Saudi Journal of Civil Engineering (SJCE) | Volume-5-Issue-06
Original Research Article
July 8, 2021
Experimental Analysis on the Effect of Calcination on the Index and Engineering Properties of Clay Soil
H. D. Mac-Eteli, S. Sopakirite
Page Numbers : 133-138
DOI : 10.36348/sjce.2021.v05i06.001
The paper aims to access and evaluate the index as well as engineering properties of clay soil when subjected to controlled thermal treatment. To achieve this, clay soil was collected from a specific location in Amassoma, Southern Nigeria, and heated up at 200oC, 400oC, 600oC and 800oC. To adequately inform the engineering society on the potentials of thermally treated clay soil in the construction industry, properties such as specific gravity, Atterberg limits, California bearing ratio test (CBR), and compactibility were determined. Specific gravity increased by 60% between the control at room temperature and the specimen produced at 800oC. The increment was direct showing flattening tendencies between 600oC and 800oC. A direct relationship was found to exist between calcination and compactibility for all specimens between 27oC and 800oC. A similar trend was observed for CBR values of which at 800oC, the soil specimen having a CBR of 13.51 had improved in CBR by 655% when compared to the control’s CBR of 1.79. An inverse relationship was observed between calcination and Plasticity Index. At 800oC, the plasticity index having a value of 6.9 had reduced by 63% when compared to the control specimen having a PI of 18.4. By the process of calcination, the soil was successfully transformed from a clayey, high plastic, cohesive soil with very high affinity for water and unsuitable subgrade for pavement purposes, into a silty, low plastic, partly cohesive soil with reduced affinity for water having a fair CBR and applicable for subbase utilization in pavement construction.
Original Research Article
July 27, 2021
Create a 3D Model for University of Baghdad Based on Aerial Photos
Ahmed Kareem Jebur
Page Numbers : 139-146
DOI : 10.36348/sjce.2021.v05i06.002
This paper includes the use of aerial images captured by a metric camera to build digital 3D models because these models have evolved greatly and increased the demands to meet the requirements of many applications. The reliability of these models depends mainly on the data processing methods, the approved tools for the solution, and the data quality. Where the automatic method was used in this research to process data, determine the three-dimensional coordinates and extract the three-dimensional model. Several programs can be used to process data and determine 3D coordinates such as Agisoft Photoscan. The results were evaluated on the basis of statistical methods in order to assess the accuracy and reliability of the results of the Agisoft Photoscan software for exact 3D modeling applications. To that aim, the study was carried out by an airborne metric camera with a height of 457 m at the University of Baghdad in Baghdad City. The evaluation was carried out based on the height of several buildings in the study area to assess the accuracy of the final 3D digital model. Whereas the overall accuracy of the 3D model dependent on the RMSE was (0.3014 m).
Original Research Article
July 30, 2021
Evaluation of Probabilistic Potential of Chloride-Induced Corrosion on Modification of Steel Bar in Reinforced Concrete Structures Exposed to Severe Media
Overo Kenneth Ejukonemu, Arube Goodnews Emuakpo, Charles Kennedy
Page Numbers : 165-182
DOI : 10.36348/sjce.2021.v05i06.004
The research evaluated the potential occurrence of corrosion in an induced media assessing the coating of reinforcing steel with Boswellia dalzielii (Burseraceae) exudates/resin gotten from the trunk of trees, the coating varies in thicknesses, embedded in concrete slabs, and exposed to the high severed coastal marine environment with acidic content. The maximum stability value calculated concrete resistivity from the controlled concrete sample was 63.55% compared to the corroded and coated values -44.28% and 84.61%, and the maximum controlled differential percentile was 2.8% compared to the corroded and 1.55% values and 5.53% coverage. The test results of controlled and coated samples with concrete resistance got a maximum average value of 14.38kΩcm and 16.28kΩcm with a value of 10 <𝜌 <20 (low) compared to a corrosion value of 8.85kΩcm with an indication of 5 < 10 (high) and the reference range of the relationship between concrete resistance and corrosion probability. The maximum obtained and corrosion potential values of the controlled and coated samples were -107.3mV and -121.5mV, indicating the relationship between corrosion potential and probability as 𝐸corr > −200mV as the reference range. The results of this potential Ecorr result show that the value of controlled and resin-coated samples is low with a 90% probability that no corrosion of reinforcing steel is observed during the measurement (10% risk of corrosion, which averages 10% for samples without coating obtained maximum value - 341.7mV, the result lies in the correlation reference value between the corrosion potential value −350mV ≤ 𝐸corr ≤ −200mV indicating a high range of values. The calculated maximum percentile ultimate tensile strength of controlled tensile strength is 2.06% compared to corrosion and coating values of 1.96% and 2.05%, and the possible differential values are 0.06% controlled, 0.01% corroded and 0.03 % coated. The calculated maximum percentile yield strength value of the controlled shear strength is 8.28% compared to the corroded and coated values of -7.61% and 8.28% and the controlled potential differential values are 0.05%, corrosion is 0.04% and 0.05% coated. The comparison results show that the low load carrying capacity is caused by the effect of corrosion attack on the exposed (corroded) elements, which damage reinforcing steel fibers, ribs and passive formations and surface modifications. The avearge values observed for the coated samples relate to the corrosion resistance potential to penetrate the reinforcing steel to form a protective membrane; This attribute indicates the effectiveness and effectiveness of the exudate/resin as an inhibitor against corrosive effects. exposed reinforced concrete structure on the edge of a strong sea area with high salinity. The maximum calculated percentile of corroded is 0.396% versus -1.17% and coated is 0.721%, the differential in the percentile of corrosion is 0.03% versus 0.003% coated. For comparison, the results of corroded samples showed reduction and reduction values compared to the diameter of the reinforcement before and after accelerated induction corrosion testing with a percentile decrease in value from 0.396% to -1.17% and an average value in the range of 11.93mm to 11.93mm. The differential in average and relative percentile between coated and corroded samples varied from 26.42% to -20.9%. The decrease in average and percentile values indicates that the corrosion effect has led to a reduction in diameter and cross-sectional area, fiber degradation, rib reduction and surface modification, while elements coated with exudates/resin confirm an increase in volume as thickness as there are shift differentials.
Original Research Article
July 30, 2021
Corrosion Inhibitive Materials Influence on Load Bearing Capacity of Reinforced Concrete Beam
Charles Kennedy, Overo Kenneth Ejukonemu, Sornaate Lucky Easy
Page Numbers : 147-164
DOI : 10.36348/sjce.2021.v05i06.003
This research studied the negative effects of corrosion attack on steel reinforcement in a marine environment with a high concentration of salt (sodium chloride) by the use of exudate/resins that was applied directly to the steel reinforcement through coatings of different thicknesses and embedded in concrete beams, and checked for suitability as a corrosion protection agent. The maximum value obtained of flexural load tests for controlled is 26.65% as compared to the value of -18.23% and 26.4% for the corroded and coated samples were examined for comparison of the flexural strength test. The results showed lower deformation loads in controlled and coated specimens with reduced values over corroded specimens with higher deformation in comparison with reference ranges (controlled). The calculated mean differential and percentile values were checked (0.03kN and 0.23%), corrosion values (0.030kN and 0.21%) and coating values (0.02kN and 0.21%). The results showed that the effect of corrosion on the mechanical properties of reinforcing steel with a decrease in diameter reduced the average and percentage of samples corroded, while the controlled and coated samples showed a preserved state due to coating due to an increase in diameter different layer thickness with exudates/resin The cross-sectional area of reinforcing steel shows a different mean value and percentile value of the corroded value (0.01 mm and 0.02%) and the coated value (0.05 mm and 2.69%). Differentially, the calculated mean and percentage values of yield strength and tensile strength are (2.13 MPa and 0.97%) and (3.435 MPa and 0.08%) and were examined, the corroded values were (3.44 MPa and 0.86%) and (4.548 MPa and 0.08%), the values of coated are (2.13MPa and 0.97%) and (4.736MPa and 0.09%). From the data obtained and compared, the yield strength and tensile strength values of the corroded samples showed a decrease in the average and percentage values for load failure with lower load applications. Comparison ratios obtained for deformation the maximum values calculated for the mean and percentile values for the controlled were -0.6% against the corroded and closed values of 1.22% and -0.29%. The difference between the mean and percentage values obtained for the control was (0.02 and 0.91%), corroded values (0.02 and 0.93%), and coated values (0.02 and 0.91%). The maximum comparison value for the controlled sample was -31.32% compared to the corroded and coated samples of 63.75% and 31.6%, respectively. The mean differential and percentile values obtained for the controlled samples were (1.69% and 7.34%), corrosion values (1.2% and 17.55%) and coated values were 1.69% and 7.33%). In comparison, the corroded samples showed higher stress values and higher elongation rates, whereas the damaged state of coated samples was lower load and reduced elongation.