limits.Practical implications – Reuse in construction applic...

A Comparative Quantitative Study of an Omani Soil Using X-Ray Diffraction Technique

Two methods for the quantification of clay minerals using X-ray diffraction techniques: the Constant Mineral Standards Method and the Constant Clay Method were applied to soil samples from Al-Khod (Northern Oman). The first method was based on the addition of different concentrations of clay to constant mineral standards while the latter was based on the additions of known internal standards to the clay sample. The clay investigated in this study contained montmorillonite, palygorskite, illite and kaolinite. The areas of the reflection peaks were found to relate linearly with additions of different proportions of clay or mineral standards. Using the two methods, the concentrations of the different components and their experimental errors were determined. From the errors and self consistency of the results obtained, and the practicality of sample preparation, it is proposed to use the Constant Mineral Standards Method.

Flexural Behaviour Of Ferrocement Roof Panels

This paper presents the experimental results of nine roof panels made of Ferrocement. Two types of channel sections and one type of box section were tested. All panels were 2m long, 470mm wide and 20mm thick. Channel type A had side edge beams 95mm deep and channel type B had side edge beams 50mm deep. The depth of the box section was 95mm. Thin hexagonal wire mesh was used as reinforcement. The number of wire mesh layers was varied between two to six. The wires were impregnated midway through the thickness of the panels. The panels were tested for bending moment with simple supports. The main variables studied were the number of wire mesh layers, the cross sectional shape of the panel and the depth of edge beam. Tests revealed that all panels showed acceptable strength for roofing systems. The increase in the number of wire mesh layers leads to an increase in the flexural strength. The box section showed strength similar to that of the channel section with 95mm edge beam. The channels with 50mm deep edge beams showed strength much less than the ones with 95mm edge beam and box section.