Thesis Bachelor of Science in Civil Engineering University of Rizal System-Morong 2023

The study entitled Armstrong Concrete: Armstrong’s Weed (Chromolaena odorata) Ashes as Partial Replacement for Cement is generally concerned to manufacture a cement-like material from Armstrong’s weed ashes that could partially replace cement manufacturing. It was conducted by fourth-year civil engineering students at the University of Rizal System in the first and second semesters of the academic year 2022-2023. The scope of the study focused on the performance of concrete using Armstrong’s weed ashes as a cement partial replacement. The study concentrated on the production of cement-like material from plants, specifically Armstrong's weed, which could be more beneficial to the environment, economy, and construction industry. This study included several processes and tests including slump test, compressive strength test, splitting tensile strength test, and water absorption. The experimental design methodology was used in this study to gain a comprehensive understanding of the performance of Armstrong's weed as a partial replacement for cement in concrete mixtures. This approach was done to determine if there were significant changes in the mechanical properties of concrete due to different replacement ratios. The hypothesis was tested by modifying and substituting the cement ratio with Armstrong's weed ashes. Through the survey, researchers found out that Armstrong's weed is an invasive alien plant species that can be easily accessible in any agricultural area and can be harvested in any municipality in the province of Rizal. In this study, the researchers examined the physical and chemical properties of Armstrong’s weed ashes. Armstrong’s weed ashes had a specific gravity of 2.010, a water absorption capacity of 5.710 %, fineness retained through a wet sieve using no.200 sieve of 36.920%, and a moisture content of 3.890%. Also, carbon and oxygen are the two most abundant elements in Armstrong's weed ashes, accounting for 39.89% and 28.36% of the total weight. Thus, Armstrong’s weed ashes contain 6.970% calcium, 1.510% silicon, 0.250 % aluminum, and so on. The workability of mixtures, as well as the strength and durability of Armstrong Concrete, were examined in this study. The ASTM 618 standard specification was not met by the raw material. The results were comparably close to the specification if Armstrong's weed ashes were further processed and treated, they could partially replace cement. Second, Armstrong's weed ashes sample contained the chemical elements necessary for cement replacement, the researchers concluded that Armstrong’s weed ashes have the potential to partially replace cement in terms of its chemical properties. Then, there were significant differences in concrete mixtures having various percentages of Armstrong’s weed ashes as cement partial replacement in terms of slump, compressive, and splitting tensile strength, as well as the water absorption capacity of concrete. The researchers recommend the following based on the summary of findings. The particle size of Armstrong’s weed ashes was greater than the specified size for cement, which was determined by the fineness, retained through the no.200 sieve of the plant ashes, therefore researchers suggested using Armstrong’s weed ashes as a sand replacement; the researchers recommended developing the most appropriate alternative methods of processing Armstrong’s weed ashes which may help to enhance its pozzolanic properties and make it more suitable for use in concrete production; other characteristics of Armstrong Concrete in terms of durability such as abrasion resistance, rapid chloride permeability, and water permeability must be examined; and future researchers should use other invasive plant species in the Philippines such as Hiptage, Lantana, and River Tamarind, that can be added with Armstrong’s weed ashes to the concrete mixtures as cement partial replacement to improve the workability of fresh concrete, as well as the strength and durability of hardened mixtures.