Optimization of Rhombus Opening Area of Shear Walls On Tall Buildings

This research was designed to determine the optimum percentage and configuration of rhombus opening on shear wall of tall building. A residential tall building of 12-storeys having base size of 20m × 10m with height of floor of 3m was analysed. In this paper, percentages of 12%, 24%, 36%, 42%, and 54% concentric rhombus opening in a shear wall in tall buildings were modeled. The effect of the opening size on the lateral displacement, base shear, and stress at the opening was determined.  It was found that the opening of 12% has less lateral displacement, base shear, and stress at the opening. This indicates that this opening delivers the best performance among the other percentages. Five models with the same percentage of rhombus opening of 12% at different configuration on the shear wall in tall buildings were modeled to determine the optimum configuration of opening on shear walls. It was found that Model-1 is the optimum configuration since this model has the lowest lateral displacement and stress at the opening. It can be concluded that Model-1 with 12% opening area is the optimum size and configuration to resist lateral force on tall buildings

Optimization of Rhombus Opening Area of Shear Walls On Tall Buildings

This research was designed to determine the optimum percentage and configuration of rhombus opening on shear wall of tall building. A residential tall building of 12-storeys having base size of 20m × 10m with height of floor of 3m was analysed. In this paper, percentages of 12%, 24%, 36%, 42%, and 54% concentric rhombus opening in a shear wall in tall buildings were modeled. The effect of the opening size on the lateral displacement, base shear, and stress at the opening was determined.  It was found that the opening of 12% has less lateral displacement, base shear, and stress at the opening. This indicates that this opening delivers the best performance among the other percentages. Five models with the same percentage of rhombus opening of 12% at different configuration on the shear wall in tall buildings were modeled to determine the optimum configuration of opening on shear walls. It was found that Model-1 is the optimum configuration since this model has the lowest lateral displacement and stress at the opening. It can be concluded that Model-1 with 12% opening area is the optimum size and configuration to resist lateral force on tall buildings

Three point bending flexural strength of cement treated tropical marine soil reinforced by lime treated natural fiber

Marine soil in the Selangor State of Malaysia was characterized with respect to its engineering properties as pavement layer in road constructions. Samples were collected from North Klang area in Selangor, Malaysia and subjected to physico-chemical, mineralogical and geotechnical analyses. Quick lime or calcium oxide (CaO) treated coconut fibers were introduced to soil cement mixture to enhance the flexural strength of tropical marine soil. Three point bending tests were carried out on treated samples after 7, 14 and 28 days respectively. The tests results showed improvements in the flexural performance of the mixture as it could be seen by the increase in the flexural strength, Young’s modulus and the toughness index especially when the treated fibers were incorporated into the mixture. It was found that, the bond strength and interaction between treated fibers and soil was the dominant mechanism controlling the reinforcement benefit. It can be concluded that, the application of the CaO treated coconut fiber reinforced cement treated marine clay from Peninsular Malaysia is useful both in strength and ductility as pavement layer in road constructions

Characterization of cenospheres from Malaysian coal generated power plants: Jimah, Kapar and Manjung

Cenosphere is a component of fly ash (FA) and has been used as part of sustainable material in wastewater treatment, automotive, ceramic, and construction industries due to its properties. This research presents the first study on characterization of cenospheres from Malaysian power plants namely Jimah, Kapar and Manjung. The characterization was conducted via X-ray fluorescence (XRF), particle size analyzer (PSA), X-ray diffraction (XRD), and scanning electron microscopy (SEM). The XRF analysis consisted of oxides elements ranged from 14.70 to 22.63% (aluminum oxide, Al2 O3 ), 3.78 to 13.44% (calcium oxide, CaO), 34.73 to 57.67% (silicon dioxide, SiO2 ), 0.42 to 1.07% (sulphur trioxide, SO3 ), 9.09 to 24.92% (iron oxide, Fe2 O3 ), 3.62 to 3.67% (potassium oxide, K2 O), 1.76 to 4.24% (titanium oxide, TiO2 ) and 0.16 to 0.93% (magnesium oxide, MgO). The classifications of cementitious materials by American Standard of Testing Materials were Class F (Jimah, Kapar) and Class C (Manjung). The classification represents the quality and capability of cementitious materials as cement replacement material, additive, and filler in concrete mix. The sizes of cenospheres were Kapar > Jimah > Manjung. The sizes of cenosphere were found to be larger than FA (Jimah: 2.720-49.21 µm, Kapar: 5.069-98.29 µm, Manjung: 1.084-3.986 µm). Cenospheres contained quarts (Jimah, Kapar, Manjung: 26°) and silicates (Kapar, Manjung: 45°). Ferrospheres, cenospheres, aluminosilicate-spheres, plerospheres and carbon fragments were observed. The cenosphere from Manjung showed high quality as cement replacement material, additive, and filler with 13.44% of CaO

Attainable region approach in analyzing the breakage behavior of a bed of olivine sand particles:optimizing impact energy and particle size

In this study, we investigated the breakage behavior of a bed of olivine sand particles using a drop-weight impact test, with drop weights of various shapes (oval, cube, and sphere). An Attainable Region (AR) technique, which is a model-free and equipment-independent technique, was then applied to optimize the impact energy during the breakage process and also to get particles in defined particle size classes. The findings revealed that the different drop weights produce products within the three different particle size classes (feed, intermediate, and fine). A higher mass fraction of materials in the fine-sized class (−75 μm) was obtained when the spherical drop weight was used relative to the cubic and oval drop weights. The drop height was found to have a significant influence on the breakage process. The AR technique proved to be a practical approach for optimizing impact energy and particle size during the breakage of a bed of olivine particles, with potential application in sustainable soil stabilization projects

The effect of the W-shape stirrups shear reinforcement on the dynamic behavior of RC flat solid slab subjected to the low-velocity impact loading

Reinforced concrete flat solid slabs may experience explosive and impact loads. Reinforced concrete flat solid slabs have been studied under static and dynamic loads. Researchers have widely explored numerous reinforcing strategies to strengthen RC slabs exposed to impact loads, yet gaps remain. Internal anchorage stirrups (W-stirrups shear reinforcement) is still rarely used to strengthen slabs against impact loading. Consequently, this study emphasized the influence of W-stirrups shear reinforcement on the dynamic response and failure modes of RC slabs subjected to impact loads.The first part examined the impact behavior of fully fixed RC flat solid slabs reinforced with W-stirrups shear reinforcement experimentally. Slabs were impacted using portable drop-weight testing equipment. Six 800-x-800-x-90-mm RC slabs were made. Three samples were reinforced with a W-stirrups orthogonally oriented in two directions, whereas three controls were without any type of strengthening. The eccentric vertical displacement of slabs, strain at four points on the W-stirrups, two on main steel, and two on concrete, and acceleration at one point over a slab were measured; also, failure modes were monitored.In the second section, ABAQUS software was used to generate finite element models of slab study samples. Numerical model results matched experimental results. Thus, the suggested finite element model may assess reinforced RC slabs under low-velocity impact loads. Finally, a parametric study was conducted in the third part to address the issue of over-reinforced design in slabs with W-stirrups. The parametric study aimed to determine the optimal steel ratio of flexural and shear reinforcement and its influence on the behavior of RC flat solid slabs reinforced with W-stirrups shear reinforcement

Development of rubberised cementitious material incorporating graphene nanoplatelets and silica fume

Rubberised cementitious material has gained significant attention within the civil engineering community. However, the gap and voids between rubber particles and cement gel remain challenge. To tackle these issues, silica fume (SF) and graphene nanoplatelets (GnPs) were used to enhance the microstructure of rubberised mortar at micro and nano scale levels. Silica fume was added at 20% of the cement weight, while, the inoculation of GnPs varied from 0.02% to 0.6% as cement replacement and the rubber powder ranged between 2% and 8% as sand replacement (by volume). The compressive (CS), flexural (FS), tensile (TS), ultrasonic pulse velocity (UPV), water absorption (WA) and porosity (P) of the proposed mortar were evaluated at the age of 28 days. The experimental and predicted outcome showed that the rubberised mortar incorporating SF and GnPs imparted superior properties compared to that of the control mixture for all rubber replacement percentage. For instance, when the rubber content was 5% and GnPs was 0.03%, the CS, FS, TS, UPV, WA and P were 45.51 MPA, 5.41 MPa, 3.13 MPa, 3.89 km/s, 5.23% and 7.22% compared to that of the control mortar without rubber (38.3 MPa, 4.1 MPa, 2.31 MPa, 3.65 km/s, 6.51% and 7.28%), respectively. FESEM also confirmed that the GnPs did not only acted as a filler material but also served as an impermeable barrier for continued crack propagation. It can be concluded that the inclusion of GnPs in rubberised cement-based material is considered as a sustainable choice in which it enhances its microstructure, specifically the interfacial transition zone (ITZ)

Failure Analysis of Plant Fibre-Reinforced Composite in Civil Building Materials Using Non-Destructive Testing Methods: Current and Future Trend

Natural plant fiber-reinforced composite (NFC) has become a preferred component in modern-day civil building construction materials because it offers, among others, an environment-friendly solution without compromising stringent engineering requirements. Such green-based composites have exhibited noteworthy level of competitiveness comparable to that of the existing commercially available nongreen materials. Furthermore, NFC can also be tailored to align with the desired functional attributes. However, lack of comprehensive guidelines and recommended applications of suitable methods to assess composite failure of such novel NFC have raised significant concerns. This paper provides a comprehensive review of the latest developments in nondestructive testing (NDT) that can be applied to investigate into NFC failures. The study further explores alternative nondestructive testing methods and technologies exhibiting potential use in plant fiber composites studies, hence paving the way to future investigation trends. Precise characterization of defects and identification of damages in NFCs present a major challenge, demanding application of advanced nondestructive testing (NDT) methodologies accompanied with expert interpretation. Findings in this review can be applied to identify and explore new areas of research to analyze failure modes and fractures in NFC by applying NDT or by integrating NDT with other advanced technologies including machine learning

Response Surface Methodology: The Improvement of Tropical Residual Soil Mechanical Properties Utilizing Calcined Seashell Powder and Treated Coir Fibre

Calcined seashell (CSS) powder and treated coir fibre (CF) are well-established additives for reinforcing poor soils. However, the absence of specific mix designs to optimize the mix additives makes it difficult to predict their combined effect on improving the mechanical behaviour of poor soils. This research explores the use of response surface methods to find the optimal proportions of CSS and CF for enhancing the mechanical properties of a tropical residual soil. This study uses a combination of Analysis of Variance (ANOVA) and regression models to examine how the independent variables of the CSS content, CF content, and curing duration influence the responses of the Unconfined Compressive Strength (UCS), Flexural Strength (FS), and Indirect Tensile Strength (ITS). The findings show that the optimal mix of 9.06% CSS, 0.30% CF, and 12 days of curing significantly improved the UCS, FS, and ITS by roughly six, four, and three times, respectively. Microstructural analysis revealed that the formation of calcium-aluminate-hydrate and calcium-silicate-hydrate are the primary components responsible for the enhanced mechanical properties of the treated soil