Omar

OMARI MUSA MWAMAIKA PORTFOLIO CIVIL & STRUCTURAL ENGINEER|CAD TECHNICIAN|AutoLISP Developer- RESUME EXPERIENCE ADDRESS 03.2018 - present Freelancing- CAD Consultant Engineer/Highway Engineer -, Mombasa, Kenya Junior Civil Engineer CONTACT • Acted as an assistant in geometric road design of Nyamira-Igonga- - Nyabioto/Nyamatutu-Igonga-Riana/Riana-Iyabe-Chisaro/Motonto-Suneka roads - using Novapoint software. - • Managed to develop an AutoLISP program to estimate as-built road quantities. - • Was involved in the estimation of quantities and material costs during project PROFILE Dedicated civil engineering graduate with a strong understanding of engineering principles and theories, bringing two years of experience and hard work to the table, and a track record of delivering road and building design projects ahead of schedule. planning to support budgeting and costing. • Performed structural design and detailing of box culverts, access culverts, and pipe culverts using RebarCAD and AutoCAD software. 11.2021 - 01.2022 KURA Industrial Attachment 2 COMPETENCIES • Performed structural analysis and design of Likoni Bridge in Nairobi. • Highway Design • Inspection of concrete works for the Upper Hill Bypass road project. • Structural analysis and design • Was involved in traversing and topographical survey of Blue sea road project in • Building code compliance Nairobi. • Drafting • Design and inspection of drainage works along Moi Avenue in Nairobi. EDUCATION • Worked with the materials department in checking the integrity of pavements. The tasks performed include CBR testing, field density tests, concrete mix design, 09.2017 - 12.2022 and gradation of aggregates. Masinde Muliro University of Science and Technology-Kakamega, Kenya • Performed survey works like leveling, setting out, and traversing to measure BSc. Civil and Structural Engineering. completed works. • Performed visual inspection of construction works CONTENTS PROJECTS THESIS SKILLS Geometric Road Design PROJECTS AutoLISP Program Development: Building Customized Solutions Highway Mapping Geometric Road Design: BomasKona Baridi Project (Kenya) Project Description Steps Sorting of topographical data in Microsoft Excel and then converting it into a CSV format. This is done prior to importing the The Project demanded a safe, efficient data into the Quadri interface, which is and economical dual carriageway road used to generate the topographical map. design. Additionally, the project required the design of junctions, bus bays, and u-turns, the production of plans and profiles for the alignment, and the provision of construction setting out data. Topographical survey map creation in the Despite the project's estimated Quadri interface. Once the map is completion time being one month, the produced, it can then be imported into design was successfully finished in just AutoCAD interface for design. five days. The budget for the project was a significant constraint, and the alignment had to remain within the existing road to avoid compensating those affected by the project. The Bomas-Kona Baridi Road Project posed a significant challenge that demanded ample expertise to ensure its success. Nonetheless, the dual carriageway met the required design standards, exceeded stakeholders' expectations, and was completed within a tight schedule and budgetary constraints. AutoCAD's interface and Novapoint plugin's road design tool used to create a horizontal alignment that considers minimum curve radii, superelevations, and widenings. Deliverables Design of vertical alignment which was accomplished through the use of Novapoint plugin's design tool, that takes into account various factors such as sight distance, road gradient, terrain, cross section type, road class, and traffic level. Exporterd finished road levels and horizontal setting out data from the Quadri design database to Excel, with some modifications made to produce the final data for construction. Plan and profile presentation plots generated from AutoCAD's layout tab prior to being printed and archived. AutoLISP Program Development: Building Customized Solutions Project Description This was a personal project aimed at assessing my coding abilities, which involved leveraging AutoLISP to automate as-built road cross section design and quantity estimation process. The inspiration for this project arose from the absence of a comprehensive software that could estimate road quantities for the majority of items typically included in bills of quantities for Kenyan road projects. My primary objective was to incorporate features such as stripping, rock filling, compaction of existing ground, and bench work into a cross-section, and enable AutoLISP to perform calculations to determine the exact quantities utilized. Steps Deliverables Cross-section drawings that demonstrates the successful utilization of AutoLISP The quantities of the items depicted in the cross-sections were exported to an excel code to automate the process of incorporating essential items like rock fill, fill in sheet, assuming a 20-meter interval between each cross-section. soft, fill in hard, and benchwork. Highway Mapping Steps Importing of horizontal alignment from design files into AutoCAD to ensure adherence to the specified coordinates. This was achieved through a copy-and-paste operation while maintaining the original coordinates. Capturing of overlapping google earth images around the project area at an eye altitude of 2.01km, to ensure comprehensive coverage. The resulting images Project Description were then stitched together using the Photoshop interface, resulting This project entailed the integration of Muhoroni-Chemelil-Kipsitet and its associated spur roads, in a high-resolution Google Earth namely Koru and Songhor Road, into a Google Earth image for the purpose of presentation. The task image that covers a wider area. was assigned to me subsequent to an inadequate presentation of the map, which failed to provide a comprehensive view of the project area. The primary objective of the presentation was to depict the alignment's features clearly, allowing the map to be utilized in stakeholder engagement. However, the previous presentation did not meet this requirement. Consequently, I utilized my expertise in Photoshop and AutoCAD to generate an improved and more distinct presentation suitable for that purpose.. Importing of the image using "attach" command in AutoCAD and aligning it to fit the designed horizontal alignment. Subsequently, printing plots for A1 were generated in the layout tab, and then presented to stakeholders for approval. THESIS Introduction Cont.’ Development of Rebound Hammer Strength Curves for Glass Fibre Reinforced Concrete Bernard Omondi1,2, Omar M. Mwamaika1, Loice C. Satia1 1Masinde Muliro University of Science and Technology, P. O. Box 190 – 50100, Kakamega, Kenya 2Corresponding author:- Fig. 1: Rebound Hammer In 2007, more enhancements were made to digitize the method of reading compressive strength from the instrument. However, its application has been limited to normal Abstract Rebound hammer test is an essential NDT tool in appraising the structural integrity of existing concrete structures. However, its application has been limited to normal concrete structures. Its application on novel concrete such as Glass Fibre Reinforced Concrete (GFRC) structures can lead to unreliable results. This study aimed at developing the correlations between compressive strength and rebound hammer index for GFRC. The fibres used were 12 mm long at a percentage of 0% to 0.12%, at intervals of 0.03%. The analysis resulted in the creation of new curves that can be applied to GFRC. A logarithm curve was determined to be the best curve for GFRC. Keywords: Non-destructive test, rebound hammer index, glass fibre-reinforced concrete, Strength curves Introduction A rebound hammer (see Fig. 1) is an instrument used to non-destructively test the compressive strength of concrete based on surface hardness and penetration resistance (Kocáb, D., Misák, P., & Cikrle, P., 2019). The instrument typically operates under impact mechanism in which, upon impact, a rebound index is recorded and a compressive strength estimated from strength curves located on the instrument's shell. concrete (Ali-Benyahia, 2017). For example, one study discovered that the rebound hammer test gives an abnormal compressive strength upon adding basalt fibres in concrete (Ali Benyahia, 2017), This is owing to the fact that rebound hammer test is sensitive to tiny changes in concrete autonomy. Despite this limitation, advancements in concrete technology has led to novel concrete such as Glass Fibre Reinforced Concrete (GFRC). This GFRC has gained acceptance due to its high durability, superior compressive and tensile strengths over normal reinforced concrete. In order to appraise structures made using GFRC, a sustainable NonDestructive Test (NDT) tool should be used. A rebound hammer is more suitable but it must be calibrated for reliable results. From this background, this study aimed at developing the rebound hammer strength curves for GFRC. The fibres used were 12 mm long and incorporated into the mix at various percentages from 0% to 0.12%, at intervals of 0.03%. The mix with 0% of GFRC acted as the control mix (normal concrete). A total of 90 concrete cubes were tested by rebound hammer method. The study confirmed that the curves that were invented by Ernst Schmidt, were solely intended to be used on normal concrete. The work was therefore extended to include the creation of new curves that could be applied to GFRC. Four functional forms were tested and a logarithm function curve was found to be the best curve for GFRC. The results of this study will be significant for non-destructive evaluations of GFRC structures. Methodology Results and Analysis A) Compressive strength and Rebound hammer Index. The research design is as represented in Fig.2. The results confirmed that increase in % of glass fibre led to increase in compressive strength at all ages of concrete (See Fig. 6 being typical for 28-day strength). It’s noted that beyond 0.06% addition of glass fibre, there was insignificant increase in compressive strength. Furthermore, the rebound hammer index reduces with increase in compressive strength and increase in % of glass fibre. Thus, glass fiber affects negatively the accuracy of rebound hammer index. Fig. 2: Research design (1) Preliminary tests (sieve analysis, specific gravity, moisture content, and water absorption) were conducted for quality control. (2) Concrete class C20/25 was designed using British (BRE) standard. Glass fibre (See Fig. 3) quantities were varied from 0% to 0.12% at interval of 0.03% of mass of wet concrete. (3) Batching was done by mass followed by dry mixing to ensure even dispersal of glass fibres before adding water. Workability of the mix was tested through slump test. Cubes of 100mm were cast after confirmation of the mix. After 24hours, the cubes were cured in water. (4) Rebound hammer tests (see Fig. 4) were conducted followed by compressive strength test (see Fig. 5) after 7, 14 and 28 days of curing. A total of 90 samples were tested. (5) The . Fig. 6: A graph of 28 Days Compressive strength and Rebound Hammer Index against the percentage of glass fibres relationship between compressive strength and rebound index (Rm) were analyzed. (6) Relative error and standard error were calculated based on comparison with the B) Percentage Error induced by Glass Fibre. strength curves on the rebound hammer. This was the basis of development of new A comparative analysis was done based on actual compressive strength and the strength curves. estimated strength from rebound hammer index charts. Both relative error and standard error were calculated based on JGT/T 23-2011 manual. Both relative and standard errors gave similar values. Typically, Fig. 7 shows the relative error at different ages of concrete and different % of glass fibre. It is seen that the relative error for control test was within the acceptable error margin. However, on addition of glass fibres, the relative errors were significant (above acceptable margin of 12%) at all ages of concrete accept for 7-day strength at 0.03% and 0.06%. It was imperative that a better correlation be developed for Fig. 3: Glass Fibre Fig. 4: Rebound hammer test Fig. 5: Compressive strength test strength curves from rebound hammer index. This was done only optimum addition of glass fibre which in this study was 0.06%. Results and Analysis Cont.’ Results and Analysis Cont.’ ADD A MAIN POINT Fig. 8: Logarithm Curve with high R2 value Fig. 7: Relative Error based on measured and estimated compressive strength at different concrete ages C) Validation of Strength Curves hammer index (Rm) as: 𝐹cu=59.198In(𝑅m )−171.62 In order to validate most appropriate strength curve for GFRC, different curve fitting were used on data points for measured compressive strength and the rebound hammer index. The curves tested and the resulting R2 values are given in Table 1. Curve Fitting R2 Value Linear 0.9003 Logarithm 0.9136 Exponential 0.8478 Power function 0.8738 Table 1 shows that logarithm curve gave highest R2 value. The corresponding logarithm curve is shown in Fig. 8. Based on the logarithm curve, the strength of GFRC, (Fcu) can be derived from rebound Conclusion Based on results and analysis, the following conclusions were made: 1. The recommended percentage of glass fibres should be 0.06% of wet concrete. This translates to increase of compressive strength of concrete by 16%. 2. Incorporation of glass fibres in concrete lowers sensitivity of the rebound hammer indices resulting into unacceptable relative error. 3. Strength curves for GFRC from rebound number can described using logarithm curve denoted by the equation: 𝐹cu=59.198In(𝑅m )−171.62 References 1. Kocáb, D. M. et al. (2019), Characteristic curve and its use in determining the ADD A MAIN POINT compressive strength of concrete by the rebound hammer test. Materials, P 12(17), 2705. 2. Ali-Benyahia, K. S. (2017), Analysis of the single and combined non-destructive test approaches for on-site concrete strength assessment: General statements based on a real case-study. 3. JGT/T-23-2011 Manual for Rebound Hammer Test. SKILLS CADS & MODELLING STRUCTURAL ANALYSIS BUILDING CODE COMPLIANCE PROGRAMMING CREATIVE EDITING MICROSOFT OFFICE