Uthenthawai Engineering and Architecture Journal

Development of Nano-silica Combined with Oil Palm Fibers and Sisal Fibers to improve the Properties of Concrete

Natthachai Bantoengsuk — 2025-06-30

The aim of this study is to investigate the compressive strength, flexural strength, and water permeability of concrete incorporating Nano-silica, oil palm fibers, and sisal fibers. Nano-silica with an average particle size of 12 nanometers was used to replace cement at 3% by weight, while oil palm fibers and sisal fibers with a length of 20 millimeters were added to the mix. The properties of the concrete were tested at 28 days of age.

The results showed that concrete containing Nano-silica and natural fibers exhibited higher flexural strength than the control concrete, indicating that these materials enhance the flexural performance of concrete. However, the compressive strength of fiber-reinforced concrete was lower than that of the control concrete. Additionally, water permeability testing revealed that fiber-reinforced concrete exhibited higher permeability than the control concrete.

In conclusion, the incorporation of nano-silica, oil palm fibers, and sisal fibers enhances the flexural strength of concrete. However, further modification of the mixture is required to improve compressive strength and water resistance.

Study on the Properties of Soil-Cement Mixed with Fly Ash and Sodium Hydroxide

Supachai Thaipum — 2025-06-30

This article presents a study on the properties of cement-stabilized clay modified with fly ash and sodium hydroxide. The clay samples were obtained from the Mor Suap Reservoir Project. Test specimens were categorized into four groups: (1) cement-stabilized clay, (2) cement-stabilized clay with fly ash, (3) cement-stabilized clay with sodium hydroxide, and (4) cement-stabilized clay with both fly ash and sodium hydroxide. Each group was prepared with five cement contents: 220, 230, 240, 250, and 260 kilograms per cubic meter by volume. The clay used was classified as CL and passed through a No. 4 sieve, while the fly ash passed through a No. 325 sieve. A 5-molar sodium hydroxide solution was used in the relevant mixtures. Unconfined compressive strength (UCS) tests were conducted after curing periods of 1, 7, 14, and 28 days. The results indicated that UCS values increased with higher cement content across all specimen groups. The specimens incorporating sodium hydroxide exhibited higher UCS and elastic modulus values compared to those with only cement or cement with fly ash. The addition of sodium hydroxide enhanced silica dissolution from the blended materials, promoting the formation of cementitious products primarily through hydration reactions. The contribution of pozzolanic reactions was found to be minimal in comparison. The UCS results were consistent with the findings from microstructural analysis.

Effect of Ammonium Ions on the Engineering Properties of Clayey Soil Improved with Calcite Powder Derived from the MICP Process

Rujira Pholtrai — 2025-06-30

Currently, improving the quality of clay soils to enhance their load-bearing capacity and reduce environmental impact is a widely discussed issue. Microbially Induced Calcite Precipitation (MICP), which facilitates the formation of calcium carbonate (CaCO₃), is considered one of the most promising and environmentally friendly techniques for enhancing the engineering properties of soil. However, this process often produces ammonium ions (NH₄⁺) as a byproduct, which may adversely affect soil behavior. This study aims to investigate the influence of NH₄⁺ on the unconfined compressive strength (q_u) and hydraulic conductivity (k) of clay soils by artificially introducing NH₄Cl to simulate the potential impact of ammonium generated in the MICP process. The results show that clay specimens treated solely with CaCO₃ exhibit a significant increase in q_u, as the CaCO₃ particles initially fill the voids between soil particles and further develop strength over the curing time due to long-term pozzolanic reactions. In contrast, specimens containing NH₄⁺ showed a reduction in compressive strength, attributed to the moisture-retaining effect of NH₄⁺ in the soil matrix, which inhibits strength development during curing. At the same void ratio (e), the hydraulic conductivity of NH₄⁺contaminated specimens was markedly lower than that of untreated clay. This is likely due to the swelling behavior induced by the NH₄⁺ ions, which restricts the flow of water. Conversely, CaCO₃-treated soils exhibited higher k values than untreated clay, as the relatively large calcite particles enhance water flow pathways. These findings underscore the importance of managing or eliminating ammonium ions in MICP-related applications to enhance the performance and sustainability of clay soil treatment, particularly for engineering projects that require both mechanical strength and adequate permeability.

Construction Design for Solid Waste Management System, Phase 2, Uthai Thani Province

Boonruk Vanborsel — 2025-06-30

This research aims to design the construction of the solid waste management system, phase 2, Uthai Thani Province. The research methods are as follows: 1) review the complete report of the research study and design of the solid waste management system, phase 2, Uthai Thani Province, 2) survey the topography and create a map according to the current conditions, 3) survey all existing buildings in the project area, 4)create detailed engineering details for the project, 5) estimate construction costs according to the detailed engineering details and 6) prepare the design documents. The results show that the appropriate waste disposal system for Uthai Thani Municipality is a sanitary landfill system. However, directly burying fresh waste will require a lot of space and fill up quickly. Therefore, waste should be treated by mechanical-biological treatment (MBT) before being landfilled, and waste that has undergone preliminary treatment should be used to produce RDF to increase its value, which will reduce the amount of waste to be landfilled and extend the lifespan of the landfill area and the wastewater treatment system and existing buildings in the project area can be renovated and repaired to be able to be reused for their intended purposes. In addition, the researcher has created detailed engineering design of the components of the solid waste management system of Uthai Thani Municipality, consisting of 1) sanitary landfill construction drawings, 2) road and drainage around the landfill construction drawings, 3) construction drawings for MBT-RDF building, 4) construction drawings for material storage building and 5) detailed engineering design for the disposal of old waste from the area and filling in phase 1, and preparing construction cost estimates and other documents related to the project (referring to the provisions of the law, practices, criteria, standards or details of government regulations, including academic principles) for Uthai Thani Province to use in preparing the construction contract plan to request budget allocation.

Knowledge Transfer on Value-Added Production from Household Waste to the Grassroots Economy: A Case Study of the Coastal Community in Saensuk Municipality, Mueang District, Chonburi Province

Thunyaphat Vattanajirapun — 2025-06-30

This research aimed to study the process of producing value-added products from household waste and the transfer of knowledge regarding the production process using household waste materials. The goal was to develop effective approaches for creating added value and promoting grassroots economic development in Saensuk Municipality, Mueang District, Chonburi Province. The findings revealed that the process of producing products from marine waste materials involved several key steps. The initial step was the separation of household waste, which served as a crucial starting point. Waste intended for transformation into raw materials was sorted. Then, in the transformation process, the sorted waste was crushed using a shredder and mixed with Portland cement at a 1:4 ratio. A removable mold was created using 15-mm thick wood, into which the mixed material was poured while still unset. The mold was left for 40 minutes before being removed, and the resulting product was polished and finished. This process was used in a knowledge transfer activity involving 33 participants. A comparison of scores before and after the knowledge transfer, analyzed using a T-test, showed statistically significant improvements (p-value < 0.05) in participants’ engagement, understanding, and production skills. These results highlight the effectiveness of the training and the relevance of the content, which can be practically applied within the local community context.