Vol 2, No 1 (Published)





Table of Contents

Original Research Articles

by Khalid Elyas Alkhidir
805 Views, 393 PDF Downloads
Sandstone samples were collected from the surface type section of the Shajara Formation of the Permo-Carboniferous Unayzah Group for detailed reservoir characterization. Capillary pressure experiment was performed to contact porosity and permeability was derived from the Data. Arithmetic relaxation time of induced polarization was calculated from the distribution of Permeability and the fractal dimension was calculated from the relationship between wetting phase saturation and Arithmetic relaxation time of induced polarization. In addition to field observation and obtained results of fractal dimension values, the Shajara reservoirs of the Shajara Formation of the permo-Carboniferous Unayzah Group were divided here into three fractal dimension units. The Units from base to top are: Lower, Middle, and Upper Shajara Arithmetic Relaxation Time Fractal dimension Units. It was also reported that the obtained fractal dimension speeds with increasing permeability and relaxation time due to an increase in pore connectivity.

Original Research Articles

by Majid Unesi, Mohammad Noaparast, Sied Ziaedin Shafaei, Esmaeil Jorjani, Mahdi Yaghobi Moghaddam, Hadi Abdollahi
695 Views, 733 PDF Downloads
Aim:The paste thickener could increase the water recovery and reduce the environmental impacts in tailings dam. The present work aimed to find the appropriate scale-up factor for bed depth to design paste thickener for copper tailings, using a lab glass cylinder and an operating pilot column. The thickening tests were carried out on the flotation tailing samples obtained from the Sarcheshmeh and Miduk copper mines located in Iran. Based on the industrial conditions, the values of influential parameters for paste thickener used in these experiments were pH=11 and feed solid=10 %. Flocculant type was NF43U and used as 25g/t with dosage of 0.25 gt. The unit area of Sarcheshmeh and Miduk paste thickeners were designed as 0.057 and 0.047m2/t/day, respectively. Based on the dry feed rates to each paste thickener as 7920 and 4320 t/day, the thickener's diameters were determined as 23.9 and 16.1 meters which are similar to the actual thickener’s diameters (24 and 16 meters), respectively. In addition to unit area, the bed depth is also important in the paste thickeners design. Hence, the ratio of industrial to lab unit bed volume for Sarcheshmeh paste thickener was obtained 75 which was equal to the ratio of industrial to lab bed depth (bed depth scale-up factor exclusively for copper flotation tailings). This procedure was validated by using the Miduk sample. The bed depth in the paste thickeners was determined as 7.5 meters, by using the bed depth scale-up factor which was comparable to the actual bed depth (8 meters). This research confirmed that the bed depth scale-up factor is able to correctly determine the bed depth of industrial paste thickeners for copper tailings. 

Original Research Articles

by Mingkun Yew, Mingchian Yew, Lip Huat Saw, Siongkang Lim, Jing Hang Beh, Tanching Ng
691 Views, 372 PDF Downloads

In this study, the effects of heat-treated and non-treated oil palm shell (OPS) species (dura and tenera) are investigated on the slump, density and compressive strength of oil palm shell concrete (OPSC). Two different species of OPS coarse aggregates are subjected to heat treatment at 65 and 130 °C with the duration of 1 h. The results show that the workability of the OPSC increases significantly with an increase in temperature of heat-treated of the tenera OPS aggregates. It is found that the maximum achievable 28-days and 180-days compressive strength is 51 and 54 MPa, respectively. Furthermore, rapid chloride penetration tests (RCPT), porosity measurement and water absorption tests were performance to signify the effects of heat treatment on different OPS species lightweight concrete (LWC). The use of heat-treated OPS LWC induced the advantageous of reducing the permeability and capillary porosity as well as water absorption. The results showed that the ideal of heat treatment method has enhanced the performance of drying shrinkage. Hence, the findings of this study are of primary importance as they revealed that the heat treatment on OPS species LWC can be used as a new environmentally friendly method to enhance the durability properties and drying shrinkage of OPS LWC.


Original Research Articles

by Ajay Kumar Naithani, L. G. Singh,, Prasnna Jain, D. S. Rawat
423 Views, 358 PDF Downloads

Geotechnical assessment of the foundation including engineering geological investigations are essential for important civil structures to provide permanent data set for geological interpretations and for recommendations of suitable engineering measures for the improvement of the foundation. Yaragol Gravity Dam for drinking water is being constructed across Markandaya river in Karnataka State of India. Engineering geological mapping on 1:200 scale was carried out for Housing Chamber of Yaragol Gravity Dam to evaluate the design basis foundation parameters. 2 m x 2 m grids were prepared for mapping of the floor. Based on the field observations and evidences, it was found that the floor area consists of foliated gneiss and granite. No evidence of faulting or shearing was observed on the surface of the floor area. Geotechnical assessment of the foundations was done on the basis of detailed engineering geological mapping and laboratory test results. Classification of rock mass using Rock Mass Rating (RMR) of Bieniawski (1989) has been attempted and based on investigations recommendations for the treatment of foundation were given. Rock type and Rock Mass Rating (RMR) methods were used for assessing the safe bearing pressure of the foundation. Consolidation grouting up to 6 m depth in the foundation using primary at 6 m spacing and secondary holes at 3 m spacing was recommended. After detailed investigations it was found that, the foundation is suitable to locate a housing chamber.


Original Research Articles

by MAGNE P, BRUZI G, CARVALHO A, ENCISO R, GIANNINI M
3121 Views, 368 PDF Downloads
Purpose. Evaluate surface treatments and silane application methods and their effect on shear bond strength (SBS) before and after aging. Materials and methods. Slices of IPS e.max CAD and Vitablocs Mark II, were embedded in acrylic resin. The block was randomly assigned to 5 groups; E:etching with hydrofluoric acid (HF), rinsing, followed by cleaning in ultrasonic bath; E/S:HFetching and cleaned as group E followed by silane application for 20s, air drying and hot drying; E/S+:HFetching and cleaned as group E, followed by silane application for 60s, air drying and hot air drying, rinsing with boiling water and hot air drying; S:silane application for 20s followed by air drying and hot air drying; S+:silane application for 60s followed by air drying, air drying and hot air drying, rinsing in boiling water and hot drying. Cylinders of composite resin (n=12) were bonded with adhesive. SBS testing was carried out after 24h or after thermocycling for groups E; E/S and E/S+. Results. For 24h SBS showed significantly higher mean bond strength with E/S, for both ceramic, compared to E and E/S+. The use of silane alone showed significantly lower mean bond strength. No significant differences were found between E/S and E/S+ for VITA. The SBS was negatively affected by simulated aging in E/S group and positively in E/S+. Conclusions. The association of HFetching and a heat-dried silane showed to be significant to obtain a high SBS. Furthermore, the optimized silane application is not relevant to the immediate SBS while it enhances after aging.